diff options
Diffstat (limited to 'xlators/features/locks/src/entrylk.c')
| -rw-r--r-- | xlators/features/locks/src/entrylk.c | 848 |
1 files changed, 848 insertions, 0 deletions
diff --git a/xlators/features/locks/src/entrylk.c b/xlators/features/locks/src/entrylk.c new file mode 100644 index 000000000..0785dc547 --- /dev/null +++ b/xlators/features/locks/src/entrylk.c @@ -0,0 +1,848 @@ +/* + Copyright (c) 2006-2012 Red Hat, Inc. <http://www.redhat.com> + This file is part of GlusterFS. + + This file is licensed to you under your choice of the GNU Lesser + General Public License, version 3 or any later version (LGPLv3 or + later), or the GNU General Public License, version 2 (GPLv2), in all + cases as published by the Free Software Foundation. +*/ +#ifndef _CONFIG_H +#define _CONFIG_H +#include "config.h" +#endif + +#include "glusterfs.h" +#include "compat.h" +#include "xlator.h" +#include "inode.h" +#include "logging.h" +#include "common-utils.h" +#include "list.h" + +#include "locks.h" +#include "common.h" + +static pl_entry_lock_t * +new_entrylk_lock (pl_inode_t *pinode, const char *basename, entrylk_type type, + client_t *client, pid_t client_pid, gf_lkowner_t *owner, + const char *volume) + +{ + pl_entry_lock_t *newlock = NULL; + + newlock = GF_CALLOC (1, sizeof (pl_entry_lock_t), + gf_locks_mt_pl_entry_lock_t); + if (!newlock) { + goto out; + } + + newlock->basename = basename ? gf_strdup (basename) : NULL; + newlock->type = type; + newlock->trans = client; + newlock->volume = volume; + newlock->client_pid = client_pid; + newlock->owner = *owner; + + INIT_LIST_HEAD (&newlock->domain_list); + INIT_LIST_HEAD (&newlock->blocked_locks); + +out: + return newlock; +} + + +/** + * all_names - does a basename represent all names? + * @basename: name to check + */ + +#define all_names(basename) ((basename == NULL) ? 1 : 0) + +/** + * names_conflict - do two names conflict? + * @n1: name + * @n2: name + */ + +static int +names_conflict (const char *n1, const char *n2) +{ + return all_names (n1) || all_names (n2) || !strcmp (n1, n2); +} + + +static inline int +__same_entrylk_owner (pl_entry_lock_t *l1, pl_entry_lock_t *l2) +{ + + return (is_same_lkowner (&l1->owner, &l2->owner) && + (l1->trans == l2->trans)); +} + + +/** + * lock_grantable - is this lock grantable? + * @inode: inode in which to look + * @basename: name we're trying to lock + * @type: type of lock + */ +static pl_entry_lock_t * +__lock_grantable (pl_dom_list_t *dom, const char *basename, entrylk_type type) +{ + pl_entry_lock_t *lock = NULL; + + if (list_empty (&dom->entrylk_list)) + return NULL; + + list_for_each_entry (lock, &dom->entrylk_list, domain_list) { + if (names_conflict (lock->basename, basename)) + return lock; + } + + return NULL; +} + +static pl_entry_lock_t * +__blocked_lock_conflict (pl_dom_list_t *dom, const char *basename, entrylk_type type) +{ + pl_entry_lock_t *lock = NULL; + + if (list_empty (&dom->blocked_entrylks)) + return NULL; + + list_for_each_entry (lock, &dom->blocked_entrylks, blocked_locks) { + if (names_conflict (lock->basename, basename)) + return lock; + } + + return NULL; +} + +static int +__owner_has_lock (pl_dom_list_t *dom, pl_entry_lock_t *newlock) +{ + pl_entry_lock_t *lock = NULL; + + list_for_each_entry (lock, &dom->entrylk_list, domain_list) { + if (__same_entrylk_owner (lock, newlock)) + return 1; + } + + list_for_each_entry (lock, &dom->blocked_entrylks, blocked_locks) { + if (__same_entrylk_owner (lock, newlock)) + return 1; + } + + return 0; +} + +static int +names_equal (const char *n1, const char *n2) +{ + return (n1 == NULL && n2 == NULL) || (n1 && n2 && !strcmp (n1, n2)); +} + +void +pl_print_entrylk (char *str, int size, entrylk_cmd cmd, entrylk_type type, + const char *basename, const char *domain) +{ + char *cmd_str = NULL; + char *type_str = NULL; + + switch (cmd) { + case ENTRYLK_LOCK: + cmd_str = "LOCK"; + break; + + case ENTRYLK_LOCK_NB: + cmd_str = "LOCK_NB"; + break; + + case ENTRYLK_UNLOCK: + cmd_str = "UNLOCK"; + break; + + default: + cmd_str = "UNKNOWN"; + break; + } + + switch (type) { + case ENTRYLK_RDLCK: + type_str = "READ"; + break; + case ENTRYLK_WRLCK: + type_str = "WRITE"; + break; + default: + type_str = "UNKNOWN"; + break; + } + + snprintf (str, size, "lock=ENTRYLK, cmd=%s, type=%s, basename=%s, domain: %s", + cmd_str, type_str, basename, domain); +} + + +void +entrylk_trace_in (xlator_t *this, call_frame_t *frame, const char *domain, + fd_t *fd, loc_t *loc, const char *basename, + entrylk_cmd cmd, entrylk_type type) +{ + posix_locks_private_t *priv = NULL; + char pl_locker[256]; + char pl_lockee[256]; + char pl_entrylk[256]; + + priv = this->private; + + if (!priv->trace) + return; + + pl_print_locker (pl_locker, 256, this, frame); + pl_print_lockee (pl_lockee, 256, fd, loc); + pl_print_entrylk (pl_entrylk, 256, cmd, type, basename, domain); + + gf_log (this->name, GF_LOG_INFO, + "[REQUEST] Locker = {%s} Lockee = {%s} Lock = {%s}", + pl_locker, pl_lockee, pl_entrylk); +} + + +void +entrylk_trace_out (xlator_t *this, call_frame_t *frame, const char *domain, + fd_t *fd, loc_t *loc, const char *basename, + entrylk_cmd cmd, entrylk_type type, int op_ret, int op_errno) +{ + posix_locks_private_t *priv = NULL; + char pl_locker[256]; + char pl_lockee[256]; + char pl_entrylk[256]; + char verdict[32]; + + priv = this->private; + + if (!priv->trace) + return; + + pl_print_locker (pl_locker, 256, this, frame); + pl_print_lockee (pl_lockee, 256, fd, loc); + pl_print_entrylk (pl_entrylk, 256, cmd, type, basename, domain); + pl_print_verdict (verdict, 32, op_ret, op_errno); + + gf_log (this->name, GF_LOG_INFO, + "[%s] Locker = {%s} Lockee = {%s} Lock = {%s}", + verdict, pl_locker, pl_lockee, pl_entrylk); +} + + +void +entrylk_trace_block (xlator_t *this, call_frame_t *frame, const char *volume, + fd_t *fd, loc_t *loc, const char *basename, + entrylk_cmd cmd, entrylk_type type) + +{ + posix_locks_private_t *priv = NULL; + char pl_locker[256]; + char pl_lockee[256]; + char pl_entrylk[256]; + + priv = this->private; + + if (!priv->trace) + return; + + pl_print_locker (pl_locker, 256, this, frame); + pl_print_lockee (pl_lockee, 256, fd, loc); + pl_print_entrylk (pl_entrylk, 256, cmd, type, basename, volume); + + gf_log (this->name, GF_LOG_INFO, + "[BLOCKED] Locker = {%s} Lockee = {%s} Lock = {%s}", + pl_locker, pl_lockee, pl_entrylk); +} + +/** + * __find_most_matching_lock - find the lock struct which most matches in order of: + * lock on the exact basename || + * an all_names lock + * + * + * @inode: inode in which to look + * @basename: name to search for + */ + +static pl_entry_lock_t * +__find_most_matching_lock (pl_dom_list_t *dom, const char *basename) +{ + pl_entry_lock_t *lock; + pl_entry_lock_t *all = NULL; + pl_entry_lock_t *exact = NULL; + + if (list_empty (&dom->entrylk_list)) + return NULL; + + list_for_each_entry (lock, &dom->entrylk_list, domain_list) { + if (all_names (lock->basename)) + all = lock; + else if (names_equal (lock->basename, basename)) + exact = lock; + } + + return (exact ? exact : all); +} + +/** + * __lock_name - lock a name in a directory + * @inode: inode for the directory in which to lock + * @basename: name of the entry to lock + * if null, lock the entire directory + * + * the entire directory being locked is represented as: a single + * pl_entry_lock_t present in the entrylk_locks list with its + * basename = NULL + */ + +int +__lock_name (pl_inode_t *pinode, const char *basename, entrylk_type type, + call_frame_t *frame, pl_dom_list_t *dom, xlator_t *this, + int nonblock, char *conn_id) +{ + pl_entry_lock_t *lock = NULL; + pl_entry_lock_t *conf = NULL; + int ret = -EINVAL; + + lock = new_entrylk_lock (pinode, basename, type, + frame->root->client, frame->root->pid, + &frame->root->lk_owner, dom->domain); + if (!lock) { + ret = -ENOMEM; + goto out; + } + + lock->frame = frame; + lock->this = this; + lock->trans = frame->root->client; + + if (conn_id) { + lock->connection_id = gf_strdup (conn_id); + } + + conf = __lock_grantable (dom, basename, type); + if (conf) { + ret = -EAGAIN; + if (nonblock){ + GF_FREE (lock->connection_id); + GF_FREE ((char *)lock->basename); + GF_FREE (lock); + goto out; + + } + + gettimeofday (&lock->blkd_time, NULL); + list_add_tail (&lock->blocked_locks, &dom->blocked_entrylks); + + gf_log (this->name, GF_LOG_TRACE, + "Blocking lock: {pinode=%p, basename=%s}", + pinode, basename); + + goto out; + } + + if ( __blocked_lock_conflict (dom, basename, type) && !(__owner_has_lock (dom, lock))) { + ret = -EAGAIN; + if (nonblock) { + GF_FREE (lock->connection_id); + GF_FREE ((char *) lock->basename); + GF_FREE (lock); + goto out; + + } + lock->frame = frame; + lock->this = this; + + gettimeofday (&lock->blkd_time, NULL); + list_add_tail (&lock->blocked_locks, &dom->blocked_entrylks); + + gf_log (this->name, GF_LOG_TRACE, + "Lock is grantable, but blocking to prevent starvation"); + gf_log (this->name, GF_LOG_TRACE, + "Blocking lock: {pinode=%p, basename=%s}", + pinode, basename); + + ret = -EAGAIN; + goto out; + } + switch (type) { + + case ENTRYLK_WRLCK: + gettimeofday (&lock->granted_time, NULL); + list_add_tail (&lock->domain_list, &dom->entrylk_list); + break; + + default: + + gf_log (this->name, GF_LOG_DEBUG, + "Invalid type for entrylk specified: %d", type); + ret = -EINVAL; + goto out; + } + + ret = 0; +out: + return ret; +} + +/** + * __unlock_name - unlock a name in a directory + * @inode: inode for the directory to unlock in + * @basename: name of the entry to unlock + * if null, unlock the entire directory + */ + +pl_entry_lock_t * +__unlock_name (pl_dom_list_t *dom, const char *basename, entrylk_type type) +{ + pl_entry_lock_t *lock = NULL; + pl_entry_lock_t *ret_lock = NULL; + + lock = __find_most_matching_lock (dom, basename); + + if (!lock) { + gf_log ("locks", GF_LOG_DEBUG, + "unlock on %s (type=ENTRYLK_WRLCK) attempted but no matching lock found", + basename); + goto out; + } + + if (names_equal (lock->basename, basename) + && lock->type == type) { + + if (type == ENTRYLK_WRLCK) { + list_del_init (&lock->domain_list); + ret_lock = lock; + } + } else { + gf_log ("locks", GF_LOG_DEBUG, + "Unlock for a non-existing lock!"); + goto out; + } + +out: + return ret_lock; +} + +uint32_t +check_entrylk_on_basename (xlator_t *this, inode_t *parent, char *basename) +{ + uint32_t entrylk = 0; + pl_inode_t *pinode = 0; + pl_dom_list_t *dom = NULL; + pl_entry_lock_t *conf = NULL; + + pinode = pl_inode_get (this, parent); + if (!pinode) + goto out; + pthread_mutex_lock (&pinode->mutex); + { + list_for_each_entry (dom, &pinode->dom_list, inode_list) { + conf = __lock_grantable (dom, basename, ENTRYLK_WRLCK); + if (conf && conf->basename) { + entrylk = 1; + break; + } + } + } + pthread_mutex_unlock (&pinode->mutex); + +out: + return entrylk; +} + +void +__grant_blocked_entry_locks (xlator_t *this, pl_inode_t *pl_inode, + pl_dom_list_t *dom, struct list_head *granted) +{ + int bl_ret = 0; + pl_entry_lock_t *bl = NULL; + pl_entry_lock_t *tmp = NULL; + + struct list_head blocked_list; + + INIT_LIST_HEAD (&blocked_list); + list_splice_init (&dom->blocked_entrylks, &blocked_list); + + list_for_each_entry_safe (bl, tmp, &blocked_list, + blocked_locks) { + + list_del_init (&bl->blocked_locks); + + + gf_log ("locks", GF_LOG_TRACE, + "Trying to unblock: {pinode=%p, basename=%s}", + pl_inode, bl->basename); + + bl_ret = __lock_name (pl_inode, bl->basename, bl->type, + bl->frame, dom, bl->this, 0, + bl->connection_id); + + if (bl_ret == 0) { + list_add (&bl->blocked_locks, granted); + } else { + gf_log (this->name, GF_LOG_DEBUG, + "should never happen"); + GF_FREE (bl->connection_id); + GF_FREE ((char *)bl->basename); + GF_FREE (bl); + } + } + return; +} + +/* Grants locks if possible which are blocked on a lock */ +void +grant_blocked_entry_locks (xlator_t *this, pl_inode_t *pl_inode, + pl_entry_lock_t *unlocked, pl_dom_list_t *dom) +{ + struct list_head granted_list; + pl_entry_lock_t *tmp = NULL; + pl_entry_lock_t *lock = NULL; + + INIT_LIST_HEAD (&granted_list); + + pthread_mutex_lock (&pl_inode->mutex); + { + __grant_blocked_entry_locks (this, pl_inode, dom, + &granted_list); + } + pthread_mutex_unlock (&pl_inode->mutex); + + list_for_each_entry_safe (lock, tmp, &granted_list, blocked_locks) { + list_del_init (&lock->blocked_locks); + + entrylk_trace_out (this, lock->frame, NULL, NULL, NULL, + lock->basename, ENTRYLK_LOCK, lock->type, + 0, 0); + + STACK_UNWIND_STRICT (entrylk, lock->frame, 0, 0, NULL); + + GF_FREE (lock->connection_id); + GF_FREE ((char *)lock->basename); + GF_FREE (lock); + } + + GF_FREE ((char *)unlocked->basename); + GF_FREE (unlocked->connection_id); + GF_FREE (unlocked); + + return; +} + +/** + * release_entry_locks_for_client: release all entry locks from this + * client for this loc_t + */ + +static int +release_entry_locks_for_client (xlator_t *this, pl_inode_t *pinode, + pl_dom_list_t *dom, client_t *client) +{ + pl_entry_lock_t *lock = NULL; + pl_entry_lock_t *tmp = NULL; + struct list_head granted; + struct list_head released; + + INIT_LIST_HEAD (&granted); + INIT_LIST_HEAD (&released); + + pthread_mutex_lock (&pinode->mutex); + { + list_for_each_entry_safe (lock, tmp, &dom->blocked_entrylks, + blocked_locks) { + if (lock->trans != client) + continue; + + list_del_init (&lock->blocked_locks); + + gf_log (this->name, GF_LOG_TRACE, + "releasing lock on held by " + "{client=%p}", client); + + list_add (&lock->blocked_locks, &released); + + } + + list_for_each_entry_safe (lock, tmp, &dom->entrylk_list, + domain_list) { + if (lock->trans != client) + continue; + + list_del_init (&lock->domain_list); + + gf_log (this->name, GF_LOG_TRACE, + "releasing lock on held by " + "{client=%p}", client); + + GF_FREE ((char *)lock->basename); + GF_FREE (lock->connection_id); + GF_FREE (lock); + } + + __grant_blocked_entry_locks (this, pinode, dom, &granted); + + } + + pthread_mutex_unlock (&pinode->mutex); + + list_for_each_entry_safe (lock, tmp, &released, blocked_locks) { + list_del_init (&lock->blocked_locks); + + STACK_UNWIND_STRICT (entrylk, lock->frame, -1, EAGAIN, NULL); + + GF_FREE ((char *)lock->basename); + GF_FREE (lock->connection_id); + GF_FREE (lock); + + } + + list_for_each_entry_safe (lock, tmp, &granted, blocked_locks) { + list_del_init (&lock->blocked_locks); + + STACK_UNWIND_STRICT (entrylk, lock->frame, 0, 0, NULL); + + GF_FREE ((char *)lock->basename); + GF_FREE (lock->connection_id); + GF_FREE (lock); + } + + return 0; +} + +/* Common entrylk code called by pl_entrylk and pl_fentrylk */ +int +pl_common_entrylk (call_frame_t *frame, xlator_t *this, + const char *volume, inode_t *inode, const char *basename, + entrylk_cmd cmd, entrylk_type type, loc_t *loc, fd_t *fd, + dict_t *xdata) + +{ + int32_t op_ret = -1; + int32_t op_errno = 0; + int ret = -1; + char unwind = 1; + GF_UNUSED int dict_ret = -1; + pl_inode_t *pinode = NULL; + pl_entry_lock_t *unlocked = NULL; + pl_dom_list_t *dom = NULL; + char *conn_id = NULL; + pl_ctx_t *ctx = NULL; + + if (xdata) + dict_ret = dict_get_str (xdata, "connection-id", &conn_id); + + pinode = pl_inode_get (this, inode); + if (!pinode) { + op_errno = ENOMEM; + goto out; + } + + dom = get_domain (pinode, volume); + if (!dom){ + op_errno = ENOMEM; + goto out; + } + + entrylk_trace_in (this, frame, volume, fd, loc, basename, cmd, type); + + if (frame->root->lk_owner.len == 0) { + /* + this is a special case that means release + all locks from this client + */ + + gf_log (this->name, GF_LOG_TRACE, + "Releasing locks for client %p", frame->root->client); + + release_entry_locks_for_client (this, pinode, dom, + frame->root->client); + op_ret = 0; + + goto out; + } + + switch (cmd) { + case ENTRYLK_LOCK: + pthread_mutex_lock (&pinode->mutex); + { + ret = __lock_name (pinode, basename, type, + frame, dom, this, 0, conn_id); + } + pthread_mutex_unlock (&pinode->mutex); + + op_errno = -ret; + if (ret < 0) { + if (ret == -EAGAIN) + unwind = 0; + else + unwind = 1; + goto out; + } else { + op_ret = 0; + op_errno = 0; + unwind = 1; + goto out; + } + + break; + + case ENTRYLK_LOCK_NB: + unwind = 1; + pthread_mutex_lock (&pinode->mutex); + { + ret = __lock_name (pinode, basename, type, + frame, dom, this, 1, conn_id); + } + pthread_mutex_unlock (&pinode->mutex); + + if (ret < 0) { + op_errno = -ret; + goto out; + } + + break; + + case ENTRYLK_UNLOCK: + pthread_mutex_lock (&pinode->mutex); + { + unlocked = __unlock_name (dom, basename, type); + } + pthread_mutex_unlock (&pinode->mutex); + + if (unlocked) + grant_blocked_entry_locks (this, pinode, unlocked, dom); + + break; + + default: + gf_log (this->name, GF_LOG_ERROR, + "Unexpected case in entrylk (cmd=%d). Please file" + "a bug report at http://bugs.gluster.com", cmd); + goto out; + } + + op_ret = 0; +out: + pl_update_refkeeper (this, inode); + if (unwind) { + entrylk_trace_out (this, frame, volume, fd, loc, basename, + cmd, type, op_ret, op_errno); + + ctx = pl_ctx_get (frame->root->client, this); + + if (ctx == NULL) { + gf_log (this->name, GF_LOG_INFO, "pl_ctx_get() failed"); + goto unwind; + } + + if (cmd == ENTRYLK_UNLOCK) + pl_del_locker (ctx->ltable, volume, loc, fd, + &frame->root->lk_owner, + GF_FOP_ENTRYLK); + else + pl_add_locker (ctx->ltable, volume, loc, fd, + frame->root->pid, + &frame->root->lk_owner, + GF_FOP_ENTRYLK); + +unwind: + STACK_UNWIND_STRICT (entrylk, frame, op_ret, op_errno, NULL); + } else { + entrylk_trace_block (this, frame, volume, fd, loc, basename, + cmd, type); + } + + + return 0; +} + +/** + * pl_entrylk: + * + * Locking on names (directory entries) + */ + +int +pl_entrylk (call_frame_t *frame, xlator_t *this, + const char *volume, loc_t *loc, const char *basename, + entrylk_cmd cmd, entrylk_type type, dict_t *xdata) +{ + pl_common_entrylk (frame, this, volume, loc->inode, basename, cmd, + type, loc, NULL, xdata); + + return 0; +} + + +/** + * pl_fentrylk: + * + * Locking on names (directory entries) + */ + +int +pl_fentrylk (call_frame_t *frame, xlator_t *this, + const char *volume, fd_t *fd, const char *basename, + entrylk_cmd cmd, entrylk_type type, dict_t *xdata) +{ + pl_common_entrylk (frame, this, volume, fd->inode, basename, cmd, + type, NULL, fd, xdata); + + return 0; +} + + +int32_t +__get_entrylk_count (xlator_t *this, pl_inode_t *pl_inode) +{ + int32_t count = 0; + pl_entry_lock_t *lock = NULL; + pl_dom_list_t *dom = NULL; + + list_for_each_entry (dom, &pl_inode->dom_list, inode_list) { + list_for_each_entry (lock, &dom->entrylk_list, domain_list) { + count++; + } + + list_for_each_entry (lock, &dom->blocked_entrylks, blocked_locks) { + count++; + } + + } + + return count; +} + +int32_t +get_entrylk_count (xlator_t *this, inode_t *inode) +{ + pl_inode_t *pl_inode = NULL; + uint64_t tmp_pl_inode = 0; + int ret = 0; + int32_t count = 0; + + ret = inode_ctx_get (inode, this, &tmp_pl_inode); + if (ret != 0) { + goto out; + } + + pl_inode = (pl_inode_t *)(long) tmp_pl_inode; + + pthread_mutex_lock (&pl_inode->mutex); + { + count = __get_entrylk_count (this, pl_inode); + } + pthread_mutex_unlock (&pl_inode->mutex); + +out: + return count; +} |