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Btrfs: fix error path when failing to submit bio for direct IO write

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Commit 61de718fce ("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@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
This commit is contained in:
Filipe Manana 2015-11-24 16:23:54 +00:00
parent 7785a663c4
commit 14543774bd
1 changed files with 27 additions and 27 deletions
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54
fs/btrfs/inode.c
View file

@ -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,
0);
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()