5.15-stable review patch. If anyone has any objections, please let me know.
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From: Wei Gao wegao@suse.com
[ Upstream commit a099b09a3342a0b28ea330e405501b5b4d0424b4 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ext2/inode.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 333fa62661d5..85b6a76378ee 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -856,9 +856,19 @@ 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);