From: Filipe Manana <fdmanana@xxxxxxxx>
Commit 61de718fceb6 ("Btrfs: fix memory corruption on failure to submit
bio for direct IO") fixed problems with the error handling code after we
fail to submit a bio for direct IO. However there were 2 problems that it
did not address when the failure is due to memory allocation failures for
direct IO writes:
1) We considered that there could be only one ordered extent for the whole
IO range, which is not always true, as we can have multiple;
2) It did not set the bit BTRFS_ORDERED_IO_DONE in the ordered extent,
which can make other tasks running btrfs_wait_logged_extents() hang
forever, since they wait for that bit to be set. The general assumption
is that regardless of an error, the BTRFS_ORDERED_IO_DONE is always set
and it precedes setting the bit BTRFS_ORDERED_COMPLETE.
Fix these issues by moving part of the btrfs_endio_direct_write() handler
into a new helper function and having that new helper function called when
we fail to allocate memory to submit the bio (and its private object) for
a direct IO write.
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
---
fs/btrfs/inode.c | 54 +++++++++++++++++++++++++++---------------------------
1 file changed, 27 insertions(+), 27 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f82d1f4..4f8560c 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7995,22 +7995,22 @@ static void btrfs_endio_direct_read(struct bio *bio)
bio_put(bio);
}
-static void btrfs_endio_direct_write(struct bio *bio)
+static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
+ const u64 offset,
+ const u64 bytes,
+ const int uptodate)
{
- struct btrfs_dio_private *dip = bio->bi_private;
- struct inode *inode = dip->inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_ordered_extent *ordered = NULL;
- u64 ordered_offset = dip->logical_offset;
- u64 ordered_bytes = dip->bytes;
- struct bio *dio_bio;
+ u64 ordered_offset = offset;
+ u64 ordered_bytes = bytes;
int ret;
again:
ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
&ordered_offset,
ordered_bytes,
- !bio->bi_error);
+ uptodate);
if (!ret)
goto out_test;
@@ -8023,13 +8023,22 @@ out_test:
* our bio might span multiple ordered extents. If we haven't
* completed the accounting for the whole dio, go back and try again
*/
- if (ordered_offset < dip->logical_offset + dip->bytes) {
- ordered_bytes = dip->logical_offset + dip->bytes -
- ordered_offset;
+ if (ordered_offset < offset + bytes) {
+ ordered_bytes = offset + bytes - ordered_offset;
ordered = NULL;
goto again;
}
- dio_bio = dip->dio_bio;
+}
+
+static void btrfs_endio_direct_write(struct bio *bio)
+{
+ struct btrfs_dio_private *dip = bio->bi_private;
+ struct bio *dio_bio = dip->dio_bio;
+
+ btrfs_endio_direct_write_update_ordered(dip->inode,
+ dip->logical_offset,
+ dip->bytes,
+ !bio->bi_error);
kfree(dip);
@@ -8365,24 +8374,15 @@ free_ordered:
dip = NULL;
io_bio = NULL;
} else {
- if (write) {
- struct btrfs_ordered_extent *ordered;
-
- ordered = btrfs_lookup_ordered_extent(inode,
- file_offset);
- set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
- /*
- * Decrements our ref on the ordered extent and removes
- * the ordered extent from the inode's ordered tree,
- * doing all the proper resource cleanup such as for the
- * reserved space and waking up any waiters for this
- * ordered extent (through btrfs_remove_ordered_extent).
- */
- btrfs_finish_ordered_io(ordered);
- } else {
+ if (write)
+ btrfs_endio_direct_write_update_ordered(inode,
+ file_offset,
+ dio_bio->bi_iter.bi_size,
+ 1);
+ else
unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
file_offset + dio_bio->bi_iter.bi_size - 1);
- }
+
dio_bio->bi_error = -EIO;
/*
* Releases and cleans up our dio_bio, no need to bio_put()
--
2.1.3
--
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