llseek: automatically add .llseek fop

All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>

38 files changed, 59 insertions, 4 deletions

diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index 6d55268..6153417 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -29,6 +29,7 @@ static void afs_mntpt_expiry_timed_out(struct work_struct *work);
 
 const struct file_operations afs_mntpt_file_operations = {
 	.open		= afs_mntpt_open,
+	.llseek		= noop_llseek,
 };
 
 const struct inode_operations afs_mntpt_inode_operations = {
diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index ba4a38b..eff9a41 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -724,6 +724,7 @@ static const struct file_operations _dev_ioctl_fops = {
 	.unlocked_ioctl	 = autofs_dev_ioctl,
 	.compat_ioctl = autofs_dev_ioctl_compat,
 	.owner	 = THIS_MODULE,
+	.llseek = noop_llseek,
 };
 
 static struct miscdevice _autofs_dev_ioctl_misc = {
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index fd0cc0b..139fc80 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -576,6 +576,7 @@ static ssize_t bm_entry_write(struct file *file, const char __user *buffer,
 static const struct file_operations bm_entry_operations = {
 	.read		= bm_entry_read,
 	.write		= bm_entry_write,
+	.llseek		= default_llseek,
 };
 
 /* /register */
@@ -643,6 +644,7 @@ out:
 
 static const struct file_operations bm_register_operations = {
 	.write		= bm_register_write,
+	.llseek		= noop_llseek,
 };
 
 /* /status */
@@ -680,6 +682,7 @@ static ssize_t bm_status_write(struct file * file, const char __user * buffer,
 static const struct file_operations bm_status_operations = {
 	.read		= bm_status_read,
 	.write		= bm_status_write,
+	.llseek		= default_llseek,
 };
 
 /* Superblock handling */
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 1776dbd..144f8a5 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -815,6 +815,7 @@ static const struct file_operations btrfs_ctl_fops = {
 	.unlocked_ioctl	 = btrfs_control_ioctl,
 	.compat_ioctl = btrfs_control_ioctl,
 	.owner	 = THIS_MODULE,
+	.llseek = noop_llseek,
 };
 
 static struct miscdevice btrfs_misc = {
diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 727caed..0a1467b 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -55,6 +55,7 @@ const struct file_operations cachefiles_daemon_fops = {
 	.read		= cachefiles_daemon_read,
 	.write		= cachefiles_daemon_write,
 	.poll		= cachefiles_daemon_poll,
+	.llseek		= noop_llseek,
 };
 
 struct cachefiles_daemon_cmd {
diff --git a/fs/char_dev.c b/fs/char_dev.c
index f80a4f2..e4a3318 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -454,6 +454,7 @@ static void cdev_purge(struct cdev *cdev)
  */
 const struct file_operations def_chr_fops = {
 	.open = chrdev_open,
+	.llseek = noop_llseek,
 };
 
 static struct kobject *exact_match(dev_t dev, int *part, void *data)
diff --git a/fs/coda/pioctl.c b/fs/coda/pioctl.c
index ca25d96..028a9a0 100644
--- a/fs/coda/pioctl.c
+++ b/fs/coda/pioctl.c
@@ -39,6 +39,7 @@ const struct inode_operations coda_ioctl_inode_operations = {
 const struct file_operations coda_ioctl_operations = {
 	.owner		= THIS_MODULE,
 	.unlocked_ioctl	= coda_pioctl,
+	.llseek		= noop_llseek,
 };
 
 /* the coda pioctl inode ops */
diff --git a/fs/coda/psdev.c b/fs/coda/psdev.c
index de89645..9fa280b 100644
--- a/fs/coda/psdev.c
+++ b/fs/coda/psdev.c
@@ -346,6 +346,7 @@ static const struct file_operations coda_psdev_fops = {
 	.unlocked_ioctl	= coda_psdev_ioctl,
 	.open		= coda_psdev_open,
 	.release	= coda_psdev_release,
+	.llseek		= noop_llseek,
 };
 
 static int init_coda_psdev(void)
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 0210898..89d394d 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -43,6 +43,7 @@ const struct file_operations debugfs_file_operations = {
 	.read =		default_read_file,
 	.write =	default_write_file,
 	.open =		default_open,
+	.llseek =	noop_llseek,
 };
 
 static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd)
@@ -454,6 +455,7 @@ static const struct file_operations fops_bool = {
 	.read =		read_file_bool,
 	.write =	write_file_bool,
 	.open =		default_open,
+	.llseek =	default_llseek,
 };
 
 /**
@@ -498,6 +500,7 @@ static ssize_t read_file_blob(struct file *file, char __user *user_buf,
 static const struct file_operations fops_blob = {
 	.read =		read_file_blob,
 	.open =		default_open,
+	.llseek =	default_llseek,
 };
 
 /**
diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c
index c6cf251..6b42ba8 100644
--- a/fs/dlm/debug_fs.c
+++ b/fs/dlm/debug_fs.c
@@ -643,7 +643,8 @@ static ssize_t waiters_read(struct file *file, char __user *userbuf,
 static const struct file_operations waiters_fops = {
 	.owner   = THIS_MODULE,
 	.open    = waiters_open,
-	.read    = waiters_read
+	.read    = waiters_read,
+	.llseek  = default_llseek,
 };
 
 void dlm_delete_debug_file(struct dlm_ls *ls)
diff --git a/fs/dlm/plock.c b/fs/dlm/plock.c
index d45c02d..30d8b85 100644
--- a/fs/dlm/plock.c
+++ b/fs/dlm/plock.c
@@ -412,7 +412,8 @@ static const struct file_operations dev_fops = {
 	.read    = dev_read,
 	.write   = dev_write,
 	.poll    = dev_poll,
-	.owner   = THIS_MODULE
+	.owner   = THIS_MODULE,
+	.llseek  = noop_llseek,
 };
 
 static struct miscdevice plock_dev_misc = {
diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index b627285..66d6c16 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -1009,6 +1009,7 @@ static const struct file_operations device_fops = {
 	.write   = device_write,
 	.poll    = device_poll,
 	.owner   = THIS_MODULE,
+	.llseek  = noop_llseek,
 };
 
 static const struct file_operations ctl_device_fops = {
@@ -1017,6 +1018,7 @@ static const struct file_operations ctl_device_fops = {
 	.read    = device_read,
 	.write   = device_write,
 	.owner   = THIS_MODULE,
+	.llseek  = noop_llseek,
 };
 
 static struct miscdevice ctl_device = {
@@ -1029,6 +1031,7 @@ static const struct file_operations monitor_device_fops = {
 	.open    = monitor_device_open,
 	.release = monitor_device_close,
 	.owner   = THIS_MODULE,
+	.llseek  = noop_llseek,
 };
 
 static struct miscdevice monitor_device = {
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 622c9514..86e9da1 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -332,6 +332,7 @@ const struct file_operations ecryptfs_dir_fops = {
 	.fsync = ecryptfs_fsync,
 	.fasync = ecryptfs_fasync,
 	.splice_read = generic_file_splice_read,
+	.llseek = default_llseek,
 };
 
 const struct file_operations ecryptfs_main_fops = {
diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c
index 00208c3..940a82e 100644
--- a/fs/ecryptfs/miscdev.c
+++ b/fs/ecryptfs/miscdev.c
@@ -482,6 +482,7 @@ static const struct file_operations ecryptfs_miscdev_fops = {
 	.read    = ecryptfs_miscdev_read,
 	.write   = ecryptfs_miscdev_write,
 	.release = ecryptfs_miscdev_release,
+	.llseek  = noop_llseek,
 };
 
 static struct miscdevice ecryptfs_miscdev = {
diff --git a/fs/eventfd.c b/fs/eventfd.c
index 6bd3f76..e0194b3 100644
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -293,6 +293,7 @@ static const struct file_operations eventfd_fops = {
 	.poll		= eventfd_poll,
 	.read		= eventfd_read,
 	.write		= eventfd_write,
+	.llseek		= noop_llseek,
 };
 
 /**
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 3817149..256bb7b 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -674,7 +674,8 @@ static unsigned int ep_eventpoll_poll(struct file *file, poll_table *wait)
 /* File callbacks that implement the eventpoll file behaviour */
 static const struct file_operations eventpoll_fops = {
 	.release	= ep_eventpoll_release,
-	.poll		= ep_eventpoll_poll
+	.poll		= ep_eventpoll_poll,
+	.llseek		= noop_llseek,
 };
 
 /* Fast test to see if the file is an evenpoll file */
diff --git a/fs/fifo.c b/fs/fifo.c
index 5d6606f..4e303c2 100644
--- a/fs/fifo.c
+++ b/fs/fifo.c
@@ -151,4 +151,5 @@ err_nocleanup:
  */
 const struct file_operations def_fifo_fops = {
 	.open		= fifo_open,	/* will set read_ or write_pipefifo_fops */
+	.llseek		= noop_llseek,
 };
diff --git a/fs/fuse/control.c b/fs/fuse/control.c
index 3773fd6..7367e17 100644
--- a/fs/fuse/control.c
+++ b/fs/fuse/control.c
@@ -179,23 +179,27 @@ static ssize_t fuse_conn_congestion_threshold_write(struct file *file,
 static const struct file_operations fuse_ctl_abort_ops = {
 	.open = nonseekable_open,
 	.write = fuse_conn_abort_write,
+	.llseek = no_llseek,
 };
 
 static const struct file_operations fuse_ctl_waiting_ops = {
 	.open = nonseekable_open,
 	.read = fuse_conn_waiting_read,
+	.llseek = no_llseek,
 };
 
 static const struct file_operations fuse_conn_max_background_ops = {
 	.open = nonseekable_open,
 	.read = fuse_conn_max_background_read,
 	.write = fuse_conn_max_background_write,
+	.llseek = no_llseek,
 };
 
 static const struct file_operations fuse_conn_congestion_threshold_ops = {
 	.open = nonseekable_open,
 	.read = fuse_conn_congestion_threshold_read,
 	.write = fuse_conn_congestion_threshold_write,
+	.llseek = no_llseek,
 };
 
 static struct dentry *fuse_ctl_add_dentry(struct dentry *parent,
diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index e1f8171..3e87cce 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -182,6 +182,7 @@ static const struct file_operations cuse_frontend_fops = {
 	.unlocked_ioctl		= cuse_file_ioctl,
 	.compat_ioctl		= cuse_file_compat_ioctl,
 	.poll			= fuse_file_poll,
+	.llseek		= noop_llseek,
 };
 
 
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 4edd662..55d25a6 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -771,6 +771,7 @@ const struct file_operations gfs2_dir_fops = {
 	.fsync		= gfs2_fsync,
 	.lock		= gfs2_lock,
 	.flock		= gfs2_flock,
+	.llseek		= default_llseek,
 };
 
 #endif /* CONFIG_GFS2_FS_LOCKING_DLM */
@@ -797,5 +798,6 @@ const struct file_operations gfs2_dir_fops_nolock = {
 	.open		= gfs2_open,
 	.release	= gfs2_close,
 	.fsync		= gfs2_fsync,
+	.llseek		= default_llseek,
 };
 
diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c
index 7b02772..4e2a45e 100644
--- a/fs/hppfs/hppfs.c
+++ b/fs/hppfs/hppfs.c
@@ -598,6 +598,7 @@ static const struct file_operations hppfs_dir_fops = {
 	.readdir	= hppfs_readdir,
 	.open		= hppfs_dir_open,
 	.fsync		= hppfs_fsync,
+	.llseek		= default_llseek,
 };
 
 static int hppfs_statfs(struct dentry *dentry, struct kstatfs *sf)
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 6e5bd42..113eba3 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -674,6 +674,7 @@ const struct file_operations hugetlbfs_file_operations = {
 	.mmap			= hugetlbfs_file_mmap,
 	.fsync			= noop_fsync,
 	.get_unmapped_area	= hugetlb_get_unmapped_area,
+	.llseek		= default_llseek,
 };
 
 static const struct inode_operations hugetlbfs_dir_inode_operations = {
diff --git a/fs/logfs/dir.c b/fs/logfs/dir.c
index 9777eb5..1eb4e89 100644
--- a/fs/logfs/dir.c
+++ b/fs/logfs/dir.c
@@ -827,4 +827,5 @@ const struct file_operations logfs_dir_fops = {
 	.unlocked_ioctl	= logfs_ioctl,
 	.readdir	= logfs_readdir,
 	.read		= generic_read_dir,
+	.llseek		= default_llseek,
 };
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index b53b1d0..06fa87e 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -137,6 +137,7 @@ static const struct file_operations transaction_ops = {
 	.write		= nfsctl_transaction_write,
 	.read		= nfsctl_transaction_read,
 	.release	= simple_transaction_release,
+	.llseek		= default_llseek,
 };
 
 static int exports_open(struct inode *inode, struct file *file)
diff --git a/fs/no-block.c b/fs/no-block.c
index d269a93..6e40e42 100644
--- a/fs/no-block.c
+++ b/fs/no-block.c
@@ -19,4 +19,5 @@ static int no_blkdev_open(struct inode * inode, struct file * filp)
 
 const struct file_operations def_blk_fops = {
 	.open		= no_blkdev_open,
+	.llseek		= noop_llseek,
 };
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 5ed8e58..bbcb98e 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -433,6 +433,7 @@ static const struct file_operations fanotify_fops = {
 	.release	= fanotify_release,
 	.unlocked_ioctl	= fanotify_ioctl,
 	.compat_ioctl	= fanotify_ioctl,
+	.llseek		= noop_llseek,
 };
 
 static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index bf7f6d7..24edc11 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -344,6 +344,7 @@ static const struct file_operations inotify_fops = {
 	.release	= inotify_release,
 	.unlocked_ioctl	= inotify_ioctl,
 	.compat_ioctl	= inotify_ioctl,
+	.llseek		= noop_llseek,
 };
 
 
diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
index c2903b8..a7ebd9d 100644
--- a/fs/ocfs2/dlmfs/dlmfs.c
+++ b/fs/ocfs2/dlmfs/dlmfs.c
@@ -612,6 +612,7 @@ static const struct file_operations dlmfs_file_operations = {
 	.poll		= dlmfs_file_poll,
 	.read		= dlmfs_file_read,
 	.write		= dlmfs_file_write,
+	.llseek		= default_llseek,
 };
 
 static const struct inode_operations dlmfs_dir_inode_operations = {
diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
index 2dc57bc..0dbc6da 100644
--- a/fs/ocfs2/stack_user.c
+++ b/fs/ocfs2/stack_user.c
@@ -628,6 +628,7 @@ static const struct file_operations ocfs2_control_fops = {
 	.read    = ocfs2_control_read,
 	.write   = ocfs2_control_write,
 	.owner   = THIS_MODULE,
+	.llseek  = default_llseek,
 };
 
 static struct miscdevice ocfs2_control_device = {
diff --git a/fs/proc/base.c b/fs/proc/base.c
index a1c43e7..bc307d7 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1151,6 +1151,7 @@ static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
 static const struct file_operations proc_oom_score_adj_operations = {
 	.read		= oom_score_adj_read,
 	.write		= oom_score_adj_write,
+	.llseek		= default_llseek,
 };
 
 #ifdef CONFIG_AUDITSYSCALL
@@ -2039,11 +2040,13 @@ static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
 static const struct file_operations proc_fdinfo_file_operations = {
 	.open           = nonseekable_open,
 	.read		= proc_fdinfo_read,
+	.llseek		= no_llseek,
 };
 
 static const struct file_operations proc_fd_operations = {
 	.read		= generic_read_dir,
 	.readdir	= proc_readfd,
+	.llseek		= default_llseek,
 };
 
 /*
@@ -2112,6 +2115,7 @@ static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
 static const struct file_operations proc_fdinfo_operations = {
 	.read		= generic_read_dir,
 	.readdir	= proc_readfdinfo,
+	.llseek		= default_llseek,
 };
 
 /*
@@ -2343,6 +2347,7 @@ static int proc_attr_dir_readdir(struct file * filp,
 static const struct file_operations proc_attr_dir_operations = {
 	.read		= generic_read_dir,
 	.readdir	= proc_attr_dir_readdir,
+	.llseek		= default_llseek,
 };
 
 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
@@ -2751,6 +2756,7 @@ static int proc_tgid_base_readdir(struct file * filp,
 static const struct file_operations proc_tgid_base_operations = {
 	.read		= generic_read_dir,
 	.readdir	= proc_tgid_base_readdir,
+	.llseek		= default_llseek,
 };
 
 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
@@ -3088,6 +3094,7 @@ static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *den
 static const struct file_operations proc_tid_base_operations = {
 	.read		= generic_read_dir,
 	.readdir	= proc_tid_base_readdir,
+	.llseek		= default_llseek,
 };
 
 static const struct inode_operations proc_tid_base_inode_operations = {
@@ -3324,4 +3331,5 @@ static const struct inode_operations proc_task_inode_operations = {
 static const struct file_operations proc_task_operations = {
 	.read		= generic_read_dir,
 	.readdir	= proc_task_readdir,
+	.llseek		= default_llseek,
 };
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 5be436e..2fc5255 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -364,6 +364,7 @@ static int proc_sys_getattr(struct vfsmount *mnt, struct dentry *dentry, struct
 static const struct file_operations proc_sys_file_operations = {
 	.read		= proc_sys_read,
 	.write		= proc_sys_write,
+	.llseek		= default_llseek,
 };
 
 static const struct file_operations proc_sys_dir_file_operations = {
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 4258384..93d99b3 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -179,6 +179,7 @@ static int proc_root_readdir(struct file * filp,
 static const struct file_operations proc_root_operations = {
 	.read		 = generic_read_dir,
 	.readdir	 = proc_root_readdir,
+	.llseek		= default_llseek,
 };
 
 /*
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 271afc4..aa56920 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -539,6 +539,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
 
 const struct file_operations proc_clear_refs_operations = {
 	.write		= clear_refs_write,
+	.llseek		= noop_llseek,
 };
 
 struct pagemapread {
diff --git a/fs/romfs/super.c b/fs/romfs/super.c
index 42d2135..2685805 100644
--- a/fs/romfs/super.c
+++ b/fs/romfs/super.c
@@ -282,6 +282,7 @@ error:
 static const struct file_operations romfs_dir_operations = {
 	.read		= generic_read_dir,
 	.readdir	= romfs_readdir,
+	.llseek		= default_llseek,
 };
 
 static const struct inode_operations romfs_dir_inode_operations = {
diff --git a/fs/signalfd.c b/fs/signalfd.c
index 1c5a6ad..7404730 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -206,6 +206,7 @@ static const struct file_operations signalfd_fops = {
 	.release	= signalfd_release,
 	.poll		= signalfd_poll,
 	.read		= signalfd_read,
+	.llseek		= noop_llseek,
 };
 
 SYSCALL_DEFINE4(signalfd4, int, ufd, sigset_t __user *, user_mask,
diff --git a/fs/squashfs/dir.c b/fs/squashfs/dir.c
index 12b933a..0dc340a 100644
--- a/fs/squashfs/dir.c
+++ b/fs/squashfs/dir.c
@@ -230,5 +230,6 @@ failed_read:
 
 const struct file_operations squashfs_dir_ops = {
 	.read = generic_read_dir,
-	.readdir = squashfs_readdir
+	.readdir = squashfs_readdir,
+	.llseek = default_llseek,
 };
diff --git a/fs/timerfd.c b/fs/timerfd.c
index b86ab8e..8c4fc14 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -144,6 +144,7 @@ static const struct file_operations timerfd_fops = {
 	.release	= timerfd_release,
 	.poll		= timerfd_poll,
 	.read		= timerfd_read,
+	.llseek		= noop_llseek,
 };
 
 static struct file *timerfd_fget(int fd)
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index c2a68ba..c6c553f 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -2625,6 +2625,7 @@ static const struct file_operations dfs_fops = {
 	.open = open_debugfs_file,
 	.write = write_debugfs_file,
 	.owner = THIS_MODULE,
+	.llseek = default_llseek,
 };
 
 /**