diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/block_dev.c | 15 | ||||
| -rw-r--r-- | fs/fs-writeback.c | 49 | ||||
| -rw-r--r-- | fs/internal.h | 16 | ||||
| -rw-r--r-- | fs/super.c | 72 | ||||
| -rw-r--r-- | fs/sync.c | 31 |
5 files changed, 50 insertions, 133 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index fe47f72..4b6a3b9 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -176,17 +176,22 @@ blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, iov, offset, nr_segs, blkdev_get_blocks, NULL); } +int __sync_blockdev(struct block_device *bdev, int wait) +{ + if (!bdev) + return 0; + if (!wait) + return filemap_flush(bdev->bd_inode->i_mapping); + return filemap_write_and_wait(bdev->bd_inode->i_mapping); +} + /* * Write out and wait upon all the dirty data associated with a block * device via its mapping. Does not take the superblock lock. */ int sync_blockdev(struct block_device *bdev) { - int ret = 0; - - if (bdev) - ret = filemap_write_and_wait(bdev->bd_inode->i_mapping); - return ret; + return __sync_blockdev(bdev, 1); } EXPORT_SYMBOL(sync_blockdev); diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 91013ff..e0fb2e7 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -679,55 +679,6 @@ void sync_inodes_sb(struct super_block *sb, int wait) } /** - * sync_inodes - writes all inodes to disk - * @wait: wait for completion - * - * sync_inodes() goes through each super block's dirty inode list, writes the - * inodes out, waits on the writeout and puts the inodes back on the normal - * list. - * - * This is for sys_sync(). fsync_dev() uses the same algorithm. The subtle - * part of the sync functions is that the blockdev "superblock" is processed - * last. This is because the write_inode() function of a typical fs will - * perform no I/O, but will mark buffers in the blockdev mapping as dirty. - * What we want to do is to perform all that dirtying first, and then write - * back all those inode blocks via the blockdev mapping in one sweep. So the - * additional (somewhat redundant) sync_blockdev() calls here are to make - * sure that really happens. Because if we call sync_inodes_sb(wait=1) with - * outstanding dirty inodes, the writeback goes block-at-a-time within the - * filesystem's write_inode(). This is extremely slow. - */ -static void __sync_inodes(int wait) -{ - struct super_block *sb; - - spin_lock(&sb_lock); -restart: - list_for_each_entry(sb, &super_blocks, s_list) { - sb->s_count++; - spin_unlock(&sb_lock); - down_read(&sb->s_umount); - if (sb->s_root) { - sync_inodes_sb(sb, wait); - sync_blockdev(sb->s_bdev); - } - up_read(&sb->s_umount); - spin_lock(&sb_lock); - if (__put_super_and_need_restart(sb)) - goto restart; - } - spin_unlock(&sb_lock); -} - -void sync_inodes(int wait) -{ - __sync_inodes(0); - - if (wait) - __sync_inodes(1); -} - -/** * write_inode_now - write an inode to disk * @inode: inode to write to disk * @sync: whether the write should be synchronous or not diff --git a/fs/internal.h b/fs/internal.h index 343a537..dbec3cc 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -25,6 +25,8 @@ static inline int sb_is_blkdev_sb(struct super_block *sb) return sb == blockdev_superblock; } +extern int __sync_blockdev(struct block_device *bdev, int wait); + #else static inline void bdev_cache_init(void) { @@ -34,6 +36,11 @@ static inline int sb_is_blkdev_sb(struct super_block *sb) { return 0; } + +static inline int __sync_blockdev(struct block_device *bdev, int wait) +{ + return 0; +} #endif /* @@ -71,12 +78,3 @@ extern void chroot_fs_refs(struct path *, struct path *); * file_table.c */ extern void mark_files_ro(struct super_block *); - -/* - * super.c - */ -#ifdef CONFIG_BLOCK -extern void sync_blockdevs(void); -#else -static inline void sync_blockdevs(void) { } -#endif @@ -284,23 +284,23 @@ EXPORT_SYMBOL(lock_super); EXPORT_SYMBOL(unlock_super); /* - * Write out and wait upon all dirty data associated with this - * superblock. Filesystem data as well as the underlying block - * device. Takes the superblock lock. Requires a second blkdev - * flush by the caller to complete the operation. + * Do the filesystem syncing work. For simple filesystems sync_inodes_sb(sb, 0) + * just dirties buffers with inodes so we have to submit IO for these buffers + * via __sync_blockdev(). This also speeds up the wait == 1 case since in that + * case write_inode() functions do sync_dirty_buffer() and thus effectively + * write one block at a time. */ -static int __fsync_super(struct super_block *sb) +static int __fsync_super(struct super_block *sb, int wait) { - sync_inodes_sb(sb, 0); vfs_dq_sync(sb); - sync_inodes_sb(sb, 1); + sync_inodes_sb(sb, wait); lock_super(sb); if (sb->s_dirt && sb->s_op->write_super) sb->s_op->write_super(sb); unlock_super(sb); if (sb->s_op->sync_fs) - sb->s_op->sync_fs(sb, 1); - return sync_blockdev(sb->s_bdev); + sb->s_op->sync_fs(sb, wait); + return __sync_blockdev(sb->s_bdev, wait); } /* @@ -310,7 +310,12 @@ static int __fsync_super(struct super_block *sb) */ int fsync_super(struct super_block *sb) { - return __fsync_super(sb); + int ret; + + ret = __fsync_super(sb, 0); + if (ret < 0) + return ret; + return __fsync_super(sb, 1); } EXPORT_SYMBOL_GPL(fsync_super); @@ -469,20 +474,18 @@ restart: } /* - * Call the ->sync_fs super_op against all filesystems which are r/w and - * which implement it. + * Sync all the data for all the filesystems (called by sys_sync() and + * emergency sync) * * This operation is careful to avoid the livelock which could easily happen - * if two or more filesystems are being continuously dirtied. s_need_sync_fs + * if two or more filesystems are being continuously dirtied. s_need_sync * is used only here. We set it against all filesystems and then clear it as * we sync them. So redirtied filesystems are skipped. * * But if process A is currently running sync_filesystems and then process B - * calls sync_filesystems as well, process B will set all the s_need_sync_fs + * calls sync_filesystems as well, process B will set all the s_need_sync * flags again, which will cause process A to resync everything. Fix that with * a local mutex. - * - * (Fabian) Avoid sync_fs with clean fs & wait mode 0 */ void sync_filesystems(int wait) { @@ -492,25 +495,23 @@ void sync_filesystems(int wait) mutex_lock(&mutex); /* Could be down_interruptible */ spin_lock(&sb_lock); list_for_each_entry(sb, &super_blocks, s_list) { - if (!sb->s_op->sync_fs) - continue; if (sb->s_flags & MS_RDONLY) continue; - sb->s_need_sync_fs = 1; + sb->s_need_sync = 1; } restart: list_for_each_entry(sb, &super_blocks, s_list) { - if (!sb->s_need_sync_fs) + if (!sb->s_need_sync) continue; - sb->s_need_sync_fs = 0; + sb->s_need_sync = 0; if (sb->s_flags & MS_RDONLY) continue; /* hm. Was remounted r/o meanwhile */ sb->s_count++; spin_unlock(&sb_lock); down_read(&sb->s_umount); if (sb->s_root) - sb->s_op->sync_fs(sb, wait); + __fsync_super(sb, wait); up_read(&sb->s_umount); /* restart only when sb is no longer on the list */ spin_lock(&sb_lock); @@ -521,33 +522,6 @@ restart: mutex_unlock(&mutex); } -#ifdef CONFIG_BLOCK -/* - * Sync all block devices underlying some superblock - */ -void sync_blockdevs(void) -{ - struct super_block *sb; - - spin_lock(&sb_lock); -restart: - list_for_each_entry(sb, &super_blocks, s_list) { - if (!sb->s_bdev) - continue; - sb->s_count++; - spin_unlock(&sb_lock); - down_read(&sb->s_umount); - if (sb->s_root) - sync_blockdev(sb->s_bdev); - up_read(&sb->s_umount); - spin_lock(&sb_lock); - if (__put_super_and_need_restart(sb)) - goto restart; - } - spin_unlock(&sb_lock); -} -#endif - /** * get_super - get the superblock of a device * @bdev: device to get the superblock for @@ -18,35 +18,24 @@ #define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \ SYNC_FILE_RANGE_WAIT_AFTER) -/* - * sync everything. Start out by waking pdflush, because that writes back - * all queues in parallel. - */ -static void do_sync(unsigned long wait) +SYSCALL_DEFINE0(sync) { - wakeup_pdflush(0); - sync_inodes(0); /* All mappings, inodes and their blockdevs */ - vfs_dq_sync(NULL); - sync_inodes(wait); /* Mappings, inodes and blockdevs, again. */ - sync_supers(); /* Write the superblocks */ - sync_filesystems(0); /* Start syncing the filesystems */ - sync_filesystems(wait); /* Waitingly sync the filesystems */ - sync_blockdevs(); - if (!wait) - printk("Emergency Sync complete\n"); + sync_filesystems(0); + sync_filesystems(1); if (unlikely(laptop_mode)) laptop_sync_completion(); -} - -SYSCALL_DEFINE0(sync) -{ - do_sync(1); return 0; } static void do_sync_work(struct work_struct *work) { - do_sync(0); + /* + * Sync twice to reduce the possibility we skipped some inodes / pages + * because they were temporarily locked + */ + sync_filesystems(0); + sync_filesystems(0); + printk("Emergency Sync complete\n"); kfree(work); } |