kill BH_Ordered flag
Christoph Hellwig [Wed, 11 Aug 2010 15:05:45 +0000 (17:05 +0200)]
Instead of abusing a buffer_head flag just add a variant of
sync_dirty_buffer which allows passing the exact type of write
flag required.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/buffer.c
fs/jbd/commit.c
fs/jbd2/commit.c
fs/nilfs2/super.c
include/linux/buffer_head.h

index 50efa33..6c8ad97 100644 (file)
@@ -2912,13 +2912,6 @@ int submit_bh(int rw, struct buffer_head * bh)
        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))
@@ -3021,7 +3014,7 @@ 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;
 
@@ -3030,7 +3023,7 @@ int sync_dirty_buffer(struct buffer_head *bh)
        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);
@@ -3043,6 +3036,12 @@ int sync_dirty_buffer(struct buffer_head *bh)
        }
        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 28a9dda..95d8c11 100644 (file)
@@ -119,7 +119,6 @@ static int journal_write_commit_record(journal_t *journal,
        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(journal_t *journal,
 
        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];
+               ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_BARRIER);
 
-               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);
+               /*
+                * 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];
 
-               /* And try again, without the barrier */
-               set_buffer_uptodate(bh);
-               set_buffer_dirty(bh);
+                       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 f52e5e8..7c068c1 100644 (file)
@@ -101,7 +101,6 @@ static int journal_submit_commit_record(journal_t *journal,
        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))
@@ -136,30 +135,22 @@ static int journal_submit_commit_record(journal_t *journal,
        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
-                      "JBD2: Disabling barriers on %s, "
-                      "not supported by device\n", journal->j_devname);
-               write_lock(&journal->j_state_lock);
-               journal->j_flags &= ~JBD2_BARRIER;
-               write_unlock(&journal->j_state_lock);
+               ret = submit_bh(WRITE_SYNC_PLUG | WRITE_BARRIER, bh);
+               if (ret == -EOPNOTSUPP) {
+                       printk(KERN_WARNING
+                              "JBD2: Disabling barriers on %s, "
+                              "not supported by device\n", journal->j_devname);
+                       write_lock(&journal->j_state_lock);
+                       journal->j_flags &= ~JBD2_BARRIER;
+                       write_unlock(&journal->j_state_lock);
 
-               /* And try again, without the barrier */
-               lock_buffer(bh);
-               set_buffer_uptodate(bh);
-               clear_buffer_dirty(bh);
+                       /* 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;
index 1fa86b9..6834543 100644 (file)
@@ -175,24 +175,24 @@ static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
 {
        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);
index 43e649a..72c1cf8 100644 (file)
@@ -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 *bh);
 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);