On Tue, Nov 24, 2015 at 05:25:18PM +0000, [email protected] wrote: > From: Filipe Manana <[email protected]> > > 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 <[email protected]> > --- > 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);
uptodate=1 won't set IOERR for ordered extent, is that expected? Thanks, -liubo > + 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
