From a6d639da63aeb838d5c0b7dc50598f2eac4014a0 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 19 Jun 2018 15:10:55 -0700 Subject: fs: factor out a __generic_write_end helper 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 Signed-off-by: Darrick J. Wong --- fs/buffer.c | 67 ++++++++++++++++++++++++++++++++----------------------------- 1 file changed, 35 insertions(+), 32 deletions(-) (limited to 'fs/buffer.c') 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); -- cgit v1.2.3 From 3d7b6b21f6c590c4d70b311bbdd78a214637c9c7 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Tue, 19 Jun 2018 15:10:55 -0700 Subject: iomap: mark newly allocated buffer heads as new In iomap_to_bh, not only mark buffer heads in IOMAP_UNWRITTEN maps as new, but also buffer heads in IOMAP_MAPPED maps with the IOMAP_F_NEW flag set. This will be used by filesystems like gfs2, which allocate blocks in iomap->begin. Minor corrections to the comment for IOMAP_UNWRITTEN maps. Signed-off-by: Andreas Gruenbacher Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/buffer.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index aba2a948b235..c8c2b7d8b8d6 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1900,15 +1900,16 @@ iomap_to_bh(struct inode *inode, sector_t block, struct buffer_head *bh, break; case IOMAP_UNWRITTEN: /* - * For unwritten regions, we always need to ensure that - * sub-block writes cause the regions in the block we are not - * writing to are zeroed. Set the buffer as new to ensure this. + * For unwritten regions, we always need to ensure that regions + * in the block we are not writing to are zeroed. Mark the + * buffer as new to ensure this. */ set_buffer_new(bh); set_buffer_unwritten(bh); /* FALLTHRU */ case IOMAP_MAPPED: - if (offset >= i_size_read(inode)) + if ((iomap->flags & IOMAP_F_NEW) || + offset >= i_size_read(inode)) set_buffer_new(bh); bh->b_blocknr = (iomap->addr + offset - iomap->offset) >> inode->i_blkbits; -- cgit v1.2.3