Merge tag 'locks-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull file locking updates from Jeff Layton:
 "This starts with a couple of fixes for potential deadlocks in the
  fowner/fasync handling.

  The next patch removes the old mandatory locking code from the kernel
  altogether.

  The last patch cleans up rw_verify_area a bit more after the mandatory
  locking removal"

* tag 'locks-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  fs: clean up after mandatory file locking support removal
  fs: remove mandatory file locking support
  fcntl: fix potential deadlock for &fasync_struct.fa_lock
  fcntl: fix potential deadlocks for &fown_struct.lock

Documentation/filesystems/mandatory-locking.rst

-.. SPDX-License-Identifier: GPL-2.0
-
-=====================================================
-Mandatory File Locking For The Linux Operating System
-=====================================================
-
-		Andy Walker <andy@lysaker.kvaerner.no>
-
-			   15 April 1996
-
-		     (Updated September 2007)
-
-0. Why you should avoid mandatory locking
------------------------------------------
-
-The Linux implementation is prey to a number of difficult-to-fix race
-conditions which in practice make it not dependable:
-
-	- The write system call checks for a mandatory lock only once
-	  at its start.  It is therefore possible for a lock request to
-	  be granted after this check but before the data is modified.
-	  A process may then see file data change even while a mandatory
-	  lock was held.
-	- Similarly, an exclusive lock may be granted on a file after
-	  the kernel has decided to proceed with a read, but before the
-	  read has actually completed, and the reading process may see
-	  the file data in a state which should not have been visible
-	  to it.
-	- Similar races make the claimed mutual exclusion between lock
-	  and mmap similarly unreliable.
-
-1. What is  mandatory locking?
-------------------------------
-
-Mandatory locking is kernel enforced file locking, as opposed to the more usual
-cooperative file locking used to guarantee sequential access to files among
-processes. File locks are applied using the flock() and fcntl() system calls
-(and the lockf() library routine which is a wrapper around fcntl().) It is
-normally a process' responsibility to check for locks on a file it wishes to
-update, before applying its own lock, updating the file and unlocking it again.
-The most commonly used example of this (and in the case of sendmail, the most
-troublesome) is access to a user's mailbox. The mail user agent and the mail
-transfer agent must guard against updating the mailbox at the same time, and
-prevent reading the mailbox while it is being updated.
-
-In a perfect world all processes would use and honour a cooperative, or
-"advisory" locking scheme. However, the world isn't perfect, and there's
-a lot of poorly written code out there.
-
-In trying to address this problem, the designers of System V UNIX came up
-with a "mandatory" locking scheme, whereby the operating system kernel would
-block attempts by a process to write to a file that another process holds a
-"read" -or- "shared" lock on, and block attempts to both read and write to a 
-file that a process holds a "write " -or- "exclusive" lock on.
-
-The System V mandatory locking scheme was intended to have as little impact as
-possible on existing user code. The scheme is based on marking individual files
-as candidates for mandatory locking, and using the existing fcntl()/lockf()
-interface for applying locks just as if they were normal, advisory locks.
-
-.. Note::
-
-   1. In saying "file" in the paragraphs above I am actually not telling
-      the whole truth. System V locking is based on fcntl(). The granularity of
-      fcntl() is such that it allows the locking of byte ranges in files, in
-      addition to entire files, so the mandatory locking rules also have byte
-      level granularity.
-
-   2. POSIX.1 does not specify any scheme for mandatory locking, despite
-      borrowing the fcntl() locking scheme from System V. The mandatory locking
-      scheme is defined by the System V Interface Definition (SVID) Version 3.
-
-2. Marking a file for mandatory locking
----------------------------------------
-
-A file is marked as a candidate for mandatory locking by setting the group-id
-bit in its file mode but removing the group-execute bit. This is an otherwise
-meaningless combination, and was chosen by the System V implementors so as not
-to break existing user programs.
-
-Note that the group-id bit is usually automatically cleared by the kernel when
-a setgid file is written to. This is a security measure. The kernel has been
-modified to recognize the special case of a mandatory lock candidate and to
-refrain from clearing this bit. Similarly the kernel has been modified not
-to run mandatory lock candidates with setgid privileges.
-
-3. Available implementations
-----------------------------
-
-I have considered the implementations of mandatory locking available with
-SunOS 4.1.x, Solaris 2.x and HP-UX 9.x.
-
-Generally I have tried to make the most sense out of the behaviour exhibited
-by these three reference systems. There are many anomalies.
-
-All the reference systems reject all calls to open() for a file on which
-another process has outstanding mandatory locks. This is in direct
-contravention of SVID 3, which states that only calls to open() with the
-O_TRUNC flag set should be rejected. The Linux implementation follows the SVID
-definition, which is the "Right Thing", since only calls with O_TRUNC can
-modify the contents of the file.
-
-HP-UX even disallows open() with O_TRUNC for a file with advisory locks, not
-just mandatory locks. That would appear to contravene POSIX.1.
-
-mmap() is another interesting case. All the operating systems mentioned
-prevent mandatory locks from being applied to an mmap()'ed file, but  HP-UX
-also disallows advisory locks for such a file. SVID actually specifies the
-paranoid HP-UX behaviour.
-
-In my opinion only MAP_SHARED mappings should be immune from locking, and then
-only from mandatory locks - that is what is currently implemented.
-
-SunOS is so hopeless that it doesn't even honour the O_NONBLOCK flag for
-mandatory locks, so reads and writes to locked files always block when they
-should return EAGAIN.
-
-I'm afraid that this is such an esoteric area that the semantics described
-below are just as valid as any others, so long as the main points seem to
-agree. 
-
-4. Semantics
-------------
-
-1. Mandatory locks can only be applied via the fcntl()/lockf() locking
-   interface - in other words the System V/POSIX interface. BSD style
-   locks using flock() never result in a mandatory lock.
-
-2. If a process has locked a region of a file with a mandatory read lock, then
-   other processes are permitted to read from that region. If any of these
-   processes attempts to write to the region it will block until the lock is
-   released, unless the process has opened the file with the O_NONBLOCK
-   flag in which case the system call will return immediately with the error
-   status EAGAIN.
-
-3. If a process has locked a region of a file with a mandatory write lock, all
-   attempts to read or write to that region block until the lock is released,
-   unless a process has opened the file with the O_NONBLOCK flag in which case
-   the system call will return immediately with the error status EAGAIN.
-
-4. Calls to open() with O_TRUNC, or to creat(), on a existing file that has
-   any mandatory locks owned by other processes will be rejected with the
-   error status EAGAIN.
-
-5. Attempts to apply a mandatory lock to a file that is memory mapped and
-   shared (via mmap() with MAP_SHARED) will be rejected with the error status
-   EAGAIN.
-
-6. Attempts to create a shared memory map of a file (via mmap() with MAP_SHARED)
-   that has any mandatory locks in effect will be rejected with the error status
-   EAGAIN.
-
-5. Which system calls are affected?
------------------------------------
-
-Those which modify a file's contents, not just the inode. That gives read(),
-write(), readv(), writev(), open(), creat(), mmap(), truncate() and
-ftruncate(). truncate() and ftruncate() are considered to be "write" actions
-for the purposes of mandatory locking.
-
-The affected region is usually defined as stretching from the current position
-for the total number of bytes read or written. For the truncate calls it is
-defined as the bytes of a file removed or added (we must also consider bytes
-added, as a lock can specify just "the whole file", rather than a specific
-range of bytes.)
-
-Note 3: I may have overlooked some system calls that need mandatory lock
-checking in my eagerness to get this code out the door. Please let me know, or
-better still fix the system calls yourself and submit a patch to me or Linus.
-
-6. Warning!
------------
-
-Not even root can override a mandatory lock, so runaway processes can wreak
-havoc if they lock crucial files. The way around it is to change the file
-permissions (remove the setgid bit) before trying to read or write to it.
-Of course, that might be a bit tricky if the system is hung :-(
-
-7. The "mand" mount option
---------------------------
-Mandatory locking is disabled on all filesystems by default, and must be
-administratively enabled by mounting with "-o mand". That mount option
-is only allowed if the mounting task has the CAP_SYS_ADMIN capability.
-
-Since kernel v4.5, it is possible to disable mandatory locking
-altogether by setting CONFIG_MANDATORY_FILE_LOCKING to "n". A kernel
-with this disabled will reject attempts to mount filesystems with the
-"mand" mount option with the error status EPERM.

fs/9p/vfs_file.c

@@ -121,10 +121,6 @@ static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
 
 	p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
 
-	/* No mandatory locks */
-	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
-		return -ENOLCK;
-
 	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
 		filemap_write_and_wait(inode->i_mapping);
 		invalidate_mapping_pages(&inode->i_data, 0, -1);
@@ -312,10 +308,6 @@ static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
 	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
 		 filp, cmd, fl, filp);
 
-	/* No mandatory locks */
-	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
-		goto out_err;
-
 	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
 		filemap_write_and_wait(inode->i_mapping);
 		invalidate_mapping_pages(&inode->i_data, 0, -1);
@@ -327,7 +319,6 @@ static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
 		ret = v9fs_file_getlock(filp, fl);
 	else
 		ret = -EINVAL;
-out_err:
 	return ret;
 }
 
@@ -348,10 +339,6 @@ static int v9fs_file_flock_dotl(struct file *filp, int cmd,
 	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
 		 filp, cmd, fl, filp);
 
-	/* No mandatory locks */
-	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
-		goto out_err;
-
 	if (!(fl->fl_flags & FL_FLOCK))
 		goto out_err;
 

fs/Kconfig

@@ -101,16 +101,6 @@ config FILE_LOCKING
           for filesystems like NFS and for the flock() system
           call. Disabling this option saves about 11k.
 
-config MANDATORY_FILE_LOCKING
-	bool "Enable Mandatory file locking"
-	depends on FILE_LOCKING
-	default y
-	help
-	  This option enables files appropriately marked files on appropriely
-	  mounted filesystems to support mandatory locking.
-
-	  To the best of my knowledge this is dead code that no one cares about.
-
 source "fs/crypto/Kconfig"
 
 source "fs/verity/Kconfig"

fs/afs/flock.c

@@ -772,10 +772,6 @@ int afs_lock(struct file *file, int cmd, struct file_lock *fl)
 	       fl->fl_type, fl->fl_flags,
 	       (long long) fl->fl_start, (long long) fl->fl_end);
 
-	/* AFS doesn't support mandatory locks */
-	if (__mandatory_lock(&vnode->vfs_inode) && fl->fl_type != F_UNLCK)
-		return -ENOLCK;
-
 	if (IS_GETLK(cmd))
 		return afs_do_getlk(file, fl);
 

fs/ceph/locks.c

@@ -240,9 +240,6 @@ int ceph_lock(struct file *file, int cmd, struct file_lock *fl)
 
 	if (!(fl->fl_flags & FL_POSIX))
 		return -ENOLCK;
-	/* No mandatory locks */
-	if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK)
-		return -ENOLCK;
 
 	dout("ceph_lock, fl_owner: %p\n", fl->fl_owner);
 

fs/fcntl.c

@@ -150,7 +150,8 @@ void f_delown(struct file *filp)
 pid_t f_getown(struct file *filp)
 {
 	pid_t pid = 0;
-	read_lock(&filp->f_owner.lock);
+
+	read_lock_irq(&filp->f_owner.lock);
 	rcu_read_lock();
 	if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type)) {
 		pid = pid_vnr(filp->f_owner.pid);
@@ -158,7 +159,7 @@ pid_t f_getown(struct file *filp)
 			pid = -pid;
 	}
 	rcu_read_unlock();
-	read_unlock(&filp->f_owner.lock);
+	read_unlock_irq(&filp->f_owner.lock);
 	return pid;
 }
 
@@ -208,7 +209,7 @@ static int f_getown_ex(struct file *filp, unsigned long arg)
 	struct f_owner_ex owner = {};
 	int ret = 0;
 
-	read_lock(&filp->f_owner.lock);
+	read_lock_irq(&filp->f_owner.lock);
 	rcu_read_lock();
 	if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type))
 		owner.pid = pid_vnr(filp->f_owner.pid);
@@ -231,7 +232,7 @@ static int f_getown_ex(struct file *filp, unsigned long arg)
 		ret = -EINVAL;
 		break;
 	}
-	read_unlock(&filp->f_owner.lock);
+	read_unlock_irq(&filp->f_owner.lock);
 
 	if (!ret) {
 		ret = copy_to_user(owner_p, &owner, sizeof(owner));
@@ -249,10 +250,10 @@ static int f_getowner_uids(struct file *filp, unsigned long arg)
 	uid_t src[2];
 	int err;
 
-	read_lock(&filp->f_owner.lock);
+	read_lock_irq(&filp->f_owner.lock);
 	src[0] = from_kuid(user_ns, filp->f_owner.uid);
 	src[1] = from_kuid(user_ns, filp->f_owner.euid);
-	read_unlock(&filp->f_owner.lock);
+	read_unlock_irq(&filp->f_owner.lock);
 
 	err  = put_user(src[0], &dst[0]);
 	err |= put_user(src[1], &dst[1]);
@@ -1003,13 +1004,14 @@ static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band)
 {
 	while (fa) {
 		struct fown_struct *fown;
+		unsigned long flags;
 
 		if (fa->magic != FASYNC_MAGIC) {
 			printk(KERN_ERR "kill_fasync: bad magic number in "
 			       "fasync_struct!\n");
 			return;
 		}
-		read_lock(&fa->fa_lock);
+		read_lock_irqsave(&fa->fa_lock, flags);
 		if (fa->fa_file) {
 			fown = &fa->fa_file->f_owner;
 			/* Don't send SIGURG to processes which have not set a
@@ -1018,7 +1020,7 @@ static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band)
 			if (!(sig == SIGURG && fown->signum == 0))
 				send_sigio(fown, fa->fa_fd, band);
 		}
-		read_unlock(&fa->fa_lock);
+		read_unlock_irqrestore(&fa->fa_lock, flags);
 		fa = rcu_dereference(fa->fa_next);
 	}
 }

fs/gfs2/file.c

@@ -1237,9 +1237,6 @@ static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
 
 	if (!(fl->fl_flags & FL_POSIX))
 		return -ENOLCK;
-	if (__mandatory_lock(&ip->i_inode) && fl->fl_type != F_UNLCK)
-		return -ENOLCK;
-
 	if (cmd == F_CANCELLK) {
 		/* Hack: */
 		cmd = F_SETLK;

fs/locks.c

@@ -1397,103 +1397,6 @@ static int posix_lock_inode_wait(struct inode *inode, struct file_lock *fl)
 	return error;
 }
 
-#ifdef CONFIG_MANDATORY_FILE_LOCKING
-/**
- * locks_mandatory_locked - Check for an active lock
- * @file: the file to check
- *
- * Searches the inode's list of locks to find any POSIX locks which conflict.
- * This function is called from locks_verify_locked() only.
- */
-int locks_mandatory_locked(struct file *file)
-{
-	int ret;
-	struct inode *inode = locks_inode(file);
-	struct file_lock_context *ctx;
-	struct file_lock *fl;
-
-	ctx = smp_load_acquire(&inode->i_flctx);
-	if (!ctx || list_empty_careful(&ctx->flc_posix))
-		return 0;
-
-	/*
-	 * Search the lock list for this inode for any POSIX locks.
-	 */
-	spin_lock(&ctx->flc_lock);
-	ret = 0;
-	list_for_each_entry(fl, &ctx->flc_posix, fl_list) {
-		if (fl->fl_owner != current->files &&
-		    fl->fl_owner != file) {
-			ret = -EAGAIN;
-			break;
-		}
-	}
-	spin_unlock(&ctx->flc_lock);
-	return ret;
-}
-
-/**
- * locks_mandatory_area - Check for a conflicting lock
- * @inode:	the file to check
- * @filp:       how the file was opened (if it was)
- * @start:	first byte in the file to check
- * @end:	lastbyte in the file to check
- * @type:	%F_WRLCK for a write lock, else %F_RDLCK
- *
- * Searches the inode's list of locks to find any POSIX locks which conflict.
- */
-int locks_mandatory_area(struct inode *inode, struct file *filp, loff_t start,
-			 loff_t end, unsigned char type)
-{
-	struct file_lock fl;
-	int error;
-	bool sleep = false;
-
-	locks_init_lock(&fl);
-	fl.fl_pid = current->tgid;
-	fl.fl_file = filp;
-	fl.fl_flags = FL_POSIX | FL_ACCESS;
-	if (filp && !(filp->f_flags & O_NONBLOCK))
-		sleep = true;
-	fl.fl_type = type;
-	fl.fl_start = start;
-	fl.fl_end = end;
-
-	for (;;) {
-		if (filp) {
-			fl.fl_owner = filp;
-			fl.fl_flags &= ~FL_SLEEP;
-			error = posix_lock_inode(inode, &fl, NULL);
-			if (!error)
-				break;
-		}
-
-		if (sleep)
-			fl.fl_flags |= FL_SLEEP;
-		fl.fl_owner = current->files;
-		error = posix_lock_inode(inode, &fl, NULL);
-		if (error != FILE_LOCK_DEFERRED)
-			break;
-		error = wait_event_interruptible(fl.fl_wait,
-					list_empty(&fl.fl_blocked_member));
-		if (!error) {
-			/*
-			 * If we've been sleeping someone might have
-			 * changed the permissions behind our back.
-			 */
-			if (__mandatory_lock(inode))
-				continue;
-		}
-
-		break;
-	}
-	locks_delete_block(&fl);
-
-	return error;
-}
-EXPORT_SYMBOL(locks_mandatory_area);
-#endif /* CONFIG_MANDATORY_FILE_LOCKING */
-
 static void lease_clear_pending(struct file_lock *fl, int arg)
 {
 	switch (arg) {
@@ -2486,14 +2389,6 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
 	if (file_lock == NULL)
 		return -ENOLCK;
 
-	/* Don't allow mandatory locks on files that may be memory mapped
-	 * and shared.
-	 */
-	if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) {
-		error = -EAGAIN;
-		goto out;
-	}
-
 	error = flock_to_posix_lock(filp, file_lock, flock);
 	if (error)
 		goto out;
@@ -2611,21 +2506,12 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
 		struct flock64 *flock)
 {
 	struct file_lock *file_lock = locks_alloc_lock();
-	struct inode *inode = locks_inode(filp);
 	struct file *f;
 	int error;
 
 	if (file_lock == NULL)
 		return -ENOLCK;
 
-	/* Don't allow mandatory locks on files that may be memory mapped
-	 * and shared.
-	 */
-	if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) {
-		error = -EAGAIN;
-		goto out;
-	}
-
 	error = flock64_to_posix_lock(filp, file_lock, flock);
 	if (error)
 		goto out;
@@ -2857,8 +2743,7 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
 			seq_puts(f, "POSIX ");
 
 		seq_printf(f, " %s ",
-			     (inode == NULL) ? "*NOINODE*" :
-			     mandatory_lock(inode) ? "MANDATORY" : "ADVISORY ");
+			     (inode == NULL) ? "*NOINODE*" : "ADVISORY ");
 	} else if (IS_FLOCK(fl)) {
 		if (fl->fl_type & LOCK_MAND) {
 			seq_puts(f, "FLOCK  MSNFS     ");

fs/namei.c

@@ -3023,9 +3023,7 @@ static int handle_truncate(struct user_namespace *mnt_userns, struct file *filp)
 	/*
 	 * Refuse to truncate files with mandatory locks held on them.
 	 */
-	error = locks_verify_locked(filp);
-	if (!error)
-		error = security_path_truncate(path);
+	error = security_path_truncate(path);
 	if (!error) {
 		error = do_truncate(mnt_userns, path->dentry, 0,
 				    ATTR_MTIME|ATTR_CTIME|ATTR_OPEN,

fs/namespace.c

@@ -1715,22 +1715,14 @@ static inline bool may_mount(void)
 	return ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN);
 }
 
-#ifdef	CONFIG_MANDATORY_FILE_LOCKING
-static bool may_mandlock(void)
+static void warn_mandlock(void)
 {
-	pr_warn_once("======================================================\n"
-		     "WARNING: the mand mount option is being deprecated and\n"
-		     "         will be removed in v5.15!\n"
-		     "======================================================\n");
-	return capable(CAP_SYS_ADMIN);
+	pr_warn_once("=======================================================\n"
+		     "WARNING: The mand mount option has been deprecated and\n"
+		     "         and is ignored by this kernel. Remove the mand\n"
+		     "         option from the mount to silence this warning.\n"
+		     "=======================================================\n");
 }
-#else
-static inline bool may_mandlock(void)
-{
-	pr_warn("VFS: \"mand\" mount option not supported");
-	return false;
-}
-#endif
 
 static int can_umount(const struct path *path, int flags)
 {
@@ -3197,8 +3189,8 @@ int path_mount(const char *dev_name, struct path *path,
 		return ret;
 	if (!may_mount())
 		return -EPERM;
-	if ((flags & SB_MANDLOCK) && !may_mandlock())
-		return -EPERM;
+	if (flags & SB_MANDLOCK)
+		warn_mandlock();
 
 	/* Default to relatime unless overriden */
 	if (!(flags & MS_NOATIME))
@@ -3581,9 +3573,8 @@ SYSCALL_DEFINE3(fsmount, int, fs_fd, unsigned int, flags,
 	if (fc->phase != FS_CONTEXT_AWAITING_MOUNT)
 		goto err_unlock;
 
-	ret = -EPERM;
-	if ((fc->sb_flags & SB_MANDLOCK) && !may_mandlock())
-		goto err_unlock;
+	if (fc->sb_flags & SB_MANDLOCK)
+		warn_mandlock();
 
 	newmount.mnt = vfs_create_mount(fc);
 	if (IS_ERR(newmount.mnt)) {

fs/nfs/file.c

@@ -806,10 +806,6 @@ int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
 
 	nfs_inc_stats(inode, NFSIOS_VFSLOCK);
 
-	/* No mandatory locks over NFS */
-	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
-		goto out_err;
-
 	if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FCNTL)
 		is_local = 1;
 

fs/nfsd/nfs4state.c

@@ -5735,16 +5735,6 @@ check_special_stateids(struct net *net, svc_fh *current_fh, stateid_t *stateid,
 				NFS4_SHARE_DENY_READ);
 }
 
-/*
- * Allow READ/WRITE during grace period on recovered state only for files
- * that are not able to provide mandatory locking.
- */
-static inline int
-grace_disallows_io(struct net *net, struct inode *inode)
-{
-	return opens_in_grace(net) && mandatory_lock(inode);
-}
-
 static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_session)
 {
 	/*
@@ -6026,7 +6016,6 @@ nfs4_preprocess_stateid_op(struct svc_rqst *rqstp,
 		stateid_t *stateid, int flags, struct nfsd_file **nfp,
 		struct nfs4_stid **cstid)
 {
-	struct inode *ino = d_inode(fhp->fh_dentry);
 	struct net *net = SVC_NET(rqstp);
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 	struct nfs4_stid *s = NULL;
@@ -6035,9 +6024,6 @@ nfs4_preprocess_stateid_op(struct svc_rqst *rqstp,
 	if (nfp)
 		*nfp = NULL;
 
-	if (grace_disallows_io(net, ino))
-		return nfserr_grace;
-
 	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid)) {
 		status = check_special_stateids(net, fhp, stateid, flags);
 		goto done;

fs/nfsd/vfs.c

@@ -333,7 +333,6 @@ nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		struct iattr *iap)
 {
 	struct inode *inode = d_inode(fhp->fh_dentry);
-	int host_err;
 
 	if (iap->ia_size < inode->i_size) {
 		__be32 err;
@@ -343,20 +342,7 @@ nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		if (err)
 			return err;
 	}
-
-	host_err = get_write_access(inode);
-	if (host_err)
-		goto out_nfserrno;
-
-	host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
-	if (host_err)
-		goto out_put_write_access;
-	return 0;
-
-out_put_write_access:
-	put_write_access(inode);
-out_nfserrno:
-	return nfserrno(host_err);
+	return nfserrno(get_write_access(inode));
 }
 
 /*
@@ -750,13 +736,6 @@ __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
 	err = nfserr_perm;
 	if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
 		goto out;
-	/*
-	 * We must ignore files (but only files) which might have mandatory
-	 * locks on them because there is no way to know if the accesser has
-	 * the lock.
-	 */
-	if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
-		goto out;
 
 	if (!inode->i_fop)
 		goto out;

fs/ocfs2/locks.c

@@ -101,8 +101,6 @@ int ocfs2_flock(struct file *file, int cmd, struct file_lock *fl)
 
 	if (!(fl->fl_flags & FL_FLOCK))
 		return -ENOLCK;
-	if (__mandatory_lock(inode))
-		return -ENOLCK;
 
 	if ((osb->s_mount_opt & OCFS2_MOUNT_LOCALFLOCKS) ||
 	    ocfs2_mount_local(osb))
@@ -121,8 +119,6 @@ int ocfs2_lock(struct file *file, int cmd, struct file_lock *fl)
 
 	if (!(fl->fl_flags & FL_POSIX))
 		return -ENOLCK;
-	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
-		return -ENOLCK;
 
 	return ocfs2_plock(osb->cconn, OCFS2_I(inode)->ip_blkno, file, cmd, fl);
 }

fs/open.c

@@ -105,9 +105,7 @@ long vfs_truncate(const struct path *path, loff_t length)
 	if (error)
 		goto put_write_and_out;
 
-	error = locks_verify_truncate(inode, NULL, length);
-	if (!error)
-		error = security_path_truncate(path);
+	error = security_path_truncate(path);
 	if (!error)
 		error = do_truncate(mnt_userns, path->dentry, length, 0, NULL);
 
@@ -189,9 +187,7 @@ long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
 	if (IS_APPEND(file_inode(f.file)))
 		goto out_putf;
 	sb_start_write(inode->i_sb);
-	error = locks_verify_truncate(inode, f.file, length);
-	if (!error)
-		error = security_path_truncate(&f.file->f_path);
+	error = security_path_truncate(&f.file->f_path);
 	if (!error)
 		error = do_truncate(file_mnt_user_ns(f.file), dentry, length,
 				    ATTR_MTIME | ATTR_CTIME, f.file);

fs/read_write.c

@@ -365,12 +365,8 @@ SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
 
 int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
 {
-	struct inode *inode;
-	int retval = -EINVAL;
-
-	inode = file_inode(file);
 	if (unlikely((ssize_t) count < 0))
-		return retval;
+		return -EINVAL;
 
 	/*
 	 * ranged mandatory locking does not apply to streams - it makes sense
@@ -381,19 +377,12 @@ int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t
 
 		if (unlikely(pos < 0)) {
 			if (!unsigned_offsets(file))
-				return retval;
+				return -EINVAL;
 			if (count >= -pos) /* both values are in 0..LLONG_MAX */
 				return -EOVERFLOW;
 		} else if (unlikely((loff_t) (pos + count) < 0)) {
 			if (!unsigned_offsets(file))
-				return retval;
-		}
-
-		if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
-			retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
-					read_write == READ ? F_RDLCK : F_WRLCK);
-			if (retval < 0)
-				return retval;
+				return -EINVAL;
 		}
 	}
 

fs/remap_range.c

@@ -99,24 +99,12 @@ static int generic_remap_checks(struct file *file_in, loff_t pos_in,
 static int remap_verify_area(struct file *file, loff_t pos, loff_t len,
 			     bool write)
 {
-	struct inode *inode = file_inode(file);
-
 	if (unlikely(pos < 0 || len < 0))
 		return -EINVAL;
 
 	if (unlikely((loff_t) (pos + len) < 0))
 		return -EINVAL;
 
-	if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
-		loff_t end = len ? pos + len - 1 : OFFSET_MAX;
-		int retval;
-
-		retval = locks_mandatory_area(inode, file, pos, end,
-				write ? F_WRLCK : F_RDLCK);
-		if (retval < 0)
-			return retval;
-	}
-
 	return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
 }
 

include/linux/fs.h

@@ -2612,90 +2612,6 @@ extern struct kobject *fs_kobj;
 
 #define MAX_RW_COUNT (INT_MAX & PAGE_MASK)
 
-#ifdef CONFIG_MANDATORY_FILE_LOCKING
-extern int locks_mandatory_locked(struct file *);
-extern int locks_mandatory_area(struct inode *, struct file *, loff_t, loff_t, unsigned char);
-
-/*
- * Candidates for mandatory locking have the setgid bit set
- * but no group execute bit -  an otherwise meaningless combination.
- */
-
-static inline int __mandatory_lock(struct inode *ino)
-{
-	return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
-}
-
-/*
- * ... and these candidates should be on SB_MANDLOCK mounted fs,
- * otherwise these will be advisory locks
- */
-
-static inline int mandatory_lock(struct inode *ino)
-{
-	return IS_MANDLOCK(ino) && __mandatory_lock(ino);
-}
-
-static inline int locks_verify_locked(struct file *file)
-{
-	if (mandatory_lock(locks_inode(file)))
-		return locks_mandatory_locked(file);
-	return 0;
-}
-
-static inline int locks_verify_truncate(struct inode *inode,
-				    struct file *f,
-				    loff_t size)
-{
-	if (!inode->i_flctx || !mandatory_lock(inode))
-		return 0;
-
-	if (size < inode->i_size) {
-		return locks_mandatory_area(inode, f, size, inode->i_size - 1,
-				F_WRLCK);
-	} else {
-		return locks_mandatory_area(inode, f, inode->i_size, size - 1,
-				F_WRLCK);
-	}
-}
-
-#else /* !CONFIG_MANDATORY_FILE_LOCKING */
-
-static inline int locks_mandatory_locked(struct file *file)
-{
-	return 0;
-}
-
-static inline int locks_mandatory_area(struct inode *inode, struct file *filp,
-                                       loff_t start, loff_t end, unsigned char type)
-{
-	return 0;
-}
-
-static inline int __mandatory_lock(struct inode *inode)
-{
-	return 0;
-}
-
-static inline int mandatory_lock(struct inode *inode)
-{
-	return 0;
-}
-
-static inline int locks_verify_locked(struct file *file)
-{
-	return 0;
-}
-
-static inline int locks_verify_truncate(struct inode *inode, struct file *filp,
-					size_t size)
-{
-	return 0;
-}
-
-#endif /* CONFIG_MANDATORY_FILE_LOCKING */
-
-
 #ifdef CONFIG_FILE_LOCKING
 static inline int break_lease(struct inode *inode, unsigned int mode)
 {

mm/mmap.c

@@ -1517,12 +1517,6 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
 			if (IS_APPEND(inode) && (file->f_mode & FMODE_WRITE))
 				return -EACCES;
 
-			/*
-			 * Make sure there are no mandatory locks on the file.
-			 */
-			if (locks_verify_locked(file))
-				return -EAGAIN;
-
 			vm_flags |= VM_SHARED | VM_MAYSHARE;
 			if (!(file->f_mode & FMODE_WRITE))
 				vm_flags &= ~(VM_MAYWRITE | VM_SHARED);

mm/nommu.c

@@ -826,9 +826,6 @@ static int validate_mmap_request(struct file *file,
 			    (file->f_mode & FMODE_WRITE))
 				return -EACCES;
 
-			if (locks_verify_locked(file))
-				return -EAGAIN;
-
 			if (!(capabilities & NOMMU_MAP_DIRECT))
 				return -ENODEV;