Commit bfe219d3 authored by Amir Goldstein's avatar Amir Goldstein Committed by Miklos Szeredi
Browse files

vfs: wrap write f_ops with file_{start,end}_write() 



Before calling write f_ops, call file_start_write() instead
of sb_start_write().

Replace {sb,file}_start_write() for {copy,clone}_file_range() and
for fallocate().

Beyond correct semantics, this avoids freeze protection to sb when
operating on special inodes, such as fallocate() on a blockdev.

Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 11cbfb10

fs/open.c

+2 −2
Original line number Diff line number Diff line
@@ -314,7 +314,7 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) 
	if (!file->f_op->fallocate)

		return -EOPNOTSUPP;



	sb_start_write(inode->i_sb);

	file_start_write(file);

	ret = file->f_op->fallocate(file, mode, offset, len);



	/*
@@ -327,7 +327,7 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) 
	if (ret == 0)

		fsnotify_modify(file);



	sb_end_write(inode->i_sb);

	file_end_write(file);

	return ret;

}

EXPORT_SYMBOL_GPL(vfs_fallocate);

fs/read_write.c

+2 −2
Original line number Diff line number Diff line
@@ -1543,7 +1543,7 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, 
	if (len == 0)

		return 0;



	sb_start_write(inode_out->i_sb);

	file_start_write(file_out);



	/*

	 * Try cloning first, this is supported by more file systems, and
@@ -1579,7 +1579,7 @@ done: 
	inc_syscr(current);

	inc_syscw(current);



	sb_end_write(inode_out->i_sb);

	file_end_write(file_out);



	return ret;

}

include/linux/fs.h

+13 −13
Original line number Diff line number Diff line
@@ -1741,19 +1741,6 @@ extern int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff, 
extern int vfs_dedupe_file_range(struct file *file,

				 struct file_dedupe_range *same);



static inline int do_clone_file_range(struct file *file_in, loff_t pos_in,

				      struct file *file_out, loff_t pos_out,

				      u64 len)

{

	int ret;



	sb_start_write(file_inode(file_out)->i_sb);

	ret = vfs_clone_file_range(file_in, pos_in, file_out, pos_out, len);

	sb_end_write(file_inode(file_out)->i_sb);



	return ret;

}



struct super_operations {

   	struct inode *(*alloc_inode)(struct super_block *sb);

	void (*destroy_inode)(struct inode *);
@@ -2564,6 +2551,19 @@ static inline void file_end_write(struct file *file) 
	__sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE);

}



static inline int do_clone_file_range(struct file *file_in, loff_t pos_in,

				      struct file *file_out, loff_t pos_out,

				      u64 len)

{

	int ret;



	file_start_write(file_out);

	ret = vfs_clone_file_range(file_in, pos_in, file_out, pos_out, len);

	file_end_write(file_out);



	return ret;

}



/*

 * get_write_access() gets write permission for a file.

 * put_write_access() releases this write permission.

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