summaryrefslogtreecommitdiff
path: root/fs/ext4/extents.c
diff options
context:
space:
mode:
authorTheodore Ts'o <tytso@mit.edu>2014-09-01 18:32:09 (GMT)
committerTheodore Ts'o <tytso@mit.edu>2014-09-01 18:32:09 (GMT)
commit713e8dde3e71e92db2d8cc8459d236ce1fb576ce (patch)
tree775c6493db0b4a15cd9e33d86f8981b3e27332df /fs/ext4/extents.c
parent19008f6dfa16d23afcd09dceaa598bb6da8de4b1 (diff)
downloadlinux-713e8dde3e71e92db2d8cc8459d236ce1fb576ce.tar.xz
ext4: fix ZERO_RANGE bug hidden by flag aliasing
We accidently aliased EXT4_EX_NOCACHE and EXT4_GET_CONVERT_UNWRITTEN falgs, which apparently was hiding a bug that was unmasked when this flag aliasing issue was addressed (see the subsequent commit). The reproduction case was: fsx -N 10000 -l 500000 -r 4096 -t 4096 -w 4096 -Z -R -W /vdb/junk ... which would cause fsx to report corruption in the data file. The fix we have is a bit of an overkill, but I'd much rather be conservative for now, and we can optimize ZERO_RANGE_FL handling later. The fact that we need to zap the extent_status cache for the inode is unfortunate, but correctness is far more important than performance. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: Namjae Jeon <namjae.jeon@samsung.com>
Diffstat (limited to 'fs/ext4/extents.c')
-rw-r--r--fs/ext4/extents.c21
1 files changed, 14 insertions, 7 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index d009373..bf205f7 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4802,7 +4802,8 @@ static long ext4_zero_range(struct file *file, loff_t offset,
max_blocks -= lblk;
flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT |
- EXT4_GET_BLOCKS_CONVERT_UNWRITTEN;
+ EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
+ EXT4_EX_NOCACHE;
if (mode & FALLOC_FL_KEEP_SIZE)
flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
@@ -4840,15 +4841,21 @@ static long ext4_zero_range(struct file *file, loff_t offset,
ext4_inode_block_unlocked_dio(inode);
inode_dio_wait(inode);
+ ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
+ flags, mode);
+ if (ret)
+ goto out_dio;
/*
* Remove entire range from the extent status tree.
+ *
+ * ext4_es_remove_extent(inode, lblk, max_blocks) is
+ * NOT sufficient. I'm not sure why this is the case,
+ * but let's be conservative and remove the extent
+ * status tree for the entire inode. There should be
+ * no outstanding delalloc extents thanks to the
+ * filemap_write_and_wait_range() call above.
*/
- ret = ext4_es_remove_extent(inode, lblk, max_blocks);
- if (ret)
- goto out_dio;
-
- ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
- flags, mode);
+ ret = ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
if (ret)
goto out_dio;
}