diff options
Diffstat (limited to 'fs/fs-writeback.c')
| -rw-r--r-- | fs/fs-writeback.c | 92 |
1 files changed, 56 insertions, 36 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index d0ff0b8cf30..e5eaa62fd17 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -421,9 +421,6 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * If we're a pdlfush thread, then implement pdflush collision avoidance * against the entire list. * - * WB_SYNC_HOLD is a hack for sys_sync(): reattach the inode to sb->s_dirty so - * that it can be located for waiting on in __writeback_single_inode(). - * * If `bdi' is non-zero then we're being asked to writeback a specific queue. * This function assumes that the blockdev superblock's inodes are backed by * a variety of queues, so all inodes are searched. For other superblocks, @@ -443,6 +440,7 @@ void generic_sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc) { const unsigned long start = jiffies; /* livelock avoidance */ + int sync = wbc->sync_mode == WB_SYNC_ALL; spin_lock(&inode_lock); if (!wbc->for_kupdate || list_empty(&sb->s_io)) @@ -499,10 +497,6 @@ void generic_sync_sb_inodes(struct super_block *sb, __iget(inode); pages_skipped = wbc->pages_skipped; __writeback_single_inode(inode, wbc); - if (wbc->sync_mode == WB_SYNC_HOLD) { - inode->dirtied_when = jiffies; - list_move(&inode->i_list, &sb->s_dirty); - } if (current_is_pdflush()) writeback_release(bdi); if (wbc->pages_skipped != pages_skipped) { @@ -523,7 +517,49 @@ void generic_sync_sb_inodes(struct super_block *sb, if (!list_empty(&sb->s_more_io)) wbc->more_io = 1; } - spin_unlock(&inode_lock); + + if (sync) { + struct inode *inode, *old_inode = NULL; + + /* + * Data integrity sync. Must wait for all pages under writeback, + * because there may have been pages dirtied before our sync + * call, but which had writeout started before we write it out. + * In which case, the inode may not be on the dirty list, but + * we still have to wait for that writeout. + */ + list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { + struct address_space *mapping; + + if (inode->i_state & (I_FREEING|I_WILL_FREE)) + continue; + mapping = inode->i_mapping; + if (mapping->nrpages == 0) + continue; + __iget(inode); + spin_unlock(&inode_lock); + /* + * We hold a reference to 'inode' so it couldn't have + * been removed from s_inodes list while we dropped the + * inode_lock. We cannot iput the inode now as we can + * be holding the last reference and we cannot iput it + * under inode_lock. So we keep the reference and iput + * it later. + */ + iput(old_inode); + old_inode = inode; + + filemap_fdatawait(mapping); + + cond_resched(); + + spin_lock(&inode_lock); + } + spin_unlock(&inode_lock); + iput(old_inode); + } else + spin_unlock(&inode_lock); + return; /* Leave any unwritten inodes on s_io */ } EXPORT_SYMBOL_GPL(generic_sync_sb_inodes); @@ -588,8 +624,7 @@ restart: /* * writeback and wait upon the filesystem's dirty inodes. The caller will - * do this in two passes - one to write, and one to wait. WB_SYNC_HOLD is - * used to park the written inodes on sb->s_dirty for the wait pass. + * do this in two passes - one to write, and one to wait. * * A finite limit is set on the number of pages which will be written. * To prevent infinite livelock of sys_sync(). @@ -600,30 +635,21 @@ restart: void sync_inodes_sb(struct super_block *sb, int wait) { struct writeback_control wbc = { - .sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_HOLD, + .sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_NONE, .range_start = 0, .range_end = LLONG_MAX, }; - unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY); - unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS); - wbc.nr_to_write = nr_dirty + nr_unstable + - (inodes_stat.nr_inodes - inodes_stat.nr_unused) + - nr_dirty + nr_unstable; - wbc.nr_to_write += wbc.nr_to_write / 2; /* Bit more for luck */ - sync_sb_inodes(sb, &wbc); -} + if (!wait) { + unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY); + unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS); -/* - * Rather lame livelock avoidance. - */ -static void set_sb_syncing(int val) -{ - struct super_block *sb; - spin_lock(&sb_lock); - list_for_each_entry_reverse(sb, &super_blocks, s_list) - sb->s_syncing = val; - spin_unlock(&sb_lock); + wbc.nr_to_write = nr_dirty + nr_unstable + + (inodes_stat.nr_inodes - inodes_stat.nr_unused); + } else + wbc.nr_to_write = LONG_MAX; /* doesn't actually matter */ + + sync_sb_inodes(sb, &wbc); } /** @@ -652,9 +678,6 @@ static void __sync_inodes(int wait) spin_lock(&sb_lock); restart: list_for_each_entry(sb, &super_blocks, s_list) { - if (sb->s_syncing) - continue; - sb->s_syncing = 1; sb->s_count++; spin_unlock(&sb_lock); down_read(&sb->s_umount); @@ -672,13 +695,10 @@ restart: void sync_inodes(int wait) { - set_sb_syncing(0); __sync_inodes(0); - if (wait) { - set_sb_syncing(0); + if (wait) __sync_inodes(1); - } } /** |