From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 30 May 2018 09:34:49 -0400 From: Brian Foster To: Christoph Hellwig Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 01/18] fs: factor out a __generic_write_end helper Message-ID: <20180530133448.GA112411@bfoster.bfoster> References: <20180530100013.31358-1-hch@lst.de> <20180530100013.31358-2-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180530100013.31358-2-hch@lst.de> Sender: owner-linux-mm@kvack.org List-ID: On Wed, May 30, 2018 at 11:59:56AM +0200, Christoph Hellwig wrote: > Bits of the buffer.c based write_end implementations that don't know > about buffer_heads and can be reused by other implementations. > > Signed-off-by: Christoph Hellwig > --- Reviewed-by: Brian Foster > fs/buffer.c | 67 +++++++++++++++++++++++++++------------------------ > fs/internal.h | 2 ++ > 2 files changed, 37 insertions(+), 32 deletions(-) > > diff --git a/fs/buffer.c b/fs/buffer.c > index 249b83fafe48..bd964b2ad99a 100644 > --- a/fs/buffer.c > +++ b/fs/buffer.c > @@ -2076,6 +2076,40 @@ int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len, > } > EXPORT_SYMBOL(block_write_begin); > > +int __generic_write_end(struct inode *inode, loff_t pos, unsigned copied, > + struct page *page) > +{ > + loff_t old_size = inode->i_size; > + bool i_size_changed = false; > + > + /* > + * No need to use i_size_read() here, the i_size cannot change under us > + * because we hold i_rwsem. > + * > + * But it's important to update i_size while still holding page lock: > + * page writeout could otherwise come in and zero beyond i_size. > + */ > + if (pos + copied > inode->i_size) { > + i_size_write(inode, pos + copied); > + i_size_changed = true; > + } > + > + unlock_page(page); > + put_page(page); > + > + if (old_size < pos) > + pagecache_isize_extended(inode, old_size, pos); > + /* > + * Don't mark the inode dirty under page lock. First, it unnecessarily > + * makes the holding time of page lock longer. Second, it forces lock > + * ordering of page lock and transaction start for journaling > + * filesystems. > + */ > + if (i_size_changed) > + mark_inode_dirty(inode); > + return copied; > +} > + > int block_write_end(struct file *file, struct address_space *mapping, > loff_t pos, unsigned len, unsigned copied, > struct page *page, void *fsdata) > @@ -2116,39 +2150,8 @@ int generic_write_end(struct file *file, struct address_space *mapping, > loff_t pos, unsigned len, unsigned copied, > struct page *page, void *fsdata) > { > - struct inode *inode = mapping->host; > - loff_t old_size = inode->i_size; > - int i_size_changed = 0; > - > copied = block_write_end(file, mapping, pos, len, copied, page, fsdata); > - > - /* > - * No need to use i_size_read() here, the i_size > - * cannot change under us because we hold i_mutex. > - * > - * But it's important to update i_size while still holding page lock: > - * page writeout could otherwise come in and zero beyond i_size. > - */ > - if (pos+copied > inode->i_size) { > - i_size_write(inode, pos+copied); > - i_size_changed = 1; > - } > - > - unlock_page(page); > - put_page(page); > - > - if (old_size < pos) > - pagecache_isize_extended(inode, old_size, pos); > - /* > - * Don't mark the inode dirty under page lock. First, it unnecessarily > - * makes the holding time of page lock longer. Second, it forces lock > - * ordering of page lock and transaction start for journaling > - * filesystems. > - */ > - if (i_size_changed) > - mark_inode_dirty(inode); > - > - return copied; > + return __generic_write_end(mapping->host, pos, copied, page); > } > EXPORT_SYMBOL(generic_write_end); > > diff --git a/fs/internal.h b/fs/internal.h > index e08972db0303..b955232d3d49 100644 > --- a/fs/internal.h > +++ b/fs/internal.h > @@ -43,6 +43,8 @@ static inline int __sync_blockdev(struct block_device *bdev, int wait) > extern void guard_bio_eod(int rw, struct bio *bio); > extern int __block_write_begin_int(struct page *page, loff_t pos, unsigned len, > get_block_t *get_block, struct iomap *iomap); > +int __generic_write_end(struct inode *inode, loff_t pos, unsigned copied, > + struct page *page); > > /* > * char_dev.c > -- > 2.17.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html