Merge branch 'block-dev'

Merge 'block-dev' branch.

I was going to just mark everything here for stable and leave it to the
3.8 merge window, but having decided on doing another -rc, I migth as
well merge it now.

This removes the bd_block_size_semaphore semaphore that was added in
this release to fix a race condition between block size changes and
block IO, and replaces it with atomicity guaratees in fs/buffer.c
instead, along with simplifying fs/block-dev.c.

This removes more lines than it adds, makes the code generally simpler,
and avoids the latency/rt issues that the block size semaphore
introduced for mount.

I'm not happy with the timing, but it wouldn't be much better doing this
during the merge window and then having some delayed back-port of it
into stable.

* block-dev:
  blkdev_max_block: make private to fs/buffer.c
  direct-io: don't read inode->i_blkbits multiple times
  blockdev: remove bd_block_size_semaphore again
  fs/buffer.c: make block-size be per-page and protected by the page lock

1 files changed, 0 insertions, 5 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index b33cfc97b9c..75fe9a13480 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -462,8 +462,6 @@ struct block_device {
         int                     bd_fsfreeze_count;
         /* Mutex for freeze */
         struct mutex            bd_fsfreeze_mutex;
-        /* A semaphore that prevents I/O while block size is being changed */
-        struct percpu_rw_semaphore      bd_block_size_semaphore;
 };
 
 /*
@@ -2049,7 +2047,6 @@ extern void unregister_blkdev(unsigned int, const char *);
 extern struct block_device *bdget(dev_t);
 extern struct block_device *bdgrab(struct block_device *bdev);
 extern void bd_set_size(struct block_device *, loff_t size);
-extern sector_t blkdev_max_block(struct block_device *bdev);
 extern void bd_forget(struct inode *inode);
 extern void bdput(struct block_device *);
 extern void invalidate_bdev(struct block_device *);
@@ -2379,8 +2376,6 @@ extern int generic_segment_checks(const struct iovec *iov,
                 unsigned long *nr_segs, size_t *count, int access_flags);
 
 /* fs/block_dev.c */
-extern ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov,
-                               unsigned long nr_segs, loff_t pos);
 extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
                                 unsigned long nr_segs, loff_t pos);
 extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,