From 4e3299eaddffd9d7d5b8bae28ad700bb775f02d0 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 29 Jun 2022 15:06:59 +0200 Subject: [PATCH] fs: do not compare against ->llseek Now vfs_llseek() can simply check for FMODE_LSEEK; if it's set, we know that ->llseek() won't be NULL and if it's not we should just fail with -ESPIPE. A couple of other places where we used to check for special values of ->llseek() (somewhat inconsistently) switched to checking FMODE_LSEEK. Signed-off-by: Jason A. Donenfeld Signed-off-by: Al Viro --- fs/coredump.c | 4 ++-- fs/overlayfs/copy_up.c | 3 +-- fs/read_write.c | 11 +++-------- 3 files changed, 6 insertions(+), 12 deletions(-) diff --git a/fs/coredump.c b/fs/coredump.c index ebc43f960b64..9f4aae202109 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -816,9 +816,9 @@ static int __dump_skip(struct coredump_params *cprm, size_t nr) { static char zeroes[PAGE_SIZE]; struct file *file = cprm->file; - if (file->f_op->llseek && file->f_op->llseek != no_llseek) { + if (file->f_mode & FMODE_LSEEK) { if (dump_interrupted() || - file->f_op->llseek(file, nr, SEEK_CUR) < 0) + vfs_llseek(file, nr, SEEK_CUR) < 0) return 0; cprm->pos += nr; return 1; diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 714ec569d25b..022606c9703b 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -226,8 +226,7 @@ static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old, /* Couldn't clone, so now we try to copy the data */ /* Check if lower fs supports seek operation */ - if (old_file->f_mode & FMODE_LSEEK && - old_file->f_op->llseek) + if (old_file->f_mode & FMODE_LSEEK) skip_hole = true; while (len) { diff --git a/fs/read_write.c b/fs/read_write.c index b1b1cdfee9d3..d94b6dbba6f9 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -290,14 +290,9 @@ EXPORT_SYMBOL(default_llseek); loff_t vfs_llseek(struct file *file, loff_t offset, int whence) { - loff_t (*fn)(struct file *, loff_t, int); - - fn = no_llseek; - if (file->f_mode & FMODE_LSEEK) { - if (file->f_op->llseek) - fn = file->f_op->llseek; - } - return fn(file, offset, whence); + if (!(file->f_mode & FMODE_LSEEK)) + return -ESPIPE; + return file->f_op->llseek(file, offset, whence); } EXPORT_SYMBOL(vfs_llseek);