Instead of abusing a buffer_head flag just add a variant of sync_dirty_buffer which allos passing the exact type of write flag required. Signed-off-by: Christoph Hellwig <hch@xxxxxx> Index: linux-2.6/fs/buffer.c =================================================================== --- linux-2.6.orig/fs/buffer.c 2010-06-18 11:09:05.778254171 +0200 +++ linux-2.6/fs/buffer.c 2010-06-18 11:10:12.421004275 +0200 @@ -3020,13 +3020,6 @@ int submit_bh(int rw, struct buffer_head BUG_ON(buffer_unwritten(bh)); /* - * Mask in barrier bit for a write (could be either a WRITE or a - * WRITE_SYNC - */ - if (buffer_ordered(bh) && (rw & WRITE)) - rw |= WRITE_BARRIER; - - /* * Only clear out a write error when rewriting */ if (test_set_buffer_req(bh) && (rw & WRITE)) @@ -3129,7 +3122,7 @@ EXPORT_SYMBOL(ll_rw_block); * and then start new I/O and then wait upon it. The caller must have a ref on * the buffer_head. */ -int sync_dirty_buffer(struct buffer_head *bh) +int __sync_dirty_buffer(struct buffer_head *bh, int rw) { int ret = 0; @@ -3138,7 +3131,7 @@ int sync_dirty_buffer(struct buffer_head if (test_clear_buffer_dirty(bh)) { get_bh(bh); bh->b_end_io = end_buffer_write_sync; - ret = submit_bh(WRITE_SYNC, bh); + ret = submit_bh(rw, bh); wait_on_buffer(bh); if (buffer_eopnotsupp(bh)) { clear_buffer_eopnotsupp(bh); @@ -3151,6 +3144,12 @@ int sync_dirty_buffer(struct buffer_head } return ret; } +EXPORT_SYMBOL(__sync_dirty_buffer); + +int sync_dirty_buffer(struct buffer_head *bh) +{ + return __sync_dirty_buffer(bh, WRITE_SYNC); +} EXPORT_SYMBOL(sync_dirty_buffer); /* Index: linux-2.6/include/linux/buffer_head.h =================================================================== --- linux-2.6.orig/include/linux/buffer_head.h 2010-06-18 11:09:05.825254171 +0200 +++ linux-2.6/include/linux/buffer_head.h 2010-06-18 11:10:12.421004275 +0200 @@ -32,7 +32,6 @@ enum bh_state_bits { BH_Delay, /* Buffer is not yet allocated on disk */ BH_Boundary, /* Block is followed by a discontiguity */ BH_Write_EIO, /* I/O error on write */ - BH_Ordered, /* ordered write */ BH_Eopnotsupp, /* operation not supported (barrier) */ BH_Unwritten, /* Buffer is allocated on disk but not written */ BH_Quiet, /* Buffer Error Prinks to be quiet */ @@ -125,7 +124,6 @@ BUFFER_FNS(Async_Write, async_write) BUFFER_FNS(Delay, delay) BUFFER_FNS(Boundary, boundary) BUFFER_FNS(Write_EIO, write_io_error) -BUFFER_FNS(Ordered, ordered) BUFFER_FNS(Eopnotsupp, eopnotsupp) BUFFER_FNS(Unwritten, unwritten) @@ -183,6 +181,7 @@ void unlock_buffer(struct buffer_head *b void __lock_buffer(struct buffer_head *bh); void ll_rw_block(int, int, struct buffer_head * bh[]); int sync_dirty_buffer(struct buffer_head *bh); +int __sync_dirty_buffer(struct buffer_head *bh, int rw); int submit_bh(int, struct buffer_head *); void write_boundary_block(struct block_device *bdev, sector_t bblock, unsigned blocksize); Index: linux-2.6/fs/jbd/commit.c =================================================================== --- linux-2.6.orig/fs/jbd/commit.c 2010-06-18 11:09:05.785254310 +0200 +++ linux-2.6/fs/jbd/commit.c 2010-06-18 11:10:12.426004206 +0200 @@ -119,7 +119,6 @@ static int journal_write_commit_record(j struct buffer_head *bh; journal_header_t *header; int ret; - int barrier_done = 0; if (is_journal_aborted(journal)) return 0; @@ -137,34 +136,36 @@ static int journal_write_commit_record(j JBUFFER_TRACE(descriptor, "write commit block"); set_buffer_dirty(bh); + if (journal->j_flags & JFS_BARRIER) { - set_buffer_ordered(bh); - barrier_done = 1; - } - ret = sync_dirty_buffer(bh); - if (barrier_done) - clear_buffer_ordered(bh); - /* is it possible for another commit to fail at roughly - * the same time as this one? If so, we don't want to - * trust the barrier flag in the super, but instead want - * to remember if we sent a barrier request - */ - if (ret == -EOPNOTSUPP && barrier_done) { - char b[BDEVNAME_SIZE]; - - printk(KERN_WARNING - "JBD: barrier-based sync failed on %s - " - "disabling barriers\n", - bdevname(journal->j_dev, b)); - spin_lock(&journal->j_state_lock); - journal->j_flags &= ~JFS_BARRIER; - spin_unlock(&journal->j_state_lock); - - /* And try again, without the barrier */ - set_buffer_uptodate(bh); - set_buffer_dirty(bh); + ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_BARRIER); + + /* + * Is it possible for another commit to fail at roughly + * the same time as this one? If so, we don't want to + * trust the barrier flag in the super, but instead want + * to remember if we sent a barrier request + */ + if (ret == -EOPNOTSUPP) { + char b[BDEVNAME_SIZE]; + + printk(KERN_WARNING + "JBD: barrier-based sync failed on %s - " + "disabling barriers\n", + bdevname(journal->j_dev, b)); + spin_lock(&journal->j_state_lock); + journal->j_flags &= ~JFS_BARRIER; + spin_unlock(&journal->j_state_lock); + + /* And try again, without the barrier */ + set_buffer_uptodate(bh); + set_buffer_dirty(bh); + ret = sync_dirty_buffer(bh); + } + } else { ret = sync_dirty_buffer(bh); } + put_bh(bh); /* One for getblk() */ journal_put_journal_head(descriptor); Index: linux-2.6/fs/jbd2/commit.c =================================================================== --- linux-2.6.orig/fs/jbd2/commit.c 2010-06-18 11:09:05.800254101 +0200 +++ linux-2.6/fs/jbd2/commit.c 2010-06-18 11:10:12.430004206 +0200 @@ -101,7 +101,6 @@ static int journal_submit_commit_record( struct commit_header *tmp; struct buffer_head *bh; int ret; - int barrier_done = 0; struct timespec now = current_kernel_time(); if (is_journal_aborted(journal)) @@ -136,32 +135,32 @@ static int journal_submit_commit_record( if (journal->j_flags & JBD2_BARRIER && !JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) { - set_buffer_ordered(bh); - barrier_done = 1; - } - ret = submit_bh(WRITE_SYNC_PLUG, bh); - if (barrier_done) - clear_buffer_ordered(bh); - - /* is it possible for another commit to fail at roughly - * the same time as this one? If so, we don't want to - * trust the barrier flag in the super, but instead want - * to remember if we sent a barrier request - */ - if (ret == -EOPNOTSUPP && barrier_done) { - printk(KERN_WARNING - "JBD: barrier-based sync failed on %s - " - "disabling barriers\n", journal->j_devname); - spin_lock(&journal->j_state_lock); - journal->j_flags &= ~JBD2_BARRIER; - spin_unlock(&journal->j_state_lock); - - /* And try again, without the barrier */ - lock_buffer(bh); - set_buffer_uptodate(bh); - clear_buffer_dirty(bh); + ret = submit_bh(WRITE_SYNC_PLUG | WRITE_BARRIER, bh); + + /* + * Is it possible for another commit to fail at roughly + * the same time as this one? If so, we don't want to + * trust the barrier flag in the super, but instead want + * to remember if we sent a barrier request + */ + if (ret == -EOPNOTSUPP) { + printk(KERN_WARNING + "JBD: barrier-based sync failed on %s - " + "disabling barriers\n", journal->j_devname); + spin_lock(&journal->j_state_lock); + journal->j_flags &= ~JBD2_BARRIER; + spin_unlock(&journal->j_state_lock); + + /* And try again, without the barrier */ + lock_buffer(bh); + set_buffer_uptodate(bh); + clear_buffer_dirty(bh); + ret = submit_bh(WRITE_SYNC_PLUG, bh); + } + } else { ret = submit_bh(WRITE_SYNC_PLUG, bh); } + *cbh = bh; return ret; } Index: linux-2.6/fs/nilfs2/super.c =================================================================== --- linux-2.6.orig/fs/nilfs2/super.c 2010-06-18 11:09:05.810254310 +0200 +++ linux-2.6/fs/nilfs2/super.c 2010-06-18 11:10:12.434003717 +0200 @@ -180,24 +180,24 @@ static int nilfs_sync_super(struct nilfs { struct the_nilfs *nilfs = sbi->s_nilfs; int err; - int barrier_done = 0; - if (nilfs_test_opt(sbi, BARRIER)) { - set_buffer_ordered(nilfs->ns_sbh[0]); - barrier_done = 1; - } retry: set_buffer_dirty(nilfs->ns_sbh[0]); - err = sync_dirty_buffer(nilfs->ns_sbh[0]); - if (err == -EOPNOTSUPP && barrier_done) { - nilfs_warning(sbi->s_super, __func__, - "barrier-based sync failed. " - "disabling barriers\n"); - nilfs_clear_opt(sbi, BARRIER); - barrier_done = 0; - clear_buffer_ordered(nilfs->ns_sbh[0]); - goto retry; + + if (nilfs_test_opt(sbi, BARRIER)) { + err = __sync_dirty_buffer(nilfs->ns_sbh[0], + WRITE_SYNC | WRITE_BARRIER); + if (err == -EOPNOTSUPP) { + nilfs_warning(sbi->s_super, __func__, + "barrier-based sync failed. " + "disabling barriers\n"); + nilfs_clear_opt(sbi, BARRIER); + goto retry; + } + } else { + err = sync_dirty_buffer(nilfs->ns_sbh[0]); } + if (unlikely(err)) { printk(KERN_ERR "NILFS: unable to write superblock (err=%d)\n", err); -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html