Make sure iomap_end is always called when iomap_begin succeeds.
Without this fix, iomap_end won't be called when a filesystem's
iomap_begin operation returns an invalid mapping, bypassing any
unlocking done in iomap_end. With this fix, the unlocking would
at least still happen.
This iomap_apply bug was found by Bob Peterson during code review.
It's unlikely that such iomap_begin bugs will survive to affect
users, so backporting this fix seems unnecessary.
Fixes: ae259a9c8593 ("fs: introduce iomap infrastructure")
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
fs/iomap/apply.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/fs/iomap/apply.c b/fs/iomap/apply.c
index 76925b40b5fd..32daf8cb411c 100644
--- a/fs/iomap/apply.c
+++ b/fs/iomap/apply.c
@@ -46,10 +46,11 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags,
ret = ops->iomap_begin(inode, pos, length, flags, &iomap, &srcmap);
if (ret)
return ret;
- if (WARN_ON(iomap.offset > pos))
- return -EIO;
- if (WARN_ON(iomap.length == 0))
- return -EIO;
+ if (WARN_ON(iomap.offset > pos) ||
+ WARN_ON(iomap.length == 0)) {
+ written = -EIO;
+ goto out;
+ }
trace_iomap_apply_dstmap(inode, &iomap);
if (srcmap.type != IOMAP_HOLE)
@@ -80,6 +81,7 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags,
written = actor(inode, pos, length, data, &iomap,
srcmap.type != IOMAP_HOLE ? &srcmap : &iomap);
+out:
/*
* Now the data has been copied, commit the range we've copied. This
* should not fail unless the filesystem has had a fatal error.
base-commit: 69119673bd50b176ded34032fadd41530fb5af21
--
2.26.2
