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>

diff --git a/fs/buffer.c b/fs/buffer.c
index cabc045..aba2a94 100644 (file)
--- 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 980d005..4a18bdb 100644 (file)
--- 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