From d187663ef24cd3d033f0cbf2867e70b36a3a90b8 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Thu, 7 Jun 2012 15:45:00 -0700 Subject: fs/direct-io.c: adjust suspicious bit operation READ is 0, so the result of the bit-and operation is 0. Rewrite with == as done elsewhere in the same file. This problem was found using Coccinelle (http://coccinelle.lip6.fr/). Signed-off-by: Julia Lawall Reviewed-by: Jeff Moyer Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Al Viro --- fs/direct-io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/direct-io.c') diff --git a/fs/direct-io.c b/fs/direct-io.c index 0c85fae3766..1faf4cb56f3 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1258,7 +1258,7 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, */ BUG_ON(retval == -EIOCBQUEUED); if (dio->is_async && retval == 0 && dio->result && - ((rw & READ) || (dio->result == sdio.size))) + ((rw == READ) || (dio->result == sdio.size))) retval = -EIOCBQUEUED; if (retval != -EIOCBQUEUED) -- cgit v1.2.3 From 647d1e4c5235763b83fbfe74a09d148edc6ca152 Mon Sep 17 00:00:00 2001 From: Fengguang Wu Date: Thu, 9 Aug 2012 15:23:09 +0200 Subject: block: move down direct IO plugging Move unplugging for direct I/O from around ->direct_IO() down to do_blockdev_direct_IO(). This implicitly adds plugging for direct writes. CC: Li Shaohua Acked-by: Jeff Moyer Signed-off-by: Wu Fengguang Signed-off-by: Jens Axboe --- fs/direct-io.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/direct-io.c') diff --git a/fs/direct-io.c b/fs/direct-io.c index 1faf4cb56f3..f86c720dba0 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1062,6 +1062,7 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, unsigned long user_addr; size_t bytes; struct buffer_head map_bh = { 0, }; + struct blk_plug plug; if (rw & WRITE) rw = WRITE_ODIRECT; @@ -1177,6 +1178,8 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, PAGE_SIZE - user_addr / PAGE_SIZE); } + blk_start_plug(&plug); + for (seg = 0; seg < nr_segs; seg++) { user_addr = (unsigned long)iov[seg].iov_base; sdio.size += bytes = iov[seg].iov_len; @@ -1235,6 +1238,8 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, if (sdio.bio) dio_bio_submit(dio, &sdio); + blk_finish_plug(&plug); + /* * It is possible that, we return short IO due to end of file. * In that case, we need to release all the pages we got hold on. -- cgit v1.2.3 From ab73857e354ab9e317613cba7db714e2c12c6547 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 29 Nov 2012 12:27:00 -0800 Subject: direct-io: don't read inode->i_blkbits multiple times Since directio can work on a raw block device, and the block size of the device can change under it, we need to do the same thing that fs/buffer.c now does: read the block size a single time, using ACCESS_ONCE(). Reading it multiple times can get different results, which will then confuse the code because it actually encodes the i_blksize in relationship to the underlying logical blocksize. Signed-off-by: Linus Torvalds --- fs/direct-io.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'fs/direct-io.c') diff --git a/fs/direct-io.c b/fs/direct-io.c index f86c720dba0..cf5b44b10c6 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -540,6 +540,7 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio, sector_t fs_endblk; /* Into file, in filesystem-sized blocks */ unsigned long fs_count; /* Number of filesystem-sized blocks */ int create; + unsigned int i_blkbits = sdio->blkbits + sdio->blkfactor; /* * If there was a memory error and we've overwritten all the @@ -554,7 +555,7 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio, fs_count = fs_endblk - fs_startblk + 1; map_bh->b_state = 0; - map_bh->b_size = fs_count << dio->inode->i_blkbits; + map_bh->b_size = fs_count << i_blkbits; /* * For writes inside i_size on a DIO_SKIP_HOLES filesystem we @@ -1053,7 +1054,8 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, int seg; size_t size; unsigned long addr; - unsigned blkbits = inode->i_blkbits; + unsigned i_blkbits = ACCESS_ONCE(inode->i_blkbits); + unsigned blkbits = i_blkbits; unsigned blocksize_mask = (1 << blkbits) - 1; ssize_t retval = -EINVAL; loff_t end = offset; @@ -1149,7 +1151,7 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, dio->inode = inode; dio->rw = rw; sdio.blkbits = blkbits; - sdio.blkfactor = inode->i_blkbits - blkbits; + sdio.blkfactor = i_blkbits - blkbits; sdio.block_in_file = offset >> blkbits; sdio.get_block = get_block; -- cgit v1.2.3