From: Christoph Hellwig Subject: [PATCH 1/6] fs: factor out a __generic_write_end helper Date: Tue, 19 Jun 2018 18:41:31 +0200 Message-ID: <20180619164137.13720-2-hch@lst.de> References: <20180619164137.13720-1-hch@lst.de> Cc: linux-fsdevel@vger.kernel.org, cluster-devel@redhat.com, Dan Williams , linux-ext4@vger.kernel.org To: Andreas Gruenbacher , linux-xfs@vger.kernel.org Return-path: In-Reply-To: <20180619164137.13720-1-hch@lst.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: cluster-devel-bounces@redhat.com Errors-To: cluster-devel-bounces@redhat.com List-Id: linux-ext4.vger.kernel.org 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 Reviewed-by: Andreas Gruenbacher Reviewed-by: Darrick J. Wong --- 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 cabc045f483d..aba2a948b235 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 980d005b21b4..4a18bdbd2214 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 -- 2.17.1