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| author | Jens Axboe <jens.axboe@oracle.com> | 2010-05-17 12:55:07 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2010-05-17 12:55:07 +0200 |
| commit | e913fc825dc685a444cb4c1d0f9d32f372f59861 (patch) | |
| tree | e470697e43ffe4028ac81c17d3ef90ee9f30bcfb /include/linux | |
| parent | 69b62d01ec44fe0d505d89917392347732135a4d (diff) | |
| download | linux-e913fc825dc685a444cb4c1d0f9d32f372f59861.tar.gz linux-e913fc825dc685a444cb4c1d0f9d32f372f59861.tar.bz2 linux-e913fc825dc685a444cb4c1d0f9d32f372f59861.zip | |
writeback: fix WB_SYNC_NONE writeback from umount
When umount calls sync_filesystem(), we first do a WB_SYNC_NONE
writeback to kick off writeback of pending dirty inodes, then follow
that up with a WB_SYNC_ALL to wait for it. Since umount already holds
the sb s_umount mutex, WB_SYNC_NONE ends up doing nothing and all
writeback happens as WB_SYNC_ALL. This can greatly slow down umount,
since WB_SYNC_ALL writeback is a data integrity operation and thus
a bigger hammer than simple WB_SYNC_NONE. For barrier aware file systems
it's a lot slower.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/backing-dev.h | 2 | ||||
| -rw-r--r-- | include/linux/writeback.h | 10 |
2 files changed, 11 insertions, 1 deletions
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 7534979d83bd..ff8bac63213f 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -106,7 +106,7 @@ int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev); void bdi_unregister(struct backing_dev_info *bdi); int bdi_setup_and_register(struct backing_dev_info *, char *, unsigned int); void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb, - long nr_pages); + long nr_pages, int sb_locked); int bdi_writeback_task(struct bdi_writeback *wb); int bdi_has_dirty_io(struct backing_dev_info *bdi); diff --git a/include/linux/writeback.h b/include/linux/writeback.h index eb38a2c645f6..47e1c686cb02 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -65,6 +65,15 @@ struct writeback_control { * so we use a single control to update them */ unsigned no_nrwrite_index_update:1; + + /* + * For WB_SYNC_ALL, the sb must always be pinned. For WB_SYNC_NONE, + * the writeback code will pin the sb for the caller. However, + * for eg umount, the caller does WB_SYNC_NONE but already has + * the sb pinned. If the below is set, caller already has the + * sb pinned. + */ + unsigned sb_pinned:1; }; /* @@ -73,6 +82,7 @@ struct writeback_control { struct bdi_writeback; int inode_wait(void *); void writeback_inodes_sb(struct super_block *); +void writeback_inodes_sb_locked(struct super_block *); int writeback_inodes_sb_if_idle(struct super_block *); void sync_inodes_sb(struct super_block *); void writeback_inodes_wbc(struct writeback_control *wbc); |