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author | Christoph Hellwig <hch@lst.de> | 2018-06-19 15:10:55 -0700 |
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committer | Darrick J. Wong <darrick.wong@oracle.com> | 2018-06-19 15:10:55 -0700 |
commit | a6d639da63aeb838d5c0b7dc50598f2eac4014a0 (patch) | |
tree | 172b65dd27e3bade9b2d99c50433786c9688132e /fs/buffer.c | |
parent | ce397d215ccd07b8ae3f71db689aedb85d56ab40 (diff) | |
download | lwn-a6d639da63aeb838d5c0b7dc50598f2eac4014a0.tar.gz lwn-a6d639da63aeb838d5c0b7dc50598f2eac4014a0.zip |
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 <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/buffer.c')
-rw-r--r-- | fs/buffer.c | 67 |
1 files changed, 35 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); |