ref: 030a65192386f34b69bc0f59b266643540f902ea
parent: b05eaa268d556f2fdb0ad212960ff64142d54bef
author: ngkaho1234 <[email protected]>
date: Thu Jan 14 23:33:56 EST 2016
Remove simple extent implementation.
--- a/lwext4/ext4_config.h
+++ b/lwext4/ext4_config.h
@@ -133,11 +133,6 @@
#define CONFIG_HAVE_OWN_OFLAGS 1
#endif
-/**@brief Use full extent implemrntation*/
-#ifndef CONFIG_EXTENT_FULL
-#define CONFIG_EXTENT_FULL 1
-#endif
-
/**@brief Maximum single truncate size. Transactions must be limited to reduce
* number of allocetions for single transaction*/
#ifndef CONFIG_MAX_TRUNCATE_SIZE
--- a/lwext4/ext4_extent.c
+++ b/lwext4/ext4_extent.c
@@ -1,12 +1,7 @@
/*
- * Copyright (c) 2013 Grzegorz Kostka ([email protected])
+ * Copyright (c) 2015 Grzegorz Kostka ([email protected])
+ * Copyright (c) 2015 Kaho Ng ([email protected])
*
- *
- * HelenOS:
- * Copyright (c) 2012 Martin Sucha
- * Copyright (c) 2012 Frantisek Princ
- * All rights reserved.
- *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
@@ -31,45 +26,287 @@
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
-/** @addtogroup lwext4
- * @{- */
-/**
- * @file ext4_extent.c
- * @brief More complex filesystem functions.
- */
-
#include "ext4_config.h"
-#include "ext4_extent.h"
-#include "ext4_inode.h"
+#include "ext4_blockdev.h"
+#include "ext4_fs.h"
#include "ext4_super.h"
#include "ext4_crc32.h"
-#include "ext4_blockdev.h"
#include "ext4_balloc.h"
-#include "ext4_fs.h"
+#include "ext4_debug.h"
-#include <string.h>
#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+#include <stddef.h>
-#if !CONFIG_EXTENT_FULL
+#include "ext4_extent.h"
+/*
+ * used by extent splitting.
+ */
+#define EXT4_EXT_MARK_UNWRIT1 0x02 /* mark first half unwritten */
+#define EXT4_EXT_MARK_UNWRIT2 0x04 /* mark second half unwritten */
+#define EXT4_EXT_DATA_VALID1 0x08 /* first half contains valid data */
+#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
+#define EXT4_EXT_NO_COMBINE 0x20 /* do not combine two extents */
+
+static struct ext4_extent_tail *
+find_ext4_extent_tail(struct ext4_extent_header *eh)
+{+ return (struct ext4_extent_tail *)(((char *)eh) +
+ EXT4_EXTENT_TAIL_OFFSET(eh));
+}
+
static struct ext4_extent_header *ext_inode_hdr(struct ext4_inode *inode)
{return (struct ext4_extent_header *)inode->blocks;
}
+static struct ext4_extent_header *ext_block_hdr(struct ext4_block *block)
+{+ return (struct ext4_extent_header *)block->data;
+}
+
static uint16_t ext_depth(struct ext4_inode *inode)
{return to_le16(ext_inode_hdr(inode)->depth);
}
-static struct ext4_extent_tail *
-find_ext4_extent_tail(struct ext4_extent_header *eh)
+static uint16_t ext4_ext_get_actual_len(struct ext4_extent *ext)
{- return (struct ext4_extent_tail *)(((char *)eh) +
- EXT4_EXTENT_TAIL_OFFSET(eh));
+ return (to_le16(ext->block_count) <= EXT_INIT_MAX_LEN
+ ? to_le16(ext->block_count)
+ : (to_le16(ext->block_count) - EXT_INIT_MAX_LEN));
}
+static void ext4_ext_mark_initialized(struct ext4_extent *ext)
+{+ ext->block_count = to_le16(ext4_ext_get_actual_len(ext));
+}
+
+static void ext4_ext_mark_unwritten(struct ext4_extent *ext)
+{+ ext->block_count |= to_le16(EXT_INIT_MAX_LEN);
+}
+
+static int ext4_ext_is_unwritten(struct ext4_extent *ext)
+{+ /* Extent with ee_len of 0x8000 is treated as an initialized extent */
+ return (to_le16(ext->block_count) > EXT_INIT_MAX_LEN);
+}
+
+/*
+ * ext4_ext_pblock:
+ * combine low and high parts of physical block number into ext4_fsblk_t
+ */
+static ext4_fsblk_t ext4_ext_pblock(struct ext4_extent *ex)
+{+ ext4_fsblk_t block;
+
+ block = to_le32(ex->start_lo);
+ block |= ((ext4_fsblk_t)to_le16(ex->start_hi) << 31) << 1;
+ return block;
+}
+
+/*
+ * ext4_idx_pblock:
+ * combine low and high parts of a leaf physical block number into ext4_fsblk_t
+ */
+static ext4_fsblk_t ext4_idx_pblock(struct ext4_extent_index *ix)
+{+ ext4_fsblk_t block;
+
+ block = to_le32(ix->leaf_lo);
+ block |= ((ext4_fsblk_t)to_le16(ix->leaf_hi) << 31) << 1;
+ return block;
+}
+
+/*
+ * ext4_ext_store_pblock:
+ * stores a large physical block number into an extent struct,
+ * breaking it into parts
+ */
+static void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb)
+{+ ex->start_lo = to_le32((uint32_t)(pb & 0xffffffff));
+ ex->start_hi = to_le16((uint16_t)((pb >> 32)) & 0xffff);
+}
+
+/*
+ * ext4_idx_store_pblock:
+ * stores a large physical block number into an index struct,
+ * breaking it into parts
+ */
+static void ext4_idx_store_pblock(struct ext4_extent_index *ix, ext4_fsblk_t pb)
+{+ ix->leaf_lo = to_le32((uint32_t)(pb & 0xffffffff));
+ ix->leaf_hi = to_le16((uint16_t)((pb >> 32)) & 0xffff);
+}
+
+static int ext4_allocate_single_block(struct ext4_inode_ref *inode_ref,
+ ext4_fsblk_t goal,
+ ext4_fsblk_t *blockp)
+{+ return ext4_balloc_alloc_block(inode_ref, goal, blockp);
+}
+
+static ext4_fsblk_t ext4_new_meta_blocks(struct ext4_inode_ref *inode_ref,
+ ext4_fsblk_t goal,
+ uint32_t flags __unused,
+ uint32_t *count, int *errp)
+{+ ext4_fsblk_t block = 0;
+
+ *errp = ext4_allocate_single_block(inode_ref, goal, &block);
+ if (count)
+ *count = 1;
+ return block;
+}
+
+static void ext4_ext_free_blocks(struct ext4_inode_ref *inode_ref,
+ ext4_fsblk_t block, uint32_t count,
+ uint32_t flags __unused)
+{+ ext4_balloc_free_blocks(inode_ref, block, count);
+}
+
+static size_t ext4_ext_space_block(struct ext4_inode_ref *inode_ref)
+{+ size_t size;
+ uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
+
+ size = (block_size - sizeof(struct ext4_extent_header)) /
+ sizeof(struct ext4_extent);
+#ifdef AGGRESSIVE_TEST
+ if (size > 6)
+ size = 6;
+#endif
+ return size;
+}
+
+static size_t ext4_ext_space_block_idx(struct ext4_inode_ref *inode_ref)
+{+ size_t size;
+ uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
+
+ size = (block_size - sizeof(struct ext4_extent_header)) /
+ sizeof(struct ext4_extent_index);
+#ifdef AGGRESSIVE_TEST
+ if (size > 5)
+ size = 5;
+#endif
+ return size;
+}
+
+static size_t ext4_ext_space_root(struct ext4_inode_ref *inode_ref)
+{+ size_t size;
+
+ size = sizeof(inode_ref->inode->blocks);
+ size -= sizeof(struct ext4_extent_header);
+ size /= sizeof(struct ext4_extent);
+#ifdef AGGRESSIVE_TEST
+ if (size > 3)
+ size = 3;
+#endif
+ return size;
+}
+
+static size_t ext4_ext_space_root_idx(struct ext4_inode_ref *inode_ref)
+{+ size_t size;
+
+ size = sizeof(inode_ref->inode->blocks);
+ size -= sizeof(struct ext4_extent_header);
+ size /= sizeof(struct ext4_extent_index);
+#ifdef AGGRESSIVE_TEST
+ if (size > 4)
+ size = 4;
+#endif
+ return size;
+}
+
+static size_t ext4_ext_max_entries(struct ext4_inode_ref *inode_ref,
+ uint32_t depth)
+{+ size_t max;
+
+ if (depth == ext_depth(inode_ref->inode)) {+ if (depth == 0)
+ max = ext4_ext_space_root(inode_ref);
+ else
+ max = ext4_ext_space_root_idx(inode_ref);
+ } else {+ if (depth == 0)
+ max = ext4_ext_space_block(inode_ref);
+ else
+ max = ext4_ext_space_block_idx(inode_ref);
+ }
+
+ return max;
+}
+
+static ext4_fsblk_t ext4_ext_find_goal(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path,
+ ext4_lblk_t block)
+{+ if (path) {+ uint32_t depth = path->depth;
+ struct ext4_extent *ex;
+
+ /*
+ * Try to predict block placement assuming that we are
+ * filling in a file which will eventually be
+ * non-sparse --- i.e., in the case of libbfd writing
+ * an ELF object sections out-of-order but in a way
+ * the eventually results in a contiguous object or
+ * executable file, or some database extending a table
+ * space file. However, this is actually somewhat
+ * non-ideal if we are writing a sparse file such as
+ * qemu or KVM writing a raw image file that is going
+ * to stay fairly sparse, since it will end up
+ * fragmenting the file system's free space. Maybe we
+ * should have some hueristics or some way to allow
+ * userspace to pass a hint to file system,
+ * especially if the latter case turns out to be
+ * common.
+ */
+ ex = path[depth].extent;
+ if (ex) {+ ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
+ ext4_lblk_t ext_block = to_le32(ex->first_block);
+
+ if (block > ext_block)
+ return ext_pblk + (block - ext_block);
+ else
+ return ext_pblk - (ext_block - block);
+ }
+
+ /* it looks like index is empty;
+ * try to find starting block from index itself */
+ if (path[depth].block.lb_id)
+ return path[depth].block.lb_id;
+ }
+
+ /* OK. use inode's group */
+ return ext4_fs_inode_to_goal_block(inode_ref);
+}
+
+/*
+ * Allocation for a meta data block
+ */
+static ext4_fsblk_t ext4_ext_new_meta_block(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path,
+ struct ext4_extent *ex, int *err,
+ uint32_t flags)
+{+ ext4_fsblk_t goal, newblock;
+
+ goal = ext4_ext_find_goal(inode_ref, path, to_le32(ex->first_block));
+ newblock = ext4_new_meta_blocks(inode_ref, goal, flags, NULL, err);
+ return newblock;
+}
+
#if CONFIG_META_CSUM_ENABLE
static uint32_t ext4_ext_block_csum(struct ext4_inode_ref *inode_ref,
struct ext4_extent_header *eh)
@@ -90,7 +327,7 @@
sizeof(ino_index));
checksum = ext4_crc32c(checksum, &ino_gen,
sizeof(ino_gen));
- /* Finally calculate crc32 checksum against
+ /* Finally calculate crc32 checksum against
* the entire extent block up to the checksum field */
checksum = ext4_crc32c(checksum, eh,
EXT4_EXTENT_TAIL_OFFSET(eh));
@@ -101,965 +338,1525 @@
#define ext4_ext_block_csum(...) 0
#endif
-static void ext4_extent_block_csum_set(struct ext4_inode_ref *inode_ref,
+static void ext4_extent_block_csum_set(struct ext4_inode_ref *inode_ref __unused,
struct ext4_extent_header *eh)
{struct ext4_extent_tail *tail;
- if (!ext4_sb_feature_ro_com(&inode_ref->fs->sb,
- EXT4_FRO_COM_METADATA_CSUM))
+
+ tail = find_ext4_extent_tail(eh);
+ tail->et_checksum = to_le32(ext4_ext_block_csum(inode_ref, eh));
+}
+
+static int ext4_ext_dirty(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path)
+{+ if (path->block.lb_id)
+ ext4_trans_set_block_dirty(path->block.buf);
+ else
+ inode_ref->dirty = true;
+
+ return EOK;
+}
+
+static void ext4_ext_drop_refs(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path, bool keep_other)
+{+ int32_t depth, i;
+
+ if (!path)
return;
+ if (keep_other)
+ depth = 0;
+ else
+ depth = path->depth;
- if (to_le16(eh->depth) < ext_depth(inode_ref->inode)) {- tail = find_ext4_extent_tail(eh);
- tail->et_checksum = to_le32(ext4_ext_block_csum(inode_ref, eh));
+ for (i = 0; i <= depth; i++, path++) {+ if (path->block.lb_id) {+ if (ext4_bcache_test_flag(path->block.buf, BC_DIRTY))
+ ext4_extent_block_csum_set(inode_ref,
+ path->header);
+
+ ext4_block_set(inode_ref->fs->bdev, &path->block);
+ }
}
}
-#if CONFIG_META_CSUM_ENABLE
-static bool
-ext4_extent_verify_block_csum(struct ext4_inode_ref *inode_ref,
- struct ext4_block *block)
+/*
+ * Check that whether the basic information inside the extent header
+ * is correct or not.
+ */
+static int ext4_ext_check(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_header *eh, uint16_t depth,
+ ext4_fsblk_t pblk __unused)
{- struct ext4_extent_header *eh;
struct ext4_extent_tail *tail;
- eh = (struct ext4_extent_header *)block->data;
- if (!ext4_sb_feature_ro_com(&inode_ref->fs->sb,
- EXT4_FRO_COM_METADATA_CSUM))
- return true;
+ struct ext4_sblock *sb = &inode_ref->fs->sb;
+ const char *error_msg;
+ (void)error_msg;
- if (to_le16(eh->depth) < ext_depth(inode_ref->inode)) {- tail = find_ext4_extent_tail(eh);
- return tail->et_checksum ==
- to_le32(ext4_ext_block_csum(inode_ref, eh));
+ if (to_le16(eh->magic) != EXT4_EXTENT_MAGIC) {+ error_msg = "invalid magic";
+ goto corrupted;
}
+ if (to_le16(eh->depth) != depth) {+ error_msg = "unexpected eh_depth";
+ goto corrupted;
+ }
+ if (eh->max_entries_count == 0) {+ error_msg = "invalid eh_max";
+ goto corrupted;
+ }
+ if (to_le16(eh->entries_count) > to_le16(eh->max_entries_count)) {+ error_msg = "invalid eh_entries";
+ goto corrupted;
+ }
- return true;
+ tail = find_ext4_extent_tail(eh);
+ if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {+ if (tail->et_checksum != to_le32(ext4_ext_block_csum(inode_ref, eh))) {+ ext4_dbg(DEBUG_EXTENT,
+ DBG_WARN "Extent block checksum failed."
+ "Blocknr: %" PRIu64"\n",
+ pblk);
+
+ }
+ }
+
+ return EOK;
+
+corrupted:
+ ext4_dbg(DEBUG_EXTENT, "Bad extents B+ tree block: %s. "
+ "Blocknr: %" PRId64 "\n",
+ error_msg, pblk);
+ return EIO;
}
-#else
-#define ext4_extent_verify_block_csum(...) true
-#endif
-/**@brief Binary search in extent index node.
- * @param header Extent header of index node
- * @param index Output value - found index will be set here
- * @param iblock Logical block number to find in index node */
-static void ext4_extent_binsearch_idx(struct ext4_extent_header *header,
- struct ext4_extent_index **index,
- uint32_t iblock)
+static int read_extent_tree_block(struct ext4_inode_ref *inode_ref,
+ ext4_fsblk_t pblk, int32_t depth,
+ struct ext4_block *bh,
+ uint32_t flags __unused)
{- struct ext4_extent_index *r;
- struct ext4_extent_index *l;
- struct ext4_extent_index *m;
+ int err;
- uint16_t entries_count = ext4_extent_header_get_entries_count(header);
+ err = ext4_trans_block_get(inode_ref->fs->bdev, bh, pblk);
+ if (err != EOK)
+ goto errout;
- /* Initialize bounds */
- l = EXT4_EXTENT_FIRST_INDEX(header) + 1;
- r = EXT4_EXTENT_FIRST_INDEX(header) + entries_count - 1;
+ err = ext4_ext_check(inode_ref, ext_block_hdr(bh), depth, pblk);
+ if (err != EOK)
+ goto errout;
- /* Do binary search */
+ return EOK;
+errout:
+ if (bh->lb_id)
+ ext4_block_set(inode_ref->fs->bdev, bh);
+
+ return err;
+}
+
+/*
+ * ext4_ext_binsearch_idx:
+ * binary search for the closest index of the given block
+ * the header must be checked before calling this
+ */
+static void ext4_ext_binsearch_idx(struct ext4_extent_path *path,
+ ext4_lblk_t block)
+{+ struct ext4_extent_header *eh = path->header;
+ struct ext4_extent_index *r, *l, *m;
+
+ l = EXT_FIRST_INDEX(eh) + 1;
+ r = EXT_LAST_INDEX(eh);
while (l <= r) {m = l + (r - l) / 2;
- uint32_t first_block = ext4_extent_index_get_first_block(m);
-
- if (iblock < first_block)
+ if (block < to_le32(m->first_block))
r = m - 1;
else
l = m + 1;
}
- /* Set output value */
- *index = l - 1;
+ path->index = l - 1;
}
-/**@brief Binary search in extent leaf node.
- * @param header Extent header of leaf node
- * @param extent Output value - found extent will be set here,
- * or NULL if node is empty
- * @param iblock Logical block number to find in leaf node */
-static void ext4_extent_binsearch(struct ext4_extent_header *header,
- struct ext4_extent **extent, uint32_t iblock)
+/*
+ * ext4_ext_binsearch:
+ * binary search for closest extent of the given block
+ * the header must be checked before calling this
+ */
+static void ext4_ext_binsearch(struct ext4_extent_path *path, ext4_lblk_t block)
{- struct ext4_extent *r;
- struct ext4_extent *l;
- struct ext4_extent *m;
+ struct ext4_extent_header *eh = path->header;
+ struct ext4_extent *r, *l, *m;
- uint16_t entries_count = ext4_extent_header_get_entries_count(header);
-
- if (entries_count == 0) {- /* this leaf is empty */
- *extent = NULL;
+ if (eh->entries_count == 0) {+ /*
+ * this leaf is empty:
+ * we get such a leaf in split/add case
+ */
return;
}
- /* Initialize bounds */
- l = EXT4_EXTENT_FIRST(header) + 1;
- r = EXT4_EXTENT_FIRST(header) + entries_count - 1;
+ l = EXT_FIRST_EXTENT(eh) + 1;
+ r = EXT_LAST_EXTENT(eh);
- /* Do binary search */
while (l <= r) {m = l + (r - l) / 2;
- uint32_t first_block = ext4_extent_get_first_block(m);
-
- if (iblock < first_block)
+ if (block < to_le32(m->first_block))
r = m - 1;
else
l = m + 1;
}
- /* Set output value */
- *extent = l - 1;
+ path->extent = l - 1;
}
-/**@brief Get physical block in the extent tree by logical block number.
- * There is no need to save path in the tree during this algorithm.
- * @param inode_ref I-node to load block from
- * @param iblock Logical block number to find
- * @param fblock Output value for physical block number
- * @return Error code*/
-static int
-ext4_extent_find_block(struct ext4_inode_ref *inode_ref, uint32_t iblock,
- ext4_fsblk_t *fblock)
+static int ext4_find_extent(struct ext4_inode_ref *inode_ref, ext4_lblk_t block,
+ struct ext4_extent_path **orig_path, uint32_t flags)
{- int rc;
- /* Compute bound defined by i-node size */
- uint64_t inode_size =
- ext4_inode_get_size(&inode_ref->fs->sb, inode_ref->inode);
+ struct ext4_extent_header *eh;
+ struct ext4_block bh = EXT4_BLOCK_ZERO();
+ ext4_fsblk_t buf_block = 0;
+ struct ext4_extent_path *path = *orig_path;
+ int32_t depth, ppos = 0;
+ int32_t i;
+ int ret;
- uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
+ eh = ext_inode_hdr(inode_ref->inode);
+ depth = ext_depth(inode_ref->inode);
- uint32_t last_idx = (inode_size - 1) / block_size;
+ if (path) {+ ext4_ext_drop_refs(inode_ref, path, 0);
+ if (depth > path[0].maxdepth) {+ free(path);
+ *orig_path = path = NULL;
+ }
+ }
+ if (!path) {+ int32_t path_depth = depth + 1;
+ /* account possible depth increase */
+ path = calloc(1, sizeof(struct ext4_extent_path) *
+ (path_depth + 1));
+ if (!path)
+ return ENOMEM;
+ path[0].maxdepth = path_depth;
+ }
+ path[0].header = eh;
+ path[0].block = bh;
- /* Check if requested iblock is not over size of i-node */
- if (iblock > last_idx) {- *fblock = 0;
- return EOK;
+ i = depth;
+ /* walk through the tree */
+ while (i) {+ ext4_ext_binsearch_idx(path + ppos, block);
+ path[ppos].p_block = ext4_idx_pblock(path[ppos].index);
+ path[ppos].depth = i;
+ path[ppos].extent = NULL;
+ buf_block = path[ppos].p_block;
+
+ i--;
+ ppos++;
+ if (!path[ppos].block.lb_id ||
+ path[ppos].block.lb_id != buf_block) {+ ret = read_extent_tree_block(inode_ref, buf_block, i,
+ &bh, flags);
+ if (ret != EOK) {+ goto err;
+ }
+ if (ppos > depth) {+ ext4_block_set(inode_ref->fs->bdev, &bh);
+ ret = EIO;
+ goto err;
+ }
+
+ eh = ext_block_hdr(&bh);
+ path[ppos].block = bh;
+ path[ppos].header = eh;
+ }
}
- struct ext4_block block;
- block.lb_id = 0;
+ path[ppos].depth = i;
+ path[ppos].extent = NULL;
+ path[ppos].index = NULL;
- /* Walk through extent tree */
- struct ext4_extent_header *header =
- ext4_inode_get_extent_header(inode_ref->inode);
+ /* find extent */
+ ext4_ext_binsearch(path + ppos, block);
+ /* if not an empty leaf */
+ if (path[ppos].extent)
+ path[ppos].p_block = ext4_ext_pblock(path[ppos].extent);
- while (ext4_extent_header_get_depth(header) != 0) {- /* Search index in node */
- struct ext4_extent_index *index;
- ext4_extent_binsearch_idx(header, &index, iblock);
+ *orig_path = path;
- /* Load child node and set values for the next iteration */
- uint64_t child = ext4_extent_index_get_leaf(index);
+ ret = EOK;
+ return ret;
- if (block.lb_id) {- rc = ext4_block_set(inode_ref->fs->bdev, &block);
- if (rc != EOK)
- return rc;
- }
+err:
+ ext4_ext_drop_refs(inode_ref, path, 0);
+ free(path);
+ if (orig_path)
+ *orig_path = NULL;
+ return ret;
+}
- int rc = ext4_trans_block_get(inode_ref->fs->bdev, &block, child);
- if (rc != EOK)
- return rc;
- if (!ext4_extent_verify_block_csum(inode_ref,
- &block)) {- ext4_dbg(DEBUG_EXTENT,
- DBG_WARN "Extent block checksum failed."
- "Blocknr: %" PRIu64"\n",
- child);
- }
+static void ext4_ext_init_header(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_header *eh, int32_t depth)
+{+ eh->entries_count = 0;
+ eh->max_entries_count = to_le16(ext4_ext_max_entries(inode_ref, depth));
+ eh->magic = to_le16(EXT4_EXTENT_MAGIC);
+ eh->depth = depth;
+}
- header = (struct ext4_extent_header *)block.data;
- }
+/*
+ * Be cautious, the buffer_head returned is not yet mark dirtied. */
+static int ext4_ext_split_node(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path, int32_t at,
+ struct ext4_extent *newext,
+ ext4_fsblk_t *sibling, struct ext4_block *new_bh)
+{+ int ret;
+ ext4_fsblk_t newblock;
+ struct ext4_block bh = EXT4_BLOCK_ZERO();
+ int32_t depth = ext_depth(inode_ref->inode);
- /* Search extent in the leaf block */
- struct ext4_extent *extent = NULL;
- ext4_extent_binsearch(header, &extent, iblock);
+ ext4_assert(sibling);
- /* Prevent empty leaf */
- if (extent == NULL) {- *fblock = 0;
- } else {- /* Compute requested physical block address */
- ext4_fsblk_t phys_block;
- uint32_t first = ext4_extent_get_first_block(extent);
- phys_block = ext4_extent_get_start(extent) + iblock - first;
+ /* FIXME: currently we split at the point after the current extent. */
+ newblock = ext4_ext_new_meta_block(inode_ref, path, newext, &ret, 0);
+ if (ret)
+ goto cleanup;
- *fblock = phys_block;
+ /* For write access.# */
+ ret = ext4_trans_block_get_noread(inode_ref->fs->bdev, &bh, newblock);
+ if (ret != EOK)
+ goto cleanup;
+
+ if (at == depth) {+ /* start copy from next extent */
+ ptrdiff_t m = EXT_MAX_EXTENT(path[at].header) - path[at].extent;
+ struct ext4_extent_header *neh;
+ neh = ext_block_hdr(&bh);
+ ext4_ext_init_header(inode_ref, neh, 0);
+ if (m) {+ struct ext4_extent *ex;
+ ex = EXT_FIRST_EXTENT(neh);
+ memmove(ex, path[at].extent + 1,
+ sizeof(struct ext4_extent) * m);
+ neh->entries_count =
+ to_le16(to_le16(neh->entries_count) + m);
+ path[at].header->entries_count = to_le16(
+ to_le16(path[at].header->entries_count) - m);
+ ret = ext4_ext_dirty(inode_ref, path + at);
+ if (ret)
+ goto cleanup;
+ }
+ } else {+ ptrdiff_t m = EXT_MAX_INDEX(path[at].header) - path[at].index;
+ struct ext4_extent_header *neh;
+ neh = ext_block_hdr(&bh);
+ ext4_ext_init_header(inode_ref, neh, depth - at);
+ if (m) {+ struct ext4_extent_index *ix;
+ ix = EXT_FIRST_INDEX(neh);
+ memmove(ix, path[at].index + 1,
+ sizeof(struct ext4_extent) * m);
+ neh->entries_count =
+ to_le16(to_le16(neh->entries_count) + m);
+ path[at].header->entries_count = to_le16(
+ to_le16(path[at].header->entries_count) - m);
+ ret = ext4_ext_dirty(inode_ref, path + at);
+ if (ret)
+ goto cleanup;
+ }
}
+cleanup:
+ if (ret) {+ if (bh.lb_id) {+ ext4_block_set(inode_ref->fs->bdev, &bh);
+ }
+ if (newblock)
+ ext4_ext_free_blocks(inode_ref, newblock, 1, 0);
- /* Cleanup */
- if (block.lb_id) {- rc = ext4_block_set(inode_ref->fs->bdev, &block);
- if (rc != EOK)
- return rc;
+ newblock = 0;
}
+ *sibling = newblock;
+ *new_bh = bh;
+ return ret;
+}
- return EOK;
+static ext4_lblk_t ext4_ext_block_index(struct ext4_extent_header *eh)
+{+ if (eh->depth)
+ return to_le32(EXT_FIRST_INDEX(eh)->first_block);
+
+ return to_le32(EXT_FIRST_EXTENT(eh)->first_block);
}
-/**@brief Find extent for specified iblock.
- * This function is used for finding block in the extent tree with
- * saving the path through the tree for possible future modifications.
- * @param inode_ref I-node to read extent tree from
- * @param iblock Iblock to find extent for
- * @param ret_path Output value for loaded path from extent tree
- * @return Error code */
-static int ext4_extent_find_extent(struct ext4_inode_ref *inode_ref,
- uint32_t iblock,
- struct ext4_extent_path **ret_path)
+struct ext_split_trans {+ ext4_fsblk_t ptr;
+ struct ext4_extent_path path;
+ int switch_to;
+};
+
+static int ext4_ext_insert_index(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path,
+ int32_t at,
+ struct ext4_extent *newext,
+ ext4_lblk_t insert_index,
+ ext4_fsblk_t insert_block,
+ struct ext_split_trans *spt,
+ bool *need_grow)
{- struct ext4_extent_header *eh =
- ext4_inode_get_extent_header(inode_ref->inode);
+ struct ext4_extent_index *ix;
+ struct ext4_extent_path *curp = path + at;
+ struct ext4_block bh = EXT4_BLOCK_ZERO();
+ int32_t len;
+ int err;
+ struct ext4_extent_header *eh;
- uint16_t depth = ext4_extent_header_get_depth(eh);
- uint16_t i;
- struct ext4_extent_path *tmp_path;
+ *need_grow = false;
- /* Added 2 for possible tree growing */
- tmp_path = malloc(sizeof(struct ext4_extent_path) * (depth + 2));
- if (tmp_path == NULL)
- return ENOMEM;
+ if (curp->index && insert_index == to_le32(curp->index->first_block))
+ return EIO;
- /* Initialize structure for algorithm start */
- tmp_path[0].block = inode_ref->block;
- tmp_path[0].header = eh;
+ if (to_le16(curp->header->entries_count) ==
+ to_le16(curp->header->max_entries_count)) {+ if (at) {+ struct ext4_extent_header *neh;
+ err = ext4_ext_split_node(inode_ref, path, at, newext,
+ &spt->ptr, &bh);
+ if (err != EOK)
+ goto out;
- /* Walk through the extent tree */
- uint16_t pos = 0;
- int rc;
- while (ext4_extent_header_get_depth(eh) != 0) {- /* Search index in index node by iblock */
- ext4_extent_binsearch_idx(tmp_path[pos].header,
- &tmp_path[pos].index, iblock);
+ neh = ext_block_hdr(&bh);
+ if (insert_index > to_le32(curp->index->first_block)) {+ /* Make decision which node should be used to
+ * insert the index.*/
+ if (to_le16(neh->entries_count) >
+ to_le16(curp->header->entries_count)) {+ eh = curp->header;
+ /* insert after */
+ ix = EXT_LAST_INDEX(eh) + 1;
+ } else {+ eh = neh;
+ ix = EXT_FIRST_INDEX(eh);
+ }
+ } else {+ eh = curp->header;
+ /* insert before */
+ ix = EXT_LAST_INDEX(eh);
+ }
+ } else {+ err = EOK;
+ *need_grow = true;
+ goto out;
+ }
+ } else {+ eh = curp->header;
+ if (curp->index == NULL) {+ ix = EXT_FIRST_INDEX(eh);
+ curp->index = ix;
+ } else if (insert_index > to_le32(curp->index->first_block)) {+ /* insert after */
+ ix = curp->index + 1;
+ } else {+ /* insert before */
+ ix = curp->index;
+ }
+ }
- tmp_path[pos].depth = depth;
- tmp_path[pos].extent = NULL;
+ len = EXT_LAST_INDEX(eh) - ix + 1;
+ ext4_assert(len >= 0);
+ if (len > 0)
+ memmove(ix + 1, ix, len * sizeof(struct ext4_extent_index));
- ext4_assert(tmp_path[pos].index != 0);
+ if (ix > EXT_MAX_INDEX(eh)) {+ err = EIO;
+ goto out;
+ }
- /* Load information for the next iteration */
- uint64_t fblock =
- ext4_extent_index_get_leaf(tmp_path[pos].index);
+ ix->first_block = to_le32(insert_index);
+ ext4_idx_store_pblock(ix, insert_block);
+ eh->entries_count = to_le16(to_le16(eh->entries_count) + 1);
- struct ext4_block block;
- rc = ext4_trans_block_get(inode_ref->fs->bdev, &block, fblock);
- if (rc != EOK)
- goto cleanup;
+ if (ix > EXT_LAST_INDEX(eh)) {+ err = EIO;
+ goto out;
+ }
- if (!ext4_extent_verify_block_csum(inode_ref,
- &block)) {- ext4_dbg(DEBUG_EXTENT,
- DBG_WARN "Extent block checksum failed."
- "Blocknr: %" PRIu64"\n",
- fblock);
- }
+ if (eh == curp->header)
+ err = ext4_ext_dirty(inode_ref, curp);
+ else
+ err = EOK;
- pos++;
+out:
+ if (err != EOK || *need_grow) {+ if (bh.lb_id)
+ ext4_block_set(inode_ref->fs->bdev, &bh);
- eh = (struct ext4_extent_header *)block.data;
- tmp_path[pos].block = block;
- tmp_path[pos].header = eh;
+ spt->ptr = 0;
+ } else if (bh.lb_id) {+ /* If we got a sibling leaf. */
+ ext4_extent_block_csum_set(inode_ref, ext_block_hdr(&bh));
+ ext4_trans_set_block_dirty(bh.buf);
+
+ spt->path.p_block = ext4_idx_pblock(ix);
+ spt->path.depth = to_le16(eh->depth);
+ spt->path.maxdepth = 0;
+ spt->path.extent = NULL;
+ spt->path.index = ix;
+ spt->path.header = eh;
+ spt->path.block = bh;
+
+ /*
+ * If newext->ee_block can be included into the
+ * right sub-tree.
+ */
+ if (to_le32(newext->first_block) >=
+ ext4_ext_block_index(ext_block_hdr(&bh)))
+ spt->switch_to = 1;
+ else {+ curp->index = ix;
+ curp->p_block = ext4_idx_pblock(ix);
+ }
+
+ } else {+ spt->ptr = 0;
+ curp->index = ix;
+ curp->p_block = ext4_idx_pblock(ix);
}
+ return err;
+}
- tmp_path[pos].depth = 0;
- tmp_path[pos].extent = NULL;
- tmp_path[pos].index = NULL;
+/*
+ * ext4_ext_correct_indexes:
+ * if leaf gets modified and modified extent is first in the leaf,
+ * then we have to correct all indexes above.
+ */
+static int ext4_ext_correct_indexes(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path)
+{+ struct ext4_extent_header *eh;
+ int32_t depth = ext_depth(inode_ref->inode);
+ struct ext4_extent *ex;
+ uint32_t border;
+ int32_t k;
+ int err = EOK;
- /* Find extent in the leaf node */
- ext4_extent_binsearch(tmp_path[pos].header, &tmp_path[pos].extent,
- iblock);
- *ret_path = tmp_path;
+ eh = path[depth].header;
+ ex = path[depth].extent;
- return EOK;
+ if (ex == NULL || eh == NULL) {+ return EIO;
+ }
-cleanup:
+ if (depth == 0) {+ /* there is no tree at all */
+ return EOK;
+ }
+
+ if (ex != EXT_FIRST_EXTENT(eh)) {+ /* we correct tree if first leaf got modified only */
+ return EOK;
+ }
+
/*
- * Put loaded blocks
- * From 1: 0 is a block with inode data
+ * TODO: we need correction if border is smaller than current one
*/
- for (i = 1; i < tmp_path->depth; ++i) {- if (tmp_path[i].block.lb_id) {- int r = ext4_block_set(inode_ref->fs->bdev,
- &tmp_path[i].block);
- if (r != EOK)
- rc = r;
- }
+ k = depth - 1;
+ border = path[depth].extent->first_block;
+ path[k].index->first_block = border;
+ err = ext4_ext_dirty(inode_ref, path + k);
+ if (err != EOK)
+ return err;
+
+ while (k--) {+ /* change all left-side indexes */
+ if (path[k + 1].index != EXT_FIRST_INDEX(path[k + 1].header))
+ break;
+ path[k].index->first_block = border;
+ err = ext4_ext_dirty(inode_ref, path + k);
+ if (err != EOK)
+ break;
}
- /* Destroy temporary data structure */
- free(tmp_path);
+ return err;
+}
- return rc;
+static bool ext4_ext_can_prepend(struct ext4_extent *ex1,
+ struct ext4_extent *ex2)
+{+ if (ext4_ext_pblock(ex2) + ext4_ext_get_actual_len(ex2) !=
+ ext4_ext_pblock(ex1))
+ return false;
+
+#ifdef AGGRESSIVE_TEST
+ if (ext4_ext_get_actual_len(ex1) + ext4_ext_get_actual_len(ex2) > 4)
+ return 0;
+#else
+ if (ext4_ext_is_unwritten(ex1)) {+ if (ext4_ext_get_actual_len(ex1) +
+ ext4_ext_get_actual_len(ex2) >
+ EXT_UNWRITTEN_MAX_LEN)
+ return false;
+ } else if (ext4_ext_get_actual_len(ex1) + ext4_ext_get_actual_len(ex2) >
+ EXT_INIT_MAX_LEN)
+ return false;
+#endif
+
+ if (to_le32(ex2->first_block) + ext4_ext_get_actual_len(ex2) !=
+ to_le32(ex1->first_block))
+ return false;
+
+ return true;
}
-/**@brief Release extent and all data blocks covered by the extent.
- * @param inode_ref I-node to release extent and block from
- * @param extent Extent to release
- * @return Error code */
-static int ext4_extent_release(struct ext4_inode_ref *inode_ref,
- struct ext4_extent *extent)
+static bool ext4_ext_can_append(struct ext4_extent *ex1,
+ struct ext4_extent *ex2)
{- /* Compute number of the first physical block to release */
- uint64_t start = ext4_extent_get_start(extent);
- uint16_t block_count = ext4_extent_get_block_count(extent);
+ if (ext4_ext_pblock(ex1) + ext4_ext_get_actual_len(ex1) !=
+ ext4_ext_pblock(ex2))
+ return false;
- return ext4_balloc_free_blocks(inode_ref, start, block_count);
+#ifdef AGGRESSIVE_TEST
+ if (ext4_ext_get_actual_len(ex1) + ext4_ext_get_actual_len(ex2) > 4)
+ return 0;
+#else
+ if (ext4_ext_is_unwritten(ex1)) {+ if (ext4_ext_get_actual_len(ex1) +
+ ext4_ext_get_actual_len(ex2) >
+ EXT_UNWRITTEN_MAX_LEN)
+ return false;
+ } else if (ext4_ext_get_actual_len(ex1) + ext4_ext_get_actual_len(ex2) >
+ EXT_INIT_MAX_LEN)
+ return false;
+#endif
+
+ if (to_le32(ex1->first_block) + ext4_ext_get_actual_len(ex1) !=
+ to_le32(ex2->first_block))
+ return false;
+
+ return true;
}
-/** Recursively release the whole branch of the extent tree.
- * For each entry of the node release the subbranch and finally release
- * the node. In the leaf node all extents will be released.
- * @param inode_ref I-node where the branch is released
- * @param index Index in the non-leaf node to be released
- * with the whole subtree
- * @return Error code */
-static int ext4_extent_release_branch(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_index *index)
+static int ext4_ext_insert_leaf(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path,
+ int32_t at,
+ struct ext4_extent *newext,
+ struct ext_split_trans *spt,
+ uint32_t flags,
+ bool *need_grow)
{- ext4_fsblk_t fblock = ext4_extent_index_get_leaf(index);
- uint32_t i;
- struct ext4_block block;
- int rc = ext4_trans_block_get(inode_ref->fs->bdev, &block, fblock);
- if (rc != EOK)
- return rc;
+ struct ext4_extent_path *curp = path + at;
+ struct ext4_extent *ex = curp->extent;
+ struct ext4_block bh = EXT4_BLOCK_ZERO();
+ int32_t len;
+ int err = EOK;
+ int unwritten;
+ struct ext4_extent_header *eh = NULL;
- if (!ext4_extent_verify_block_csum(inode_ref,
- &block)) {- ext4_dbg(DEBUG_EXTENT,
- DBG_WARN "Extent block checksum failed."
- "Blocknr: %" PRIu64"\n",
- fblock);
- }
+ *need_grow = false;
- struct ext4_extent_header *header = (void *)block.data;
+ if (curp->extent &&
+ to_le32(newext->first_block) == to_le32(curp->extent->first_block))
+ return EIO;
- if (ext4_extent_header_get_depth(header)) {- /* The node is non-leaf, do recursion */
- struct ext4_extent_index *idx = EXT4_EXTENT_FIRST_INDEX(header);
+ if (!(flags & EXT4_EXT_NO_COMBINE)) {+ if (curp->extent && ext4_ext_can_append(curp->extent, newext)) {+ unwritten = ext4_ext_is_unwritten(curp->extent);
+ curp->extent->block_count =
+ to_le16(ext4_ext_get_actual_len(curp->extent) +
+ ext4_ext_get_actual_len(newext));
+ if (unwritten)
+ ext4_ext_mark_unwritten(curp->extent);
+ err = ext4_ext_dirty(inode_ref, curp);
+ goto out;
+ }
- /* Release all subbranches */
- for (i = 0; i < ext4_extent_header_get_entries_count(header);
- ++i, ++idx) {- rc = ext4_extent_release_branch(inode_ref, idx);
- if (rc != EOK)
- return rc;
+ if (curp->extent &&
+ ext4_ext_can_prepend(curp->extent, newext)) {+ unwritten = ext4_ext_is_unwritten(curp->extent);
+ curp->extent->first_block = newext->first_block;
+ curp->extent->block_count =
+ to_le16(ext4_ext_get_actual_len(curp->extent) +
+ ext4_ext_get_actual_len(newext));
+ if (unwritten)
+ ext4_ext_mark_unwritten(curp->extent);
+ err = ext4_ext_dirty(inode_ref, curp);
+ goto out;
}
- } else {- /* Leaf node reached */
- struct ext4_extent *ext = EXT4_EXTENT_FIRST(header);
+ }
- /* Release all extents and stop recursion */
- for (i = 0; i < ext4_extent_header_get_entries_count(header);
- ++i, ++ext) {- rc = ext4_extent_release(inode_ref, ext);
- if (rc != EOK)
- return rc;
+ if (to_le16(curp->header->entries_count) ==
+ to_le16(curp->header->max_entries_count)) {+ if (at) {+ struct ext4_extent_header *neh;
+ err = ext4_ext_split_node(inode_ref, path, at, newext,
+ &spt->ptr, &bh);
+ if (err != EOK)
+ goto out;
+
+ neh = ext_block_hdr(&bh);
+ if (to_le32(newext->first_block) >
+ to_le32(curp->extent->first_block)) {+ if (to_le16(neh->entries_count) >
+ to_le16(curp->header->entries_count)) {+ eh = curp->header;
+ /* insert after */
+ ex = EXT_LAST_EXTENT(eh) + 1;
+ } else {+ eh = neh;
+ ex = EXT_FIRST_EXTENT(eh);
+ }
+ } else {+ eh = curp->header;
+ /* insert before */
+ ex = EXT_LAST_EXTENT(eh);
+ }
+ } else {+ err = EOK;
+ *need_grow = true;
+ goto out;
}
+ } else {+ eh = curp->header;
+ if (curp->extent == NULL) {+ ex = EXT_FIRST_EXTENT(eh);
+ curp->extent = ex;
+ } else if (to_le32(newext->first_block) >
+ to_le32(curp->extent->first_block)) {+ /* insert after */
+ ex = curp->extent + 1;
+ } else {+ /* insert before */
+ ex = curp->extent;
+ }
}
- /* Release data block where the node was stored */
+ len = EXT_LAST_EXTENT(eh) - ex + 1;
+ ext4_assert(len >= 0);
+ if (len > 0)
+ memmove(ex + 1, ex, len * sizeof(struct ext4_extent));
- rc = ext4_block_set(inode_ref->fs->bdev, &block);
- if (rc != EOK)
- return rc;
+ if (ex > EXT_MAX_EXTENT(eh)) {+ err = EIO;
+ goto out;
+ }
- return ext4_balloc_free_block(inode_ref, fblock);
-}
+ ex->first_block = newext->first_block;
+ ex->block_count = newext->block_count;
+ ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
+ eh->entries_count = to_le16(to_le16(eh->entries_count) + 1);
-int ext4_extent_remove_space(struct ext4_inode_ref *inode_ref, ext4_lblk_t from,
- ext4_lblk_t to)
-{- if (to != EXT_MAX_BLOCKS)
- return ENOTSUP;
+ if (ex > EXT_LAST_EXTENT(eh)) {+ err = EIO;
+ goto out;
+ }
- /* Find the first extent to modify */
- struct ext4_extent_path *path;
- uint16_t i;
- int rc = ext4_extent_find_extent(inode_ref, from, &path);
- if (rc != EOK)
- return rc;
+ if (eh == curp->header) {+ err = ext4_ext_correct_indexes(inode_ref, path);
+ if (err != EOK)
+ goto out;
+ err = ext4_ext_dirty(inode_ref, curp);
+ } else
+ err = EOK;
- /* Jump to last item of the path (extent) */
- struct ext4_extent_path *path_ptr = path;
- while (path_ptr->depth != 0)
- path_ptr++;
+out:
+ if (err != EOK || *need_grow) {+ if (bh.lb_id)
+ ext4_block_set(inode_ref->fs->bdev, &bh);
- ext4_assert(path_ptr->extent != NULL);
+ spt->ptr = 0;
+ } else if (bh.lb_id) {+ /* If we got a sibling leaf. */
+ ext4_extent_block_csum_set(inode_ref, ext_block_hdr(&bh));
+ ext4_trans_set_block_dirty(bh.buf);
- /* First extent maybe released partially */
- uint32_t first_iblock = ext4_extent_get_first_block(path_ptr->extent);
- ext4_fsblk_t first_fblock = ext4_extent_get_start(path_ptr->extent) +
- from - first_iblock;
+ spt->path.p_block = ext4_ext_pblock(ex);
+ spt->path.depth = to_le16(eh->depth);
+ spt->path.maxdepth = 0;
+ spt->path.extent = ex;
+ spt->path.index = NULL;
+ spt->path.header = eh;
+ spt->path.block = bh;
- uint16_t block_count = ext4_extent_get_block_count(path_ptr->extent);
+ /*
+ * If newext->ee_block can be included into the
+ * right sub-tree.
+ */
+ if (to_le32(newext->first_block) >=
+ ext4_ext_block_index(ext_block_hdr(&bh)))
+ spt->switch_to = 1;
+ else {+ curp->extent = ex;
+ curp->p_block = ext4_ext_pblock(ex);
+ }
- uint16_t delete_count =
- block_count -
- (ext4_extent_get_start(path_ptr->extent) - first_fblock);
+ } else {+ spt->ptr = 0;
+ curp->extent = ex;
+ curp->p_block = ext4_ext_pblock(ex);
+ }
- /* Release all blocks */
- rc = ext4_balloc_free_blocks(inode_ref, first_fblock, delete_count);
- if (rc != EOK)
- goto cleanup;
+ return err;
+}
- /* Correct counter */
- block_count -= delete_count;
- ext4_extent_set_block_count(path_ptr->extent, block_count,
- EXT4_EXT_IS_UNWRITTEN(path_ptr->extent));
+/*
+ * ext4_ext_grow_indepth:
+ * implements tree growing procedure:
+ * - allocates new block
+ * - moves top-level data (index block or leaf) into the new block
+ * - initializes new top-level, creating index that points to the
+ * just created block
+ */
+static int ext4_ext_grow_indepth(struct ext4_inode_ref *inode_ref,
+ uint32_t flags)
+{+ struct ext4_extent_header *neh;
+ struct ext4_block bh = EXT4_BLOCK_ZERO();
+ ext4_fsblk_t newblock, goal = 0;
+ int err = EOK;
- /* Initialize the following loop */
- uint16_t entries =
- ext4_extent_header_get_entries_count(path_ptr->header);
- struct ext4_extent *tmp_ext = path_ptr->extent + 1;
- struct ext4_extent *stop_ext =
- EXT4_EXTENT_FIRST(path_ptr->header) + entries;
+ /* Try to prepend new index to old one */
+ if (ext_depth(inode_ref->inode))
+ goal = ext4_idx_pblock(
+ EXT_FIRST_INDEX(ext_inode_hdr(inode_ref->inode)));
+ else
+ goal = ext4_fs_inode_to_goal_block(inode_ref);
- /* If first extent empty, release it */
- if (block_count == 0)
- entries--;
+ newblock = ext4_new_meta_blocks(inode_ref, goal, flags, NULL, &err);
+ if (newblock == 0)
+ return err;
- /* Release all successors of the first extent in the same node */
- while (tmp_ext < stop_ext) {- first_fblock = ext4_extent_get_start(tmp_ext);
- delete_count = ext4_extent_get_block_count(tmp_ext);
+ /* # */
+ err = ext4_trans_block_get_noread(inode_ref->fs->bdev, &bh, newblock);
+ if (err != EOK) {+ ext4_ext_free_blocks(inode_ref, newblock, 1, 0);
+ return err;
+ }
- rc = ext4_balloc_free_blocks(inode_ref, first_fblock,
- delete_count);
- if (rc != EOK)
- goto cleanup;
+ /* move top-level index/leaf into new block */
+ memmove(bh.data, inode_ref->inode->blocks,
+ sizeof(inode_ref->inode->blocks));
- entries--;
- tmp_ext++;
+ /* set size of new block */
+ neh = ext_block_hdr(&bh);
+ /* old root could have indexes or leaves
+ * so calculate e_max right way */
+ if (ext_depth(inode_ref->inode))
+ neh->max_entries_count =
+ to_le16(ext4_ext_space_block_idx(inode_ref));
+ else
+ neh->max_entries_count =
+ to_le16(ext4_ext_space_block(inode_ref));
+
+ neh->magic = to_le16(EXT4_EXTENT_MAGIC);
+ ext4_extent_block_csum_set(inode_ref, neh);
+
+ /* Update top-level index: num,max,pointer */
+ neh = ext_inode_hdr(inode_ref->inode);
+ neh->entries_count = to_le16(1);
+ ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
+ if (neh->depth == 0) {+ /* Root extent block becomes index block */
+ neh->max_entries_count =
+ to_le16(ext4_ext_space_root_idx(inode_ref));
+ EXT_FIRST_INDEX(neh)
+ ->first_block = EXT_FIRST_EXTENT(neh)->first_block;
}
+ neh->depth = to_le16(to_le16(neh->depth) + 1);
- ext4_extent_header_set_entries_count(path_ptr->header, entries);
- ext4_extent_block_csum_set(inode_ref, path_ptr->header);
- ext4_trans_set_block_dirty(path_ptr->block.buf);
+ ext4_trans_set_block_dirty(bh.buf);
+ inode_ref->dirty = true;
+ ext4_block_set(inode_ref->fs->bdev, &bh);
- /* If leaf node is empty, parent entry must be modified */
- bool remove_parent_record = false;
+ return err;
+}
- /* Don't release root block (including inode data) !!! */
- if ((path_ptr != path) && (entries == 0)) {- rc = ext4_balloc_free_block(inode_ref, path_ptr->block.lb_id);
- if (rc != EOK)
- goto cleanup;
+__unused static void print_path(struct ext4_extent_path *path)
+{+ int32_t i = path->depth;
+ while (i >= 0) {- remove_parent_record = true;
+ ptrdiff_t a =
+ (path->extent)
+ ? (path->extent - EXT_FIRST_EXTENT(path->header))
+ : 0;
+ ptrdiff_t b =
+ (path->index)
+ ? (path->index - EXT_FIRST_INDEX(path->header))
+ : 0;
+
+ (void)a;
+ (void)b;
+ ext4_dbg(DEBUG_EXTENT,
+ "depth %" PRId32 ", p_block: %" PRIu64 ","
+ "p_ext offset: %td, p_idx offset: %td\n",
+ i, path->p_block, a, b);
+ i--;
+ path++;
}
+}
- /* Jump to the parent */
- --path_ptr;
+static void ext4_ext_replace_path(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path,
+ struct ext_split_trans *spt,
+ int32_t level)
+{+ int32_t depth = ext_depth(inode_ref->inode);
+ int32_t i = depth - level;
+ ext4_ext_drop_refs(inode_ref, path + i, 1);
+ path[i] = spt[level].path;
+}
- /* Release all successors in all tree levels */
- while (path_ptr >= path) {- entries =
- ext4_extent_header_get_entries_count(path_ptr->header);
- struct ext4_extent_index *index = path_ptr->index + 1;
- struct ext4_extent_index *stop =
- EXT4_EXTENT_FIRST_INDEX(path_ptr->header) + entries;
+static int ext4_ext_insert_extent(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path **ppath,
+ struct ext4_extent *newext, uint32_t flags)
+{+ int32_t i, depth, level;
+ int ret = EOK;
+ ext4_fsblk_t ptr = 0;
+ bool need_grow = false;
+ struct ext4_extent_path *path = *ppath;
+ struct ext_split_trans *spt = NULL;
+ struct ext_split_trans newblock;
- /* Correct entries count because of changes in the previous
- * iteration */
- if (remove_parent_record)
- entries--;
+ memset(&newblock, 0, sizeof(newblock));
- /* Iterate over all entries and release the whole subtrees */
- while (index < stop) {- rc = ext4_extent_release_branch(inode_ref, index);
- if (rc != EOK)
- goto cleanup;
+ depth = ext_depth(inode_ref->inode);
+ for (i = depth, level = 0; i >= 0; i--, level++)
+ if (EXT_HAS_FREE_INDEX(path + i))
+ break;
- ++index;
- --entries;
+ if (level) {+ spt = calloc(1, sizeof(struct ext_split_trans) * (level));
+ if (!spt) {+ ret = ENOMEM;
+ goto out;
}
+ }
+ i = 0;
+again:
+ depth = ext_depth(inode_ref->inode);
- ext4_extent_header_set_entries_count(path_ptr->header, entries);
- ext4_extent_block_csum_set(inode_ref, path_ptr->header);
- ext4_trans_set_block_dirty(path_ptr->block.buf);
+ do {+ if (!i) {+ ret = ext4_ext_insert_leaf(inode_ref, path, depth - i,
+ newext, &newblock, flags,
+ &need_grow);
+ } else {+ ret = ext4_ext_insert_index(
+ inode_ref, path, depth - i, newext,
+ ext4_ext_block_index(
+ ext_block_hdr(&spt[i - 1].path.block)),
+ spt[i - 1].ptr, &newblock,
+ &need_grow);
+ }
+ ptr = newblock.ptr;
- /* Free the node if it is empty */
- if ((entries == 0) && (path_ptr != path)) {- rc = ext4_balloc_free_block(inode_ref,
- path_ptr->block.lb_id);
- if (rc != EOK)
- goto cleanup;
+ if (ret != EOK)
+ goto out;
- /* Mark parent to be checked */
- remove_parent_record = true;
- } else
- remove_parent_record = false;
+ else if (spt && ptr && !ret) {+ /* Prepare for the next iteration after splitting. */
+ spt[i] = newblock;
+ }
- --path_ptr;
+ i++;
+ } while (ptr != 0 && i <= depth);
+
+ if (need_grow) {+ ret = ext4_ext_grow_indepth(inode_ref, 0);
+ if (ret)
+ goto out;
+ ret = ext4_find_extent(inode_ref, to_le32(newext->first_block),
+ ppath, 0);
+ if (ret)
+ goto out;
+ i = depth;
+ path = *ppath;
+ goto again;
}
+out:
+ if (ret) {+ if (path)
+ ext4_ext_drop_refs(inode_ref, path, 0);
- if (!entries)
- ext4_extent_header_set_depth(path->header, 0);
-
-cleanup:
- /*
- * Put loaded blocks
- * starting from 1: 0 is a block with inode data
- */
- for (i = 1; i <= path->depth; ++i) {- if (path[i].block.lb_id) {- int r =
- ext4_block_set(inode_ref->fs->bdev, &path[i].block);
- if (r != EOK)
- rc = r;
+ while (--level >= 0 && spt) {+ if (spt[level].ptr) {+ ext4_ext_free_blocks(inode_ref, spt[level].ptr,
+ 1, 0);
+ ext4_ext_drop_refs(inode_ref, &spt[level].path,
+ 1);
+ }
}
+ } else {+ while (--level >= 0 && spt) {+ if (spt[level].switch_to)
+ ext4_ext_replace_path(inode_ref, path, spt,
+ level);
+ else if (spt[level].ptr)
+ ext4_ext_drop_refs(inode_ref, &spt[level].path,
+ 1);
+ }
}
+ if (spt)
+ free(spt);
- /* Destroy temporary data structure */
- free(path);
-
- return rc;
+ return ret;
}
-/**@brief Append new extent to the i-node and do some splitting if necessary.
- * @param inode_ref I-node to append extent to
- * @param path Path in the extent tree for possible splitting
- * @param last_path_item Input/output parameter for pointer to the last
- * valid item in the extent tree path
- * @param iblock Logical index of block to append extent for
- * @return Error code */
-static int ext4_extent_append_extent(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path,
- uint32_t iblock)
+static void ext4_ext_remove_blocks(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent *ex, ext4_lblk_t from,
+ ext4_lblk_t to)
{- struct ext4_extent_path *path_ptr = path + path->depth;
+ ext4_lblk_t len = to - from + 1;
+ ext4_lblk_t num;
+ ext4_fsblk_t start;
+ num = from - to_le32(ex->first_block);
+ start = ext4_ext_pblock(ex) + num;
+ ext4_dbg(DEBUG_EXTENT,
+ "Freeing %" PRIu32 " at %" PRIu64 ", %" PRIu32 "\n", from,
+ start, len);
- uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
+ ext4_ext_free_blocks(inode_ref, start, len, 0);
+}
- /* Start splitting */
- while (path_ptr > path) {- uint16_t entries =
- ext4_extent_header_get_entries_count(path_ptr->header);
- uint16_t limit =
- ext4_extent_header_get_max_entries_count(path_ptr->header);
+static int ext4_ext_remove_idx(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path, int32_t depth)
+{+ int err = EOK;
+ int32_t i = depth;
+ ext4_fsblk_t leaf;
- if (entries == limit) {- /* Full node - allocate block for new one */
- ext4_fsblk_t goal, fblock;
- int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
- if (rc != EOK)
- return rc;
+ /* free index block */
+ leaf = ext4_idx_pblock(path[i].index);
- rc = ext4_balloc_alloc_block(inode_ref, goal, &fblock);
- if (rc != EOK)
- return rc;
+ if (path[i].index != EXT_LAST_INDEX(path[i].header)) {+ ptrdiff_t len = EXT_LAST_INDEX(path[i].header) - path[i].index;
+ memmove(path[i].index, path[i].index + 1,
+ len * sizeof(struct ext4_extent_index));
+ }
- struct ext4_block block;
- rc =
- ext4_trans_block_get_noread(inode_ref->fs->bdev, &block, fblock);
- if (rc != EOK) {- ext4_balloc_free_block(inode_ref, fblock);
- return rc;
- }
+ path[i].header->entries_count =
+ to_le16(to_le16(path[i].header->entries_count) - 1);
+ err = ext4_ext_dirty(inode_ref, path + i);
+ if (err != EOK)
+ return err;
- /* Put back not modified old block */
- rc = ext4_block_set(inode_ref->fs->bdev,
- &path_ptr->block);
- if (rc != EOK) {- ext4_balloc_free_block(inode_ref, fblock);
- return rc;
- }
+ ext4_dbg(DEBUG_EXTENT, "IDX: Freeing %" PRIu32 " at %" PRIu64 ", %d\n",
+ to_le32(path[i].index->first_block), leaf, 1);
+ ext4_ext_free_blocks(inode_ref, leaf, 1, 0);
- /* Initialize newly allocated block and remember it */
- memset(block.data, 0, block_size);
- path_ptr->block = block;
+ while (i > 0) {+ if (path[i].index != EXT_FIRST_INDEX(path[i].header))
+ break;
- /* Update pointers in extent path structure */
- path_ptr->header = (void *)block.data;
- if (path_ptr->depth) {- path_ptr->index =
- EXT4_EXTENT_FIRST_INDEX(path_ptr->header);
- ext4_extent_index_set_first_block(
- path_ptr->index, iblock);
- ext4_extent_index_set_leaf(
- path_ptr->index,
- (path_ptr + 1)->block.lb_id);
- limit = (block_size -
- sizeof(struct ext4_extent_header)) /
- sizeof(struct ext4_extent_index);
- } else {- path_ptr->extent =
- EXT4_EXTENT_FIRST(path_ptr->header);
- ext4_extent_set_first_block(path_ptr->extent,
- iblock);
- limit = (block_size -
- sizeof(struct ext4_extent_header)) /
- sizeof(struct ext4_extent);
- }
+ path[i - 1].index->first_block = path[i].index->first_block;
+ err = ext4_ext_dirty(inode_ref, path + i - 1);
+ if (err != EOK)
+ break;
- /* Initialize on-disk structure (header) */
- ext4_extent_header_set_entries_count(path_ptr->header,
- 1);
- ext4_extent_header_set_max_entries_count(
- path_ptr->header, limit);
- ext4_extent_header_set_magic(path_ptr->header,
- EXT4_EXTENT_MAGIC);
- ext4_extent_header_set_depth(path_ptr->header,
- path_ptr->depth);
- ext4_extent_header_set_generation(path_ptr->header, 0);
+ i--;
+ }
+ return err;
+}
- ext4_extent_block_csum_set(inode_ref, path_ptr->header);
- ext4_trans_set_block_dirty(path_ptr->block.buf);
+static int ext4_ext_remove_leaf(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path, ext4_lblk_t from,
+ ext4_lblk_t to)
+{- /* Jump to the preceding item */
- path_ptr--;
+ int32_t depth = ext_depth(inode_ref->inode);
+ struct ext4_extent *ex = path[depth].extent;
+ struct ext4_extent *start_ex, *ex2 = NULL;
+ struct ext4_extent_header *eh = path[depth].header;
+ int32_t len;
+ int err = EOK;
+ uint16_t new_entries;
+
+ start_ex = ex;
+ new_entries = to_le16(eh->entries_count);
+ while (ex <= EXT_LAST_EXTENT(path[depth].header) &&
+ to_le32(ex->first_block) <= to) {+ int32_t new_len = 0;
+ int unwritten;
+ ext4_lblk_t start, new_start;
+ ext4_fsblk_t newblock;
+ new_start = start = to_le32(ex->first_block);
+ len = ext4_ext_get_actual_len(ex);
+ newblock = ext4_ext_pblock(ex);
+ if (start < from) {+ len -= from - start;
+ new_len = from - start;
+ start = from;
+ start_ex++;
} else {- /* Node with free space */
- if (path_ptr->depth) {- path_ptr->index =
- EXT4_EXTENT_FIRST_INDEX(path_ptr->header) +
- entries;
- ext4_extent_index_set_first_block(
- path_ptr->index, iblock);
- ext4_extent_index_set_leaf(
- path_ptr->index,
- (path_ptr + 1)->block.lb_id);
- } else {- path_ptr->extent =
- EXT4_EXTENT_FIRST(path_ptr->header) +
- entries;
- ext4_extent_set_first_block(path_ptr->extent,
- iblock);
+ if (start + len - 1 > to) {+ len -= start + len - 1 - to;
+ new_len = start + len - 1 - to;
+ new_start = to + 1;
+ newblock += to + 1 - start;
+ ex2 = ex;
}
+ }
- ext4_extent_header_set_entries_count(path_ptr->header,
- entries + 1);
- ext4_extent_block_csum_set(inode_ref, path_ptr->header);
- ext4_trans_set_block_dirty(path_ptr->block.buf);
-
- /* No more splitting needed */
- return EOK;
+ ext4_ext_remove_blocks(inode_ref, ex, start, start + len - 1);
+ ex->first_block = to_le32(new_start);
+ if (!new_len)
+ new_entries--;
+ else {+ unwritten = ext4_ext_is_unwritten(ex);
+ ex->block_count = to_le16(new_len);
+ ext4_ext_store_pblock(ex, newblock);
+ if (unwritten)
+ ext4_ext_mark_unwritten(ex);
}
+
+ ex += 1;
}
- ext4_assert(path_ptr == path);
+ if (ex2 == NULL)
+ ex2 = ex;
- /* Should be the root split too? */
+ if (ex2 <= EXT_LAST_EXTENT(eh))
+ memmove(start_ex, ex2, EXT_LAST_EXTENT(eh) - ex2 + 1);
- uint16_t entries = ext4_extent_header_get_entries_count(path->header);
- uint16_t limit = ext4_extent_header_get_max_entries_count(path->header);
+ eh->entries_count = to_le16(new_entries);
+ ext4_ext_dirty(inode_ref, path + depth);
+ if (path[depth].extent == EXT_FIRST_EXTENT(eh) && eh->entries_count)
+ err = ext4_ext_correct_indexes(inode_ref, path);
- if (entries == limit) {- ext4_fsblk_t goal, new_fblock;
- int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
- if (rc != EOK)
- return rc;
+ /* if this leaf is free, then we should
+ * remove it from index block above */
+ if (err == EOK && eh->entries_count == 0 && path[depth].block.lb_id)
+ err = ext4_ext_remove_idx(inode_ref, path, depth - 1);
+ else if (depth > 0)
+ path[depth - 1].index++;
- rc = ext4_balloc_alloc_block(inode_ref, goal, &new_fblock);
- if (rc != EOK)
- return rc;
+ return err;
+}
- struct ext4_block block;
- rc = ext4_trans_block_get_noread(inode_ref->fs->bdev, &block, new_fblock);
- if (rc != EOK)
- return rc;
+static bool ext4_ext_more_to_rm(struct ext4_extent_path *path, ext4_lblk_t to)
+{+ if (!to_le16(path->header->entries_count))
+ return false;
- /* Initialize newly allocated block */
- memset(block.data, 0, block_size);
+ if (path->index > EXT_LAST_INDEX(path->header))
+ return false;
- /* Move data from root to the new block */
- memcpy(block.data, inode_ref->inode->blocks,
- EXT4_INODE_BLOCKS * sizeof(uint32_t));
+ if (to_le32(path->index->first_block) > to)
+ return false;
- /* Data block is initialized */
+ return true;
+}
- struct ext4_block *root_block = &path->block;
- uint16_t root_depth = path->depth;
- struct ext4_extent_header *root_header = path->header;
+int ext4_extent_remove_space(struct ext4_inode_ref *inode_ref, ext4_lblk_t from,
+ ext4_lblk_t to)
+{+ struct ext4_extent_path *path = NULL;
+ int ret = EOK;
+ int32_t depth = ext_depth(inode_ref->inode);
+ int32_t i;
- /* Make space for tree growing */
- struct ext4_extent_path *new_root = path;
- struct ext4_extent_path *old_root = path + 1;
+ ret = ext4_find_extent(inode_ref, from, &path, 0);
+ if (ret)
+ goto out;
- size_t nbytes =
- sizeof(struct ext4_extent_path) * (path->depth + 1);
- memmove(old_root, new_root, nbytes);
- memset(new_root, 0, sizeof(struct ext4_extent_path));
+ if (!path[depth].extent) {+ ret = EOK;
+ goto out;
+ }
- /* Update old root structure */
- old_root->block = block;
- old_root->header = (struct ext4_extent_header *)block.data;
+ bool in_range = IN_RANGE(from, to_le32(path[depth].extent->first_block),
+ ext4_ext_get_actual_len(path[depth].extent));
- /* Add new entry and update limit for entries */
- if (old_root->depth) {- limit =
- (block_size - sizeof(struct ext4_extent_header)) /
- sizeof(struct ext4_extent_index);
- old_root->index =
- EXT4_EXTENT_FIRST_INDEX(old_root->header) + entries;
- ext4_extent_index_set_first_block(old_root->index,
- iblock);
- ext4_extent_index_set_leaf(old_root->index,
- (old_root + 1)->block.lb_id);
- old_root->extent = NULL;
- } else {- limit =
- (block_size - sizeof(struct ext4_extent_header)) /
- sizeof(struct ext4_extent);
- old_root->extent =
- EXT4_EXTENT_FIRST(old_root->header) + entries;
- ext4_extent_set_first_block(old_root->extent, iblock);
- old_root->index = NULL;
- }
+ if (!in_range) {+ ret = EOK;
+ goto out;
+ }
- ext4_extent_header_set_entries_count(old_root->header,
- entries + 1);
- ext4_extent_header_set_max_entries_count(old_root->header,
- limit);
+ /* If we do remove_space inside the range of an extent */
+ if ((to_le32(path[depth].extent->first_block) < from) &&
+ (to < to_le32(path[depth].extent->first_block) +
+ ext4_ext_get_actual_len(path[depth].extent) - 1)) {- ext4_extent_block_csum_set(inode_ref, old_root->header);
- ext4_trans_set_block_dirty(old_root->block.buf);
+ struct ext4_extent *ex = path[depth].extent, newex;
+ int unwritten = ext4_ext_is_unwritten(ex);
+ ext4_lblk_t ee_block = to_le32(ex->first_block);
+ int32_t len = ext4_ext_get_actual_len(ex);
+ ext4_fsblk_t newblock =
+ to + 1 - ee_block + ext4_ext_pblock(ex);
- /* Re-initialize new root metadata */
- new_root->depth = root_depth + 1;
- new_root->block = *root_block;
- new_root->header = root_header;
- new_root->extent = NULL;
- new_root->index = EXT4_EXTENT_FIRST_INDEX(new_root->header);
+ ex->block_count = to_le16(from - ee_block);
+ if (unwritten)
+ ext4_ext_mark_unwritten(ex);
- ext4_extent_header_set_depth(new_root->header, new_root->depth);
+ ext4_ext_dirty(inode_ref, path + depth);
- /* Create new entry in root */
- ext4_extent_header_set_entries_count(new_root->header, 1);
- ext4_extent_index_set_first_block(new_root->index, 0);
- ext4_extent_index_set_leaf(new_root->index, new_fblock);
+ newex.first_block = to_le32(to + 1);
+ newex.block_count = to_le16(ee_block + len - 1 - to);
+ ext4_ext_store_pblock(&newex, newblock);
+ if (unwritten)
+ ext4_ext_mark_unwritten(&newex);
- /* Since new_root belongs to on-disk inode,
- * we don't do checksum here */
- ext4_trans_set_block_dirty(new_root->block.buf);
- } else {- if (path->depth) {- path->index =
- EXT4_EXTENT_FIRST_INDEX(path->header) + entries;
- ext4_extent_index_set_first_block(path->index, iblock);
- ext4_extent_index_set_leaf(path->index,
- (path + 1)->block.lb_id);
+ ret = ext4_ext_insert_extent(inode_ref, &path, &newex, 0);
+ goto out;
+ }
+
+ i = depth;
+ while (i >= 0) {+ if (i == depth) {+ struct ext4_extent_header *eh;
+ struct ext4_extent *first_ex, *last_ex;
+ ext4_lblk_t leaf_from, leaf_to;
+ eh = path[i].header;
+ ext4_assert(to_le16(eh->entries_count) > 0);
+ first_ex = EXT_FIRST_EXTENT(eh);
+ last_ex = EXT_LAST_EXTENT(eh);
+ leaf_from = to_le32(first_ex->first_block);
+ leaf_to = to_le32(last_ex->first_block) +
+ ext4_ext_get_actual_len(last_ex) - 1;
+ if (leaf_from < from)
+ leaf_from = from;
+
+ if (leaf_to > to)
+ leaf_to = to;
+
+ ext4_ext_remove_leaf(inode_ref, path, leaf_from,
+ leaf_to);
+ ext4_ext_drop_refs(inode_ref, path + i, 0);
+ i--;
+ continue;
+ }
+
+ struct ext4_extent_header *eh;
+ eh = path[i].header;
+ if (ext4_ext_more_to_rm(path + i, to)) {+ struct ext4_block bh = EXT4_BLOCK_ZERO();
+ if (path[i + 1].block.lb_id)
+ ext4_ext_drop_refs(inode_ref, path + i + 1, 0);
+
+ ret = read_extent_tree_block(inode_ref,
+ ext4_idx_pblock(path[i].index),
+ depth - i - 1, &bh, 0);
+ if (ret)
+ goto out;
+
+ path[i].p_block =
+ ext4_idx_pblock(path[i].index);
+ path[i + 1].block = bh;
+ path[i + 1].header = ext_block_hdr(&bh);
+ path[i + 1].depth = depth - i - 1;
+ if (i + 1 == depth)
+ path[i + 1].extent = EXT_FIRST_EXTENT(
+ path[i + 1].header);
+ else
+ path[i + 1].index =
+ EXT_FIRST_INDEX(path[i + 1].header);
+
+ i++;
} else {- path->extent =
- EXT4_EXTENT_FIRST(path->header) + entries;
- ext4_extent_set_first_block(path->extent, iblock);
+ if (i > 0) {+ if (!eh->entries_count)
+ ret = ext4_ext_remove_idx(inode_ref, path,
+ i - 1);
+ else
+ path[i - 1].index++;
+
+ }
+
+ if (i)
+ ext4_block_set(inode_ref->fs->bdev,
+ &path[i].block);
+
+
+ i--;
}
- ext4_extent_header_set_entries_count(path->header, entries + 1);
- /* Since new_root belongs to on-disk inode,
- * we don't do checksum here */
- ext4_trans_set_block_dirty(path->block.buf);
}
- return EOK;
+ /* TODO: flexible tree reduction should be here */
+ if (path->header->entries_count == 0) {+ /*
+ * truncate to zero freed all the tree,
+ * so we need to correct eh_depth
+ */
+ ext_inode_hdr(inode_ref->inode)->depth = 0;
+ ext_inode_hdr(inode_ref->inode)->max_entries_count =
+ to_le16(ext4_ext_space_root(inode_ref));
+ ret = ext4_ext_dirty(inode_ref, path);
+ }
+
+out:
+ ext4_ext_drop_refs(inode_ref, path, 0);
+ free(path);
+ path = NULL;
+ return ret;
}
-/**@brief Append data block to the i-node.
- * This function allocates data block, tries to append it
- * to some existing extent or creates new extents.
- * It includes possible extent tree modifications (splitting).
- * @param inode_ref I-node to append block to
- * @param iblock Output logical number of newly allocated block
- * @param fblock Output physical block address of newly allocated block
- *
- * @return Error code*/
-static int
-ext4_extent_append_block(struct ext4_inode_ref *inode_ref, uint32_t *iblock,
- ext4_fsblk_t *fblock, bool update_size)
+static int ext4_ext_split_extent_at(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path **ppath,
+ ext4_lblk_t split, uint32_t split_flag)
{- uint16_t i;
- ext4_fsblk_t goal;
- struct ext4_sblock *sb = &inode_ref->fs->sb;
- uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
- uint32_t block_size = ext4_sb_get_block_size(sb);
+ struct ext4_extent *ex, newex;
+ ext4_fsblk_t newblock;
+ ext4_lblk_t ee_block;
+ int32_t ee_len;
+ int32_t depth = ext_depth(inode_ref->inode);
+ int err = EOK;
- /* Calculate number of new logical block */
- uint32_t new_block_idx = 0;
- if (inode_size > 0) {- if ((inode_size % block_size) != 0)
- inode_size += block_size - (inode_size % block_size);
+ ex = (*ppath)[depth].extent;
+ ee_block = to_le32(ex->first_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ newblock = split - ee_block + ext4_ext_pblock(ex);
- new_block_idx = inode_size / block_size;
+ if (split == ee_block) {+ /*
+ * case b: block @split is the block that the extent begins with
+ * then we just change the state of the extent, and splitting
+ * is not needed.
+ */
+ if (split_flag & EXT4_EXT_MARK_UNWRIT2)
+ ext4_ext_mark_unwritten(ex);
+ else
+ ext4_ext_mark_initialized(ex);
+
+ err = ext4_ext_dirty(inode_ref, *ppath + depth);
+ goto out;
}
- /* Load the nearest leaf (with extent) */
- struct ext4_extent_path *path;
- int rc = ext4_extent_find_extent(inode_ref, new_block_idx, &path);
- if (rc != EOK)
- return rc;
+ ex->block_count = to_le16(split - ee_block);
+ if (split_flag & EXT4_EXT_MARK_UNWRIT1)
+ ext4_ext_mark_unwritten(ex);
- /* Jump to last item of the path (extent) */
- struct ext4_extent_path *path_ptr = path;
- while (path_ptr->depth != 0)
- path_ptr++;
+ err = ext4_ext_dirty(inode_ref, *ppath + depth);
+ if (err != EOK)
+ goto out;
- /* Add new extent to the node if not present */
- if (path_ptr->extent == NULL)
- goto append_extent;
+ newex.first_block = to_le32(split);
+ newex.block_count = to_le16(ee_len - (split - ee_block));
+ ext4_ext_store_pblock(&newex, newblock);
+ if (split_flag & EXT4_EXT_MARK_UNWRIT2)
+ ext4_ext_mark_unwritten(&newex);
+ err = ext4_ext_insert_extent(inode_ref, ppath, &newex,
+ EXT4_EXT_NO_COMBINE);
+ if (err != EOK)
+ goto restore_extent_len;
- uint16_t block_count = ext4_extent_get_block_count(path_ptr->extent);
- uint16_t block_limit = (1 << 15);
+out:
+ return err;
+restore_extent_len:
+ ex->block_count = to_le16(ee_len);
+ err = ext4_ext_dirty(inode_ref, *ppath + depth);
+ return err;
+}
- ext4_fsblk_t phys_block = 0;
- if (block_count < block_limit) {- /* There is space for new block in the extent */
- if (block_count == 0) {- int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
- if (rc != EOK)
- goto finish;
+static int ext4_ext_convert_to_initialized(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path **ppath,
+ ext4_lblk_t split, uint32_t blocks)
+{+ int32_t depth = ext_depth(inode_ref->inode), err = EOK;
+ struct ext4_extent *ex = (*ppath)[depth].extent;
- /* Existing extent is empty */
- rc = ext4_balloc_alloc_block(inode_ref, goal, &phys_block);
- if (rc != EOK)
- goto finish;
+ ext4_assert(to_le32(ex->first_block) <= split);
- /* Initialize extent */
- ext4_extent_set_first_block(path_ptr->extent,
- new_block_idx);
- ext4_extent_set_start(path_ptr->extent, phys_block);
- ext4_extent_set_block_count(path_ptr->extent, 1,
- false);
+ if (split + blocks ==
+ to_le32(ex->first_block) + ext4_ext_get_actual_len(ex)) {+ /* split and initialize right part */
+ err = ext4_ext_split_extent_at(inode_ref, ppath, split,
+ EXT4_EXT_MARK_UNWRIT1);
+ } else if (to_le32(ex->first_block) == split) {+ /* split and initialize left part */
+ err = ext4_ext_split_extent_at(inode_ref, ppath, split + blocks,
+ EXT4_EXT_MARK_UNWRIT2);
+ } else {+ /* split 1 extent to 3 and initialize the 2nd */
+ err = ext4_ext_split_extent_at(inode_ref, ppath, split + blocks,
+ EXT4_EXT_MARK_UNWRIT1 |
+ EXT4_EXT_MARK_UNWRIT2);
+ if (!err) {+ err = ext4_ext_split_extent_at(inode_ref, ppath, split,
+ EXT4_EXT_MARK_UNWRIT1);
+ }
+ }
- /* Update i-node */
- if (update_size) {- ext4_inode_set_size(inode_ref->inode,
- inode_size + block_size);
- inode_ref->dirty = true;
- }
+ return err;
+}
- ext4_extent_block_csum_set(inode_ref, path_ptr->header);
- ext4_trans_set_block_dirty(path_ptr->block.buf);
+static ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_extent_path *path)
+{+ int32_t depth;
- goto finish;
+ depth = path->depth;
+
+ if (depth == 0 && path->extent == NULL)
+ return EXT_MAX_BLOCKS;
+
+ while (depth >= 0) {+ if (depth == path->depth) {+ /* leaf */
+ if (path[depth].extent &&
+ path[depth].extent !=
+ EXT_LAST_EXTENT(path[depth].header))
+ return to_le32(
+ path[depth].extent[1].first_block);
} else {- ext4_fsblk_t goal;
- int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
- if (rc != EOK)
- goto finish;
+ /* index */
+ if (path[depth].index !=
+ EXT_LAST_INDEX(path[depth].header))
+ return to_le32(
+ path[depth].index[1].first_block);
+ }
+ depth--;
+ }
- /* Existing extent contains some blocks */
- phys_block = ext4_extent_get_start(path_ptr->extent);
- phys_block +=
- ext4_extent_get_block_count(path_ptr->extent);
+ return EXT_MAX_BLOCKS;
+}
- /* Check if the following block is free for allocation
- */
- bool free;
- rc = ext4_balloc_try_alloc_block(inode_ref, phys_block,
- &free);
- if (rc != EOK)
- goto finish;
+static int ext4_ext_zero_unwritten_range(struct ext4_inode_ref *inode_ref,
+ ext4_fsblk_t block,
+ uint32_t blocks_count)
+{+ int err = EOK;
+ uint32_t i;
+ uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
+ for (i = 0; i < blocks_count; i++) {+ struct ext4_block bh = EXT4_BLOCK_ZERO();
+ err = ext4_trans_block_get_noread(inode_ref->fs->bdev, &bh, block + i);
+ if (err != EOK)
+ break;
- if (!free) {- /* Target is not free, new block must be
- * appended to new extent
- */
- goto append_extent;
- }
+ memset(bh.data, 0, block_size);
+ ext4_trans_set_block_dirty(bh.buf);
+ err = ext4_block_set(inode_ref->fs->bdev, &bh);
+ if (err != EOK)
+ break;
+ }
+ return err;
+}
- /* Update extent */
- ext4_extent_set_block_count(path_ptr->extent,
- block_count + 1,
- false);
+int ext4_extent_get_blocks(struct ext4_inode_ref *inode_ref, ext4_fsblk_t iblock,
+ uint32_t max_blocks, ext4_fsblk_t *result, bool create,
+ uint32_t *blocks_count)
+{+ struct ext4_extent_path *path = NULL;
+ struct ext4_extent newex, *ex;
+ ext4_fsblk_t goal;
+ int err = EOK;
+ int32_t depth;
+ uint32_t allocated = 0;
+ ext4_fsblk_t next, newblock;
- /* Update i-node */
- if (update_size) {- ext4_inode_set_size(inode_ref->inode,
- inode_size + block_size);
- inode_ref->dirty = true;
- }
+ if (result)
+ *result = 0;
- ext4_extent_block_csum_set(inode_ref, path_ptr->header);
- ext4_trans_set_block_dirty(path_ptr->block.buf);
+ if (blocks_count)
+ *blocks_count = 0;
- goto finish;
- }
+ /* find extent for this block */
+ err = ext4_find_extent(inode_ref, iblock, &path, 0);
+ if (err != EOK) {+ path = NULL;
+ goto out2;
}
-append_extent:
- /* Append new extent to the tree */
- phys_block = 0;
+ depth = ext_depth(inode_ref->inode);
- rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
- if (rc != EOK)
- goto finish;
+ /*
+ * consistent leaf must not be empty
+ * this situations is possible, though, _during_ tree modification
+ * this is why assert can't be put in ext4_ext_find_extent()
+ */
+ ex = path[depth].extent;
+ if (ex) {+ ext4_lblk_t ee_block = to_le32(ex->first_block);
+ ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
+ uint16_t ee_len = ext4_ext_get_actual_len(ex);
+ /* if found exent covers block, simple return it */
+ if (IN_RANGE(iblock, ee_block, ee_len)) {+ /* number of remain blocks in the extent */
+ allocated = ee_len - (iblock - ee_block);
- /* Allocate new data block */
- rc = ext4_balloc_alloc_block(inode_ref, goal, &phys_block);
- if (rc != EOK)
- goto finish;
+ if (!ext4_ext_is_unwritten(ex)) {+ newblock = iblock - ee_block + ee_start;
+ goto out;
+ }
- /* Append extent for new block (includes tree splitting if needed) */
- rc = ext4_extent_append_extent(inode_ref, path, new_block_idx);
- if (rc != EOK) {- ext4_balloc_free_block(inode_ref, phys_block);
- goto finish;
- }
+ if (!create) {+ newblock = 0;
+ goto out;
+ }
- uint32_t tree_depth = ext4_extent_header_get_depth(path->header);
- path_ptr = path + tree_depth;
+ uint32_t zero_range;
+ zero_range = allocated;
+ if (zero_range > max_blocks)
+ zero_range = max_blocks;
- /* Initialize newly created extent */
- ext4_extent_set_block_count(path_ptr->extent, 1, false);
- ext4_extent_set_first_block(path_ptr->extent, new_block_idx);
- ext4_extent_set_start(path_ptr->extent, phys_block);
+ newblock = iblock - ee_block + ee_start;
+ err = ext4_ext_zero_unwritten_range(inode_ref, newblock,
+ zero_range);
+ if (err != EOK)
+ goto out2;
- /* Update i-node */
- if (update_size) {- ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
- inode_ref->dirty = true;
+ err = ext4_ext_convert_to_initialized(inode_ref, &path,
+ iblock, zero_range);
+ if (err != EOK)
+ goto out2;
+
+ goto out;
+ }
}
- ext4_extent_block_csum_set(inode_ref, path_ptr->header);
- ext4_trans_set_block_dirty(path_ptr->block.buf);
-
-finish:
- /* Set return values */
- *iblock = new_block_idx;
- *fblock = phys_block;
-
/*
- * Put loaded blocks
- * starting from 1: 0 is a block with inode data
+ * requested block isn't allocated yet
+ * we couldn't try to create block if create flag is zero
*/
- for (i = 1; i <= path->depth; ++i) {- if (path[i].block.lb_id) {- int r =
- ext4_block_set(inode_ref->fs->bdev, &path[i].block);
- if (r != EOK)
- rc = r;
- }
+ if (!create) {+ goto out2;
}
- /* Destroy temporary data structure */
- free(path);
+ /* find next allocated block so that we know how many
+ * blocks we can allocate without ovelapping next extent */
+ next = ext4_ext_next_allocated_block(path);
+ allocated = next - iblock;
+ if (allocated > max_blocks)
+ allocated = max_blocks;
- return rc;
-}
+ /* allocate new block */
+ goal = ext4_ext_find_goal(inode_ref, path, iblock);
+ newblock = ext4_new_meta_blocks(inode_ref, goal, 0, &allocated, &err);
+ if (!newblock)
+ goto out2;
-int ext4_extent_get_blocks(struct ext4_inode_ref *inode_ref, ext4_fsblk_t iblock,
- ext4_lblk_t max_blocks, ext4_fsblk_t *result, bool create,
- ext4_lblk_t *blocks_count)
-{- uint32_t iblk = iblock;
- ext4_fsblk_t fblk = 0;
- int r;
+ /* try to insert new extent into found leaf and return */
+ newex.first_block = to_le32(iblock);
+ ext4_ext_store_pblock(&newex, newblock);
+ newex.block_count = to_le16(allocated);
+ err = ext4_ext_insert_extent(inode_ref, &path, &newex, 0);
+ if (err != EOK) {+ /* free data blocks we just allocated */
+ ext4_ext_free_blocks(inode_ref, ext4_ext_pblock(&newex),
+ to_le16(newex.block_count), 0);
+ goto out2;
+ }
+ /* previous routine could use block we allocated */
+ newblock = ext4_ext_pblock(&newex);
+
+out:
+ if (allocated > max_blocks)
+ allocated = max_blocks;
+
+ if (result)
+ *result = newblock;
+
if (blocks_count)
- return ENOTSUP;
- if (max_blocks != 1)
- return ENOTSUP;
+ *blocks_count = allocated;
- if (!create)
- r = ext4_extent_find_block(inode_ref, iblk, &fblk);
- else
- r = ext4_extent_append_block(inode_ref, &iblk, &fblk, false);
+out2:
+ if (path) {+ ext4_ext_drop_refs(inode_ref, path, 0);
+ free(path);
+ }
- *result = fblk;
- return r;
+ return err;
}
-
-#endif
-/**
- * @}
- */
--- a/lwext4/ext4_extent_full.c
+++ /dev/null
@@ -1,1865 +1,0 @@
-/*
- * Copyright (c) 2015 Grzegorz Kostka ([email protected])
- * Copyright (c) 2015 Kaho Ng ([email protected])
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * - Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * - The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "ext4_config.h"
-#include "ext4_blockdev.h"
-#include "ext4_fs.h"
-#include "ext4_super.h"
-#include "ext4_crc32.h"
-#include "ext4_balloc.h"
-#include "ext4_debug.h"
-
-#include <stdlib.h>
-#include <string.h>
-#include <inttypes.h>
-#include <stddef.h>
-
-#include "ext4_extent.h"
-
-#if CONFIG_EXTENT_FULL
-
-/*
- * used by extent splitting.
- */
-#define EXT4_EXT_MARK_UNWRIT1 0x02 /* mark first half unwritten */
-#define EXT4_EXT_MARK_UNWRIT2 0x04 /* mark second half unwritten */
-#define EXT4_EXT_DATA_VALID1 0x08 /* first half contains valid data */
-#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
-#define EXT4_EXT_NO_COMBINE 0x20 /* do not combine two extents */
-
-static struct ext4_extent_tail *
-find_ext4_extent_tail(struct ext4_extent_header *eh)
-{- return (struct ext4_extent_tail *)(((char *)eh) +
- EXT4_EXTENT_TAIL_OFFSET(eh));
-}
-
-static struct ext4_extent_header *ext_inode_hdr(struct ext4_inode *inode)
-{- return (struct ext4_extent_header *)inode->blocks;
-}
-
-static struct ext4_extent_header *ext_block_hdr(struct ext4_block *block)
-{- return (struct ext4_extent_header *)block->data;
-}
-
-static uint16_t ext_depth(struct ext4_inode *inode)
-{- return to_le16(ext_inode_hdr(inode)->depth);
-}
-
-static uint16_t ext4_ext_get_actual_len(struct ext4_extent *ext)
-{- return (to_le16(ext->block_count) <= EXT_INIT_MAX_LEN
- ? to_le16(ext->block_count)
- : (to_le16(ext->block_count) - EXT_INIT_MAX_LEN));
-}
-
-static void ext4_ext_mark_initialized(struct ext4_extent *ext)
-{- ext->block_count = to_le16(ext4_ext_get_actual_len(ext));
-}
-
-static void ext4_ext_mark_unwritten(struct ext4_extent *ext)
-{- ext->block_count |= to_le16(EXT_INIT_MAX_LEN);
-}
-
-static int ext4_ext_is_unwritten(struct ext4_extent *ext)
-{- /* Extent with ee_len of 0x8000 is treated as an initialized extent */
- return (to_le16(ext->block_count) > EXT_INIT_MAX_LEN);
-}
-
-/*
- * ext4_ext_pblock:
- * combine low and high parts of physical block number into ext4_fsblk_t
- */
-static ext4_fsblk_t ext4_ext_pblock(struct ext4_extent *ex)
-{- ext4_fsblk_t block;
-
- block = to_le32(ex->start_lo);
- block |= ((ext4_fsblk_t)to_le16(ex->start_hi) << 31) << 1;
- return block;
-}
-
-/*
- * ext4_idx_pblock:
- * combine low and high parts of a leaf physical block number into ext4_fsblk_t
- */
-static ext4_fsblk_t ext4_idx_pblock(struct ext4_extent_index *ix)
-{- ext4_fsblk_t block;
-
- block = to_le32(ix->leaf_lo);
- block |= ((ext4_fsblk_t)to_le16(ix->leaf_hi) << 31) << 1;
- return block;
-}
-
-/*
- * ext4_ext_store_pblock:
- * stores a large physical block number into an extent struct,
- * breaking it into parts
- */
-static void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb)
-{- ex->start_lo = to_le32((uint32_t)(pb & 0xffffffff));
- ex->start_hi = to_le16((uint16_t)((pb >> 32)) & 0xffff);
-}
-
-/*
- * ext4_idx_store_pblock:
- * stores a large physical block number into an index struct,
- * breaking it into parts
- */
-static void ext4_idx_store_pblock(struct ext4_extent_index *ix, ext4_fsblk_t pb)
-{- ix->leaf_lo = to_le32((uint32_t)(pb & 0xffffffff));
- ix->leaf_hi = to_le16((uint16_t)((pb >> 32)) & 0xffff);
-}
-
-static int ext4_allocate_single_block(struct ext4_inode_ref *inode_ref,
- ext4_fsblk_t goal,
- ext4_fsblk_t *blockp)
-{- return ext4_balloc_alloc_block(inode_ref, goal, blockp);
-}
-
-static ext4_fsblk_t ext4_new_meta_blocks(struct ext4_inode_ref *inode_ref,
- ext4_fsblk_t goal,
- uint32_t flags __unused,
- uint32_t *count, int *errp)
-{- ext4_fsblk_t block = 0;
-
- *errp = ext4_allocate_single_block(inode_ref, goal, &block);
- if (count)
- *count = 1;
- return block;
-}
-
-static void ext4_ext_free_blocks(struct ext4_inode_ref *inode_ref,
- ext4_fsblk_t block, uint32_t count,
- uint32_t flags __unused)
-{- ext4_balloc_free_blocks(inode_ref, block, count);
-}
-
-static size_t ext4_ext_space_block(struct ext4_inode_ref *inode_ref)
-{- size_t size;
- uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
-
- size = (block_size - sizeof(struct ext4_extent_header)) /
- sizeof(struct ext4_extent);
-#ifdef AGGRESSIVE_TEST
- if (size > 6)
- size = 6;
-#endif
- return size;
-}
-
-static size_t ext4_ext_space_block_idx(struct ext4_inode_ref *inode_ref)
-{- size_t size;
- uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
-
- size = (block_size - sizeof(struct ext4_extent_header)) /
- sizeof(struct ext4_extent_index);
-#ifdef AGGRESSIVE_TEST
- if (size > 5)
- size = 5;
-#endif
- return size;
-}
-
-static size_t ext4_ext_space_root(struct ext4_inode_ref *inode_ref)
-{- size_t size;
-
- size = sizeof(inode_ref->inode->blocks);
- size -= sizeof(struct ext4_extent_header);
- size /= sizeof(struct ext4_extent);
-#ifdef AGGRESSIVE_TEST
- if (size > 3)
- size = 3;
-#endif
- return size;
-}
-
-static size_t ext4_ext_space_root_idx(struct ext4_inode_ref *inode_ref)
-{- size_t size;
-
- size = sizeof(inode_ref->inode->blocks);
- size -= sizeof(struct ext4_extent_header);
- size /= sizeof(struct ext4_extent_index);
-#ifdef AGGRESSIVE_TEST
- if (size > 4)
- size = 4;
-#endif
- return size;
-}
-
-static size_t ext4_ext_max_entries(struct ext4_inode_ref *inode_ref,
- uint32_t depth)
-{- size_t max;
-
- if (depth == ext_depth(inode_ref->inode)) {- if (depth == 0)
- max = ext4_ext_space_root(inode_ref);
- else
- max = ext4_ext_space_root_idx(inode_ref);
- } else {- if (depth == 0)
- max = ext4_ext_space_block(inode_ref);
- else
- max = ext4_ext_space_block_idx(inode_ref);
- }
-
- return max;
-}
-
-static ext4_fsblk_t ext4_ext_find_goal(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path,
- ext4_lblk_t block)
-{- if (path) {- uint32_t depth = path->depth;
- struct ext4_extent *ex;
-
- /*
- * Try to predict block placement assuming that we are
- * filling in a file which will eventually be
- * non-sparse --- i.e., in the case of libbfd writing
- * an ELF object sections out-of-order but in a way
- * the eventually results in a contiguous object or
- * executable file, or some database extending a table
- * space file. However, this is actually somewhat
- * non-ideal if we are writing a sparse file such as
- * qemu or KVM writing a raw image file that is going
- * to stay fairly sparse, since it will end up
- * fragmenting the file system's free space. Maybe we
- * should have some hueristics or some way to allow
- * userspace to pass a hint to file system,
- * especially if the latter case turns out to be
- * common.
- */
- ex = path[depth].extent;
- if (ex) {- ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
- ext4_lblk_t ext_block = to_le32(ex->first_block);
-
- if (block > ext_block)
- return ext_pblk + (block - ext_block);
- else
- return ext_pblk - (ext_block - block);
- }
-
- /* it looks like index is empty;
- * try to find starting block from index itself */
- if (path[depth].block.lb_id)
- return path[depth].block.lb_id;
- }
-
- /* OK. use inode's group */
- return ext4_fs_inode_to_goal_block(inode_ref);
-}
-
-/*
- * Allocation for a meta data block
- */
-static ext4_fsblk_t ext4_ext_new_meta_block(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path,
- struct ext4_extent *ex, int *err,
- uint32_t flags)
-{- ext4_fsblk_t goal, newblock;
-
- goal = ext4_ext_find_goal(inode_ref, path, to_le32(ex->first_block));
- newblock = ext4_new_meta_blocks(inode_ref, goal, flags, NULL, err);
- return newblock;
-}
-
-#if CONFIG_META_CSUM_ENABLE
-static uint32_t ext4_ext_block_csum(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_header *eh)
-{- uint32_t checksum = 0;
- struct ext4_sblock *sb = &inode_ref->fs->sb;
-
- if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {- uint32_t ino_index = to_le32(inode_ref->index);
- uint32_t ino_gen =
- to_le32(ext4_inode_get_generation(inode_ref->inode));
- /* First calculate crc32 checksum against fs uuid */
- checksum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid,
- sizeof(sb->uuid));
- /* Then calculate crc32 checksum against inode number
- * and inode generation */
- checksum = ext4_crc32c(checksum, &ino_index,
- sizeof(ino_index));
- checksum = ext4_crc32c(checksum, &ino_gen,
- sizeof(ino_gen));
- /* Finally calculate crc32 checksum against
- * the entire extent block up to the checksum field */
- checksum = ext4_crc32c(checksum, eh,
- EXT4_EXTENT_TAIL_OFFSET(eh));
- }
- return checksum;
-}
-#else
-#define ext4_ext_block_csum(...) 0
-#endif
-
-static void ext4_extent_block_csum_set(struct ext4_inode_ref *inode_ref __unused,
- struct ext4_extent_header *eh)
-{- struct ext4_extent_tail *tail;
-
- tail = find_ext4_extent_tail(eh);
- tail->et_checksum = to_le32(ext4_ext_block_csum(inode_ref, eh));
-}
-
-static int ext4_ext_dirty(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path)
-{- if (path->block.lb_id)
- ext4_trans_set_block_dirty(path->block.buf);
- else
- inode_ref->dirty = true;
-
- return EOK;
-}
-
-static void ext4_ext_drop_refs(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path, bool keep_other)
-{- int32_t depth, i;
-
- if (!path)
- return;
- if (keep_other)
- depth = 0;
- else
- depth = path->depth;
-
- for (i = 0; i <= depth; i++, path++) {- if (path->block.lb_id) {- if (ext4_bcache_test_flag(path->block.buf, BC_DIRTY))
- ext4_extent_block_csum_set(inode_ref,
- path->header);
-
- ext4_block_set(inode_ref->fs->bdev, &path->block);
- }
- }
-}
-
-/*
- * Check that whether the basic information inside the extent header
- * is correct or not.
- */
-static int ext4_ext_check(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_header *eh, uint16_t depth,
- ext4_fsblk_t pblk __unused)
-{- struct ext4_extent_tail *tail;
- struct ext4_sblock *sb = &inode_ref->fs->sb;
- const char *error_msg;
- (void)error_msg;
-
- if (to_le16(eh->magic) != EXT4_EXTENT_MAGIC) {- error_msg = "invalid magic";
- goto corrupted;
- }
- if (to_le16(eh->depth) != depth) {- error_msg = "unexpected eh_depth";
- goto corrupted;
- }
- if (eh->max_entries_count == 0) {- error_msg = "invalid eh_max";
- goto corrupted;
- }
- if (to_le16(eh->entries_count) > to_le16(eh->max_entries_count)) {- error_msg = "invalid eh_entries";
- goto corrupted;
- }
-
- tail = find_ext4_extent_tail(eh);
- if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {- if (tail->et_checksum != to_le32(ext4_ext_block_csum(inode_ref, eh))) {- ext4_dbg(DEBUG_EXTENT,
- DBG_WARN "Extent block checksum failed."
- "Blocknr: %" PRIu64"\n",
- pblk);
-
- }
- }
-
- return EOK;
-
-corrupted:
- ext4_dbg(DEBUG_EXTENT, "Bad extents B+ tree block: %s. "
- "Blocknr: %" PRId64 "\n",
- error_msg, pblk);
- return EIO;
-}
-
-static int read_extent_tree_block(struct ext4_inode_ref *inode_ref,
- ext4_fsblk_t pblk, int32_t depth,
- struct ext4_block *bh,
- uint32_t flags __unused)
-{- int err;
-
- err = ext4_trans_block_get(inode_ref->fs->bdev, bh, pblk);
- if (err != EOK)
- goto errout;
-
- err = ext4_ext_check(inode_ref, ext_block_hdr(bh), depth, pblk);
- if (err != EOK)
- goto errout;
-
- return EOK;
-errout:
- if (bh->lb_id)
- ext4_block_set(inode_ref->fs->bdev, bh);
-
- return err;
-}
-
-/*
- * ext4_ext_binsearch_idx:
- * binary search for the closest index of the given block
- * the header must be checked before calling this
- */
-static void ext4_ext_binsearch_idx(struct ext4_extent_path *path,
- ext4_lblk_t block)
-{- struct ext4_extent_header *eh = path->header;
- struct ext4_extent_index *r, *l, *m;
-
- l = EXT_FIRST_INDEX(eh) + 1;
- r = EXT_LAST_INDEX(eh);
- while (l <= r) {- m = l + (r - l) / 2;
- if (block < to_le32(m->first_block))
- r = m - 1;
- else
- l = m + 1;
- }
-
- path->index = l - 1;
-}
-
-/*
- * ext4_ext_binsearch:
- * binary search for closest extent of the given block
- * the header must be checked before calling this
- */
-static void ext4_ext_binsearch(struct ext4_extent_path *path, ext4_lblk_t block)
-{- struct ext4_extent_header *eh = path->header;
- struct ext4_extent *r, *l, *m;
-
- if (eh->entries_count == 0) {- /*
- * this leaf is empty:
- * we get such a leaf in split/add case
- */
- return;
- }
-
- l = EXT_FIRST_EXTENT(eh) + 1;
- r = EXT_LAST_EXTENT(eh);
-
- while (l <= r) {- m = l + (r - l) / 2;
- if (block < to_le32(m->first_block))
- r = m - 1;
- else
- l = m + 1;
- }
-
- path->extent = l - 1;
-}
-
-static int ext4_find_extent(struct ext4_inode_ref *inode_ref, ext4_lblk_t block,
- struct ext4_extent_path **orig_path, uint32_t flags)
-{- struct ext4_extent_header *eh;
- struct ext4_block bh = EXT4_BLOCK_ZERO();
- ext4_fsblk_t buf_block = 0;
- struct ext4_extent_path *path = *orig_path;
- int32_t depth, ppos = 0;
- int32_t i;
- int ret;
-
- eh = ext_inode_hdr(inode_ref->inode);
- depth = ext_depth(inode_ref->inode);
-
- if (path) {- ext4_ext_drop_refs(inode_ref, path, 0);
- if (depth > path[0].maxdepth) {- free(path);
- *orig_path = path = NULL;
- }
- }
- if (!path) {- int32_t path_depth = depth + 1;
- /* account possible depth increase */
- path = calloc(1, sizeof(struct ext4_extent_path) *
- (path_depth + 1));
- if (!path)
- return ENOMEM;
- path[0].maxdepth = path_depth;
- }
- path[0].header = eh;
- path[0].block = bh;
-
- i = depth;
- /* walk through the tree */
- while (i) {- ext4_ext_binsearch_idx(path + ppos, block);
- path[ppos].p_block = ext4_idx_pblock(path[ppos].index);
- path[ppos].depth = i;
- path[ppos].extent = NULL;
- buf_block = path[ppos].p_block;
-
- i--;
- ppos++;
- if (!path[ppos].block.lb_id ||
- path[ppos].block.lb_id != buf_block) {- ret = read_extent_tree_block(inode_ref, buf_block, i,
- &bh, flags);
- if (ret != EOK) {- goto err;
- }
- if (ppos > depth) {- ext4_block_set(inode_ref->fs->bdev, &bh);
- ret = EIO;
- goto err;
- }
-
- eh = ext_block_hdr(&bh);
- path[ppos].block = bh;
- path[ppos].header = eh;
- }
- }
-
- path[ppos].depth = i;
- path[ppos].extent = NULL;
- path[ppos].index = NULL;
-
- /* find extent */
- ext4_ext_binsearch(path + ppos, block);
- /* if not an empty leaf */
- if (path[ppos].extent)
- path[ppos].p_block = ext4_ext_pblock(path[ppos].extent);
-
- *orig_path = path;
-
- ret = EOK;
- return ret;
-
-err:
- ext4_ext_drop_refs(inode_ref, path, 0);
- free(path);
- if (orig_path)
- *orig_path = NULL;
- return ret;
-}
-
-static void ext4_ext_init_header(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_header *eh, int32_t depth)
-{- eh->entries_count = 0;
- eh->max_entries_count = to_le16(ext4_ext_max_entries(inode_ref, depth));
- eh->magic = to_le16(EXT4_EXTENT_MAGIC);
- eh->depth = depth;
-}
-
-/*
- * Be cautious, the buffer_head returned is not yet mark dirtied. */
-static int ext4_ext_split_node(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path, int32_t at,
- struct ext4_extent *newext,
- ext4_fsblk_t *sibling, struct ext4_block *new_bh)
-{- int ret;
- ext4_fsblk_t newblock;
- struct ext4_block bh = EXT4_BLOCK_ZERO();
- int32_t depth = ext_depth(inode_ref->inode);
-
- ext4_assert(sibling);
-
- /* FIXME: currently we split at the point after the current extent. */
- newblock = ext4_ext_new_meta_block(inode_ref, path, newext, &ret, 0);
- if (ret)
- goto cleanup;
-
- /* For write access.# */
- ret = ext4_trans_block_get_noread(inode_ref->fs->bdev, &bh, newblock);
- if (ret != EOK)
- goto cleanup;
-
- if (at == depth) {- /* start copy from next extent */
- ptrdiff_t m = EXT_MAX_EXTENT(path[at].header) - path[at].extent;
- struct ext4_extent_header *neh;
- neh = ext_block_hdr(&bh);
- ext4_ext_init_header(inode_ref, neh, 0);
- if (m) {- struct ext4_extent *ex;
- ex = EXT_FIRST_EXTENT(neh);
- memmove(ex, path[at].extent + 1,
- sizeof(struct ext4_extent) * m);
- neh->entries_count =
- to_le16(to_le16(neh->entries_count) + m);
- path[at].header->entries_count = to_le16(
- to_le16(path[at].header->entries_count) - m);
- ret = ext4_ext_dirty(inode_ref, path + at);
- if (ret)
- goto cleanup;
- }
- } else {- ptrdiff_t m = EXT_MAX_INDEX(path[at].header) - path[at].index;
- struct ext4_extent_header *neh;
- neh = ext_block_hdr(&bh);
- ext4_ext_init_header(inode_ref, neh, depth - at);
- if (m) {- struct ext4_extent_index *ix;
- ix = EXT_FIRST_INDEX(neh);
- memmove(ix, path[at].index + 1,
- sizeof(struct ext4_extent) * m);
- neh->entries_count =
- to_le16(to_le16(neh->entries_count) + m);
- path[at].header->entries_count = to_le16(
- to_le16(path[at].header->entries_count) - m);
- ret = ext4_ext_dirty(inode_ref, path + at);
- if (ret)
- goto cleanup;
- }
- }
-cleanup:
- if (ret) {- if (bh.lb_id) {- ext4_block_set(inode_ref->fs->bdev, &bh);
- }
- if (newblock)
- ext4_ext_free_blocks(inode_ref, newblock, 1, 0);
-
- newblock = 0;
- }
- *sibling = newblock;
- *new_bh = bh;
- return ret;
-}
-
-static ext4_lblk_t ext4_ext_block_index(struct ext4_extent_header *eh)
-{- if (eh->depth)
- return to_le32(EXT_FIRST_INDEX(eh)->first_block);
-
- return to_le32(EXT_FIRST_EXTENT(eh)->first_block);
-}
-
-struct ext_split_trans {- ext4_fsblk_t ptr;
- struct ext4_extent_path path;
- int switch_to;
-};
-
-static int ext4_ext_insert_index(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path,
- int32_t at,
- struct ext4_extent *newext,
- ext4_lblk_t insert_index,
- ext4_fsblk_t insert_block,
- struct ext_split_trans *spt,
- bool *need_grow)
-{- struct ext4_extent_index *ix;
- struct ext4_extent_path *curp = path + at;
- struct ext4_block bh = EXT4_BLOCK_ZERO();
- int32_t len;
- int err;
- struct ext4_extent_header *eh;
-
- *need_grow = false;
-
- if (curp->index && insert_index == to_le32(curp->index->first_block))
- return EIO;
-
- if (to_le16(curp->header->entries_count) ==
- to_le16(curp->header->max_entries_count)) {- if (at) {- struct ext4_extent_header *neh;
- err = ext4_ext_split_node(inode_ref, path, at, newext,
- &spt->ptr, &bh);
- if (err != EOK)
- goto out;
-
- neh = ext_block_hdr(&bh);
- if (insert_index > to_le32(curp->index->first_block)) {- /* Make decision which node should be used to
- * insert the index.*/
- if (to_le16(neh->entries_count) >
- to_le16(curp->header->entries_count)) {- eh = curp->header;
- /* insert after */
- ix = EXT_LAST_INDEX(eh) + 1;
- } else {- eh = neh;
- ix = EXT_FIRST_INDEX(eh);
- }
- } else {- eh = curp->header;
- /* insert before */
- ix = EXT_LAST_INDEX(eh);
- }
- } else {- err = EOK;
- *need_grow = true;
- goto out;
- }
- } else {- eh = curp->header;
- if (curp->index == NULL) {- ix = EXT_FIRST_INDEX(eh);
- curp->index = ix;
- } else if (insert_index > to_le32(curp->index->first_block)) {- /* insert after */
- ix = curp->index + 1;
- } else {- /* insert before */
- ix = curp->index;
- }
- }
-
- len = EXT_LAST_INDEX(eh) - ix + 1;
- ext4_assert(len >= 0);
- if (len > 0)
- memmove(ix + 1, ix, len * sizeof(struct ext4_extent_index));
-
- if (ix > EXT_MAX_INDEX(eh)) {- err = EIO;
- goto out;
- }
-
- ix->first_block = to_le32(insert_index);
- ext4_idx_store_pblock(ix, insert_block);
- eh->entries_count = to_le16(to_le16(eh->entries_count) + 1);
-
- if (ix > EXT_LAST_INDEX(eh)) {- err = EIO;
- goto out;
- }
-
- if (eh == curp->header)
- err = ext4_ext_dirty(inode_ref, curp);
- else
- err = EOK;
-
-out:
- if (err != EOK || *need_grow) {- if (bh.lb_id)
- ext4_block_set(inode_ref->fs->bdev, &bh);
-
- spt->ptr = 0;
- } else if (bh.lb_id) {- /* If we got a sibling leaf. */
- ext4_extent_block_csum_set(inode_ref, ext_block_hdr(&bh));
- ext4_trans_set_block_dirty(bh.buf);
-
- spt->path.p_block = ext4_idx_pblock(ix);
- spt->path.depth = to_le16(eh->depth);
- spt->path.maxdepth = 0;
- spt->path.extent = NULL;
- spt->path.index = ix;
- spt->path.header = eh;
- spt->path.block = bh;
-
- /*
- * If newext->ee_block can be included into the
- * right sub-tree.
- */
- if (to_le32(newext->first_block) >=
- ext4_ext_block_index(ext_block_hdr(&bh)))
- spt->switch_to = 1;
- else {- curp->index = ix;
- curp->p_block = ext4_idx_pblock(ix);
- }
-
- } else {- spt->ptr = 0;
- curp->index = ix;
- curp->p_block = ext4_idx_pblock(ix);
- }
- return err;
-}
-
-/*
- * ext4_ext_correct_indexes:
- * if leaf gets modified and modified extent is first in the leaf,
- * then we have to correct all indexes above.
- */
-static int ext4_ext_correct_indexes(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path)
-{- struct ext4_extent_header *eh;
- int32_t depth = ext_depth(inode_ref->inode);
- struct ext4_extent *ex;
- uint32_t border;
- int32_t k;
- int err = EOK;
-
- eh = path[depth].header;
- ex = path[depth].extent;
-
- if (ex == NULL || eh == NULL) {- return EIO;
- }
-
- if (depth == 0) {- /* there is no tree at all */
- return EOK;
- }
-
- if (ex != EXT_FIRST_EXTENT(eh)) {- /* we correct tree if first leaf got modified only */
- return EOK;
- }
-
- /*
- * TODO: we need correction if border is smaller than current one
- */
- k = depth - 1;
- border = path[depth].extent->first_block;
- path[k].index->first_block = border;
- err = ext4_ext_dirty(inode_ref, path + k);
- if (err != EOK)
- return err;
-
- while (k--) {- /* change all left-side indexes */
- if (path[k + 1].index != EXT_FIRST_INDEX(path[k + 1].header))
- break;
- path[k].index->first_block = border;
- err = ext4_ext_dirty(inode_ref, path + k);
- if (err != EOK)
- break;
- }
-
- return err;
-}
-
-static bool ext4_ext_can_prepend(struct ext4_extent *ex1,
- struct ext4_extent *ex2)
-{- if (ext4_ext_pblock(ex2) + ext4_ext_get_actual_len(ex2) !=
- ext4_ext_pblock(ex1))
- return false;
-
-#ifdef AGGRESSIVE_TEST
- if (ext4_ext_get_actual_len(ex1) + ext4_ext_get_actual_len(ex2) > 4)
- return 0;
-#else
- if (ext4_ext_is_unwritten(ex1)) {- if (ext4_ext_get_actual_len(ex1) +
- ext4_ext_get_actual_len(ex2) >
- EXT_UNWRITTEN_MAX_LEN)
- return false;
- } else if (ext4_ext_get_actual_len(ex1) + ext4_ext_get_actual_len(ex2) >
- EXT_INIT_MAX_LEN)
- return false;
-#endif
-
- if (to_le32(ex2->first_block) + ext4_ext_get_actual_len(ex2) !=
- to_le32(ex1->first_block))
- return false;
-
- return true;
-}
-
-static bool ext4_ext_can_append(struct ext4_extent *ex1,
- struct ext4_extent *ex2)
-{- if (ext4_ext_pblock(ex1) + ext4_ext_get_actual_len(ex1) !=
- ext4_ext_pblock(ex2))
- return false;
-
-#ifdef AGGRESSIVE_TEST
- if (ext4_ext_get_actual_len(ex1) + ext4_ext_get_actual_len(ex2) > 4)
- return 0;
-#else
- if (ext4_ext_is_unwritten(ex1)) {- if (ext4_ext_get_actual_len(ex1) +
- ext4_ext_get_actual_len(ex2) >
- EXT_UNWRITTEN_MAX_LEN)
- return false;
- } else if (ext4_ext_get_actual_len(ex1) + ext4_ext_get_actual_len(ex2) >
- EXT_INIT_MAX_LEN)
- return false;
-#endif
-
- if (to_le32(ex1->first_block) + ext4_ext_get_actual_len(ex1) !=
- to_le32(ex2->first_block))
- return false;
-
- return true;
-}
-
-static int ext4_ext_insert_leaf(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path,
- int32_t at,
- struct ext4_extent *newext,
- struct ext_split_trans *spt,
- uint32_t flags,
- bool *need_grow)
-{- struct ext4_extent_path *curp = path + at;
- struct ext4_extent *ex = curp->extent;
- struct ext4_block bh = EXT4_BLOCK_ZERO();
- int32_t len;
- int err = EOK;
- int unwritten;
- struct ext4_extent_header *eh = NULL;
-
- *need_grow = false;
-
- if (curp->extent &&
- to_le32(newext->first_block) == to_le32(curp->extent->first_block))
- return EIO;
-
- if (!(flags & EXT4_EXT_NO_COMBINE)) {- if (curp->extent && ext4_ext_can_append(curp->extent, newext)) {- unwritten = ext4_ext_is_unwritten(curp->extent);
- curp->extent->block_count =
- to_le16(ext4_ext_get_actual_len(curp->extent) +
- ext4_ext_get_actual_len(newext));
- if (unwritten)
- ext4_ext_mark_unwritten(curp->extent);
- err = ext4_ext_dirty(inode_ref, curp);
- goto out;
- }
-
- if (curp->extent &&
- ext4_ext_can_prepend(curp->extent, newext)) {- unwritten = ext4_ext_is_unwritten(curp->extent);
- curp->extent->first_block = newext->first_block;
- curp->extent->block_count =
- to_le16(ext4_ext_get_actual_len(curp->extent) +
- ext4_ext_get_actual_len(newext));
- if (unwritten)
- ext4_ext_mark_unwritten(curp->extent);
- err = ext4_ext_dirty(inode_ref, curp);
- goto out;
- }
- }
-
- if (to_le16(curp->header->entries_count) ==
- to_le16(curp->header->max_entries_count)) {- if (at) {- struct ext4_extent_header *neh;
- err = ext4_ext_split_node(inode_ref, path, at, newext,
- &spt->ptr, &bh);
- if (err != EOK)
- goto out;
-
- neh = ext_block_hdr(&bh);
- if (to_le32(newext->first_block) >
- to_le32(curp->extent->first_block)) {- if (to_le16(neh->entries_count) >
- to_le16(curp->header->entries_count)) {- eh = curp->header;
- /* insert after */
- ex = EXT_LAST_EXTENT(eh) + 1;
- } else {- eh = neh;
- ex = EXT_FIRST_EXTENT(eh);
- }
- } else {- eh = curp->header;
- /* insert before */
- ex = EXT_LAST_EXTENT(eh);
- }
- } else {- err = EOK;
- *need_grow = true;
- goto out;
- }
- } else {- eh = curp->header;
- if (curp->extent == NULL) {- ex = EXT_FIRST_EXTENT(eh);
- curp->extent = ex;
- } else if (to_le32(newext->first_block) >
- to_le32(curp->extent->first_block)) {- /* insert after */
- ex = curp->extent + 1;
- } else {- /* insert before */
- ex = curp->extent;
- }
- }
-
- len = EXT_LAST_EXTENT(eh) - ex + 1;
- ext4_assert(len >= 0);
- if (len > 0)
- memmove(ex + 1, ex, len * sizeof(struct ext4_extent));
-
- if (ex > EXT_MAX_EXTENT(eh)) {- err = EIO;
- goto out;
- }
-
- ex->first_block = newext->first_block;
- ex->block_count = newext->block_count;
- ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
- eh->entries_count = to_le16(to_le16(eh->entries_count) + 1);
-
- if (ex > EXT_LAST_EXTENT(eh)) {- err = EIO;
- goto out;
- }
-
- if (eh == curp->header) {- err = ext4_ext_correct_indexes(inode_ref, path);
- if (err != EOK)
- goto out;
- err = ext4_ext_dirty(inode_ref, curp);
- } else
- err = EOK;
-
-out:
- if (err != EOK || *need_grow) {- if (bh.lb_id)
- ext4_block_set(inode_ref->fs->bdev, &bh);
-
- spt->ptr = 0;
- } else if (bh.lb_id) {- /* If we got a sibling leaf. */
- ext4_extent_block_csum_set(inode_ref, ext_block_hdr(&bh));
- ext4_trans_set_block_dirty(bh.buf);
-
- spt->path.p_block = ext4_ext_pblock(ex);
- spt->path.depth = to_le16(eh->depth);
- spt->path.maxdepth = 0;
- spt->path.extent = ex;
- spt->path.index = NULL;
- spt->path.header = eh;
- spt->path.block = bh;
-
- /*
- * If newext->ee_block can be included into the
- * right sub-tree.
- */
- if (to_le32(newext->first_block) >=
- ext4_ext_block_index(ext_block_hdr(&bh)))
- spt->switch_to = 1;
- else {- curp->extent = ex;
- curp->p_block = ext4_ext_pblock(ex);
- }
-
- } else {- spt->ptr = 0;
- curp->extent = ex;
- curp->p_block = ext4_ext_pblock(ex);
- }
-
- return err;
-}
-
-/*
- * ext4_ext_grow_indepth:
- * implements tree growing procedure:
- * - allocates new block
- * - moves top-level data (index block or leaf) into the new block
- * - initializes new top-level, creating index that points to the
- * just created block
- */
-static int ext4_ext_grow_indepth(struct ext4_inode_ref *inode_ref,
- uint32_t flags)
-{- struct ext4_extent_header *neh;
- struct ext4_block bh = EXT4_BLOCK_ZERO();
- ext4_fsblk_t newblock, goal = 0;
- int err = EOK;
-
- /* Try to prepend new index to old one */
- if (ext_depth(inode_ref->inode))
- goal = ext4_idx_pblock(
- EXT_FIRST_INDEX(ext_inode_hdr(inode_ref->inode)));
- else
- goal = ext4_fs_inode_to_goal_block(inode_ref);
-
- newblock = ext4_new_meta_blocks(inode_ref, goal, flags, NULL, &err);
- if (newblock == 0)
- return err;
-
- /* # */
- err = ext4_trans_block_get_noread(inode_ref->fs->bdev, &bh, newblock);
- if (err != EOK) {- ext4_ext_free_blocks(inode_ref, newblock, 1, 0);
- return err;
- }
-
- /* move top-level index/leaf into new block */
- memmove(bh.data, inode_ref->inode->blocks,
- sizeof(inode_ref->inode->blocks));
-
- /* set size of new block */
- neh = ext_block_hdr(&bh);
- /* old root could have indexes or leaves
- * so calculate e_max right way */
- if (ext_depth(inode_ref->inode))
- neh->max_entries_count =
- to_le16(ext4_ext_space_block_idx(inode_ref));
- else
- neh->max_entries_count =
- to_le16(ext4_ext_space_block(inode_ref));
-
- neh->magic = to_le16(EXT4_EXTENT_MAGIC);
- ext4_extent_block_csum_set(inode_ref, neh);
-
- /* Update top-level index: num,max,pointer */
- neh = ext_inode_hdr(inode_ref->inode);
- neh->entries_count = to_le16(1);
- ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
- if (neh->depth == 0) {- /* Root extent block becomes index block */
- neh->max_entries_count =
- to_le16(ext4_ext_space_root_idx(inode_ref));
- EXT_FIRST_INDEX(neh)
- ->first_block = EXT_FIRST_EXTENT(neh)->first_block;
- }
- neh->depth = to_le16(to_le16(neh->depth) + 1);
-
- ext4_trans_set_block_dirty(bh.buf);
- inode_ref->dirty = true;
- ext4_block_set(inode_ref->fs->bdev, &bh);
-
- return err;
-}
-
-__unused static void print_path(struct ext4_extent_path *path)
-{- int32_t i = path->depth;
- while (i >= 0) {-
- ptrdiff_t a =
- (path->extent)
- ? (path->extent - EXT_FIRST_EXTENT(path->header))
- : 0;
- ptrdiff_t b =
- (path->index)
- ? (path->index - EXT_FIRST_INDEX(path->header))
- : 0;
-
- (void)a;
- (void)b;
- ext4_dbg(DEBUG_EXTENT,
- "depth %" PRId32 ", p_block: %" PRIu64 ","
- "p_ext offset: %td, p_idx offset: %td\n",
- i, path->p_block, a, b);
- i--;
- path++;
- }
-}
-
-static void ext4_ext_replace_path(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path,
- struct ext_split_trans *spt,
- int32_t level)
-{- int32_t depth = ext_depth(inode_ref->inode);
- int32_t i = depth - level;
- ext4_ext_drop_refs(inode_ref, path + i, 1);
- path[i] = spt[level].path;
-}
-
-static int ext4_ext_insert_extent(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path **ppath,
- struct ext4_extent *newext, uint32_t flags)
-{- int32_t i, depth, level;
- int ret = EOK;
- ext4_fsblk_t ptr = 0;
- bool need_grow = false;
- struct ext4_extent_path *path = *ppath;
- struct ext_split_trans *spt = NULL;
- struct ext_split_trans newblock;
-
- memset(&newblock, 0, sizeof(newblock));
-
- depth = ext_depth(inode_ref->inode);
- for (i = depth, level = 0; i >= 0; i--, level++)
- if (EXT_HAS_FREE_INDEX(path + i))
- break;
-
- if (level) {- spt = calloc(1, sizeof(struct ext_split_trans) * (level));
- if (!spt) {- ret = ENOMEM;
- goto out;
- }
- }
- i = 0;
-again:
- depth = ext_depth(inode_ref->inode);
-
- do {- if (!i) {- ret = ext4_ext_insert_leaf(inode_ref, path, depth - i,
- newext, &newblock, flags,
- &need_grow);
- } else {- ret = ext4_ext_insert_index(
- inode_ref, path, depth - i, newext,
- ext4_ext_block_index(
- ext_block_hdr(&spt[i - 1].path.block)),
- spt[i - 1].ptr, &newblock,
- &need_grow);
- }
- ptr = newblock.ptr;
-
- if (ret != EOK)
- goto out;
-
- else if (spt && ptr && !ret) {- /* Prepare for the next iteration after splitting. */
- spt[i] = newblock;
- }
-
- i++;
- } while (ptr != 0 && i <= depth);
-
- if (need_grow) {- ret = ext4_ext_grow_indepth(inode_ref, 0);
- if (ret)
- goto out;
- ret = ext4_find_extent(inode_ref, to_le32(newext->first_block),
- ppath, 0);
- if (ret)
- goto out;
- i = depth;
- path = *ppath;
- goto again;
- }
-out:
- if (ret) {- if (path)
- ext4_ext_drop_refs(inode_ref, path, 0);
-
- while (--level >= 0 && spt) {- if (spt[level].ptr) {- ext4_ext_free_blocks(inode_ref, spt[level].ptr,
- 1, 0);
- ext4_ext_drop_refs(inode_ref, &spt[level].path,
- 1);
- }
- }
- } else {- while (--level >= 0 && spt) {- if (spt[level].switch_to)
- ext4_ext_replace_path(inode_ref, path, spt,
- level);
- else if (spt[level].ptr)
- ext4_ext_drop_refs(inode_ref, &spt[level].path,
- 1);
- }
- }
- if (spt)
- free(spt);
-
- return ret;
-}
-
-static void ext4_ext_remove_blocks(struct ext4_inode_ref *inode_ref,
- struct ext4_extent *ex, ext4_lblk_t from,
- ext4_lblk_t to)
-{- ext4_lblk_t len = to - from + 1;
- ext4_lblk_t num;
- ext4_fsblk_t start;
- num = from - to_le32(ex->first_block);
- start = ext4_ext_pblock(ex) + num;
- ext4_dbg(DEBUG_EXTENT,
- "Freeing %" PRIu32 " at %" PRIu64 ", %" PRIu32 "\n", from,
- start, len);
-
- ext4_ext_free_blocks(inode_ref, start, len, 0);
-}
-
-static int ext4_ext_remove_idx(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path, int32_t depth)
-{- int err = EOK;
- int32_t i = depth;
- ext4_fsblk_t leaf;
-
- /* free index block */
- leaf = ext4_idx_pblock(path[i].index);
-
- if (path[i].index != EXT_LAST_INDEX(path[i].header)) {- ptrdiff_t len = EXT_LAST_INDEX(path[i].header) - path[i].index;
- memmove(path[i].index, path[i].index + 1,
- len * sizeof(struct ext4_extent_index));
- }
-
- path[i].header->entries_count =
- to_le16(to_le16(path[i].header->entries_count) - 1);
- err = ext4_ext_dirty(inode_ref, path + i);
- if (err != EOK)
- return err;
-
- ext4_dbg(DEBUG_EXTENT, "IDX: Freeing %" PRIu32 " at %" PRIu64 ", %d\n",
- to_le32(path[i].index->first_block), leaf, 1);
- ext4_ext_free_blocks(inode_ref, leaf, 1, 0);
-
- while (i > 0) {- if (path[i].index != EXT_FIRST_INDEX(path[i].header))
- break;
-
- path[i - 1].index->first_block = path[i].index->first_block;
- err = ext4_ext_dirty(inode_ref, path + i - 1);
- if (err != EOK)
- break;
-
- i--;
- }
- return err;
-}
-
-static int ext4_ext_remove_leaf(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path *path, ext4_lblk_t from,
- ext4_lblk_t to)
-{-
- int32_t depth = ext_depth(inode_ref->inode);
- struct ext4_extent *ex = path[depth].extent;
- struct ext4_extent *start_ex, *ex2 = NULL;
- struct ext4_extent_header *eh = path[depth].header;
- int32_t len;
- int err = EOK;
- uint16_t new_entries;
-
- start_ex = ex;
- new_entries = to_le16(eh->entries_count);
- while (ex <= EXT_LAST_EXTENT(path[depth].header) &&
- to_le32(ex->first_block) <= to) {- int32_t new_len = 0;
- int unwritten;
- ext4_lblk_t start, new_start;
- ext4_fsblk_t newblock;
- new_start = start = to_le32(ex->first_block);
- len = ext4_ext_get_actual_len(ex);
- newblock = ext4_ext_pblock(ex);
- if (start < from) {- len -= from - start;
- new_len = from - start;
- start = from;
- start_ex++;
- } else {- if (start + len - 1 > to) {- len -= start + len - 1 - to;
- new_len = start + len - 1 - to;
- new_start = to + 1;
- newblock += to + 1 - start;
- ex2 = ex;
- }
- }
-
- ext4_ext_remove_blocks(inode_ref, ex, start, start + len - 1);
- ex->first_block = to_le32(new_start);
- if (!new_len)
- new_entries--;
- else {- unwritten = ext4_ext_is_unwritten(ex);
- ex->block_count = to_le16(new_len);
- ext4_ext_store_pblock(ex, newblock);
- if (unwritten)
- ext4_ext_mark_unwritten(ex);
- }
-
- ex += 1;
- }
-
- if (ex2 == NULL)
- ex2 = ex;
-
- if (ex2 <= EXT_LAST_EXTENT(eh))
- memmove(start_ex, ex2, EXT_LAST_EXTENT(eh) - ex2 + 1);
-
- eh->entries_count = to_le16(new_entries);
- ext4_ext_dirty(inode_ref, path + depth);
- if (path[depth].extent == EXT_FIRST_EXTENT(eh) && eh->entries_count)
- err = ext4_ext_correct_indexes(inode_ref, path);
-
- /* if this leaf is free, then we should
- * remove it from index block above */
- if (err == EOK && eh->entries_count == 0 && path[depth].block.lb_id)
- err = ext4_ext_remove_idx(inode_ref, path, depth - 1);
- else if (depth > 0)
- path[depth - 1].index++;
-
- return err;
-}
-
-static bool ext4_ext_more_to_rm(struct ext4_extent_path *path, ext4_lblk_t to)
-{- if (!to_le16(path->header->entries_count))
- return false;
-
- if (path->index > EXT_LAST_INDEX(path->header))
- return false;
-
- if (to_le32(path->index->first_block) > to)
- return false;
-
- return true;
-}
-
-int ext4_extent_remove_space(struct ext4_inode_ref *inode_ref, ext4_lblk_t from,
- ext4_lblk_t to)
-{- struct ext4_extent_path *path = NULL;
- int ret = EOK;
- int32_t depth = ext_depth(inode_ref->inode);
- int32_t i;
-
- ret = ext4_find_extent(inode_ref, from, &path, 0);
- if (ret)
- goto out;
-
- if (!path[depth].extent) {- ret = EOK;
- goto out;
- }
-
- bool in_range = IN_RANGE(from, to_le32(path[depth].extent->first_block),
- ext4_ext_get_actual_len(path[depth].extent));
-
- if (!in_range) {- ret = EOK;
- goto out;
- }
-
- /* If we do remove_space inside the range of an extent */
- if ((to_le32(path[depth].extent->first_block) < from) &&
- (to < to_le32(path[depth].extent->first_block) +
- ext4_ext_get_actual_len(path[depth].extent) - 1)) {-
- struct ext4_extent *ex = path[depth].extent, newex;
- int unwritten = ext4_ext_is_unwritten(ex);
- ext4_lblk_t ee_block = to_le32(ex->first_block);
- int32_t len = ext4_ext_get_actual_len(ex);
- ext4_fsblk_t newblock =
- to + 1 - ee_block + ext4_ext_pblock(ex);
-
- ex->block_count = to_le16(from - ee_block);
- if (unwritten)
- ext4_ext_mark_unwritten(ex);
-
- ext4_ext_dirty(inode_ref, path + depth);
-
- newex.first_block = to_le32(to + 1);
- newex.block_count = to_le16(ee_block + len - 1 - to);
- ext4_ext_store_pblock(&newex, newblock);
- if (unwritten)
- ext4_ext_mark_unwritten(&newex);
-
- ret = ext4_ext_insert_extent(inode_ref, &path, &newex, 0);
- goto out;
- }
-
- i = depth;
- while (i >= 0) {- if (i == depth) {- struct ext4_extent_header *eh;
- struct ext4_extent *first_ex, *last_ex;
- ext4_lblk_t leaf_from, leaf_to;
- eh = path[i].header;
- ext4_assert(to_le16(eh->entries_count) > 0);
- first_ex = EXT_FIRST_EXTENT(eh);
- last_ex = EXT_LAST_EXTENT(eh);
- leaf_from = to_le32(first_ex->first_block);
- leaf_to = to_le32(last_ex->first_block) +
- ext4_ext_get_actual_len(last_ex) - 1;
- if (leaf_from < from)
- leaf_from = from;
-
- if (leaf_to > to)
- leaf_to = to;
-
- ext4_ext_remove_leaf(inode_ref, path, leaf_from,
- leaf_to);
- ext4_ext_drop_refs(inode_ref, path + i, 0);
- i--;
- continue;
- }
-
- struct ext4_extent_header *eh;
- eh = path[i].header;
- if (ext4_ext_more_to_rm(path + i, to)) {- struct ext4_block bh = EXT4_BLOCK_ZERO();
- if (path[i + 1].block.lb_id)
- ext4_ext_drop_refs(inode_ref, path + i + 1, 0);
-
- ret = read_extent_tree_block(inode_ref,
- ext4_idx_pblock(path[i].index),
- depth - i - 1, &bh, 0);
- if (ret)
- goto out;
-
- path[i].p_block =
- ext4_idx_pblock(path[i].index);
- path[i + 1].block = bh;
- path[i + 1].header = ext_block_hdr(&bh);
- path[i + 1].depth = depth - i - 1;
- if (i + 1 == depth)
- path[i + 1].extent = EXT_FIRST_EXTENT(
- path[i + 1].header);
- else
- path[i + 1].index =
- EXT_FIRST_INDEX(path[i + 1].header);
-
- i++;
- } else {- if (i > 0) {- if (!eh->entries_count)
- ret = ext4_ext_remove_idx(inode_ref, path,
- i - 1);
- else
- path[i - 1].index++;
-
- }
-
- if (i)
- ext4_block_set(inode_ref->fs->bdev,
- &path[i].block);
-
-
- i--;
- }
-
- }
-
- /* TODO: flexible tree reduction should be here */
- if (path->header->entries_count == 0) {- /*
- * truncate to zero freed all the tree,
- * so we need to correct eh_depth
- */
- ext_inode_hdr(inode_ref->inode)->depth = 0;
- ext_inode_hdr(inode_ref->inode)->max_entries_count =
- to_le16(ext4_ext_space_root(inode_ref));
- ret = ext4_ext_dirty(inode_ref, path);
- }
-
-out:
- ext4_ext_drop_refs(inode_ref, path, 0);
- free(path);
- path = NULL;
- return ret;
-}
-
-static int ext4_ext_split_extent_at(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path **ppath,
- ext4_lblk_t split, uint32_t split_flag)
-{- struct ext4_extent *ex, newex;
- ext4_fsblk_t newblock;
- ext4_lblk_t ee_block;
- int32_t ee_len;
- int32_t depth = ext_depth(inode_ref->inode);
- int err = EOK;
-
- ex = (*ppath)[depth].extent;
- ee_block = to_le32(ex->first_block);
- ee_len = ext4_ext_get_actual_len(ex);
- newblock = split - ee_block + ext4_ext_pblock(ex);
-
- if (split == ee_block) {- /*
- * case b: block @split is the block that the extent begins with
- * then we just change the state of the extent, and splitting
- * is not needed.
- */
- if (split_flag & EXT4_EXT_MARK_UNWRIT2)
- ext4_ext_mark_unwritten(ex);
- else
- ext4_ext_mark_initialized(ex);
-
- err = ext4_ext_dirty(inode_ref, *ppath + depth);
- goto out;
- }
-
- ex->block_count = to_le16(split - ee_block);
- if (split_flag & EXT4_EXT_MARK_UNWRIT1)
- ext4_ext_mark_unwritten(ex);
-
- err = ext4_ext_dirty(inode_ref, *ppath + depth);
- if (err != EOK)
- goto out;
-
- newex.first_block = to_le32(split);
- newex.block_count = to_le16(ee_len - (split - ee_block));
- ext4_ext_store_pblock(&newex, newblock);
- if (split_flag & EXT4_EXT_MARK_UNWRIT2)
- ext4_ext_mark_unwritten(&newex);
- err = ext4_ext_insert_extent(inode_ref, ppath, &newex,
- EXT4_EXT_NO_COMBINE);
- if (err != EOK)
- goto restore_extent_len;
-
-out:
- return err;
-restore_extent_len:
- ex->block_count = to_le16(ee_len);
- err = ext4_ext_dirty(inode_ref, *ppath + depth);
- return err;
-}
-
-static int ext4_ext_convert_to_initialized(struct ext4_inode_ref *inode_ref,
- struct ext4_extent_path **ppath,
- ext4_lblk_t split, uint32_t blocks)
-{- int32_t depth = ext_depth(inode_ref->inode), err = EOK;
- struct ext4_extent *ex = (*ppath)[depth].extent;
-
- ext4_assert(to_le32(ex->first_block) <= split);
-
- if (split + blocks ==
- to_le32(ex->first_block) + ext4_ext_get_actual_len(ex)) {- /* split and initialize right part */
- err = ext4_ext_split_extent_at(inode_ref, ppath, split,
- EXT4_EXT_MARK_UNWRIT1);
- } else if (to_le32(ex->first_block) == split) {- /* split and initialize left part */
- err = ext4_ext_split_extent_at(inode_ref, ppath, split + blocks,
- EXT4_EXT_MARK_UNWRIT2);
- } else {- /* split 1 extent to 3 and initialize the 2nd */
- err = ext4_ext_split_extent_at(inode_ref, ppath, split + blocks,
- EXT4_EXT_MARK_UNWRIT1 |
- EXT4_EXT_MARK_UNWRIT2);
- if (!err) {- err = ext4_ext_split_extent_at(inode_ref, ppath, split,
- EXT4_EXT_MARK_UNWRIT1);
- }
- }
-
- return err;
-}
-
-static ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_extent_path *path)
-{- int32_t depth;
-
- depth = path->depth;
-
- if (depth == 0 && path->extent == NULL)
- return EXT_MAX_BLOCKS;
-
- while (depth >= 0) {- if (depth == path->depth) {- /* leaf */
- if (path[depth].extent &&
- path[depth].extent !=
- EXT_LAST_EXTENT(path[depth].header))
- return to_le32(
- path[depth].extent[1].first_block);
- } else {- /* index */
- if (path[depth].index !=
- EXT_LAST_INDEX(path[depth].header))
- return to_le32(
- path[depth].index[1].first_block);
- }
- depth--;
- }
-
- return EXT_MAX_BLOCKS;
-}
-
-static int ext4_ext_zero_unwritten_range(struct ext4_inode_ref *inode_ref,
- ext4_fsblk_t block,
- uint32_t blocks_count)
-{- int err = EOK;
- uint32_t i;
- uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
- for (i = 0; i < blocks_count; i++) {- struct ext4_block bh = EXT4_BLOCK_ZERO();
- err = ext4_trans_block_get_noread(inode_ref->fs->bdev, &bh, block + i);
- if (err != EOK)
- break;
-
- memset(bh.data, 0, block_size);
- ext4_trans_set_block_dirty(bh.buf);
- err = ext4_block_set(inode_ref->fs->bdev, &bh);
- if (err != EOK)
- break;
- }
- return err;
-}
-
-int ext4_extent_get_blocks(struct ext4_inode_ref *inode_ref, ext4_fsblk_t iblock,
- uint32_t max_blocks, ext4_fsblk_t *result, bool create,
- uint32_t *blocks_count)
-{- struct ext4_extent_path *path = NULL;
- struct ext4_extent newex, *ex;
- ext4_fsblk_t goal;
- int err = EOK;
- int32_t depth;
- uint32_t allocated = 0;
- ext4_fsblk_t next, newblock;
-
- if (result)
- *result = 0;
-
- if (blocks_count)
- *blocks_count = 0;
-
- /* find extent for this block */
- err = ext4_find_extent(inode_ref, iblock, &path, 0);
- if (err != EOK) {- path = NULL;
- goto out2;
- }
-
- depth = ext_depth(inode_ref->inode);
-
- /*
- * consistent leaf must not be empty
- * this situations is possible, though, _during_ tree modification
- * this is why assert can't be put in ext4_ext_find_extent()
- */
- ex = path[depth].extent;
- if (ex) {- ext4_lblk_t ee_block = to_le32(ex->first_block);
- ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
- uint16_t ee_len = ext4_ext_get_actual_len(ex);
- /* if found exent covers block, simple return it */
- if (IN_RANGE(iblock, ee_block, ee_len)) {- /* number of remain blocks in the extent */
- allocated = ee_len - (iblock - ee_block);
-
- if (!ext4_ext_is_unwritten(ex)) {- newblock = iblock - ee_block + ee_start;
- goto out;
- }
-
- if (!create) {- newblock = 0;
- goto out;
- }
-
- uint32_t zero_range;
- zero_range = allocated;
- if (zero_range > max_blocks)
- zero_range = max_blocks;
-
- newblock = iblock - ee_block + ee_start;
- err = ext4_ext_zero_unwritten_range(inode_ref, newblock,
- zero_range);
- if (err != EOK)
- goto out2;
-
- err = ext4_ext_convert_to_initialized(inode_ref, &path,
- iblock, zero_range);
- if (err != EOK)
- goto out2;
-
- goto out;
- }
- }
-
- /*
- * requested block isn't allocated yet
- * we couldn't try to create block if create flag is zero
- */
- if (!create) {- goto out2;
- }
-
- /* find next allocated block so that we know how many
- * blocks we can allocate without ovelapping next extent */
- next = ext4_ext_next_allocated_block(path);
- allocated = next - iblock;
- if (allocated > max_blocks)
- allocated = max_blocks;
-
- /* allocate new block */
- goal = ext4_ext_find_goal(inode_ref, path, iblock);
- newblock = ext4_new_meta_blocks(inode_ref, goal, 0, &allocated, &err);
- if (!newblock)
- goto out2;
-
- /* try to insert new extent into found leaf and return */
- newex.first_block = to_le32(iblock);
- ext4_ext_store_pblock(&newex, newblock);
- newex.block_count = to_le16(allocated);
- err = ext4_ext_insert_extent(inode_ref, &path, &newex, 0);
- if (err != EOK) {- /* free data blocks we just allocated */
- ext4_ext_free_blocks(inode_ref, ext4_ext_pblock(&newex),
- to_le16(newex.block_count), 0);
- goto out2;
- }
-
- /* previous routine could use block we allocated */
- newblock = ext4_ext_pblock(&newex);
-
-out:
- if (allocated > max_blocks)
- allocated = max_blocks;
-
- if (result)
- *result = newblock;
-
- if (blocks_count)
- *blocks_count = allocated;
-
-out2:
- if (path) {- ext4_ext_drop_refs(inode_ref, path, 0);
- free(path);
- }
-
- return err;
-}
-#endif