diff --git a/Documentation/filesystems/mandatory-locking.rst b/Documentation/filesystems/mandatory-locking.rst deleted file mode 100644 index 9ce73544a8f0..000000000000 --- a/Documentation/filesystems/mandatory-locking.rst +++ /dev/null @@ -1,188 +0,0 @@ -.. SPDX-License-Identifier: GPL-2.0 - -===================================================== -Mandatory File Locking For The Linux Operating System -===================================================== - - Andy Walker - - 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. diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 59c32c9b799f..c4a2dc41beac 100644 --- a/fs/9p/vfs_file.c +++ b/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; diff --git a/fs/Kconfig b/fs/Kconfig index a7749c126b8e..949128bf86c9 100644 --- a/fs/Kconfig +++ b/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" diff --git a/fs/afs/flock.c b/fs/afs/flock.c index cb3054c7843e..c4210a3964d8 100644 --- a/fs/afs/flock.c +++ b/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); diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c index fa8a847743d0..bdeb271f47d9 100644 --- a/fs/ceph/locks.c +++ b/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); diff --git a/fs/fcntl.c b/fs/fcntl.c index f946bec8f1f1..68added37c15 100644 --- a/fs/fcntl.c +++ b/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); } } diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 84ec053d43b4..c559827cb6f9 100644 --- a/fs/gfs2/file.c +++ b/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; diff --git a/fs/locks.c b/fs/locks.c index 74b2a1dfe8d8..3d6fb4ae847b 100644 --- a/fs/locks.c +++ b/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 "); diff --git a/fs/namei.c b/fs/namei.c index bf6d8a738c59..471eb9fead6e 100644 --- a/fs/namei.c +++ b/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, diff --git a/fs/namespace.c b/fs/namespace.c index 97adcb5ab5d5..20caa4b4c539 100644 --- a/fs/namespace.c +++ b/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)) { diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 1fef107961bc..514be5d28d70 100644 --- a/fs/nfs/file.c +++ b/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; diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index fa67ecd5fe63..8313e1dbb5dc 100644 --- a/fs/nfsd/nfs4state.c +++ b/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; diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index a224a5e23cc1..92e77f92268a 100644 --- a/fs/nfsd/vfs.c +++ b/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; diff --git a/fs/ocfs2/locks.c b/fs/ocfs2/locks.c index fab7c6a4a7d0..73a3854b2afb 100644 --- a/fs/ocfs2/locks.c +++ b/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); } diff --git a/fs/open.c b/fs/open.c index 94bef26ff1b6..daa324606a41 100644 --- a/fs/open.c +++ b/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); diff --git a/fs/read_write.c b/fs/read_write.c index 9db7adf160d2..af057c57bdc6 100644 --- a/fs/read_write.c +++ b/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; } } diff --git a/fs/remap_range.c b/fs/remap_range.c index e4a5fdd7ad7b..6d4a9beaa097 100644 --- a/fs/remap_range.c +++ b/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); } diff --git a/include/linux/fs.h b/include/linux/fs.h index eb668b58f7f6..719345723911 100644 --- a/include/linux/fs.h +++ b/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) { diff --git a/mm/mmap.c b/mm/mmap.c index ca54d36d203a..181a113b545d 100644 --- a/mm/mmap.c +++ b/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); diff --git a/mm/nommu.c b/mm/nommu.c index 3a93d4054810..9d0ad98f838c 100644 --- a/mm/nommu.c +++ b/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;