| Message ID | 20181107164541.72742-1-bvanassche@acm.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs/direct-io: Avoid duplicating the check whether or not locking is required | expand |
On Wed 07-11-18 08:45:41, Bart Van Assche wrote: > Instead of repeating the check whether inode locking is required, perform > that check once and store the result in a variable. Remove the obsolete > comment that refers to direct_io_worker() since that function has been > removed. This patch does not change the behavior of the direct I/O code. > > Signed-off-by: Bart Van Assche <bvanassche@acm.org> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Jan Kara <jack@suse.cz> Looks good. You can add: Reviewed-by: Jan Kara <jack@suse.cz> BTW Jens often merges direct IO patches... Honza > --- > fs/direct-io.c | 30 +++++++++++++----------------- > 1 file changed, 13 insertions(+), 17 deletions(-) > > diff --git a/fs/direct-io.c b/fs/direct-io.c > index d4a218b45383..b5a691ba2271 100644 > --- a/fs/direct-io.c > +++ b/fs/direct-io.c > @@ -1185,6 +1185,8 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, > struct buffer_head map_bh = { 0, }; > struct blk_plug plug; > unsigned long align = offset | iov_iter_alignment(iter); > + const bool lock_inode = flags & DIO_LOCKING && > + iov_iter_rw(iter) == READ; > > /* > * Avoid references to bdev if not absolutely needed to give > @@ -1215,28 +1217,22 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, > memset(dio, 0, offsetof(struct dio, pages)); > > dio->flags = flags; > - if (dio->flags & DIO_LOCKING) { > - if (iov_iter_rw(iter) == READ) { > - struct address_space *mapping = > - iocb->ki_filp->f_mapping; > - > - /* will be released by direct_io_worker */ > - inode_lock(inode); > - > - retval = filemap_write_and_wait_range(mapping, offset, > - end - 1); > - if (retval) { > - inode_unlock(inode); > - kmem_cache_free(dio_cache, dio); > - goto out; > - } > + if (lock_inode) { > + struct address_space *mapping = iocb->ki_filp->f_mapping; > + > + inode_lock(inode); > + retval = filemap_write_and_wait_range(mapping, offset, end - 1); > + if (retval) { > + inode_unlock(inode); > + kmem_cache_free(dio_cache, dio); > + goto out; > } > } > > /* Once we sampled i_size check for reads beyond EOF */ > dio->i_size = i_size_read(inode); > if (iov_iter_rw(iter) == READ && offset >= dio->i_size) { > - if (dio->flags & DIO_LOCKING) > + if (lock_inode) > inode_unlock(inode); > kmem_cache_free(dio_cache, dio); > retval = 0; > @@ -1370,7 +1366,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, > * we can let i_mutex go now that its achieved its purpose > * of protecting us from looking up uninitialized blocks. > */ > - if (iov_iter_rw(iter) == READ && (dio->flags & DIO_LOCKING)) > + if (lock_inode) > inode_unlock(dio->inode); > > /* > -- > 2.19.1.930.g4563a0d9d0-goog >
diff --git a/fs/direct-io.c b/fs/direct-io.c index d4a218b45383..b5a691ba2271 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1185,6 +1185,8 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, struct buffer_head map_bh = { 0, }; struct blk_plug plug; unsigned long align = offset | iov_iter_alignment(iter); + const bool lock_inode = flags & DIO_LOCKING && + iov_iter_rw(iter) == READ; /* * Avoid references to bdev if not absolutely needed to give @@ -1215,28 +1217,22 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, memset(dio, 0, offsetof(struct dio, pages)); dio->flags = flags; - if (dio->flags & DIO_LOCKING) { - if (iov_iter_rw(iter) == READ) { - struct address_space *mapping = - iocb->ki_filp->f_mapping; - - /* will be released by direct_io_worker */ - inode_lock(inode); - - retval = filemap_write_and_wait_range(mapping, offset, - end - 1); - if (retval) { - inode_unlock(inode); - kmem_cache_free(dio_cache, dio); - goto out; - } + if (lock_inode) { + struct address_space *mapping = iocb->ki_filp->f_mapping; + + inode_lock(inode); + retval = filemap_write_and_wait_range(mapping, offset, end - 1); + if (retval) { + inode_unlock(inode); + kmem_cache_free(dio_cache, dio); + goto out; } } /* Once we sampled i_size check for reads beyond EOF */ dio->i_size = i_size_read(inode); if (iov_iter_rw(iter) == READ && offset >= dio->i_size) { - if (dio->flags & DIO_LOCKING) + if (lock_inode) inode_unlock(inode); kmem_cache_free(dio_cache, dio); retval = 0; @@ -1370,7 +1366,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, * we can let i_mutex go now that its achieved its purpose * of protecting us from looking up uninitialized blocks. */ - if (iov_iter_rw(iter) == READ && (dio->flags & DIO_LOCKING)) + if (lock_inode) inode_unlock(dio->inode); /*
Instead of repeating the check whether inode locking is required, perform that check once and store the result in a variable. Remove the obsolete comment that refers to direct_io_worker() since that function has been removed. This patch does not change the behavior of the direct I/O code. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> --- fs/direct-io.c | 30 +++++++++++++----------------- 1 file changed, 13 insertions(+), 17 deletions(-)