From e09b41010ba33a20a87472ee821fa407a5b8da36 Mon Sep 17 00:00:00 2001 From: José Pekkarinen Date: Mon, 11 Apr 2016 10:41:07 +0300 Subject: These changes are the raw update to linux-4.4.6-rt14. Kernel sources are taken from kernel.org, and rt patch from the rt wiki download page. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen --- kernel/fs/locks.c | 180 ++++++++++++++++++++++++++++++++---------------------- 1 file changed, 108 insertions(+), 72 deletions(-) (limited to 'kernel/fs/locks.c') diff --git a/kernel/fs/locks.c b/kernel/fs/locks.c index 653faabb0..6333263b7 100644 --- a/kernel/fs/locks.c +++ b/kernel/fs/locks.c @@ -205,28 +205,32 @@ static struct kmem_cache *filelock_cache __read_mostly; static struct file_lock_context * locks_get_lock_context(struct inode *inode, int type) { - struct file_lock_context *new; + struct file_lock_context *ctx; - if (likely(inode->i_flctx) || type == F_UNLCK) + /* paired with cmpxchg() below */ + ctx = smp_load_acquire(&inode->i_flctx); + if (likely(ctx) || type == F_UNLCK) goto out; - new = kmem_cache_alloc(flctx_cache, GFP_KERNEL); - if (!new) + ctx = kmem_cache_alloc(flctx_cache, GFP_KERNEL); + if (!ctx) goto out; - spin_lock_init(&new->flc_lock); - INIT_LIST_HEAD(&new->flc_flock); - INIT_LIST_HEAD(&new->flc_posix); - INIT_LIST_HEAD(&new->flc_lease); + spin_lock_init(&ctx->flc_lock); + INIT_LIST_HEAD(&ctx->flc_flock); + INIT_LIST_HEAD(&ctx->flc_posix); + INIT_LIST_HEAD(&ctx->flc_lease); /* * Assign the pointer if it's not already assigned. If it is, then * free the context we just allocated. */ - if (cmpxchg(&inode->i_flctx, NULL, new)) - kmem_cache_free(flctx_cache, new); + if (cmpxchg(&inode->i_flctx, NULL, ctx)) { + kmem_cache_free(flctx_cache, ctx); + ctx = smp_load_acquire(&inode->i_flctx); + } out: - return inode->i_flctx; + return ctx; } void @@ -762,7 +766,7 @@ posix_test_lock(struct file *filp, struct file_lock *fl) struct file_lock_context *ctx; struct inode *inode = file_inode(filp); - ctx = inode->i_flctx; + ctx = smp_load_acquire(&inode->i_flctx); if (!ctx || list_empty_careful(&ctx->flc_posix)) { fl->fl_type = F_UNLCK; return; @@ -862,12 +866,11 @@ static int posix_locks_deadlock(struct file_lock *caller_fl, * whether or not a lock was successfully freed by testing the return * value for -ENOENT. */ -static int flock_lock_file(struct file *filp, struct file_lock *request) +static int flock_lock_inode(struct inode *inode, struct file_lock *request) { struct file_lock *new_fl = NULL; struct file_lock *fl; struct file_lock_context *ctx; - struct inode *inode = file_inode(filp); int error = 0; bool found = false; LIST_HEAD(dispose); @@ -890,7 +893,7 @@ static int flock_lock_file(struct file *filp, struct file_lock *request) goto find_conflict; list_for_each_entry(fl, &ctx->flc_flock, fl_list) { - if (filp != fl->fl_file) + if (request->fl_file != fl->fl_file) continue; if (request->fl_type == fl->fl_type) goto out; @@ -1164,20 +1167,18 @@ int posix_lock_file(struct file *filp, struct file_lock *fl, EXPORT_SYMBOL(posix_lock_file); /** - * posix_lock_file_wait - Apply a POSIX-style lock to a file - * @filp: The file to apply the lock to + * posix_lock_inode_wait - Apply a POSIX-style lock to a file + * @inode: inode of file to which lock request should be applied * @fl: The lock to be applied * - * Add a POSIX style lock to a file. - * We merge adjacent & overlapping locks whenever possible. - * POSIX locks are sorted by owner task, then by starting address + * Apply a POSIX style lock request to an inode. */ -int posix_lock_file_wait(struct file *filp, struct file_lock *fl) +static int posix_lock_inode_wait(struct inode *inode, struct file_lock *fl) { int error; might_sleep (); for (;;) { - error = posix_lock_file(filp, fl, NULL); + error = __posix_lock_file(inode, fl, NULL); if (error != FILE_LOCK_DEFERRED) break; error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); @@ -1189,7 +1190,6 @@ int posix_lock_file_wait(struct file *filp, struct file_lock *fl) } return error; } -EXPORT_SYMBOL(posix_lock_file_wait); /** * locks_mandatory_locked - Check for an active lock @@ -1205,7 +1205,7 @@ int locks_mandatory_locked(struct file *file) struct file_lock_context *ctx; struct file_lock *fl; - ctx = inode->i_flctx; + ctx = smp_load_acquire(&inode->i_flctx); if (!ctx || list_empty_careful(&ctx->flc_posix)) return 0; @@ -1390,7 +1390,7 @@ any_leases_conflict(struct inode *inode, struct file_lock *breaker) int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) { int error = 0; - struct file_lock_context *ctx = inode->i_flctx; + struct file_lock_context *ctx; struct file_lock *new_fl, *fl, *tmp; unsigned long break_time; int want_write = (mode & O_ACCMODE) != O_RDONLY; @@ -1402,6 +1402,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) new_fl->fl_flags = type; /* typically we will check that ctx is non-NULL before calling */ + ctx = smp_load_acquire(&inode->i_flctx); if (!ctx) { WARN_ON_ONCE(1); return error; @@ -1496,9 +1497,10 @@ EXPORT_SYMBOL(__break_lease); void lease_get_mtime(struct inode *inode, struct timespec *time) { bool has_lease = false; - struct file_lock_context *ctx = inode->i_flctx; + struct file_lock_context *ctx; struct file_lock *fl; + ctx = smp_load_acquire(&inode->i_flctx); if (ctx && !list_empty_careful(&ctx->flc_lease)) { spin_lock(&ctx->flc_lock); if (!list_empty(&ctx->flc_lease)) { @@ -1545,10 +1547,11 @@ int fcntl_getlease(struct file *filp) { struct file_lock *fl; struct inode *inode = file_inode(filp); - struct file_lock_context *ctx = inode->i_flctx; + struct file_lock_context *ctx; int type = F_UNLCK; LIST_HEAD(dispose); + ctx = smp_load_acquire(&inode->i_flctx); if (ctx && !list_empty_careful(&ctx->flc_lease)) { spin_lock(&ctx->flc_lock); time_out_leases(file_inode(filp), &dispose); @@ -1570,6 +1573,7 @@ int fcntl_getlease(struct file *filp) * desired lease. * @dentry: dentry to check * @arg: type of lease that we're trying to acquire + * @flags: current lock flags * * Check to see if there's an existing open fd on this file that would * conflict with the lease we're trying to set. @@ -1712,11 +1716,11 @@ static int generic_delete_lease(struct file *filp, void *owner) { int error = -EAGAIN; struct file_lock *fl, *victim = NULL; - struct dentry *dentry = filp->f_path.dentry; - struct inode *inode = dentry->d_inode; - struct file_lock_context *ctx = inode->i_flctx; + struct inode *inode = file_inode(filp); + struct file_lock_context *ctx; LIST_HEAD(dispose); + ctx = smp_load_acquire(&inode->i_flctx); if (!ctx) { trace_generic_delete_lease(inode, NULL); return error; @@ -1752,8 +1756,7 @@ static int generic_delete_lease(struct file *filp, void *owner) int generic_setlease(struct file *filp, long arg, struct file_lock **flp, void **priv) { - struct dentry *dentry = filp->f_path.dentry; - struct inode *inode = dentry->d_inode; + struct inode *inode = file_inode(filp); int error; if ((!uid_eq(current_fsuid(), inode->i_uid)) && !capable(CAP_LEASE)) @@ -1851,18 +1854,18 @@ int fcntl_setlease(unsigned int fd, struct file *filp, long arg) } /** - * flock_lock_file_wait - Apply a FLOCK-style lock to a file - * @filp: The file to apply the lock to + * flock_lock_inode_wait - Apply a FLOCK-style lock to a file + * @inode: inode of the file to apply to * @fl: The lock to be applied * - * Add a FLOCK style lock to a file. + * Apply a FLOCK style lock request to an inode. */ -int flock_lock_file_wait(struct file *filp, struct file_lock *fl) +static int flock_lock_inode_wait(struct inode *inode, struct file_lock *fl) { int error; might_sleep(); for (;;) { - error = flock_lock_file(filp, fl); + error = flock_lock_inode(inode, fl); if (error != FILE_LOCK_DEFERRED) break; error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); @@ -1875,7 +1878,29 @@ int flock_lock_file_wait(struct file *filp, struct file_lock *fl) return error; } -EXPORT_SYMBOL(flock_lock_file_wait); +/** + * locks_lock_inode_wait - Apply a lock to an inode + * @inode: inode of the file to apply to + * @fl: The lock to be applied + * + * Apply a POSIX or FLOCK style lock request to an inode. + */ +int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl) +{ + int res = 0; + switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { + case FL_POSIX: + res = posix_lock_inode_wait(inode, fl); + break; + case FL_FLOCK: + res = flock_lock_inode_wait(inode, fl); + break; + default: + BUG(); + } + return res; +} +EXPORT_SYMBOL(locks_lock_inode_wait); /** * sys_flock: - flock() system call. @@ -1933,7 +1958,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) (can_sleep) ? F_SETLKW : F_SETLK, lock); else - error = flock_lock_file_wait(f.file, lock); + error = locks_lock_file_wait(f.file, lock); out_free: locks_free_lock(lock); @@ -2109,7 +2134,7 @@ static int do_lock_file_wait(struct file *filp, unsigned int cmd, return error; } -/* Ensure that fl->fl_filp has compatible f_mode for F_SETLK calls */ +/* Ensure that fl->fl_file has compatible f_mode for F_SETLK calls */ static int check_fmode_for_setlk(struct file_lock *fl) { @@ -2157,7 +2182,6 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, goto out; } -again: error = flock_to_posix_lock(filp, file_lock, &flock); if (error) goto out; @@ -2199,19 +2223,22 @@ again: * Attempt to detect a close/fcntl race and recover by * releasing the lock that was just acquired. */ - /* - * we need that spin_lock here - it prevents reordering between - * update of i_flctx->flc_posix and check for it done in close(). - * rcu_read_lock() wouldn't do. - */ - spin_lock(¤t->files->file_lock); - f = fcheck(fd); - spin_unlock(¤t->files->file_lock); - if (!error && f != filp && flock.l_type != F_UNLCK) { - flock.l_type = F_UNLCK; - goto again; + if (!error && file_lock->fl_type != F_UNLCK) { + /* + * We need that spin_lock here - it prevents reordering between + * update of i_flctx->flc_posix and check for it done in + * close(). rcu_read_lock() wouldn't do. + */ + spin_lock(¤t->files->file_lock); + f = fcheck(fd); + spin_unlock(¤t->files->file_lock); + if (f != filp) { + file_lock->fl_type = F_UNLCK; + error = do_lock_file_wait(filp, cmd, file_lock); + WARN_ON_ONCE(error); + error = -EBADF; + } } - out: locks_free_lock(file_lock); return error; @@ -2297,7 +2324,6 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, goto out; } -again: error = flock64_to_posix_lock(filp, file_lock, &flock); if (error) goto out; @@ -2339,14 +2365,22 @@ again: * Attempt to detect a close/fcntl race and recover by * releasing the lock that was just acquired. */ - spin_lock(¤t->files->file_lock); - f = fcheck(fd); - spin_unlock(¤t->files->file_lock); - if (!error && f != filp && flock.l_type != F_UNLCK) { - flock.l_type = F_UNLCK; - goto again; + if (!error && file_lock->fl_type != F_UNLCK) { + /* + * We need that spin_lock here - it prevents reordering between + * update of i_flctx->flc_posix and check for it done in + * close(). rcu_read_lock() wouldn't do. + */ + spin_lock(¤t->files->file_lock); + f = fcheck(fd); + spin_unlock(¤t->files->file_lock); + if (f != filp) { + file_lock->fl_type = F_UNLCK; + error = do_lock_file_wait(filp, cmd, file_lock); + WARN_ON_ONCE(error); + error = -EBADF; + } } - out: locks_free_lock(file_lock); return error; @@ -2361,13 +2395,14 @@ out: void locks_remove_posix(struct file *filp, fl_owner_t owner) { struct file_lock lock; - struct file_lock_context *ctx = file_inode(filp)->i_flctx; + struct file_lock_context *ctx; /* * If there are no locks held on this file, we don't need to call * posix_lock_file(). Another process could be setting a lock on this * file at the same time, but we wouldn't remove that lock anyway. */ + ctx = smp_load_acquire(&file_inode(filp)->i_flctx); if (!ctx || list_empty(&ctx->flc_posix)) return; @@ -2391,7 +2426,7 @@ EXPORT_SYMBOL(locks_remove_posix); /* The i_flctx must be valid when calling into here */ static void -locks_remove_flock(struct file *filp) +locks_remove_flock(struct file *filp, struct file_lock_context *flctx) { struct file_lock fl = { .fl_owner = filp, @@ -2401,7 +2436,7 @@ locks_remove_flock(struct file *filp) .fl_type = F_UNLCK, .fl_end = OFFSET_MAX, }; - struct file_lock_context *flctx = file_inode(filp)->i_flctx; + struct inode *inode = file_inode(filp); if (list_empty(&flctx->flc_flock)) return; @@ -2409,7 +2444,7 @@ locks_remove_flock(struct file *filp) if (filp->f_op->flock) filp->f_op->flock(filp, F_SETLKW, &fl); else - flock_lock_file(filp, &fl); + flock_lock_inode(inode, &fl); if (fl.fl_ops && fl.fl_ops->fl_release_private) fl.fl_ops->fl_release_private(&fl); @@ -2417,10 +2452,8 @@ locks_remove_flock(struct file *filp) /* The i_flctx must be valid when calling into here */ static void -locks_remove_lease(struct file *filp) +locks_remove_lease(struct file *filp, struct file_lock_context *ctx) { - struct inode *inode = file_inode(filp); - struct file_lock_context *ctx = inode->i_flctx; struct file_lock *fl, *tmp; LIST_HEAD(dispose); @@ -2440,17 +2473,20 @@ locks_remove_lease(struct file *filp) */ void locks_remove_file(struct file *filp) { - if (!file_inode(filp)->i_flctx) + struct file_lock_context *ctx; + + ctx = smp_load_acquire(&file_inode(filp)->i_flctx); + if (!ctx) return; /* remove any OFD locks */ locks_remove_posix(filp, filp); /* remove flock locks */ - locks_remove_flock(filp); + locks_remove_flock(filp, ctx); /* remove any leases */ - locks_remove_lease(filp); + locks_remove_lease(filp, ctx); } /** @@ -2617,7 +2653,7 @@ void show_fd_locks(struct seq_file *f, struct file_lock_context *ctx; int id = 0; - ctx = inode->i_flctx; + ctx = smp_load_acquire(&inode->i_flctx); if (!ctx) return; -- cgit 1.2.3-korg