block: export 'ro' sysfs attribute for partitions

[pandora-kernel.git] / fs / buffer.c

diff --git a/fs/buffer.c b/fs/buffer.c
index 50efa33..3e7dca2 100644 (file)
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -770,11 +770,12 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
                                spin_unlock(lock);
                                /*
                                 * Ensure any pending I/O completes so that
-                                * ll_rw_block() actually writes the current
-                                * contents - it is a noop if I/O is still in
-                                * flight on potentially older contents.
+                                * write_dirty_buffer() actually writes the
+                                * current contents - it is a noop if I/O is
+                                * still in flight on potentially older
+                                * contents.
                                 */
-                               ll_rw_block(SWRITE_SYNC_PLUG, 1, &bh);
+                               write_dirty_buffer(bh, WRITE_SYNC_PLUG);
 
                                /*
                                 * Kick off IO for the previous mapping. Note
@@ -2911,13 +2912,6 @@ int submit_bh(int rw, struct buffer_head * bh)
        BUG_ON(buffer_delay(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
         */
@@ -2956,22 +2950,21 @@ EXPORT_SYMBOL(submit_bh);
 
 /**
  * ll_rw_block: low-level access to block devices (DEPRECATED)
- * @rw: whether to %READ or %WRITE or %SWRITE or maybe %READA (readahead)
+ * @rw: whether to %READ or %WRITE or maybe %READA (readahead)
  * @nr: number of &struct buffer_heads in the array
  * @bhs: array of pointers to &struct buffer_head
  *
  * ll_rw_block() takes an array of pointers to &struct buffer_heads, and
  * requests an I/O operation on them, either a %READ or a %WRITE.  The third
- * %SWRITE is like %WRITE only we make sure that the *current* data in buffers
- * are sent to disk. The fourth %READA option is described in the documentation
- * for generic_make_request() which ll_rw_block() calls.
+ * %READA option is described in the documentation for generic_make_request()
+ * which ll_rw_block() calls.
  *
  * This function drops any buffer that it cannot get a lock on (with the
- * BH_Lock state bit) unless SWRITE is required, any buffer that appears to be
- * clean when doing a write request, and any buffer that appears to be
- * up-to-date when doing read request.  Further it marks as clean buffers that
- * are processed for writing (the buffer cache won't assume that they are
- * actually clean until the buffer gets unlocked).
+ * BH_Lock state bit), any buffer that appears to be clean when doing a write
+ * request, and any buffer that appears to be up-to-date when doing read
+ * request.  Further it marks as clean buffers that are processed for
+ * writing (the buffer cache won't assume that they are actually clean
+ * until the buffer gets unlocked).
  *
  * ll_rw_block sets b_end_io to simple completion handler that marks
  * the buffer up-to-date (if approriate), unlocks the buffer and wakes
@@ -2987,20 +2980,13 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
        for (i = 0; i < nr; i++) {
                struct buffer_head *bh = bhs[i];
 
-               if (rw == SWRITE || rw == SWRITE_SYNC || rw == SWRITE_SYNC_PLUG)
-                       lock_buffer(bh);
-               else if (!trylock_buffer(bh))
+               if (!trylock_buffer(bh))
                        continue;
-
-               if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC ||
-                   rw == SWRITE_SYNC_PLUG) {
+               if (rw == WRITE) {
                        if (test_clear_buffer_dirty(bh)) {
                                bh->b_end_io = end_buffer_write_sync;
                                get_bh(bh);
-                               if (rw == SWRITE_SYNC)
-                                       submit_bh(WRITE_SYNC, bh);
-                               else
-                                       submit_bh(WRITE, bh);
+                               submit_bh(WRITE, bh);
                                continue;
                        }
                } else {
@@ -3016,12 +3002,25 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
 }
 EXPORT_SYMBOL(ll_rw_block);
 
+void write_dirty_buffer(struct buffer_head *bh, int rw)
+{
+       lock_buffer(bh);
+       if (!test_clear_buffer_dirty(bh)) {
+               unlock_buffer(bh);
+               return;
+       }
+       bh->b_end_io = end_buffer_write_sync;
+       get_bh(bh);
+       submit_bh(rw, bh);
+}
+EXPORT_SYMBOL(write_dirty_buffer);
+
 /*
  * For a data-integrity writeout, we need to wait upon any in-progress I/O
  * 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 +3029,7 @@ 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 +3042,12 @@ 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);
 
 /*