diff options
| -rw-r--r-- | fs/ext4/extents.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index d279ea8c4661..668d82e494dd 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2212,6 +2212,8 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) return ret; } +#define EXT4_EXT_ZERO_LEN 7 + /* * This function is called by ext4_ext_get_blocks() if someone tries to write * to an uninitialized extent. It may result in splitting the uninitialized @@ -2254,6 +2256,18 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, 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) { + 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, ext_pblock(&orig_ex)); + ext4_ext_dirty(handle, inode, path + depth); + return le16_to_cpu(ex->ee_len); + } /* ex1: ee_block to iblock - 1 : uninitialized */ if (iblock > ee_block) { @@ -2272,6 +2286,38 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, /* ex3: to ee_block + ee_len : uninitialised */ if (allocated > max_blocks) { unsigned int newdepth; + /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */ + if (allocated <= EXT4_EXT_ZERO_LEN) { + /* 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, ext_pblock(&orig_ex)); + ext4_ext_dirty(handle, inode, path + depth); + + ex3 = &newex; + ex3->ee_block = cpu_to_le32(iblock); + ext4_ext_store_pblock(ex3, newblock); + ex3->ee_len = cpu_to_le16(allocated); + err = ext4_ext_insert_extent(handle, inode, path, ex3); + 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, ext_pblock(&orig_ex)); + ext4_ext_dirty(handle, inode, path + depth); + return le16_to_cpu(ex->ee_len); + + } else if (err) + goto fix_extent_len; + + return allocated; + } ex3 = &newex; ex3->ee_block = cpu_to_le32(iblock + max_blocks); ext4_ext_store_pblock(ex3, newblock + max_blocks); @@ -2320,6 +2366,23 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, goto out; } allocated = max_blocks; + + /* 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 && + iblock != ee_block) { + 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, ext_pblock(&orig_ex)); + ext4_ext_dirty(handle, inode, path + depth); + return le16_to_cpu(ex->ee_len); + } } /* * If there was a change of depth as part of the |