On Wed 22-11-23 14:27:01, Amir Goldstein wrote: > All callers of do_splice_direct() have a call to rw_verify_area() for > the entire range that is being copied, e.g. by vfs_copy_file_range() or > do_sendfile() before calling do_splice_direct(). > > The rw_verify_area() check inside do_splice_direct() is redundant and > is called after sb_start_write(), so it is not "start-write-safe". > Remove this redundant check. > > This is needed for fanotify "pre content" events. > > Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx> > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> Looks good. Feel free to add: Reviewed-by: Jan Kara <jack@xxxxxxx> Honza > --- > fs/splice.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/fs/splice.c b/fs/splice.c > index d983d375ff11..6e917db6f49a 100644 > --- a/fs/splice.c > +++ b/fs/splice.c > @@ -1166,6 +1166,7 @@ static void direct_file_splice_eof(struct splice_desc *sd) > * (splice in + splice out, as compared to just sendfile()). So this helper > * can splice directly through a process-private pipe. > * > + * Callers already called rw_verify_area() on the entire range. > */ > long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, > loff_t *opos, size_t len, unsigned int flags) > @@ -1187,10 +1188,6 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, > if (unlikely(out->f_flags & O_APPEND)) > return -EINVAL; > > - ret = rw_verify_area(WRITE, out, opos, len); > - if (unlikely(ret < 0)) > - return ret; > - > ret = splice_direct_to_actor(in, &sd, direct_splice_actor); > if (ret > 0) > *ppos = sd.pos; > -- > 2.34.1 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
