diff options
Diffstat (limited to 'fs/fs-writeback.c')
-rw-r--r-- | fs/fs-writeback.c | 78 |
1 files changed, 39 insertions, 39 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 06557679ca41..ae45f77765c0 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c | |||
@@ -25,6 +25,45 @@ | |||
25 | #include <linux/buffer_head.h> | 25 | #include <linux/buffer_head.h> |
26 | #include "internal.h" | 26 | #include "internal.h" |
27 | 27 | ||
28 | |||
29 | /** | ||
30 | * writeback_acquire - attempt to get exclusive writeback access to a device | ||
31 | * @bdi: the device's backing_dev_info structure | ||
32 | * | ||
33 | * It is a waste of resources to have more than one pdflush thread blocked on | ||
34 | * a single request queue. Exclusion at the request_queue level is obtained | ||
35 | * via a flag in the request_queue's backing_dev_info.state. | ||
36 | * | ||
37 | * Non-request_queue-backed address_spaces will share default_backing_dev_info, | ||
38 | * unless they implement their own. Which is somewhat inefficient, as this | ||
39 | * may prevent concurrent writeback against multiple devices. | ||
40 | */ | ||
41 | static int writeback_acquire(struct backing_dev_info *bdi) | ||
42 | { | ||
43 | return !test_and_set_bit(BDI_pdflush, &bdi->state); | ||
44 | } | ||
45 | |||
46 | /** | ||
47 | * writeback_in_progress - determine whether there is writeback in progress | ||
48 | * @bdi: the device's backing_dev_info structure. | ||
49 | * | ||
50 | * Determine whether there is writeback in progress against a backing device. | ||
51 | */ | ||
52 | int writeback_in_progress(struct backing_dev_info *bdi) | ||
53 | { | ||
54 | return test_bit(BDI_pdflush, &bdi->state); | ||
55 | } | ||
56 | |||
57 | /** | ||
58 | * writeback_release - relinquish exclusive writeback access against a device. | ||
59 | * @bdi: the device's backing_dev_info structure | ||
60 | */ | ||
61 | static void writeback_release(struct backing_dev_info *bdi) | ||
62 | { | ||
63 | BUG_ON(!writeback_in_progress(bdi)); | ||
64 | clear_bit(BDI_pdflush, &bdi->state); | ||
65 | } | ||
66 | |||
28 | /** | 67 | /** |
29 | * __mark_inode_dirty - internal function | 68 | * __mark_inode_dirty - internal function |
30 | * @inode: inode to mark | 69 | * @inode: inode to mark |
@@ -747,43 +786,4 @@ int generic_osync_inode(struct inode *inode, struct address_space *mapping, int | |||
747 | 786 | ||
748 | return err; | 787 | return err; |
749 | } | 788 | } |
750 | |||
751 | EXPORT_SYMBOL(generic_osync_inode); | 789 | EXPORT_SYMBOL(generic_osync_inode); |
752 | |||
753 | /** | ||
754 | * writeback_acquire - attempt to get exclusive writeback access to a device | ||
755 | * @bdi: the device's backing_dev_info structure | ||
756 | * | ||
757 | * It is a waste of resources to have more than one pdflush thread blocked on | ||
758 | * a single request queue. Exclusion at the request_queue level is obtained | ||
759 | * via a flag in the request_queue's backing_dev_info.state. | ||
760 | * | ||
761 | * Non-request_queue-backed address_spaces will share default_backing_dev_info, | ||
762 | * unless they implement their own. Which is somewhat inefficient, as this | ||
763 | * may prevent concurrent writeback against multiple devices. | ||
764 | */ | ||
765 | int writeback_acquire(struct backing_dev_info *bdi) | ||
766 | { | ||
767 | return !test_and_set_bit(BDI_pdflush, &bdi->state); | ||
768 | } | ||
769 | |||
770 | /** | ||
771 | * writeback_in_progress - determine whether there is writeback in progress | ||
772 | * @bdi: the device's backing_dev_info structure. | ||
773 | * | ||
774 | * Determine whether there is writeback in progress against a backing device. | ||
775 | */ | ||
776 | int writeback_in_progress(struct backing_dev_info *bdi) | ||
777 | { | ||
778 | return test_bit(BDI_pdflush, &bdi->state); | ||
779 | } | ||
780 | |||
781 | /** | ||
782 | * writeback_release - relinquish exclusive writeback access against a device. | ||
783 | * @bdi: the device's backing_dev_info structure | ||
784 | */ | ||
785 | void writeback_release(struct backing_dev_info *bdi) | ||
786 | { | ||
787 | BUG_ON(!writeback_in_progress(bdi)); | ||
788 | clear_bit(BDI_pdflush, &bdi->state); | ||
789 | } | ||