From 8d3e72a180b42c01ec00045e1bb8eb91175adafe Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Thu, 27 Jun 2019 17:28:40 -0700 Subject: [PATCH] iomap: don't mark the inode dirty in iomap_write_end Marking the inode dirty for each page copied into the page cache can be very inefficient for file systems that use the VFS dirty inode tracking, and is completely pointless for those that don't use the VFS dirty inode tracking. So instead, only set an iomap flag when changing the in-core inode size, and open code the rest of __generic_write_end. Partially based on code from Christoph Hellwig. Signed-off-by: Andreas Gruenbacher Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/gfs2/bmap.c | 2 ++ fs/iomap.c | 15 ++++++++++++++- include/linux/iomap.h | 1 + 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index c78ccaf83ef8..8e8768685264 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -1179,6 +1179,8 @@ static int gfs2_iomap_end(struct inode *inode, loff_t pos, loff_t length, if (ip->i_qadata && ip->i_qadata->qa_qd_num) gfs2_quota_unlock(ip); + if (iomap->flags & IOMAP_F_SIZE_CHANGED) + mark_inode_dirty(inode); gfs2_write_unlock(inode); out: diff --git a/fs/iomap.c b/fs/iomap.c index 23ef63fd1669..c4acf69b7196 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -773,6 +773,7 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, unsigned copied, struct page *page, struct iomap *iomap) { const struct iomap_page_ops *page_ops = iomap->page_ops; + loff_t old_size = inode->i_size; int ret; if (iomap->type == IOMAP_INLINE) { @@ -784,7 +785,19 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, ret = __iomap_write_end(inode, pos, len, copied, page, iomap); } - __generic_write_end(inode, pos, ret, page); + /* + * Update the in-memory inode size after copying the data into the page + * cache. It's up to the file system to write the updated size to disk, + * preferably after I/O completion so that no stale data is exposed. + */ + if (pos + ret > old_size) { + i_size_write(inode, pos + ret); + iomap->flags |= IOMAP_F_SIZE_CHANGED; + } + unlock_page(page); + + if (old_size < pos) + pagecache_isize_extended(inode, old_size, pos); if (page_ops && page_ops->page_done) page_ops->page_done(inode, pos, copied, page, iomap); put_page(page); diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 2103b94cb1bf..1df9ea187a9a 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -35,6 +35,7 @@ struct vm_fault; #define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */ #define IOMAP_F_DIRTY 0x02 /* uncommitted metadata */ #define IOMAP_F_BUFFER_HEAD 0x04 /* file system requires buffer heads */ +#define IOMAP_F_SIZE_CHANGED 0x08 /* file size has changed */ /* * Flags that only need to be reported for IOMAP_REPORT requests: