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![]() If a file has FI_COMPRESS_RELEASED, all writes for it should not be
allowed. However, as of now, in case of compress_mode=user, writes
triggered by IOCTLs like F2FS_IOC_DE/COMPRESS_FILE are allowed unexpectly,
which could crash that file.
To fix it, let's do not allow F2FS_IOC_DE/COMPRESS_IOCTL if a file already
has FI_COMPRESS_RELEASED flag.
This is the reproduction process:
1. $ touch ./file
2. $ chattr +c ./file
3. $ dd if=/dev/random of=./file bs=4096 count=30 conv=notrunc
4. $ dd if=/dev/zero of=./file bs=4096 count=34 seek=30 conv=notrunc
5. $ sync
6. $ do_compress ./file ; call F2FS_IOC_COMPRESS_FILE
7. $ get_compr_blocks ./file ; call F2FS_IOC_GET_COMPRESS_BLOCKS
8. $ release ./file ; call F2FS_IOC_RELEASE_COMPRESS_BLOCKS
9. $ do_compress ./file ; call F2FS_IOC_COMPRESS_FILE again
10. $ get_compr_blocks ./file ; call F2FS_IOC_GET_COMPRESS_BLOCKS again
This reproduction process is tested in 128kb cluster size.
You can find compr_blocks has a negative value.
Fixes:
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.. | ||
acl.c | ||
acl.h | ||
checkpoint.c | ||
compress.c | ||
data.c | ||
debug.c | ||
dir.c | ||
extent_cache.c | ||
f2fs.h | ||
file.c | ||
gc.c | ||
gc.h | ||
hash.c | ||
inline.c | ||
inode.c | ||
iostat.c | ||
iostat.h | ||
Kconfig | ||
Makefile | ||
namei.c | ||
node.c | ||
node.h | ||
recovery.c | ||
segment.c | ||
segment.h | ||
shrinker.c | ||
super.c | ||
sysfs.c | ||
verity.c | ||
xattr.c | ||
xattr.h |