[PATCH V2] f2fs: fix to adjust appropriate length for fiemap
From: Zhiguo Niu
Date: Sun Nov 03 2024 - 20:57:37 EST
If user give a file size as "length" parameter for fiemap
operations, but if this size is non-block size aligned,
it will show 2 segments fiemap results even this whole file
is contiguous on disk, such as the following results:
./f2fs_io fiemap 0 19034 ylog/analyzer.py
Fiemap: offset = 0 len = 19034
logical addr. physical addr. length flags
0 0000000000000000 0000000020baa000 0000000000004000 00001000
1 0000000000004000 0000000020bae000 0000000000001000 00001001
after this patch:
./f2fs_io fiemap 0 19034 ylog/analyzer.py
Fiemap: offset = 0 len = 19034
logical addr. physical addr. length flags
0 0000000000000000 00000000315f3000 0000000000005000 00001001
Signed-off-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
---
V2: correct commit msg according to Chao's questions
f2fs_io has been modified for testing, the length for fiemap is
real file size, not block number
---
fs/f2fs/data.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 306b86b0..9fc229d 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1966,8 +1966,8 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
goto out;
}
- if (bytes_to_blks(inode, len) == 0)
- len = blks_to_bytes(inode, 1);
+ if (len & (blks_to_bytes(inode, 1) - 1))
+ len = round_up(len, blks_to_bytes(inode, 1));
start_blk = bytes_to_blks(inode, start);
last_blk = bytes_to_blks(inode, start + len - 1);
--
1.9.1