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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>
hifive-unleashed-5.1
Christoph Hellwig 2018-06-19 15:10:55 -07:00 committed by Darrick J. Wong
parent ce397d215c
commit a6d639da63
2 changed files with 37 additions and 32 deletions

View File

@ -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);

View File

@ -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