Commit 868941b1 authored by Jason A. Donenfeld's avatar Jason A. Donenfeld Committed by Al Viro
Browse files

fs: remove no_llseek 



Now that all callers of ->llseek are going through vfs_llseek(), we
don't gain anything by keeping no_llseek around. Nothing actually calls
it and setting ->llseek to no_lseek is completely equivalent to
leaving it NULL.

Longer term (== by the end of merge window) we want to remove all such
intializations.  To simplify the merge window this commit does *not*
touch initializers - it only defines no_llseek as NULL (and simplifies
the tests on file opening).

At -rc1 we'll need do a mechanical removal of no_llseek -

git grep -l -w no_llseek | grep -v porting.rst | while read i; do
	sed -i '/\<no_llseek\>/d' $i
done
would do it.

Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 97ef77c5

Documentation/filesystems/porting.rst

+8 −0
Original line number Diff line number Diff line
@@ -914,3 +914,11 @@ Calling conventions for file_open_root() changed; now it takes struct path * 
instead of passing mount and dentry separately.  For callers that used to

pass <mnt, mnt->mnt_root> pair (i.e. the root of given mount), a new helper

is provided - file_open_root_mnt().  In-tree users adjusted.



---



**mandatory**



no_llseek is gone; don't set .llseek to that - just leave it NULL instead.

Checks for "does that file have llseek(2), or should it fail with ESPIPE"

should be done by looking at FMODE_LSEEK in file->f_mode.

drivers/gpu/drm/drm_file.c

+1 −2
Original line number Diff line number Diff line
@@ -552,8 +552,7 @@ EXPORT_SYMBOL(drm_release_noglobal); 
 * Since events are used by the KMS API for vblank and page flip completion this

 * means all modern display drivers must use it.

 *

 * @offset is ignored, DRM events are read like a pipe. Therefore drivers also

 * must set the &file_operation.llseek to no_llseek(). Polling support is

 * @offset is ignored, DRM events are read like a pipe. Polling support is

 * provided by drm_poll().

 *

 * This function will only ever read a full event. Therefore userspace must

fs/file_table.c

+1 −1
Original line number Diff line number Diff line
@@ -235,7 +235,7 @@ static struct file *alloc_file(const struct path *path, int flags, 
	file->f_mapping = path->dentry->d_inode->i_mapping;

	file->f_wb_err = filemap_sample_wb_err(file->f_mapping);

	file->f_sb_err = file_sample_sb_err(file);

	if (fop->llseek && fop->llseek != no_llseek)

	if (fop->llseek)

		file->f_mode |= FMODE_LSEEK;

	if ((file->f_mode & FMODE_READ) &&

	     likely(fop->read || fop->read_iter))

fs/open.c

+0 −2
Original line number Diff line number Diff line
@@ -860,8 +860,6 @@ static int do_dentry_open(struct file *f, 
		f->f_mode |= FMODE_CAN_WRITE;

	if ((f->f_mode & FMODE_LSEEK) && !f->f_op->llseek)

		f->f_mode &= ~FMODE_LSEEK;

	if ((f->f_mode & FMODE_LSEEK) && f->f_op->llseek == no_llseek)

		f->f_mode &= ~FMODE_LSEEK;

	if (f->f_mapping->a_ops && f->f_mapping->a_ops->direct_IO)

		f->f_mode |= FMODE_CAN_ODIRECT;

fs/read_write.c

+0 −6
Original line number Diff line number Diff line
@@ -227,12 +227,6 @@ loff_t noop_llseek(struct file *file, loff_t offset, int whence) 
}

EXPORT_SYMBOL(noop_llseek);



loff_t no_llseek(struct file *file, loff_t offset, int whence)

{

	return -ESPIPE;

}

EXPORT_SYMBOL(no_llseek);



loff_t default_llseek(struct file *file, loff_t offset, int whence)

{

	struct inode *inode = file_inode(file);