From 13ced29cb28996a9bc4f68e43ff0c57eafdb1e21 Mon Sep 17 00:00:00 2001 From: Prasad Joshi Date: Sat, 28 Jan 2012 11:36:06 +0530 Subject: [PATCH] logfs: take write mutex lock during fsync and sync LogFS uses super->s_write_mutex while writing data to disk. Taking the same mutex lock in sync and fsync code path solves the following BUG: ------------[ cut here ]------------ kernel BUG at /home/prasad/logfs/dev_bdev.c:134! Pid: 2387, comm: flush-253:16 Not tainted 3.0.0+ #4 Bochs Bochs RIP: 0010:[] [] bdev_writeseg+0x25d/0x270 [logfs] Call Trace: [] logfs_open_area+0x91/0x150 [logfs] [] ? find_level.clone.9+0x62/0x100 [] __logfs_segment_write.clone.20+0x5c/0x190 [logfs] [] ? mempool_kmalloc+0x15/0x20 [] ? mempool_alloc+0x53/0x130 [] logfs_segment_write+0x1d4/0x230 [logfs] [] logfs_write_i0+0x12e/0x190 [logfs] [] __logfs_write_rec+0x140/0x220 [logfs] [] logfs_write_rec+0x64/0xd0 [logfs] [] __logfs_write_buf+0x106/0x110 [logfs] [] logfs_write_buf+0x4e/0x80 [logfs] [] __logfs_writepage+0x23/0x80 [logfs] [] logfs_writepage+0xdc/0x110 [logfs] [] __writepage+0x17/0x40 [] write_cache_pages+0x208/0x4f0 [] ? set_page_dirty+0x70/0x70 [] generic_writepages+0x4a/0x70 [] do_writepages+0x21/0x40 [] writeback_single_inode+0x101/0x250 [] writeback_sb_inodes+0xed/0x1c0 [] writeback_inodes_wb+0x7b/0x1e0 [] wb_writeback+0x4c3/0x530 [] ? sub_preempt_count+0x9d/0xd0 [] wb_do_writeback+0xdb/0x290 [] ? sub_preempt_count+0x9d/0xd0 [] ? _raw_spin_unlock_irqrestore+0x18/0x40 [] ? del_timer+0x8a/0x120 [] bdi_writeback_thread+0x8c/0x2e0 [] ? wb_do_writeback+0x290/0x290 [] kthread+0x96/0xa0 [] kernel_thread_helper+0x4/0x10 [] ? kthread_worker_fn+0x190/0x190 [] ? gs_change+0xb/0xb RIP [] bdev_writeseg+0x25d/0x270 [logfs] ---[ end trace 0211ad60a57657c4 ]--- Reviewed-by: Joern Engel Signed-off-by: Prasad Joshi --- fs/logfs/file.c | 2 ++ fs/logfs/inode.c | 2 ++ fs/logfs/logfs.h | 2 ++ fs/logfs/readwrite.c | 6 ++---- 4 files changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/logfs/file.c b/fs/logfs/file.c index b548c87a86f..3886cded283 100644 --- a/fs/logfs/file.c +++ b/fs/logfs/file.c @@ -230,7 +230,9 @@ int logfs_fsync(struct file *file, loff_t start, loff_t end, int datasync) return ret; mutex_lock(&inode->i_mutex); + logfs_get_wblocks(sb, NULL, WF_LOCK); logfs_write_anchor(sb); + logfs_put_wblocks(sb, NULL, WF_LOCK); mutex_unlock(&inode->i_mutex); return 0; diff --git a/fs/logfs/inode.c b/fs/logfs/inode.c index 7e441ad5f79..388d7c5a7be 100644 --- a/fs/logfs/inode.c +++ b/fs/logfs/inode.c @@ -364,7 +364,9 @@ static void logfs_init_once(void *_li) static int logfs_sync_fs(struct super_block *sb, int wait) { + logfs_get_wblocks(sb, NULL, WF_LOCK); logfs_write_anchor(sb); + logfs_put_wblocks(sb, NULL, WF_LOCK); return 0; } diff --git a/fs/logfs/logfs.h b/fs/logfs/logfs.h index 398ecff6e54..bb4340850c1 100644 --- a/fs/logfs/logfs.h +++ b/fs/logfs/logfs.h @@ -577,6 +577,8 @@ void initialize_block_counters(struct page *page, struct logfs_block *block, __be64 *array, int page_is_empty); int logfs_exist_block(struct inode *inode, u64 bix); int get_page_reserve(struct inode *inode, struct page *page); +void logfs_get_wblocks(struct super_block *sb, struct page *page, int lock); +void logfs_put_wblocks(struct super_block *sb, struct page *page, int lock); extern struct logfs_block_ops indirect_block_ops; /* segment.c */ diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c index 6d663e8ea6d..7b10e8aecce 100644 --- a/fs/logfs/readwrite.c +++ b/fs/logfs/readwrite.c @@ -244,8 +244,7 @@ static void preunlock_page(struct super_block *sb, struct page *page, int lock) * is waiting for s_write_mutex. We annotate this fact by setting PG_pre_locked * in addition to PG_locked. */ -static void logfs_get_wblocks(struct super_block *sb, struct page *page, - int lock) +void logfs_get_wblocks(struct super_block *sb, struct page *page, int lock) { struct logfs_super *super = logfs_super(sb); @@ -260,8 +259,7 @@ static void logfs_get_wblocks(struct super_block *sb, struct page *page, } } -static void logfs_put_wblocks(struct super_block *sb, struct page *page, - int lock) +void logfs_put_wblocks(struct super_block *sb, struct page *page, int lock) { struct logfs_super *super = logfs_super(sb); -- 2.11.4.GIT