Merge branch 'core/urgent' into core/futexes

Merge reason: this branch was on an pre -rc1 base, merge it up to -rc6+
              to get the latest upstream fixes.

Conflicts:
	kernel/futex.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 78 insertions, 23 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 5d55a896ff78..aed297739eb0 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -360,7 +360,7 @@ still_busy:
  * Completion handler for block_write_full_page() - pages which are unlocked
  * during I/O, and which have PageWriteback cleared upon I/O completion.
  */
-static void end_buffer_async_write(struct buffer_head *bh, int uptodate)
+void end_buffer_async_write(struct buffer_head *bh, int uptodate)
 {
         char b[BDEVNAME_SIZE];
         unsigned long flags;
@@ -438,11 +438,17 @@ static void mark_buffer_async_read(struct buffer_head *bh)
         set_buffer_async_read(bh);
 }
 
-void mark_buffer_async_write(struct buffer_head *bh)
+void mark_buffer_async_write_endio(struct buffer_head *bh,
+                                   bh_end_io_t *handler)
 {
-        bh->b_end_io = end_buffer_async_write;
+        bh->b_end_io = handler;
         set_buffer_async_write(bh);
 }
+
+void mark_buffer_async_write(struct buffer_head *bh)
+{
+        mark_buffer_async_write_endio(bh, end_buffer_async_write);
+}
 EXPORT_SYMBOL(mark_buffer_async_write);
 
 
@@ -547,7 +553,7 @@ repeat:
         return err;
 }
 
-void do_thaw_all(unsigned long unused)
+void do_thaw_all(struct work_struct *work)
 {
         struct super_block *sb;
         char b[BDEVNAME_SIZE];
@@ -567,6 +573,7 @@ restart:
                         goto restart;
         }
         spin_unlock(&sb_lock);
+        kfree(work);
         printk(KERN_WARNING "Emergency Thaw complete\n");
 }
 
@@ -577,7 +584,13 @@ restart:
  */
 void emergency_thaw_all(void)
 {
-        pdflush_operation(do_thaw_all, 0);
+        struct work_struct *work;
+
+        work = kmalloc(sizeof(*work), GFP_ATOMIC);
+        if (work) {
+                INIT_WORK(work, do_thaw_all);
+                schedule_work(work);
+        }
 }
 
 /**
@@ -737,7 +750,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
 {
         struct buffer_head *bh;
         struct list_head tmp;
-        struct address_space *mapping;
+        struct address_space *mapping, *prev_mapping = NULL;
         int err = 0, err2;
 
         INIT_LIST_HEAD(&tmp);
@@ -762,7 +775,18 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
                                  * contents - it is a noop if I/O is still in
                                  * flight on potentially older contents.
                                  */
-                                ll_rw_block(SWRITE_SYNC, 1, &bh);
+                                ll_rw_block(SWRITE_SYNC_PLUG, 1, &bh);
+
+                                /*
+                                 * Kick off IO for the previous mapping. Note
+                                 * that we will not run the very last mapping,
+                                 * wait_on_buffer() will do that for us
+                                 * through sync_buffer().
+                                 */
+                                if (prev_mapping && prev_mapping != mapping)
+                                        blk_run_address_space(prev_mapping);
+                                prev_mapping = mapping;
+
                                 brelse(bh);
                                 spin_lock(lock);
                         }
@@ -1585,9 +1609,20 @@ EXPORT_SYMBOL(unmap_underlying_metadata);
  * locked buffer.   This only can happen if someone has written the buffer
  * directly, with submit_bh().  At the address_space level PageWriteback
  * prevents this contention from occurring.
+ *
+ * If block_write_full_page() is called with wbc->sync_mode ==
+ * WB_SYNC_ALL, the writes are posted using WRITE_SYNC_PLUG; this
+ * causes the writes to be flagged as synchronous writes, but the
+ * block device queue will NOT be unplugged, since usually many pages
+ * will be pushed to the out before the higher-level caller actually
+ * waits for the writes to be completed.  The various wait functions,
+ * such as wait_on_writeback_range() will ultimately call sync_page()
+ * which will ultimately call blk_run_backing_dev(), which will end up
+ * unplugging the device queue.
  */
 static int __block_write_full_page(struct inode *inode, struct page *page,
-                        get_block_t *get_block, struct writeback_control *wbc)
+                        get_block_t *get_block, struct writeback_control *wbc,
+                        bh_end_io_t *handler)
 {
         int err;
         sector_t block;
@@ -1595,7 +1630,8 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
         struct buffer_head *bh, *head;
         const unsigned blocksize = 1 << inode->i_blkbits;
         int nr_underway = 0;
-        int write_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE);
+        int write_op = (wbc->sync_mode == WB_SYNC_ALL ?
+                        WRITE_SYNC_PLUG : WRITE);
 
         BUG_ON(!PageLocked(page));
 
@@ -1671,7 +1707,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
                         continue;
                 }
                 if (test_clear_buffer_dirty(bh)) {
-                        mark_buffer_async_write(bh);
+                        mark_buffer_async_write_endio(bh, handler);
                 } else {
                         unlock_buffer(bh);
                 }
@@ -1724,7 +1760,7 @@ recover:
                 if (buffer_mapped(bh) && buffer_dirty(bh) &&
                     !buffer_delay(bh)) {
                         lock_buffer(bh);
-                        mark_buffer_async_write(bh);
+                        mark_buffer_async_write_endio(bh, handler);
                 } else {
                         /*
                          * The buffer may have been set dirty during
@@ -2361,7 +2397,8 @@ block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
         if ((page->mapping != inode->i_mapping) ||
             (page_offset(page) > size)) {
                 /* page got truncated out from underneath us */
-                goto out_unlock;
+                unlock_page(page);
+                goto out;
         }
 
         /* page is wholly or partially inside EOF */
@@ -2375,14 +2412,15 @@ block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
                 ret = block_commit_write(page, 0, end);
 
         if (unlikely(ret)) {
+                unlock_page(page);
                 if (ret == -ENOMEM)
                         ret = VM_FAULT_OOM;
                 else /* -ENOSPC, -EIO, etc */
                         ret = VM_FAULT_SIGBUS;
-        }
+        } else
+                ret = VM_FAULT_LOCKED;
 
-out_unlock:
-        unlock_page(page);
+out:
         return ret;
 }
 
@@ -2650,7 +2688,8 @@ int nobh_writepage(struct page *page, get_block_t *get_block,
 out:
         ret = mpage_writepage(page, get_block, wbc);
         if (ret == -EAGAIN)
-                ret = __block_write_full_page(inode, page, get_block, wbc);
+                ret = __block_write_full_page(inode, page, get_block, wbc,
+                                              end_buffer_async_write);
         return ret;
 }
 EXPORT_SYMBOL(nobh_writepage);
@@ -2808,9 +2847,10 @@ out:
 
 /*
  * The generic ->writepage function for buffer-backed address_spaces
+ * this form passes in the end_io handler used to finish the IO.
  */
-int block_write_full_page(struct page *page, get_block_t *get_block,
-                        struct writeback_control *wbc)
+int block_write_full_page_endio(struct page *page, get_block_t *get_block,
+                        struct writeback_control *wbc, bh_end_io_t *handler)
 {
         struct inode * const inode = page->mapping->host;
         loff_t i_size = i_size_read(inode);
@@ -2819,7 +2859,8 @@ int block_write_full_page(struct page *page, get_block_t *get_block,
 
         /* Is the page fully inside i_size? */
         if (page->index < end_index)
-                return __block_write_full_page(inode, page, get_block, wbc);
+                return __block_write_full_page(inode, page, get_block, wbc,
+                                               handler);
 
         /* Is the page fully outside i_size? (truncate in progress) */
         offset = i_size & (PAGE_CACHE_SIZE-1);
@@ -2842,9 +2883,20 @@ int block_write_full_page(struct page *page, get_block_t *get_block,
          * writes to that region are not written out to the file."
          */
         zero_user_segment(page, offset, PAGE_CACHE_SIZE);
-        return __block_write_full_page(inode, page, get_block, wbc);
+        return __block_write_full_page(inode, page, get_block, wbc, handler);
 }
 
+/*
+ * The generic ->writepage function for buffer-backed address_spaces
+ */
+int block_write_full_page(struct page *page, get_block_t *get_block,
+                        struct writeback_control *wbc)
+{
+        return block_write_full_page_endio(page, get_block, wbc,
+                                           end_buffer_async_write);
+}
+
+
 sector_t generic_block_bmap(struct address_space *mapping, sector_t block,
                             get_block_t *get_block)
 {
@@ -2957,12 +3009,13 @@ 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)
+                if (rw == SWRITE || rw == SWRITE_SYNC || rw == SWRITE_SYNC_PLUG)
                         lock_buffer(bh);
                 else if (!trylock_buffer(bh))
                         continue;
 
-                if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC) {
+                if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC ||
+                    rw == SWRITE_SYNC_PLUG) {
                         if (test_clear_buffer_dirty(bh)) {
                                 bh->b_end_io = end_buffer_write_sync;
                                 get_bh(bh);
@@ -2998,7 +3051,7 @@ 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, bh);
+                ret = submit_bh(WRITE_SYNC, bh);
                 wait_on_buffer(bh);
                 if (buffer_eopnotsupp(bh)) {
                         clear_buffer_eopnotsupp(bh);
@@ -3312,9 +3365,11 @@ EXPORT_SYMBOL(block_read_full_page);
 EXPORT_SYMBOL(block_sync_page);
 EXPORT_SYMBOL(block_truncate_page);
 EXPORT_SYMBOL(block_write_full_page);
+EXPORT_SYMBOL(block_write_full_page_endio);
 EXPORT_SYMBOL(cont_write_begin);
 EXPORT_SYMBOL(end_buffer_read_sync);
 EXPORT_SYMBOL(end_buffer_write_sync);
+EXPORT_SYMBOL(end_buffer_async_write);
 EXPORT_SYMBOL(file_fsync);
 EXPORT_SYMBOL(generic_block_bmap);
 EXPORT_SYMBOL(generic_cont_expand_simple);