Commit 46a1c2c7 authored by Jie Liu's avatar Jie Liu Committed by Al Viro
Browse files

vfs: export lseek_execute() to modules 



For those file systems(btrfs/ext4/ocfs2/tmpfs) that support
SEEK_DATA/SEEK_HOLE functions, we end up handling the similar
matter in lseek_execute() to update the current file offset
to the desired offset if it is valid, ceph also does the
simliar things at ceph_llseek().

To reduce the duplications, this patch make lseek_execute()
public accessible so that we can call it directly from the
underlying file systems.

Thanks Dave Chinner for this suggestion.

[AV: call it vfs_setpos(), don't bring the removed 'inode' argument back]

v2->v1:
- Add kernel-doc comments for lseek_execute()
- Call lseek_execute() in ceph->llseek()

Signed-off-by: default avatarJie Liu <jeff.liu@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Cc: Ben Myers <bpm@sgi.com>
Cc: Ted Tso <tytso@mit.edu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Sage Weil <sage@inktank.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 2142914e

fs/btrfs/file.c

+1 −14
Original line number Diff line number Diff line
@@ -2425,20 +2425,7 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence) 
		}

	}



	if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {

		offset = -EINVAL;

		goto out;

	}

	if (offset > inode->i_sb->s_maxbytes) {

		offset = -EINVAL;

		goto out;

	}



	/* Special lock needed here? */

	if (offset != file->f_pos) {

		file->f_pos = offset;

		file->f_version = 0;

	}

	offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);

out:

	mutex_unlock(&inode->i_mutex);

	return offset;

fs/ceph/file.c

+1 −10
Original line number Diff line number Diff line
@@ -866,16 +866,7 @@ static loff_t ceph_llseek(struct file *file, loff_t offset, int whence) 
		break;

	}



	if (offset < 0 || offset > inode->i_sb->s_maxbytes) {

		offset = -EINVAL;

		goto out;

	}



	/* Special lock needed here? */

	if (offset != file->f_pos) {

		file->f_pos = offset;

		file->f_version = 0;

	}

	offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);



out:

	mutex_unlock(&inode->i_mutex);

fs/ext4/file.c

+2 −22
Original line number Diff line number Diff line
@@ -494,17 +494,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) 
	if (dataoff > isize)

		return -ENXIO;



	if (dataoff < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET))

		return -EINVAL;

	if (dataoff > maxsize)

		return -EINVAL;



	if (dataoff != file->f_pos) {

		file->f_pos = dataoff;

		file->f_version = 0;

	}



	return dataoff;

	return vfs_setpos(file, dataoff, maxsize);

}



/*
@@ -580,17 +570,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) 
	if (holeoff > isize)

		holeoff = isize;



	if (holeoff < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET))

		return -EINVAL;

	if (holeoff > maxsize)

		return -EINVAL;



	if (holeoff != file->f_pos) {

		file->f_pos = holeoff;

		file->f_version = 0;

	}



	return holeoff;

	return vfs_setpos(file, holeoff, maxsize);

}



/*

fs/ocfs2/file.c

+1 −11
Original line number Diff line number Diff line
@@ -2646,17 +2646,7 @@ static loff_t ocfs2_file_llseek(struct file *file, loff_t offset, int whence) 
		goto out;

	}



	if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET))

		ret = -EINVAL;

	if (!ret && offset > inode->i_sb->s_maxbytes)

		ret = -EINVAL;

	if (ret)

		goto out;



	if (offset != file->f_pos) {

		file->f_pos = offset;

		file->f_version = 0;

	}

	offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);



out:

	mutex_unlock(&inode->i_mutex);

fs/read_write.c

+16 −3
Original line number Diff line number Diff line
@@ -41,7 +41,19 @@ static inline int unsigned_offsets(struct file *file) 
	return file->f_mode & FMODE_UNSIGNED_OFFSET;

}



static loff_t lseek_execute(struct file *file, loff_t offset, loff_t maxsize)

/**

 * vfs_setpos - update the file offset for lseek

 * @file:	file structure in question

 * @offset:	file offset to seek to

 * @maxsize:	maximum file size

 *

 * This is a low-level filesystem helper for updating the file offset to

 * the value specified by @offset if the given offset is valid and it is

 * not equal to the current file offset.

 *

 * Return the specified offset on success and -EINVAL on invalid offset.

 */

loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)

{

	if (offset < 0 && !unsigned_offsets(file))

		return -EINVAL;
@@ -54,6 +66,7 @@ static loff_t lseek_execute(struct file *file, loff_t offset, loff_t maxsize) 
	}

	return offset;

}

EXPORT_SYMBOL(vfs_setpos);



/**

 * generic_file_llseek_size - generic llseek implementation for regular files
@@ -94,7 +107,7 @@ generic_file_llseek_size(struct file *file, loff_t offset, int whence, 
		 * like SEEK_SET.

		 */

		spin_lock(&file->f_lock);

		offset = lseek_execute(file, file->f_pos + offset, maxsize);

		offset = vfs_setpos(file, file->f_pos + offset, maxsize);

		spin_unlock(&file->f_lock);

		return offset;

	case SEEK_DATA:
@@ -116,7 +129,7 @@ generic_file_llseek_size(struct file *file, loff_t offset, int whence, 
		break;

	}



	return lseek_execute(file, offset, maxsize);

	return vfs_setpos(file, offset, maxsize);

}

EXPORT_SYMBOL(generic_file_llseek_size);

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