diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2009-01-03 09:47:09 -0500 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2009-01-03 09:47:09 -0500 |
| commit | 87d8fe1ee6b8d2f95076142d58c440dba4e7bdc2 (patch) | |
| tree | 8c91506978a16c22268b086f693e307de0ca57db | |
| parent | 0087d9fb3f29f59e8d42c8b058376d80e5adde4c (diff) | |
add releasepage hooks to block devices which can be used by file systems
Implement blkdev_releasepage() to release the buffer_heads and pages
after we release private data belonging to a mounted filesystem.
Cc: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
| -rw-r--r-- | fs/block_dev.c | 15 | ||||
| -rw-r--r-- | fs/super.c | 2 | ||||
| -rw-r--r-- | include/linux/fs.h | 2 |
3 files changed, 19 insertions, 0 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 349a26c1000..1dd07e66e98 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1220,6 +1220,20 @@ static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) return blkdev_ioctl(bdev, mode, cmd, arg); } +/* + * Try to release a page associated with block device when the system + * is under memory pressure. + */ +static int blkdev_releasepage(struct page *page, gfp_t wait) +{ + struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super; + + if (super && super->s_op->bdev_try_to_free_page) + return super->s_op->bdev_try_to_free_page(super, page, wait); + + return try_to_free_buffers(page); +} + static const struct address_space_operations def_blk_aops = { .readpage = blkdev_readpage, .writepage = blkdev_writepage, @@ -1227,6 +1241,7 @@ static const struct address_space_operations def_blk_aops = { .write_begin = blkdev_write_begin, .write_end = blkdev_write_end, .writepages = generic_writepages, + .releasepage = blkdev_releasepage, .direct_IO = blkdev_direct_IO, }; diff --git a/fs/super.c b/fs/super.c index ddba069d7a9..d5fd4498548 100644 --- a/fs/super.c +++ b/fs/super.c @@ -800,6 +800,7 @@ int get_sb_bdev(struct file_system_type *fs_type, } s->s_flags |= MS_ACTIVE; + bdev->bd_super = s; } return simple_set_mnt(mnt, s); @@ -819,6 +820,7 @@ void kill_block_super(struct super_block *sb) struct block_device *bdev = sb->s_bdev; fmode_t mode = sb->s_mode; + bdev->bd_super = 0; generic_shutdown_super(sb); sync_blockdev(bdev); close_bdev_exclusive(bdev, mode); diff --git a/include/linux/fs.h b/include/linux/fs.h index f2a3010140e..0f54ae0f0cc 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -565,6 +565,7 @@ struct address_space { struct block_device { dev_t bd_dev; /* not a kdev_t - it's a search key */ struct inode * bd_inode; /* will die */ + struct super_block * bd_super; int bd_openers; struct mutex bd_mutex; /* open/close mutex */ struct semaphore bd_mount_sem; @@ -1385,6 +1386,7 @@ struct super_operations { ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t); ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); #endif + int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t); }; /* |