X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Flocks.c;h=1aead65f29ab5b5abcdbf2ccb076b45509e0afc5;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=5cfa9653da236497e7cd2fd0d14c7513c546c297;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git diff --git a/fs/locks.c b/fs/locks.c index 5cfa9653d..1aead65f2 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -124,6 +124,7 @@ #include #include #include +#include #include #include @@ -139,13 +140,10 @@ int lease_break_time = 45; #define for_each_lock(inode, lockp) \ for (lockp = &inode->i_flock; *lockp != NULL; lockp = &(*lockp)->fl_next) -LIST_HEAD(file_lock_list); - -EXPORT_SYMBOL(file_lock_list); - +static LIST_HEAD(file_lock_list); static LIST_HEAD(blocked_list); -static kmem_cache_t *filelock_cache; +static kmem_cache_t *filelock_cache __read_mostly; /* Allocate an empty lock structure. */ static struct file_lock *locks_alloc_lock(void) @@ -155,36 +153,30 @@ static struct file_lock *locks_alloc_lock(void) return kmem_cache_alloc(filelock_cache, SLAB_KERNEL); } -/* Free a lock which is not in use. */ -static inline void locks_free_lock(struct file_lock *fl) +static void locks_release_private(struct file_lock *fl) { - vx_locks_dec(fl); - - if (fl == NULL) { - BUG(); - return; - } - if (waitqueue_active(&fl->fl_wait)) - panic("Attempting to free lock with active wait queue"); - - if (!list_empty(&fl->fl_block)) - panic("Attempting to free lock with active block list"); - - if (!list_empty(&fl->fl_link)) - panic("Attempting to free lock on active lock list"); - if (fl->fl_ops) { if (fl->fl_ops->fl_release_private) fl->fl_ops->fl_release_private(fl); fl->fl_ops = NULL; } - if (fl->fl_lmops) { if (fl->fl_lmops->fl_release_private) fl->fl_lmops->fl_release_private(fl); fl->fl_lmops = NULL; } +} + +/* Free a lock which is not in use. */ +static void locks_free_lock(struct file_lock *fl) +{ + BUG_ON(waitqueue_active(&fl->fl_wait)); + BUG_ON(!list_empty(&fl->fl_block)); + BUG_ON(!list_empty(&fl->fl_link)); + + vx_locks_dec(fl); + locks_release_private(fl); kmem_cache_free(filelock_cache, fl); } @@ -223,26 +215,47 @@ static void init_once(void *foo, kmem_cache_t *cache, unsigned long flags) locks_init_lock(lock); } +static void locks_copy_private(struct file_lock *new, struct file_lock *fl) +{ + if (fl->fl_ops) { + if (fl->fl_ops->fl_copy_lock) + fl->fl_ops->fl_copy_lock(new, fl); + new->fl_ops = fl->fl_ops; + } + if (fl->fl_lmops) { + if (fl->fl_lmops->fl_copy_lock) + fl->fl_lmops->fl_copy_lock(new, fl); + new->fl_lmops = fl->fl_lmops; + } +} + /* * Initialize a new lock from an existing file_lock structure. */ -void locks_copy_lock(struct file_lock *new, struct file_lock *fl) +static void __locks_copy_lock(struct file_lock *new, const struct file_lock *fl) { new->fl_owner = fl->fl_owner; new->fl_pid = fl->fl_pid; - new->fl_file = fl->fl_file; + new->fl_file = NULL; new->fl_flags = fl->fl_flags; new->fl_type = fl->fl_type; new->fl_start = fl->fl_start; new->fl_end = fl->fl_end; + new->fl_ops = NULL; + new->fl_lmops = NULL; +} + +void locks_copy_lock(struct file_lock *new, struct file_lock *fl) +{ + locks_release_private(new); + + __locks_copy_lock(new, fl); + new->fl_file = fl->fl_file; new->fl_ops = fl->fl_ops; new->fl_lmops = fl->fl_lmops; - if (fl->fl_ops && fl->fl_ops->fl_copy_lock) - fl->fl_ops->fl_copy_lock(new, fl); - if (fl->fl_lmops && fl->fl_lmops->fl_copy_lock) - fl->fl_lmops->fl_copy_lock(new, fl); - new->fl_xid = fl->fl_xid; + + locks_copy_private(new, fl); } EXPORT_SYMBOL(locks_copy_lock); @@ -280,8 +293,9 @@ static int flock_make_lock(struct file *filp, struct file_lock **lock, fl->fl_type = type; fl->fl_end = OFFSET_MAX; - /* check against file xid maybe ? */ - fl->fl_xid = vx_current_xid(); + vxd_assert(filp->f_xid == vx_current_xid(), + "f_xid(%d) == current(%d)", filp->f_xid, vx_current_xid()); + fl->fl_xid = filp->f_xid; vx_locks_inc(fl); *lock = fl; @@ -327,21 +341,22 @@ static int flock_to_posix_lock(struct file *filp, struct file_lock *fl, /* POSIX-1996 leaves the case l->l_len < 0 undefined; POSIX-2001 defines it. */ start += l->l_start; - end = start + l->l_len - 1; - if (l->l_len < 0) { + if (start < 0) + return -EINVAL; + fl->fl_end = OFFSET_MAX; + if (l->l_len > 0) { + end = start + l->l_len - 1; + fl->fl_end = end; + } else if (l->l_len < 0) { end = start - 1; + fl->fl_end = end; start += l->l_len; + if (start < 0) + return -EINVAL; } - - if (start < 0) - return -EINVAL; - if (l->l_len > 0 && end < 0) - return -EOVERFLOW; - fl->fl_start = start; /* we record the absolute position */ - fl->fl_end = end; - if (l->l_len == 0) - fl->fl_end = OFFSET_MAX; + if (fl->fl_end < fl->fl_start) + return -EOVERFLOW; fl->fl_owner = current->files; fl->fl_pid = current->tgid; @@ -373,14 +388,21 @@ static int flock64_to_posix_lock(struct file *filp, struct file_lock *fl, return -EINVAL; } - if (((start += l->l_start) < 0) || (l->l_len < 0)) + start += l->l_start; + if (start < 0) return -EINVAL; - fl->fl_end = start + l->l_len - 1; - if (l->l_len > 0 && fl->fl_end < 0) - return -EOVERFLOW; + fl->fl_end = OFFSET_MAX; + if (l->l_len > 0) { + fl->fl_end = start + l->l_len - 1; + } else if (l->l_len < 0) { + fl->fl_end = start - 1; + start += l->l_len; + if (start < 0) + return -EINVAL; + } fl->fl_start = start; /* we record the absolute position */ - if (l->l_len == 0) - fl->fl_end = OFFSET_MAX; + if (fl->fl_end < fl->fl_start) + return -EOVERFLOW; fl->fl_owner = current->files; fl->fl_pid = current->tgid; @@ -435,15 +457,15 @@ static struct lock_manager_operations lease_manager_ops = { */ static int lease_init(struct file *filp, int type, struct file_lock *fl) { + if (assign_type(fl, type) != 0) + return -EINVAL; + fl->fl_owner = current->files; fl->fl_pid = current->tgid; + fl->fl_xid = vx_current_xid(); fl->fl_file = filp; fl->fl_flags = FL_LEASE; - if (assign_type(fl, type) != 0) { - locks_free_lock(fl); - return -EINVAL; - } fl->fl_start = 0; fl->fl_end = OFFSET_MAX; fl->fl_ops = NULL; @@ -455,18 +477,24 @@ static int lease_init(struct file *filp, int type, struct file_lock *fl) static int lease_alloc(struct file *filp, int type, struct file_lock **flp) { struct file_lock *fl = locks_alloc_lock(); - int error; + int error = -ENOMEM; if (fl == NULL) - return -ENOMEM; + goto out; fl->fl_xid = vx_current_xid(); + if (filp) + vxd_assert(filp->f_xid == fl->fl_xid, + "f_xid(%d) == fl_xid(%d)", filp->f_xid, fl->fl_xid); vx_locks_inc(fl); error = lease_init(filp, type, fl); - if (error) - return error; + if (error) { + locks_free_lock(fl); + fl = NULL; + } +out: *flp = fl; - return 0; + return error; } /* Check if two locks overlap each other. @@ -480,8 +508,7 @@ static inline int locks_overlap(struct file_lock *fl1, struct file_lock *fl2) /* * Check whether two locks have the same owner. */ -static inline int -posix_same_owner(struct file_lock *fl1, struct file_lock *fl2) +static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2) { if (fl1->fl_lmops && fl1->fl_lmops->fl_compare_owner) return fl2->fl_lmops == fl1->fl_lmops && @@ -492,7 +519,7 @@ posix_same_owner(struct file_lock *fl1, struct file_lock *fl2) /* Remove waiter from blocker's block list. * When blocker ends up pointing to itself then the list is empty. */ -static inline void __locks_delete_block(struct file_lock *waiter) +static void __locks_delete_block(struct file_lock *waiter) { list_del_init(&waiter->fl_block); list_del_init(&waiter->fl_link); @@ -516,12 +543,7 @@ static void locks_delete_block(struct file_lock *waiter) static void locks_insert_block(struct file_lock *blocker, struct file_lock *waiter) { - if (!list_empty(&waiter->fl_block)) { - printk(KERN_ERR "locks_insert_block: removing duplicated lock " - "(pid=%d %Ld-%Ld type=%d)\n", waiter->fl_pid, - waiter->fl_start, waiter->fl_end, waiter->fl_type); - __locks_delete_block(waiter); - } + BUG_ON(!list_empty(&waiter->fl_block)); list_add_tail(&waiter->fl_block, &blocker->fl_block); waiter->fl_next = blocker; if (IS_POSIX(blocker)) @@ -660,8 +682,9 @@ static int locks_block_on_timeout(struct file_lock *blocker, struct file_lock *w return result; } -struct file_lock * -posix_test_lock(struct file *filp, struct file_lock *fl) +int +posix_test_lock(struct file *filp, struct file_lock *fl, + struct file_lock *conflock) { struct file_lock *cfl; @@ -672,9 +695,13 @@ posix_test_lock(struct file *filp, struct file_lock *fl) if (posix_locks_conflict(cfl, fl)) break; } + if (cfl) { + __locks_copy_lock(conflock, cfl); + unlock_kernel(); + return 1; + } unlock_kernel(); - - return (cfl); + return 0; } EXPORT_SYMBOL(posix_test_lock); @@ -718,8 +745,9 @@ EXPORT_SYMBOL(posix_locks_deadlock); * at the head of the list, but that's secret knowledge known only to * flock_lock_file and posix_lock_file. */ -static int flock_lock_file(struct file *filp, struct file_lock *new_fl) +static int flock_lock_file(struct file *filp, struct file_lock *request) { + struct file_lock *new_fl = NULL; struct file_lock **before; struct inode * inode = filp->f_dentry->d_inode; int error = 0; @@ -734,17 +762,20 @@ static int flock_lock_file(struct file *filp, struct file_lock *new_fl) continue; if (filp != fl->fl_file) continue; - if (new_fl->fl_type == fl->fl_type) + if (request->fl_type == fl->fl_type) goto out; found = 1; locks_delete_lock(before); break; } - unlock_kernel(); - if (new_fl->fl_type == F_UNLCK) - return 0; + if (request->fl_type == F_UNLCK) + goto out; + error = -ENOMEM; + new_fl = locks_alloc_lock(); + if (new_fl == NULL) + goto out; /* * If a higher-priority process was blocked on the old file lock, * give it the opportunity to lock the file. @@ -752,32 +783,34 @@ static int flock_lock_file(struct file *filp, struct file_lock *new_fl) if (found) cond_resched(); - lock_kernel(); for_each_lock(inode, before) { struct file_lock *fl = *before; if (IS_POSIX(fl)) break; if (IS_LEASE(fl)) continue; - if (!flock_locks_conflict(new_fl, fl)) + if (!flock_locks_conflict(request, fl)) continue; error = -EAGAIN; - if (new_fl->fl_flags & FL_SLEEP) { - locks_insert_block(fl, new_fl); - } + if (request->fl_flags & FL_SLEEP) + locks_insert_block(fl, request); goto out; } + locks_copy_lock(new_fl, request); + vx_locks_inc(new_fl); locks_insert_lock(&inode->i_flock, new_fl); + new_fl = NULL; error = 0; out: unlock_kernel(); + if (new_fl) + locks_free_lock(new_fl); return error; } -EXPORT_SYMBOL(posix_lock_file); - -static int __posix_lock_file(struct inode *inode, struct file_lock *request) +static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request, + struct file_lock *conflock, xid_t xid) { struct file_lock *fl; struct file_lock *new_fl, *new_fl2; @@ -786,15 +819,17 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request) struct file_lock **before; int error, added = 0; + vxd_assert(xid == vx_current_xid(), + "xid(%d) == current(%d)", xid, vx_current_xid()); /* * We may need two file_lock structures for this operation, * so we get them in advance to avoid races. */ new_fl = locks_alloc_lock(); - new_fl->fl_xid = vx_current_xid(); + new_fl->fl_xid = xid; vx_locks_inc(new_fl); new_fl2 = locks_alloc_lock(); - new_fl2->fl_xid = vx_current_xid(); + new_fl2->fl_xid = xid; vx_locks_inc(new_fl2); lock_kernel(); @@ -805,6 +840,8 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request) continue; if (!posix_locks_conflict(request, fl)) continue; + if (conflock) + locks_copy_lock(conflock, fl); error = -EAGAIN; if (!(request->fl_flags & FL_SLEEP)) goto out; @@ -846,12 +883,16 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request) /* Detect adjacent or overlapping regions (if same lock type) */ if (request->fl_type == fl->fl_type) { + /* In all comparisons of start vs end, use + * "start - 1" rather than "end + 1". If end + * is OFFSET_MAX, end + 1 will become negative. + */ if (fl->fl_end < request->fl_start - 1) goto next_lock; /* If the next lock in the list has entirely bigger * addresses than the new one, insert the lock here. */ - if (fl->fl_start > request->fl_end + 1) + if (fl->fl_start - 1 > request->fl_end) break; /* If we come here, the new and old lock are of the @@ -910,7 +951,8 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request) fl->fl_start = request->fl_start; fl->fl_end = request->fl_end; fl->fl_type = request->fl_type; - fl->fl_u = request->fl_u; + locks_release_private(fl); + locks_copy_private(fl, request); request = fl; added = 1; } @@ -969,8 +1011,26 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request) */ int posix_lock_file(struct file *filp, struct file_lock *fl) { - return __posix_lock_file(filp->f_dentry->d_inode, fl); + return __posix_lock_file_conf(filp->f_dentry->d_inode, + fl, NULL, filp->f_xid); +} +EXPORT_SYMBOL(posix_lock_file); + +/** + * posix_lock_file_conf - Apply a POSIX-style lock to a file + * @filp: The file to apply the lock to + * @fl: The lock to be applied + * @conflock: Place to return a copy of the conflicting lock, if found. + * + * Except for the conflock parameter, acts just like posix_lock_file. + */ +int posix_lock_file_conf(struct file *filp, struct file_lock *fl, + struct file_lock *conflock) +{ + return __posix_lock_file_conf(filp->f_dentry->d_inode, + fl, conflock, filp->f_xid); } +EXPORT_SYMBOL(posix_lock_file_conf); /** * posix_lock_file_wait - Apply a POSIX-style lock to a file @@ -986,7 +1046,7 @@ int posix_lock_file_wait(struct file *filp, struct file_lock *fl) int error; might_sleep (); for (;;) { - error = __posix_lock_file(filp->f_dentry->d_inode, fl); + error = posix_lock_file(filp, fl); if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP)) break; error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); @@ -1058,7 +1118,7 @@ int locks_mandatory_area(int read_write, struct inode *inode, fl.fl_end = offset + count - 1; for (;;) { - error = __posix_lock_file(inode, &fl); + error = __posix_lock_file_conf(inode, &fl, NULL, filp->f_xid); if (error != -EAGAIN) break; if (!(fl.fl_flags & FL_SLEEP)) @@ -1110,7 +1170,6 @@ static void time_out_leases(struct inode *inode) before = &fl->fl_next; continue; } - printk(KERN_INFO "lease broken - owner pid = %d\n", fl->fl_pid); lease_modify(before, fl->fl_type & ~F_INPROGRESS); if (fl == *before) /* lease_modify may have freed fl */ before = &fl->fl_next; @@ -1294,7 +1353,7 @@ int fcntl_getlease(struct file *filp) */ static int __setlease(struct file *filp, long arg, struct file_lock **flp) { - struct file_lock *fl, **before, **my_before = NULL, *lease = *flp; + struct file_lock *fl, **before, **my_before = NULL, *lease; struct dentry *dentry = filp->f_dentry; struct inode *inode = dentry->d_inode; int error, rdlease_count = 0, wrlease_count = 0; @@ -1305,6 +1364,8 @@ static int __setlease(struct file *filp, long arg, struct file_lock **flp) if (!flp || !(*flp) || !(*flp)->fl_lmops || !(*flp)->fl_lmops->fl_break) goto out; + lease = *flp; + error = -EAGAIN; if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0)) goto out; @@ -1342,6 +1403,7 @@ static int __setlease(struct file *filp, long arg, struct file_lock **flp) goto out; if (my_before != NULL) { + *flp = *my_before; error = lease->fl_lmops->fl_change(my_before, arg); goto out; } @@ -1433,7 +1495,7 @@ int fcntl_setlease(unsigned int fd, struct file *filp, long arg) lock_kernel(); error = __setlease(filp, arg, &flp); - if (error) + if (error || arg == F_UNLCK) goto out_unlock; error = fasync_helper(fd, filp, 1, &flp->fl_fasync); @@ -1534,9 +1596,7 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd) error = flock_lock_file_wait(filp, lock); out_free: - if (list_empty(&lock->fl_link)) { - locks_free_lock(lock); - } + locks_free_lock(lock); out_putf: fput(filp); @@ -1549,7 +1609,7 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd) */ int fcntl_getlk(struct file *filp, struct flock __user *l) { - struct file_lock *fl, file_lock; + struct file_lock *fl, cfl, file_lock; struct flock flock; int error; @@ -1566,12 +1626,14 @@ int fcntl_getlk(struct file *filp, struct flock __user *l) if (filp->f_op && filp->f_op->lock) { error = filp->f_op->lock(filp, F_GETLK, &file_lock); + if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private) + file_lock.fl_ops->fl_release_private(&file_lock); if (error < 0) goto out; else fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock); } else { - fl = posix_test_lock(filp, &file_lock); + fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL); } flock.l_type = F_UNLCK; @@ -1605,7 +1667,8 @@ out: /* Apply the lock described by l to an open file descriptor. * This implements both the F_SETLK and F_SETLKW commands of fcntl(). */ -int fcntl_setlk(struct file *filp, unsigned int cmd, struct flock __user *l) +int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, + struct flock __user *l) { struct file_lock *file_lock = locks_alloc_lock(); struct flock flock; @@ -1615,7 +1678,9 @@ int fcntl_setlk(struct file *filp, unsigned int cmd, struct flock __user *l) if (file_lock == NULL) return -ENOLCK; - file_lock->fl_xid = vx_current_xid(); + vxd_assert(filp->f_xid == vx_current_xid(), + "f_xid(%d) == current(%d)", filp->f_xid, vx_current_xid()); + file_lock->fl_xid = filp->f_xid; vx_locks_inc(file_lock); /* @@ -1637,6 +1702,7 @@ int fcntl_setlk(struct file *filp, unsigned int cmd, struct flock __user *l) goto out; } +again: error = flock_to_posix_lock(filp, file_lock, &flock); if (error) goto out; @@ -1665,25 +1731,33 @@ int fcntl_setlk(struct file *filp, unsigned int cmd, struct flock __user *l) if (error) goto out; - if (filp->f_op && filp->f_op->lock != NULL) { + if (filp->f_op && filp->f_op->lock != NULL) error = filp->f_op->lock(filp, cmd, file_lock); - goto out; - } + else { + for (;;) { + error = posix_lock_file(filp, file_lock); + if ((error != -EAGAIN) || (cmd == F_SETLK)) + break; + error = wait_event_interruptible(file_lock->fl_wait, + !file_lock->fl_next); + if (!error) + continue; - for (;;) { - error = __posix_lock_file(inode, file_lock); - if ((error != -EAGAIN) || (cmd == F_SETLK)) + locks_delete_block(file_lock); break; - error = wait_event_interruptible(file_lock->fl_wait, - !file_lock->fl_next); - if (!error) - continue; + } + } - locks_delete_block(file_lock); - break; + /* + * Attempt to detect a close/fcntl race and recover by + * releasing the lock that was just acquired. + */ + if (!error && fcheck(fd) != filp && flock.l_type != F_UNLCK) { + flock.l_type = F_UNLCK; + goto again; } - out: +out: locks_free_lock(file_lock); return error; } @@ -1694,7 +1768,7 @@ int fcntl_setlk(struct file *filp, unsigned int cmd, struct flock __user *l) */ int fcntl_getlk64(struct file *filp, struct flock64 __user *l) { - struct file_lock *fl, file_lock; + struct file_lock *fl, cfl, file_lock; struct flock64 flock; int error; @@ -1711,12 +1785,14 @@ int fcntl_getlk64(struct file *filp, struct flock64 __user *l) if (filp->f_op && filp->f_op->lock) { error = filp->f_op->lock(filp, F_GETLK, &file_lock); + if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private) + file_lock.fl_ops->fl_release_private(&file_lock); if (error < 0) goto out; else fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock); } else { - fl = posix_test_lock(filp, &file_lock); + fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL); } flock.l_type = F_UNLCK; @@ -1739,7 +1815,8 @@ out: /* Apply the lock described by l to an open file descriptor. * This implements both the F_SETLK and F_SETLKW commands of fcntl(). */ -int fcntl_setlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) +int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, + struct flock64 __user *l) { struct file_lock *file_lock = locks_alloc_lock(); struct flock64 flock; @@ -1749,7 +1826,9 @@ int fcntl_setlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) if (file_lock == NULL) return -ENOLCK; - file_lock->fl_xid = vx_current_xid(); + vxd_assert(filp->f_xid == vx_current_xid(), + "f_xid(%d) == current(%d)", filp->f_xid, vx_current_xid()); + file_lock->fl_xid = filp->f_xid; vx_locks_inc(file_lock); /* @@ -1771,6 +1850,7 @@ int fcntl_setlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) goto out; } +again: error = flock64_to_posix_lock(filp, file_lock, &flock); if (error) goto out; @@ -1799,22 +1879,30 @@ int fcntl_setlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) if (error) goto out; - if (filp->f_op && filp->f_op->lock != NULL) { + if (filp->f_op && filp->f_op->lock != NULL) error = filp->f_op->lock(filp, cmd, file_lock); - goto out; - } + else { + for (;;) { + error = posix_lock_file(filp, file_lock); + if ((error != -EAGAIN) || (cmd == F_SETLK64)) + break; + error = wait_event_interruptible(file_lock->fl_wait, + !file_lock->fl_next); + if (!error) + continue; - for (;;) { - error = __posix_lock_file(inode, file_lock); - if ((error != -EAGAIN) || (cmd == F_SETLK64)) + locks_delete_block(file_lock); break; - error = wait_event_interruptible(file_lock->fl_wait, - !file_lock->fl_next); - if (!error) - continue; + } + } - locks_delete_block(file_lock); - break; + /* + * Attempt to detect a close/fcntl race and recover by + * releasing the lock that was just acquired. + */ + if (!error && fcheck(fd) != filp && flock.l_type != F_UNLCK) { + flock.l_type = F_UNLCK; + goto again; } out: @@ -1897,6 +1985,8 @@ void locks_remove_flock(struct file *filp) .fl_end = OFFSET_MAX, }; filp->f_op->flock(filp, F_SETLKW, &fl); + if (fl.fl_ops && fl.fl_ops->fl_release_private) + fl.fl_ops->fl_release_private(&fl); } lock_kernel(); @@ -1904,12 +1994,7 @@ void locks_remove_flock(struct file *filp) while ((fl = *before) != NULL) { if (fl->fl_file == filp) { - /* - * We might have a POSIX lock that was created at the same time - * the filp was closed for the last time. Just remove that too, - * regardless of ownership, since nobody can own it. - */ - if (IS_FLOCK(fl) || IS_POSIX(fl)) { + if (IS_FLOCK(fl)) { locks_delete_lock(before); continue; } @@ -1925,21 +2010,6 @@ void locks_remove_flock(struct file *filp) unlock_kernel(); } -/** - * posix_block_lock - blocks waiting for a file lock - * @blocker: the lock which is blocking - * @waiter: the lock which conflicts and has to wait - * - * lockd needs to block waiting for locks. - */ -void -posix_block_lock(struct file_lock *blocker, struct file_lock *waiter) -{ - locks_insert_block(blocker, waiter); -} - -EXPORT_SYMBOL(posix_block_lock); - /** * posix_unblock_lock - stop waiting for a file lock * @filp: how the file was opened @@ -1947,22 +2017,18 @@ EXPORT_SYMBOL(posix_block_lock); * * lockd needs to block waiting for locks. */ -void +int posix_unblock_lock(struct file *filp, struct file_lock *waiter) { - /* - * A remote machine may cancel the lock request after it's been - * granted locally. If that happens, we need to delete the lock. - */ + int status = 0; + lock_kernel(); - if (waiter->fl_next) { + if (waiter->fl_next) __locks_delete_block(waiter); - unlock_kernel(); - } else { - unlock_kernel(); - waiter->fl_type = F_UNLCK; - posix_lock_file(filp, waiter); - } + else + status = -ENOENT; + unlock_kernel(); + return status; } EXPORT_SYMBOL(posix_unblock_lock); @@ -2075,6 +2141,10 @@ int get_locks_status(char *buffer, char **start, off_t offset, int length) list_for_each(tmp, &file_lock_list) { struct list_head *btmp; struct file_lock *fl = list_entry(tmp, struct file_lock, fl_link); + + if (!vx_check(fl->fl_xid, VX_IDENT|VX_WATCH)) + continue; + lock_get_status(q, fl, ++i, ""); move_lock_status(&q, &pos, offset); @@ -2199,21 +2269,29 @@ void steal_locks(fl_owner_t from) { struct files_struct *files = current->files; int i, j; + struct fdtable *fdt; if (from == files) return; lock_kernel(); j = 0; + + /* + * We are not taking a ref to the file structures, so + * we need to acquire ->file_lock. + */ + spin_lock(&files->file_lock); + fdt = files_fdtable(files); for (;;) { unsigned long set; i = j * __NFDBITS; - if (i >= files->max_fdset || i >= files->max_fds) + if (i >= fdt->max_fdset || i >= fdt->max_fds) break; - set = files->open_fds->fds_bits[j++]; + set = fdt->open_fds->fds_bits[j++]; while (set) { if (set & 1) { - struct file *file = files->fd[i]; + struct file *file = fdt->fd[i]; if (file) __steal_locks(file, from); } @@ -2221,6 +2299,7 @@ void steal_locks(fl_owner_t from) set >>= 1; } } + spin_unlock(&files->file_lock); unlock_kernel(); } EXPORT_SYMBOL(steal_locks);