// SPDX-License-Identifier: GPL-2.0-only/* * linux/fs/locks.c * * We implement four types of file locks: BSD locks, posix locks, open * file description locks, and leases. For details about BSD locks, * see the flock(2) man page; for details about the other three, see * fcntl(2). * * * Locking conflicts and dependencies: * If multiple threads attempt to lock the same byte (or flock the same file) * only one can be granted the lock, and other must wait their turn. * The first lock has been "applied" or "granted", the others are "waiting" * and are "blocked" by the "applied" lock.. * * Waiting and applied locks are all kept in trees whose properties are: * * - the root of a tree may be an applied or waiting lock. * - every other node in the tree is a waiting lock that * conflicts with every ancestor of that node. * * Every such tree begins life as a waiting singleton which obviously * satisfies the above properties. * * The only ways we modify trees preserve these properties: * * 1. We may add a new leaf node, but only after first verifying that it * conflicts with all of its ancestors. * 2. We may remove the root of a tree, creating a new singleton * tree from the root and N new trees rooted in the immediate * children. * 3. If the root of a tree is not currently an applied lock, we may * apply it (if possible). * 4. We may upgrade the root of the tree (either extend its range, * or upgrade its entire range from read to write). * * When an applied lock is modified in a way that reduces or downgrades any * part of its range, we remove all its children (2 above). This particularly * happens when a lock is unlocked. * * For each of those child trees we "wake up" the thread which is * waiting for the lock so it can continue handling as follows: if the * root of the tree applies, we do so (3). If it doesn't, it must * conflict with some applied lock. We remove (wake up) all of its children * (2), and add it is a new leaf to the tree rooted in the applied * lock (1). We then repeat the process recursively with those * children. * */#include <linux/capability.h>#include <linux/file.h>#include <linux/fdtable.h>#include <linux/filelock.h>#include <linux/fs.h>#include <linux/init.h>#include <linux/security.h>#include <linux/slab.h>#include <linux/syscalls.h>#include <linux/time.h>#include <linux/rcupdate.h>#include <linux/pid_namespace.h>#include <linux/hashtable.h>#include <linux/percpu.h>#include <linux/sysctl.h> #define CREATE_TRACE_POINTS#include <trace/events/filelock.h> #include <linux/uaccess.h> static struct file_lock *file_lock(struct file_lock_core *flc){ return container_of(flc, struct file_lock, c);} static struct file_lease *file_lease(struct file_lock_core *flc){ return container_of(flc, struct file_lease, c);} static bool lease_breaking(struct file_lease *fl){ return fl->c.flc_flags & (FL_UNLOCK_PENDING | FL_DOWNGRADE_PENDING);} static int target_leasetype(struct file_lease *fl){ if (fl->c.flc_flags & FL_UNLOCK_PENDING) return F_UNLCK; if (fl->c.flc_flags & FL_DOWNGRADE_PENDING) return F_RDLCK; return fl->c.flc_type;} static int leases_enable = 1;static int lease_break_time = 45; #ifdef CONFIG_SYSCTLstatic const struct ctl_table locks_sysctls[] = { { .procname = "leases-enable", .data = &leases_enable, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, },#ifdef CONFIG_MMU { .procname = "lease-break-time", .data = &lease_break_time, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, },#endif /* CONFIG_MMU */}; static int __init init_fs_locks_sysctls(void){ register_sysctl_init("fs", locks_sysctls); return 0;}early_initcall(init_fs_locks_sysctls);#endif /* CONFIG_SYSCTL */ /* * The global file_lock_list is only used for displaying /proc/locks, so we * keep a list on each CPU, with each list protected by its own spinlock. * Global serialization is done using file_rwsem. * * Note that alterations to the list also require that the relevant flc_lock is * held. */struct file_lock_list_struct { spinlock_t lock; struct hlist_head hlist;};static DEFINE_PER_CPU(struct file_lock_list_struct, file_lock_list);DEFINE_STATIC_PERCPU_RWSEM(file_rwsem); /* * The blocked_hash is used to find POSIX lock loops for deadlock detection. * It is protected by blocked_lock_lock. * * We hash locks by lockowner in order to optimize searching for the lock a * particular lockowner is waiting on. * * FIXME: make this value scale via some heuristic? We generally will want more * buckets when we have more lockowners holding locks, but that's a little * difficult to determine without knowing what the workload will look like. */#define BLOCKED_HASH_BITS 7static DEFINE_HASHTABLE(blocked_hash, BLOCKED_HASH_BITS); /* * This lock protects the blocked_hash. Generally, if you're accessing it, you * want to be holding this lock. * * In addition, it also protects the fl->fl_blocked_requests list, and the * fl->fl_blocker pointer for file_lock structures that are acting as lock * requests (in contrast to those that are acting as records of acquired locks). * * Note that when we acquire this lock in order to change the above fields, * we often hold the flc_lock as well. In certain cases, when reading the fields * protected by this lock, we can skip acquiring it iff we already hold the * flc_lock. */static DEFINE_SPINLOCK(blocked_lock_lock); static struct kmem_cache *flctx_cache __ro_after_init;static struct kmem_cache *filelock_cache __ro_after_init;static struct kmem_cache *filelease_cache __ro_after_init; static struct file_lock_context *locks_get_lock_context(struct inode *inode, int type){ struct file_lock_context *ctx; ctx = locks_inode_context(inode); if (likely(ctx) || type == F_UNLCK) goto out; ctx = kmem_cache_alloc(flctx_cache, GFP_KERNEL); if (!ctx) goto out; 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. */ spin_lock(&inode->i_lock); if (!(inode->i_opflags & IOP_FLCTX)) { VFS_BUG_ON_INODE(inode->i_flctx, inode); WRITE_ONCE(inode->i_flctx, ctx); /* * Paired with locks_inode_context(). */ smp_store_release(&inode->i_opflags, inode->i_opflags | IOP_FLCTX); spin_unlock(&inode->i_lock); } else { VFS_BUG_ON_INODE(!inode->i_flctx, inode); spin_unlock(&inode->i_lock); kmem_cache_free(flctx_cache, ctx); ctx = locks_inode_context(inode); }out: trace_locks_get_lock_context(inode, type, ctx); return ctx;} static voidlocks_dump_ctx_list(struct list_head *list, char *list_type){ struct file_lock_core *flc; list_for_each_entry(flc, list, flc_list) pr_warn("%s: fl_owner=%p fl_flags=0x%x fl_type=0x%x fl_pid=%u\n", list_type, flc->flc_owner, flc->flc_flags, flc->flc_type, flc->flc_pid);} static voidlocks_check_ctx_lists(struct inode *inode){ struct file_lock_context *ctx = inode->i_flctx; if (unlikely(!list_empty(&ctx->flc_flock) || !list_empty(&ctx->flc_posix) || !list_empty(&ctx->flc_lease))) { pr_warn("Leaked locks on dev=0x%x:0x%x ino=0x%llx:\n", MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev), inode->i_ino); locks_dump_ctx_list(&ctx->flc_flock, "FLOCK"); locks_dump_ctx_list(&ctx->flc_posix, "POSIX"); locks_dump_ctx_list(&ctx->flc_lease, "LEASE"); }} static voidlocks_check_ctx_file_list(struct file *filp, struct list_head *list, char *list_type){ struct file_lock_core *flc; struct inode *inode = file_inode(filp); list_for_each_entry(flc, list, flc_list) if (flc->flc_file == filp) pr_warn("Leaked %s lock on dev=0x%x:0x%x ino=0x%llx " " fl_owner=%p fl_flags=0x%x fl_type=0x%x fl_pid=%u\n", list_type, MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev), inode->i_ino, flc->flc_owner, flc->flc_flags, flc->flc_type, flc->flc_pid);} voidlocks_free_lock_context(struct inode *inode){ struct file_lock_context *ctx = locks_inode_context(inode); if (unlikely(ctx)) { locks_check_ctx_lists(inode); kmem_cache_free(flctx_cache, ctx); }} static void locks_init_lock_heads(struct file_lock_core *flc){ INIT_HLIST_NODE(&flc->flc_link); INIT_LIST_HEAD(&flc->flc_list); INIT_LIST_HEAD(&flc->flc_blocked_requests); INIT_LIST_HEAD(&flc->flc_blocked_member); init_waitqueue_head(&flc->flc_wait);} /* Allocate an empty lock structure. */struct file_lock *locks_alloc_lock(void){ struct file_lock *fl = kmem_cache_zalloc(filelock_cache, GFP_KERNEL); if (fl) locks_init_lock_heads(&fl->c); return fl;}EXPORT_SYMBOL_GPL(locks_alloc_lock); /* Allocate an empty lock structure. */struct file_lease *locks_alloc_lease(void){ struct file_lease *fl = kmem_cache_zalloc(filelease_cache, GFP_KERNEL); if (fl) locks_init_lock_heads(&fl->c); return fl;}EXPORT_SYMBOL_GPL(locks_alloc_lease); void locks_release_private(struct file_lock *fl){ struct file_lock_core *flc = &fl->c; BUG_ON(waitqueue_active(&flc->flc_wait)); BUG_ON(!list_empty(&flc->flc_list)); BUG_ON(!list_empty(&flc->flc_blocked_requests)); BUG_ON(!list_empty(&flc->flc_blocked_member)); BUG_ON(!hlist_unhashed(&flc->flc_link)); 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->lm_put_owner) { fl->fl_lmops->lm_put_owner(flc->flc_owner); flc->flc_owner = NULL; } fl->fl_lmops = NULL; }}EXPORT_SYMBOL_GPL(locks_release_private); /** * locks_owner_has_blockers - Check for blocking lock requests * @flctx: file lock context * @owner: lock owner * * Return values: * %true: @owner has at least one blocker * %false: @owner has no blockers */bool locks_owner_has_blockers(struct file_lock_context *flctx, fl_owner_t owner){ struct file_lock_core *flc; spin_lock(&flctx->flc_lock); list_for_each_entry(flc, &flctx->flc_posix, flc_list) { if (flc->flc_owner != owner) continue; if (!list_empty(&flc->flc_blocked_requests)) { spin_unlock(&flctx->flc_lock); return true; } } spin_unlock(&flctx->flc_lock); return false;}EXPORT_SYMBOL_GPL(locks_owner_has_blockers); /* Free a lock which is not in use. */void locks_free_lock(struct file_lock *fl){ locks_release_private(fl); kmem_cache_free(filelock_cache, fl);}EXPORT_SYMBOL(locks_free_lock); /* Free a lease which is not in use. */void locks_free_lease(struct file_lease *fl){ kmem_cache_free(filelease_cache, fl);}EXPORT_SYMBOL(locks_free_lease); static voidlocks_dispose_list(struct list_head *dispose){ struct file_lock_core *flc; while (!list_empty(dispose)) { flc = list_first_entry(dispose, struct file_lock_core, flc_list); list_del_init(&flc->flc_list); locks_free_lock(file_lock(flc)); }} static voidlease_dispose_list(struct list_head *dispose){ struct file_lock_core *flc; while (!list_empty(dispose)) { flc = list_first_entry(dispose, struct file_lock_core, flc_list); list_del_init(&flc->flc_list); locks_free_lease(file_lease(flc)); }} void locks_init_lock(struct file_lock *fl){ memset(fl, 0, sizeof(struct file_lock)); locks_init_lock_heads(&fl->c);}EXPORT_SYMBOL(locks_init_lock); void locks_init_lease(struct file_lease *fl){ memset(fl, 0, sizeof(*fl)); locks_init_lock_heads(&fl->c);}EXPORT_SYMBOL(locks_init_lease); /* * Initialize a new lock from an existing file_lock structure. */void locks_copy_conflock(struct file_lock *new, struct file_lock *fl){ new->c.flc_owner = fl->c.flc_owner; new->c.flc_pid = fl->c.flc_pid; new->c.flc_file = NULL; new->c.flc_flags = fl->c.flc_flags; new->c.flc_type = fl->c.flc_type; new->fl_start = fl->fl_start; new->fl_end = fl->fl_end; new->fl_lmops = fl->fl_lmops; new->fl_ops = NULL; if (fl->fl_lmops) { if (fl->fl_lmops->lm_get_owner) fl->fl_lmops->lm_get_owner(fl->c.flc_owner); }}EXPORT_SYMBOL(locks_copy_conflock); void locks_copy_lock(struct file_lock *new, struct file_lock *fl){ /* "new" must be a freshly-initialized lock */ WARN_ON_ONCE(new->fl_ops); locks_copy_conflock(new, fl); new->c.flc_file = fl->c.flc_file; new->fl_ops = fl->fl_ops; if (fl->fl_ops) { if (fl->fl_ops->fl_copy_lock) fl->fl_ops->fl_copy_lock(new, fl); }}EXPORT_SYMBOL(locks_copy_lock); static void locks_move_blocks(struct file_lock *new, struct file_lock *fl){ struct file_lock *f; /* * As ctx->flc_lock is held, new requests cannot be added to * ->flc_blocked_requests, so we don't need a lock to check if it * is empty. */ if (list_empty(&fl->c.flc_blocked_requests)) return; spin_lock(&blocked_lock_lock); list_splice_init(&fl->c.flc_blocked_requests, &new->c.flc_blocked_requests); list_for_each_entry(f, &new->c.flc_blocked_requests, c.flc_blocked_member) f->c.flc_blocker = &new->c; spin_unlock(&blocked_lock_lock);} static inline int flock_translate_cmd(int cmd) { switch (cmd) { case LOCK_SH: return F_RDLCK; case LOCK_EX: return F_WRLCK; case LOCK_UN: return F_UNLCK; } return -EINVAL;} /* Fill in a file_lock structure with an appropriate FLOCK lock. */static void flock_make_lock(struct file *filp, struct file_lock *fl, int type){ locks_init_lock(fl); fl->c.flc_file = filp; fl->c.flc_owner = filp; fl->c.flc_pid = current->tgid; fl->c.flc_flags = FL_FLOCK; fl->c.flc_type = type; fl->fl_end = OFFSET_MAX;} static int assign_type(struct file_lock_core *flc, int type){ switch (type) { case F_RDLCK: case F_WRLCK:Lines 1–500 of 3163. 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// SPDX-License-Identifier: GPL-2.0-only /* * linux/fs/locks.c * * We implement four types of file locks: BSD locks, posix locks, open * file description locks, and leases. For details about BSD locks, * see the flock(2) man page; for details about the other three, see * fcntl(2). * * * Locking conflicts and dependencies: * If multiple threads attempt to lock the same byte (or flock the same file) * only one can be granted the lock, and other must wait their turn. * The first lock has been "applied" or "granted", the others are "waiting" * and are "blocked" by the "applied" lock.. * * Waiting and applied locks are all kept in trees whose properties are: * * - the root of a tree may be an applied or waiting lock. * - every other node in the tree is a waiting lock that * conflicts with every ancestor of that node. * * Every such tree begins life as a waiting singleton which obviously * satisfies the above properties. * * The only ways we modify trees preserve these properties: * * 1. We may add a new leaf node, but only after first verifying that it * conflicts with all of its ancestors. * 2. We may remove the root of a tree, creating a new singleton * tree from the root and N new trees rooted in the immediate * children. * 3. If the root of a tree is not currently an applied lock, we may * apply it (if possible). * 4. We may upgrade the root of the tree (either extend its range, * or upgrade its entire range from read to write). * * When an applied lock is modified in a way that reduces or downgrades any * part of its range, we remove all its children (2 above). This particularly * happens when a lock is unlocked. * * For each of those child trees we "wake up" the thread which is * waiting for the lock so it can continue handling as follows: if the * root of the tree applies, we do so (3). If it doesn't, it must * conflict with some applied lock. We remove (wake up) all of its children * (2), and add it is a new leaf to the tree rooted in the applied * lock (1). We then repeat the process recursively with those * children. * */ #include <linux/capability.h> #include <linux/file.h> #include <linux/fdtable.h> #include <linux/filelock.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/security.h> #include <linux/slab.h> #include <linux/syscalls.h> #include <linux/time.h> #include <linux/rcupdate.h> #include <linux/pid_namespace.h> #include <linux/hashtable.h> #include <linux/percpu.h> #include <linux/sysctl.h> #define CREATE_TRACE_POINTS #include <trace/events/filelock.h> #include <linux/uaccess.h> static struct file_lock *file_lock(struct file_lock_core *flc) { return container_of(flc, struct file_lock, c); } static struct file_lease *file_lease(struct file_lock_core *flc) { return container_of(flc, struct file_lease, c); } static bool lease_breaking(struct file_lease *fl) { return fl->c.flc_flags & (FL_UNLOCK_PENDING | FL_DOWNGRADE_PENDING); } static int target_leasetype(struct file_lease *fl) { if (fl->c.flc_flags & FL_UNLOCK_PENDING) return F_UNLCK; if (fl->c.flc_flags & FL_DOWNGRADE_PENDING) return F_RDLCK; return fl->c.flc_type; } static int leases_enable = 1; static int lease_break_time = 45; #ifdef CONFIG_SYSCTL static const struct ctl_table locks_sysctls[] = { { .procname = "leases-enable", .data = &leases_enable, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #ifdef CONFIG_MMU { .procname = "lease-break-time", .data = &lease_break_time, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif /* CONFIG_MMU */ }; static int __init init_fs_locks_sysctls(void) { register_sysctl_init("fs", locks_sysctls); return 0; } early_initcall(init_fs_locks_sysctls); #endif /* CONFIG_SYSCTL */ /* * The global file_lock_list is only used for displaying /proc/locks, so we * keep a list on each CPU, with each list protected by its own spinlock. * Global serialization is done using file_rwsem. * * Note that alterations to the list also require that the relevant flc_lock is * held. */ struct file_lock_list_struct { spinlock_t lock; struct hlist_head hlist; }; static DEFINE_PER_CPU(struct file_lock_list_struct, file_lock_list); DEFINE_STATIC_PERCPU_RWSEM(file_rwsem); /* * The blocked_hash is used to find POSIX lock loops for deadlock detection. * It is protected by blocked_lock_lock. * * We hash locks by lockowner in order to optimize searching for the lock a * particular lockowner is waiting on. * * FIXME: make this value scale via some heuristic? We generally will want more * buckets when we have more lockowners holding locks, but that's a little * difficult to determine without knowing what the workload will look like. */ #define BLOCKED_HASH_BITS 7 static DEFINE_HASHTABLE(blocked_hash, BLOCKED_HASH_BITS); /* * This lock protects the blocked_hash. Generally, if you're accessing it, you * want to be holding this lock. * * In addition, it also protects the fl->fl_blocked_requests list, and the * fl->fl_blocker pointer for file_lock structures that are acting as lock * requests (in contrast to those that are acting as records of acquired locks). * * Note that when we acquire this lock in order to change the above fields, * we often hold the flc_lock as well. In certain cases, when reading the fields * protected by this lock, we can skip acquiring it iff we already hold the * flc_lock. */ static DEFINE_SPINLOCK(blocked_lock_lock); static struct kmem_cache *flctx_cache __ro_after_init; static struct kmem_cache *filelock_cache __ro_after_init; static struct kmem_cache *filelease_cache __ro_after_init; static struct file_lock_context * locks_get_lock_context(struct inode *inode, int type) { struct file_lock_context *ctx; ctx = locks_inode_context(inode); if (likely(ctx) || type == F_UNLCK) goto out; ctx = kmem_cache_alloc(flctx_cache, GFP_KERNEL); if (!ctx) goto out; 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. */ spin_lock(&inode->i_lock); if (!(inode->i_opflags & IOP_FLCTX)) { VFS_BUG_ON_INODE(inode->i_flctx, inode); WRITE_ONCE(inode->i_flctx, ctx); /* * Paired with locks_inode_context(). */ smp_store_release(&inode->i_opflags, inode->i_opflags | IOP_FLCTX); spin_unlock(&inode->i_lock); } else { VFS_BUG_ON_INODE(!inode->i_flctx, inode); spin_unlock(&inode->i_lock); kmem_cache_free(flctx_cache, ctx); ctx = locks_inode_context(inode); } out: trace_locks_get_lock_context(inode, type, ctx); return ctx; } static void locks_dump_ctx_list(struct list_head *list, char *list_type) { struct file_lock_core *flc; list_for_each_entry(flc, list, flc_list) pr_warn("%s: fl_owner=%p fl_flags=0x%x fl_type=0x%x fl_pid=%u\n", list_type, flc->flc_owner, flc->flc_flags, flc->flc_type, flc->flc_pid); } static void locks_check_ctx_lists(struct inode *inode) { struct file_lock_context *ctx = inode->i_flctx; if (unlikely(!list_empty(&ctx->flc_flock) || !list_empty(&ctx->flc_posix) || !list_empty(&ctx->flc_lease))) { pr_warn("Leaked locks on dev=0x%x:0x%x ino=0x%llx:\n", MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev), inode->i_ino); locks_dump_ctx_list(&ctx->flc_flock, "FLOCK"); locks_dump_ctx_list(&ctx->flc_posix, "POSIX"); locks_dump_ctx_list(&ctx->flc_lease, "LEASE"); } } static void locks_check_ctx_file_list(struct file *filp, struct list_head *list, char *list_type) { struct file_lock_core *flc; struct inode *inode = file_inode(filp); list_for_each_entry(flc, list, flc_list) if (flc->flc_file == filp) pr_warn("Leaked %s lock on dev=0x%x:0x%x ino=0x%llx " " fl_owner=%p fl_flags=0x%x fl_type=0x%x fl_pid=%u\n", list_type, MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev), inode->i_ino, flc->flc_owner, flc->flc_flags, flc->flc_type, flc->flc_pid); } void locks_free_lock_context(struct inode *inode) { struct file_lock_context *ctx = locks_inode_context(inode); if (unlikely(ctx)) { locks_check_ctx_lists(inode); kmem_cache_free(flctx_cache, ctx); } } static void locks_init_lock_heads(struct file_lock_core *flc) { INIT_HLIST_NODE(&flc->flc_link); INIT_LIST_HEAD(&flc->flc_list); INIT_LIST_HEAD(&flc->flc_blocked_requests); INIT_LIST_HEAD(&flc->flc_blocked_member); init_waitqueue_head(&flc->flc_wait); } /* Allocate an empty lock structure. */ struct file_lock *locks_alloc_lock(void) { struct file_lock *fl = kmem_cache_zalloc(filelock_cache, GFP_KERNEL); if (fl) locks_init_lock_heads(&fl->c); return fl; } EXPORT_SYMBOL_GPL(locks_alloc_lock); /* Allocate an empty lock structure. */ struct file_lease *locks_alloc_lease(void) { struct file_lease *fl = kmem_cache_zalloc(filelease_cache, GFP_KERNEL); if (fl) locks_init_lock_heads(&fl->c); return fl; } EXPORT_SYMBOL_GPL(locks_alloc_lease); void locks_release_private(struct file_lock *fl) { struct file_lock_core *flc = &fl->c; BUG_ON(waitqueue_active(&flc->flc_wait)); BUG_ON(!list_empty(&flc->flc_list)); BUG_ON(!list_empty(&flc->flc_blocked_requests)); BUG_ON(!list_empty(&flc->flc_blocked_member)); BUG_ON(!hlist_unhashed(&flc->flc_link)); 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->lm_put_owner) { fl->fl_lmops->lm_put_owner(flc->flc_owner); flc->flc_owner = NULL; } fl->fl_lmops = NULL; } } EXPORT_SYMBOL_GPL(locks_release_private); /** * locks_owner_has_blockers - Check for blocking lock requests * @flctx: file lock context * @owner: lock owner * * Return values: * %true: @owner has at least one blocker * %false: @owner has no blockers */ bool locks_owner_has_blockers(struct file_lock_context *flctx, fl_owner_t owner) { struct file_lock_core *flc; spin_lock(&flctx->flc_lock); list_for_each_entry(flc, &flctx->flc_posix, flc_list) { if (flc->flc_owner != owner) continue; if (!list_empty(&flc->flc_blocked_requests)) { spin_unlock(&flctx->flc_lock); return true; } } spin_unlock(&flctx->flc_lock); return false; } EXPORT_SYMBOL_GPL(locks_owner_has_blockers); /* Free a lock which is not in use. */ void locks_free_lock(struct file_lock *fl) { locks_release_private(fl); kmem_cache_free(filelock_cache, fl); } EXPORT_SYMBOL(locks_free_lock); /* Free a lease which is not in use. */ void locks_free_lease(struct file_lease *fl) { kmem_cache_free(filelease_cache, fl); } EXPORT_SYMBOL(locks_free_lease); static void locks_dispose_list(struct list_head *dispose) { struct file_lock_core *flc; while (!list_empty(dispose)) { flc = list_first_entry(dispose, struct file_lock_core, flc_list); list_del_init(&flc->flc_list); locks_free_lock(file_lock(flc)); } } static void lease_dispose_list(struct list_head *dispose) { struct file_lock_core *flc; while (!list_empty(dispose)) { flc = list_first_entry(dispose, struct file_lock_core, flc_list); list_del_init(&flc->flc_list); locks_free_lease(file_lease(flc)); } } void locks_init_lock(struct file_lock *fl) { memset(fl, 0, sizeof(struct file_lock)); locks_init_lock_heads(&fl->c); } EXPORT_SYMBOL(locks_init_lock); void locks_init_lease(struct file_lease *fl) { memset(fl, 0, sizeof(*fl)); locks_init_lock_heads(&fl->c); } EXPORT_SYMBOL(locks_init_lease); /* * Initialize a new lock from an existing file_lock structure. */ void locks_copy_conflock(struct file_lock *new, struct file_lock *fl) { new->c.flc_owner = fl->c.flc_owner; new->c.flc_pid = fl->c.flc_pid; new->c.flc_file = NULL; new->c.flc_flags = fl->c.flc_flags; new->c.flc_type = fl->c.flc_type; new->fl_start = fl->fl_start; new->fl_end = fl->fl_end; new->fl_lmops = fl->fl_lmops; new->fl_ops = NULL; if (fl->fl_lmops) { if (fl->fl_lmops->lm_get_owner) fl->fl_lmops->lm_get_owner(fl->c.flc_owner); } } EXPORT_SYMBOL(locks_copy_conflock); void locks_copy_lock(struct file_lock *new, struct file_lock *fl) { /* "new" must be a freshly-initialized lock */ WARN_ON_ONCE(new->fl_ops); locks_copy_conflock(new, fl); new->c.flc_file = fl->c.flc_file; new->fl_ops = fl->fl_ops; if (fl->fl_ops) { if (fl->fl_ops->fl_copy_lock) fl->fl_ops->fl_copy_lock(new, fl); } } EXPORT_SYMBOL(locks_copy_lock); static void locks_move_blocks(struct file_lock *new, struct file_lock *fl) { struct file_lock *f; /* * As ctx->flc_lock is held, new requests cannot be added to * ->flc_blocked_requests, so we don't need a lock to check if it * is empty. */ if (list_empty(&fl->c.flc_blocked_requests)) return; spin_lock(&blocked_lock_lock); list_splice_init(&fl->c.flc_blocked_requests, &new->c.flc_blocked_requests); list_for_each_entry(f, &new->c.flc_blocked_requests, c.flc_blocked_member) f->c.flc_blocker = &new->c; spin_unlock(&blocked_lock_lock); } static inline int flock_translate_cmd(int cmd) { switch (cmd) { case LOCK_SH: return F_RDLCK; case LOCK_EX: return F_WRLCK; case LOCK_UN: return F_UNLCK; } return -EINVAL; } /* Fill in a file_lock structure with an appropriate FLOCK lock. */ static void flock_make_lock(struct file *filp, struct file_lock *fl, int type) { locks_init_lock(fl); fl->c.flc_file = filp; fl->c.flc_owner = filp; fl->c.flc_pid = current->tgid; fl->c.flc_flags = FL_FLOCK; fl->c.flc_type = type; fl->fl_end = OFFSET_MAX; } static int assign_type(struct file_lock_core *flc, int type) { switch (type) { case F_RDLCK: case F_WRLCK: