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Message-Id: <1304388301-9452-4-git-send-email-xiaoqiangnk@gmail.com>
Date: Mon, 2 May 2011 19:05:01 -0700
From: Yongqiang Yang <xiaoqiangnk@...il.com>
To: linux-ext4@...r.kernel.org
Cc: tytso@....edu, achender@...ux.vnet.ibm.com, cmm@...ibm.com,
Yongqiang Yang <xiaoqiangnk@...il.com>
Subject: [PATCH v2 3/3] ext4:Reimplement convert and split_unwritten.
v0->v1:
-- ext4_ext_convert_initialized() zeroout whole extent when the extent's
length is less than 14.
convert and split unwritten are reimplemented based on ext4_split_extent()
added in last patch.
Signed-off-by: Yongqiang Yang <xiaoqiangnk@...il.com>
Tested-by: Allison Henderson <achender@...ux.vnet.ibm.com>
---
fs/ext4/extents.c | 480 ++++++++---------------------------------------------
1 files changed, 72 insertions(+), 408 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index db1d67c..9e7c7b3 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2757,17 +2757,13 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
struct ext4_map_blocks *map,
struct ext4_ext_path *path)
{
- struct ext4_extent *ex, newex, orig_ex;
- struct ext4_extent *ex1 = NULL;
- struct ext4_extent *ex2 = NULL;
- struct ext4_extent *ex3 = NULL;
- struct ext4_extent_header *eh;
+ struct ext4_map_blocks split_map;
+ struct ext4_extent zero_ex;
+ struct ext4_extent *ex;
ext4_lblk_t ee_block, eof_block;
unsigned int allocated, ee_len, depth;
- ext4_fsblk_t newblock;
int err = 0;
- int ret = 0;
- int may_zeroout;
+ int split_flag = 0;
ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
"block %llu, max_blocks %u\n", inode->i_ino,
@@ -2779,280 +2775,87 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
eof_block = map->m_lblk + map->m_len;
depth = ext_depth(inode);
- eh = path[depth].p_hdr;
ex = path[depth].p_ext;
ee_block = le32_to_cpu(ex->ee_block);
ee_len = ext4_ext_get_actual_len(ex);
allocated = ee_len - (map->m_lblk - ee_block);
- newblock = map->m_lblk - ee_block + ext4_ext_pblock(ex);
-
- ex2 = ex;
- orig_ex.ee_block = ex->ee_block;
- orig_ex.ee_len = cpu_to_le16(ee_len);
- ext4_ext_store_pblock(&orig_ex, ext4_ext_pblock(ex));
+ WARN_ON(map->m_lblk < ee_block);
/*
* It is safe to convert extent to initialized via explicit
* zeroout only if extent is fully insde i_size or new_size.
*/
- may_zeroout = ee_block + ee_len <= eof_block;
+ split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
- err = ext4_ext_get_access(handle, inode, path + depth);
- if (err)
- goto out;
/* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
- if (ee_len <= 2*EXT4_EXT_ZERO_LEN && may_zeroout) {
- err = ext4_ext_zeroout(inode, &orig_ex);
+ if (ee_len <= 2*EXT4_EXT_ZERO_LEN &&
+ (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
+ err = ext4_ext_zeroout(inode, ex);
if (err)
- goto fix_extent_len;
- /* update the extent length and mark as initialized */
- ex->ee_block = orig_ex.ee_block;
- ex->ee_len = orig_ex.ee_len;
- ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
- ext4_ext_dirty(handle, inode, path + depth);
- /* zeroed the full extent */
- return allocated;
- }
-
- /* ex1: ee_block to map->m_lblk - 1 : uninitialized */
- if (map->m_lblk > ee_block) {
- ex1 = ex;
- ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
- ext4_ext_mark_uninitialized(ex1);
- ex2 = &newex;
- }
- /*
- * for sanity, update the length of the ex2 extent before
- * we insert ex3, if ex1 is NULL. This is to avoid temporary
- * overlap of blocks.
- */
- if (!ex1 && allocated > map->m_len)
- ex2->ee_len = cpu_to_le16(map->m_len);
- /* ex3: to ee_block + ee_len : uninitialised */
- if (allocated > map->m_len) {
- unsigned int newdepth;
- /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
- if (allocated <= EXT4_EXT_ZERO_LEN && may_zeroout) {
- /*
- * map->m_lblk == ee_block is handled by the zerouout
- * at the beginning.
- * Mark first half uninitialized.
- * Mark second half initialized and zero out the
- * initialized extent
- */
- ex->ee_block = orig_ex.ee_block;
- ex->ee_len = cpu_to_le16(ee_len - allocated);
- ext4_ext_mark_uninitialized(ex);
- ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
- ext4_ext_dirty(handle, inode, path + depth);
-
- ex3 = &newex;
- ex3->ee_block = cpu_to_le32(map->m_lblk);
- ext4_ext_store_pblock(ex3, newblock);
- ex3->ee_len = cpu_to_le16(allocated);
- err = ext4_ext_insert_extent(handle, inode, path,
- ex3, 0);
- if (err == -ENOSPC) {
- err = ext4_ext_zeroout(inode, &orig_ex);
- if (err)
- goto fix_extent_len;
- ex->ee_block = orig_ex.ee_block;
- ex->ee_len = orig_ex.ee_len;
- ext4_ext_store_pblock(ex,
- ext4_ext_pblock(&orig_ex));
- ext4_ext_dirty(handle, inode, path + depth);
- /* blocks available from map->m_lblk */
- return allocated;
-
- } else if (err)
- goto fix_extent_len;
-
- /*
- * We need to zero out the second half because
- * an fallocate request can update file size and
- * converting the second half to initialized extent
- * implies that we can leak some junk data to user
- * space.
- */
- err = ext4_ext_zeroout(inode, ex3);
- if (err) {
- /*
- * We should actually mark the
- * second half as uninit and return error
- * Insert would have changed the extent
- */
- depth = ext_depth(inode);
- ext4_ext_drop_refs(path);
- path = ext4_ext_find_extent(inode, map->m_lblk,
- path);
- if (IS_ERR(path)) {
- err = PTR_ERR(path);
- return err;
- }
- /* get the second half extent details */
- ex = path[depth].p_ext;
- err = ext4_ext_get_access(handle, inode,
- path + depth);
- if (err)
- return err;
- ext4_ext_mark_uninitialized(ex);
- ext4_ext_dirty(handle, inode, path + depth);
- return err;
- }
-
- /* zeroed the second half */
- return allocated;
- }
- ex3 = &newex;
- ex3->ee_block = cpu_to_le32(map->m_lblk + map->m_len);
- ext4_ext_store_pblock(ex3, newblock + map->m_len);
- ex3->ee_len = cpu_to_le16(allocated - map->m_len);
- ext4_ext_mark_uninitialized(ex3);
- err = ext4_ext_insert_extent(handle, inode, path, ex3, 0);
- if (err == -ENOSPC && may_zeroout) {
- err = ext4_ext_zeroout(inode, &orig_ex);
- if (err)
- goto fix_extent_len;
- /* update the extent length and mark as initialized */
- ex->ee_block = orig_ex.ee_block;
- ex->ee_len = orig_ex.ee_len;
- ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
- ext4_ext_dirty(handle, inode, path + depth);
- /* zeroed the full extent */
- /* blocks available from map->m_lblk */
- return allocated;
-
- } else if (err)
- goto fix_extent_len;
- /*
- * The depth, and hence eh & ex might change
- * as part of the insert above.
- */
- newdepth = ext_depth(inode);
- /*
- * update the extent length after successful insert of the
- * split extent
- */
- ee_len -= ext4_ext_get_actual_len(ex3);
- orig_ex.ee_len = cpu_to_le16(ee_len);
- may_zeroout = ee_block + ee_len <= eof_block;
-
- depth = newdepth;
- ext4_ext_drop_refs(path);
- path = ext4_ext_find_extent(inode, map->m_lblk, path);
- if (IS_ERR(path)) {
- err = PTR_ERR(path);
goto out;
- }
- eh = path[depth].p_hdr;
- ex = path[depth].p_ext;
- if (ex2 != &newex)
- ex2 = ex;
err = ext4_ext_get_access(handle, inode, path + depth);
if (err)
goto out;
-
- allocated = map->m_len;
-
- /* If extent has less than EXT4_EXT_ZERO_LEN and we are trying
- * to insert a extent in the middle zerout directly
- * otherwise give the extent a chance to merge to left
- */
- if (le16_to_cpu(orig_ex.ee_len) <= EXT4_EXT_ZERO_LEN &&
- map->m_lblk != ee_block && may_zeroout) {
- err = ext4_ext_zeroout(inode, &orig_ex);
- if (err)
- goto fix_extent_len;
- /* update the extent length and mark as initialized */
- ex->ee_block = orig_ex.ee_block;
- ex->ee_len = orig_ex.ee_len;
- ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
- ext4_ext_dirty(handle, inode, path + depth);
- /* zero out the first half */
- /* blocks available from map->m_lblk */
- return allocated;
- }
- }
- /*
- * If there was a change of depth as part of the
- * insertion of ex3 above, we need to update the length
- * of the ex1 extent again here
- */
- if (ex1 && ex1 != ex) {
- ex1 = ex;
- ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
- ext4_ext_mark_uninitialized(ex1);
- ex2 = &newex;
- }
- /* ex2: map->m_lblk to map->m_lblk + maxblocks-1 : initialised */
- ex2->ee_block = cpu_to_le32(map->m_lblk);
- ext4_ext_store_pblock(ex2, newblock);
- ex2->ee_len = cpu_to_le16(allocated);
- if (ex2 != ex)
- goto insert;
- /*
- * New (initialized) extent starts from the first block
- * in the current extent. i.e., ex2 == ex
- * We have to see if it can be merged with the extent
- * on the left.
- */
- if (ex2 > EXT_FIRST_EXTENT(eh)) {
- /*
- * To merge left, pass "ex2 - 1" to try_to_merge(),
- * since it merges towards right _only_.
- */
- ret = ext4_ext_try_to_merge(inode, path, ex2 - 1);
- if (ret) {
- err = ext4_ext_correct_indexes(handle, inode, path);
- if (err)
- goto out;
- depth = ext_depth(inode);
- ex2--;
- }
+ ext4_ext_mark_initialized(ex);
+ ext4_ext_try_to_merge(inode, path, ex);
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ goto out;
}
+
/*
- * Try to Merge towards right. This might be required
- * only when the whole extent is being written to.
- * i.e. ex2 == ex and ex3 == NULL.
+ * four cases:
+ * 1. split the extent into three extents.
+ * 2. split the extent into two extents, zeroout the first half.
+ * 3. split the extent into two extents, zeroout the second half.
+ * 4. split the extent into two extents with out zeroout.
*/
- if (!ex3) {
- ret = ext4_ext_try_to_merge(inode, path, ex2);
- if (ret) {
- err = ext4_ext_correct_indexes(handle, inode, path);
+ split_map.m_lblk = map->m_lblk;
+ split_map.m_len = map->m_len;
+
+ if (allocated > map->m_len) {
+ if (allocated <= EXT4_EXT_ZERO_LEN &&
+ (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
+ /* case 3 */
+ zero_ex.ee_block =
+ cpu_to_le32(map->m_lblk + map->m_len);
+ zero_ex.ee_len = cpu_to_le16(allocated - map->m_len);
+ ext4_ext_store_pblock(&zero_ex,
+ ext4_ext_pblock(ex) + map->m_lblk - ee_block);
+ err = ext4_ext_zeroout(inode, &zero_ex);
if (err)
goto out;
+ split_map.m_lblk = map->m_lblk;
+ split_map.m_len = allocated;
+ } else if ((map->m_lblk - ee_block + map->m_len <
+ EXT4_EXT_ZERO_LEN) &&
+ (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
+ /* case 2 */
+ if (map->m_lblk != ee_block) {
+ zero_ex.ee_block = ex->ee_block;
+ zero_ex.ee_len = cpu_to_le16(map->m_lblk -
+ ee_block);
+ ext4_ext_store_pblock(&zero_ex,
+ ext4_ext_pblock(ex));
+ err = ext4_ext_zeroout(inode, &zero_ex);
+ if (err)
+ goto out;
+ }
+
+ allocated = map->m_lblk - ee_block + map->m_len;
+
+ split_map.m_lblk = ee_block;
+ split_map.m_len = allocated;
}
}
- /* Mark modified extent as dirty */
- err = ext4_ext_dirty(handle, inode, path + depth);
- goto out;
-insert:
- err = ext4_ext_insert_extent(handle, inode, path, &newex, 0);
- if (err == -ENOSPC && may_zeroout) {
- err = ext4_ext_zeroout(inode, &orig_ex);
- if (err)
- goto fix_extent_len;
- /* update the extent length and mark as initialized */
- ex->ee_block = orig_ex.ee_block;
- ex->ee_len = orig_ex.ee_len;
- ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
- ext4_ext_dirty(handle, inode, path + depth);
- /* zero out the first half */
- return allocated;
- } else if (err)
- goto fix_extent_len;
+
+ allocated = ext4_split_extent(handle, inode, path,
+ &split_map, split_flag, 0);
+ if (allocated < 0)
+ err = allocated;
+
out:
- ext4_ext_show_leaf(inode, path);
return err ? err : allocated;
-
-fix_extent_len:
- ex->ee_block = orig_ex.ee_block;
- ex->ee_len = orig_ex.ee_len;
- ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
- ext4_ext_mark_uninitialized(ex);
- ext4_ext_dirty(handle, inode, path + depth);
- return err;
}
/*
@@ -3083,15 +2886,11 @@ static int ext4_split_unwritten_extents(handle_t *handle,
struct ext4_ext_path *path,
int flags)
{
- struct ext4_extent *ex, newex, orig_ex;
- struct ext4_extent *ex1 = NULL;
- struct ext4_extent *ex2 = NULL;
- struct ext4_extent *ex3 = NULL;
- ext4_lblk_t ee_block, eof_block;
- unsigned int allocated, ee_len, depth;
- ext4_fsblk_t newblock;
- int err = 0;
- int may_zeroout;
+ ext4_lblk_t eof_block;
+ ext4_lblk_t ee_block;
+ struct ext4_extent *ex;
+ unsigned int ee_len;
+ int split_flag = 0, depth;
ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
"block %llu, max_blocks %u\n", inode->i_ino,
@@ -3101,155 +2900,20 @@ static int ext4_split_unwritten_extents(handle_t *handle,
inode->i_sb->s_blocksize_bits;
if (eof_block < map->m_lblk + map->m_len)
eof_block = map->m_lblk + map->m_len;
-
- depth = ext_depth(inode);
- ex = path[depth].p_ext;
- ee_block = le32_to_cpu(ex->ee_block);
- ee_len = ext4_ext_get_actual_len(ex);
- allocated = ee_len - (map->m_lblk - ee_block);
- newblock = map->m_lblk - ee_block + ext4_ext_pblock(ex);
-
- ex2 = ex;
- orig_ex.ee_block = ex->ee_block;
- orig_ex.ee_len = cpu_to_le16(ee_len);
- ext4_ext_store_pblock(&orig_ex, ext4_ext_pblock(ex));
-
/*
* It is safe to convert extent to initialized via explicit
* zeroout only if extent is fully insde i_size or new_size.
*/
- may_zeroout = ee_block + ee_len <= eof_block;
-
- /*
- * If the uninitialized extent begins at the same logical
- * block where the write begins, and the write completely
- * covers the extent, then we don't need to split it.
- */
- if ((map->m_lblk == ee_block) && (allocated <= map->m_len))
- return allocated;
-
- err = ext4_ext_get_access(handle, inode, path + depth);
- if (err)
- goto out;
- /* ex1: ee_block to map->m_lblk - 1 : uninitialized */
- if (map->m_lblk > ee_block) {
- ex1 = ex;
- ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
- ext4_ext_mark_uninitialized(ex1);
- ex2 = &newex;
- }
- /*
- * for sanity, update the length of the ex2 extent before
- * we insert ex3, if ex1 is NULL. This is to avoid temporary
- * overlap of blocks.
- */
- if (!ex1 && allocated > map->m_len)
- ex2->ee_len = cpu_to_le16(map->m_len);
- /* ex3: to ee_block + ee_len : uninitialised */
- if (allocated > map->m_len) {
- unsigned int newdepth;
- ex3 = &newex;
- ex3->ee_block = cpu_to_le32(map->m_lblk + map->m_len);
- ext4_ext_store_pblock(ex3, newblock + map->m_len);
- ex3->ee_len = cpu_to_le16(allocated - map->m_len);
- ext4_ext_mark_uninitialized(ex3);
- err = ext4_ext_insert_extent(handle, inode, path, ex3, flags);
- if (err == -ENOSPC && may_zeroout) {
- err = ext4_ext_zeroout(inode, &orig_ex);
- if (err)
- goto fix_extent_len;
- /* update the extent length and mark as initialized */
- ex->ee_block = orig_ex.ee_block;
- ex->ee_len = orig_ex.ee_len;
- ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
- ext4_ext_dirty(handle, inode, path + depth);
- /* zeroed the full extent */
- /* blocks available from map->m_lblk */
- return allocated;
-
- } else if (err)
- goto fix_extent_len;
- /*
- * The depth, and hence eh & ex might change
- * as part of the insert above.
- */
- newdepth = ext_depth(inode);
- /*
- * update the extent length after successful insert of the
- * split extent
- */
- ee_len -= ext4_ext_get_actual_len(ex3);
- orig_ex.ee_len = cpu_to_le16(ee_len);
- may_zeroout = ee_block + ee_len <= eof_block;
-
- depth = newdepth;
- ext4_ext_drop_refs(path);
- path = ext4_ext_find_extent(inode, map->m_lblk, path);
- if (IS_ERR(path)) {
- err = PTR_ERR(path);
- goto out;
- }
- ex = path[depth].p_ext;
- if (ex2 != &newex)
- ex2 = ex;
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
- err = ext4_ext_get_access(handle, inode, path + depth);
- if (err)
- goto out;
+ split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
+ split_flag |= EXT4_EXT_MARK_UNINIT2;
- allocated = map->m_len;
- }
- /*
- * If there was a change of depth as part of the
- * insertion of ex3 above, we need to update the length
- * of the ex1 extent again here
- */
- if (ex1 && ex1 != ex) {
- ex1 = ex;
- ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
- ext4_ext_mark_uninitialized(ex1);
- ex2 = &newex;
- }
- /*
- * ex2: map->m_lblk to map->m_lblk + map->m_len-1 : to be written
- * using direct I/O, uninitialised still.
- */
- ex2->ee_block = cpu_to_le32(map->m_lblk);
- ext4_ext_store_pblock(ex2, newblock);
- ex2->ee_len = cpu_to_le16(allocated);
- ext4_ext_mark_uninitialized(ex2);
- if (ex2 != ex)
- goto insert;
- /* Mark modified extent as dirty */
- err = ext4_ext_dirty(handle, inode, path + depth);
- ext_debug("out here\n");
- goto out;
-insert:
- err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
- if (err == -ENOSPC && may_zeroout) {
- err = ext4_ext_zeroout(inode, &orig_ex);
- if (err)
- goto fix_extent_len;
- /* update the extent length and mark as initialized */
- ex->ee_block = orig_ex.ee_block;
- ex->ee_len = orig_ex.ee_len;
- ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
- ext4_ext_dirty(handle, inode, path + depth);
- /* zero out the first half */
- return allocated;
- } else if (err)
- goto fix_extent_len;
-out:
- ext4_ext_show_leaf(inode, path);
- return err ? err : allocated;
-
-fix_extent_len:
- ex->ee_block = orig_ex.ee_block;
- ex->ee_len = orig_ex.ee_len;
- ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
- ext4_ext_mark_uninitialized(ex);
- ext4_ext_dirty(handle, inode, path + depth);
- return err;
+ flags |= EXT4_GET_BLOCKS_PRE_IO;
+ return ext4_split_extent(handle, inode, path, map, split_flag, flags);
}
static int ext4_convert_unwritten_extents_endio(handle_t *handle,
--
1.7.4.4
--
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