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| author |   Wei Gao <wegao@suse.com> | 2025-06-13 11:18:38 -0400 |
|---|---|---|
| committer |   Jan Kara <jack@suse.cz> | 2025-06-13 11:38:25 +0200 |
| commit | a099b09a3342a0b28ea330e405501b5b4d0424b4 (patch) | |
| tree | 625dadeade164f588826ed83d1a4cdca12ed6110 | |
| parent | Merge tag 'net-6.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net (diff) | |
| download | wireguard-linux-a099b09a3342a0b28ea330e405501b5b4d0424b4.tar.xz wireguard-linux-a099b09a3342a0b28ea330e405501b5b4d0424b4.zip | |
ext2: Handle fiemap on empty files to prevent EINVAL
Previously, ext2_fiemap would unconditionally apply "len = min_t(u64, len,
i_size_read(inode));", When inode->i_size was 0 (for an empty file), this
would reduce the requested len to 0. Passing len = 0 to iomap_fiemap could
then result in an -EINVAL error, even for valid queries on empty files.
Link: https://github.com/linux-test-project/ltp/issues/1246
Signed-off-by: Wei Gao <wegao@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250613152402.3432135-1-wegao@suse.com
| -rw-r--r-- | fs/ext2/inode.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 30f8201c155f..177b1f852b63 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -895,9 +895,19 @@ int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len) { int ret; + loff_t i_size; inode_lock(inode); - len = min_t(u64, len, i_size_read(inode)); + i_size = i_size_read(inode); + /* + * iomap_fiemap() returns EINVAL for 0 length. Make sure we don't trim + * length to 0 but still trim the range as much as possible since + * ext2_get_blocks() iterates unmapped space block by block which is + * slow. + */ + if (i_size == 0) + i_size = 1; + len = min_t(u64, len, i_size); ret = iomap_fiemap(inode, fieinfo, start, len, &ext2_iomap_ops); inode_unlock(inode); |