diff options
Diffstat (limited to 'fs/gfs2')
-rw-r--r-- | fs/gfs2/ops_address.c | 74 |
1 files changed, 45 insertions, 29 deletions
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c index d8d69a72a10d..0118aa439c1d 100644 --- a/fs/gfs2/ops_address.c +++ b/fs/gfs2/ops_address.c | |||
@@ -594,6 +594,36 @@ static void gfs2_invalidatepage(struct page *page, unsigned long offset) | |||
594 | return; | 594 | return; |
595 | } | 595 | } |
596 | 596 | ||
597 | /** | ||
598 | * gfs2_ok_for_dio - check that dio is valid on this file | ||
599 | * @ip: The inode | ||
600 | * @rw: READ or WRITE | ||
601 | * @offset: The offset at which we are reading or writing | ||
602 | * | ||
603 | * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o) | ||
604 | * 1 (to accept the i/o request) | ||
605 | */ | ||
606 | static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset) | ||
607 | { | ||
608 | /* | ||
609 | * Should we return an error here? I can't see that O_DIRECT for | ||
610 | * a journaled file makes any sense. For now we'll silently fall | ||
611 | * back to buffered I/O, likewise we do the same for stuffed | ||
612 | * files since they are (a) small and (b) unaligned. | ||
613 | */ | ||
614 | if (gfs2_is_jdata(ip)) | ||
615 | return 0; | ||
616 | |||
617 | if (gfs2_is_stuffed(ip)) | ||
618 | return 0; | ||
619 | |||
620 | if (offset > i_size_read(&ip->i_inode)) | ||
621 | return 0; | ||
622 | return 1; | ||
623 | } | ||
624 | |||
625 | |||
626 | |||
597 | static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb, | 627 | static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb, |
598 | const struct iovec *iov, loff_t offset, | 628 | const struct iovec *iov, loff_t offset, |
599 | unsigned long nr_segs) | 629 | unsigned long nr_segs) |
@@ -604,42 +634,28 @@ static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb, | |||
604 | struct gfs2_holder gh; | 634 | struct gfs2_holder gh; |
605 | int rv; | 635 | int rv; |
606 | 636 | ||
607 | if (rw == READ) | ||
608 | mutex_lock(&inode->i_mutex); | ||
609 | /* | 637 | /* |
610 | * Shared lock, even if its a write, since we do no allocation | 638 | * Deferred lock, even if its a write, since we do no allocation |
611 | * on this path. All we need change is atime. | 639 | * on this path. All we need change is atime, and this lock mode |
640 | * ensures that other nodes have flushed their buffered read caches | ||
641 | * (i.e. their page cache entries for this inode). We do not, | ||
642 | * unfortunately have the option of only flushing a range like | ||
643 | * the VFS does. | ||
612 | */ | 644 | */ |
613 | gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh); | 645 | gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, GL_ATIME, &gh); |
614 | rv = gfs2_glock_nq_atime(&gh); | 646 | rv = gfs2_glock_nq_atime(&gh); |
615 | if (rv) | 647 | if (rv) |
616 | goto out; | 648 | return rv; |
617 | 649 | rv = gfs2_ok_for_dio(ip, rw, offset); | |
618 | if (offset > i_size_read(inode)) | 650 | if (rv != 1) |
619 | goto out; | 651 | goto out; /* dio not valid, fall back to buffered i/o */ |
620 | 652 | ||
621 | /* | 653 | rv = blockdev_direct_IO_no_locking(rw, iocb, inode, inode->i_sb->s_bdev, |
622 | * Should we return an error here? I can't see that O_DIRECT for | 654 | iov, offset, nr_segs, |
623 | * a journaled file makes any sense. For now we'll silently fall | 655 | gfs2_get_block_direct, NULL); |
624 | * back to buffered I/O, likewise we do the same for stuffed | ||
625 | * files since they are (a) small and (b) unaligned. | ||
626 | */ | ||
627 | if (gfs2_is_jdata(ip)) | ||
628 | goto out; | ||
629 | |||
630 | if (gfs2_is_stuffed(ip)) | ||
631 | goto out; | ||
632 | |||
633 | rv = blockdev_direct_IO_own_locking(rw, iocb, inode, | ||
634 | inode->i_sb->s_bdev, | ||
635 | iov, offset, nr_segs, | ||
636 | gfs2_get_block_direct, NULL); | ||
637 | out: | 656 | out: |
638 | gfs2_glock_dq_m(1, &gh); | 657 | gfs2_glock_dq_m(1, &gh); |
639 | gfs2_holder_uninit(&gh); | 658 | gfs2_holder_uninit(&gh); |
640 | if (rw == READ) | ||
641 | mutex_unlock(&inode->i_mutex); | ||
642 | |||
643 | return rv; | 659 | return rv; |
644 | } | 660 | } |
645 | 661 | ||