diff options
Diffstat (limited to 'fs/notify')
| -rw-r--r-- | fs/notify/Kconfig | 12 | ||||
| -rw-r--r-- | fs/notify/dnotify/Kconfig | 2 | ||||
| -rw-r--r-- | fs/notify/fsnotify.c | 4 | ||||
| -rw-r--r-- | fs/notify/inotify/Kconfig | 2 | ||||
| -rw-r--r-- | fs/notify/inotify/inotify_fsnotify.c | 46 | ||||
| -rw-r--r-- | fs/notify/inotify/inotify_user.c | 274 | ||||
| -rw-r--r-- | fs/notify/notification.c | 30 |
7 files changed, 254 insertions, 116 deletions
diff --git a/fs/notify/Kconfig b/fs/notify/Kconfig index 31dac7e3b0f..dffbb0911d0 100644 --- a/fs/notify/Kconfig +++ b/fs/notify/Kconfig @@ -1,15 +1,5 @@ config FSNOTIFY - bool "Filesystem notification backend" - default y - ---help--- - fsnotify is a backend for filesystem notification. fsnotify does - not provide any userspace interface but does provide the basis - needed for other notification schemes such as dnotify, inotify, - and fanotify. - - Say Y here to enable fsnotify suport. - - If unsure, say Y. + def_bool n source "fs/notify/dnotify/Kconfig" source "fs/notify/inotify/Kconfig" diff --git a/fs/notify/dnotify/Kconfig b/fs/notify/dnotify/Kconfig index 904ff8d5405..f9c1ca139d8 100644 --- a/fs/notify/dnotify/Kconfig +++ b/fs/notify/dnotify/Kconfig @@ -1,6 +1,6 @@ config DNOTIFY bool "Dnotify support" - depends on FSNOTIFY + select FSNOTIFY default y help Dnotify is a directory-based per-fd file change notification system diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index ec2f7bd7681..037e878e03f 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -159,7 +159,9 @@ void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const if (!group->ops->should_send_event(group, to_tell, mask)) continue; if (!event) { - event = fsnotify_create_event(to_tell, mask, data, data_is, file_name, cookie); + event = fsnotify_create_event(to_tell, mask, data, + data_is, file_name, cookie, + GFP_KERNEL); /* shit, we OOM'd and now we can't tell, maybe * someday someone else will want to do something * here */ diff --git a/fs/notify/inotify/Kconfig b/fs/notify/inotify/Kconfig index 5356884289a..3e56dbffe72 100644 --- a/fs/notify/inotify/Kconfig +++ b/fs/notify/inotify/Kconfig @@ -15,7 +15,7 @@ config INOTIFY config INOTIFY_USER bool "Inotify support for userspace" - depends on FSNOTIFY + select FSNOTIFY default y ---help--- Say Y here to enable inotify support for userspace, including the diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c index 47cd258fd24..c9ee67b442e 100644 --- a/fs/notify/inotify/inotify_fsnotify.c +++ b/fs/notify/inotify/inotify_fsnotify.c @@ -62,13 +62,14 @@ static int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_ev event_priv->wd = wd; ret = fsnotify_add_notify_event(group, event, fsn_event_priv); - /* EEXIST is not an error */ - if (ret == -EEXIST) - ret = 0; - - /* did event_priv get attached? */ - if (list_empty(&fsn_event_priv->event_list)) + if (ret) { inotify_free_event_priv(fsn_event_priv); + /* EEXIST says we tail matched, EOVERFLOW isn't something + * to report up the stack. */ + if ((ret == -EEXIST) || + (ret == -EOVERFLOW)) + ret = 0; + } /* * If we hold the entry until after the event is on the queue @@ -104,16 +105,45 @@ static bool inotify_should_send_event(struct fsnotify_group *group, struct inode return send; } +/* + * This is NEVER supposed to be called. Inotify marks should either have been + * removed from the idr when the watch was removed or in the + * fsnotify_destroy_mark_by_group() call when the inotify instance was being + * torn down. This is only called if the idr is about to be freed but there + * are still marks in it. + */ static int idr_callback(int id, void *p, void *data) { - BUG(); + struct fsnotify_mark_entry *entry; + struct inotify_inode_mark_entry *ientry; + static bool warned = false; + + if (warned) + return 0; + + warned = false; + entry = p; + ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); + + WARN(1, "inotify closing but id=%d for entry=%p in group=%p still in " + "idr. Probably leaking memory\n", id, p, data); + + /* + * I'm taking the liberty of assuming that the mark in question is a + * valid address and I'm dereferencing it. This might help to figure + * out why we got here and the panic is no worse than the original + * BUG() that was here. + */ + if (entry) + printk(KERN_WARNING "entry->group=%p inode=%p wd=%d\n", + entry->group, entry->inode, ientry->wd); return 0; } static void inotify_free_group_priv(struct fsnotify_group *group) { /* ideally the idr is empty and we won't hit the BUG in teh callback */ - idr_for_each(&group->inotify_data.idr, idr_callback, NULL); + idr_for_each(&group->inotify_data.idr, idr_callback, group); idr_remove_all(&group->inotify_data.idr); idr_destroy(&group->inotify_data.idr); } diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index ff231ad2389..dcd2040d330 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -47,9 +47,6 @@ static struct vfsmount *inotify_mnt __read_mostly; -/* this just sits here and wastes global memory. used to just pad userspace messages with zeros */ -static struct inotify_event nul_inotify_event; - /* these are configurable via /proc/sys/fs/inotify/ */ static int inotify_max_user_instances __read_mostly; static int inotify_max_queued_events __read_mostly; @@ -57,7 +54,6 @@ int inotify_max_user_watches __read_mostly; static struct kmem_cache *inotify_inode_mark_cachep __read_mostly; struct kmem_cache *event_priv_cachep __read_mostly; -static struct fsnotify_event *inotify_ignored_event; /* * When inotify registers a new group it increments this and uses that @@ -158,7 +154,8 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group, event = fsnotify_peek_notify_event(group); - event_size += roundup(event->name_len, event_size); + if (event->name_len) + event_size += roundup(event->name_len + 1, event_size); if (event_size > count) return ERR_PTR(-EINVAL); @@ -184,7 +181,7 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, struct fsnotify_event_private_data *fsn_priv; struct inotify_event_private_data *priv; size_t event_size = sizeof(struct inotify_event); - size_t name_len; + size_t name_len = 0; /* we get the inotify watch descriptor from the event private data */ spin_lock(&event->lock); @@ -200,8 +197,12 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, inotify_free_event_priv(fsn_priv); } - /* round up event->name_len so it is a multiple of event_size */ - name_len = roundup(event->name_len, event_size); + /* + * round up event->name_len so it is a multiple of event_size + * plus an extra byte for the terminating '\0'. + */ + if (event->name_len) + name_len = roundup(event->name_len + 1, event_size); inotify_event.len = name_len; inotify_event.mask = inotify_mask_to_arg(event->mask); @@ -225,8 +226,8 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, return -EFAULT; buf += event->name_len; - /* fill userspace with 0's from nul_inotify_event */ - if (copy_to_user(buf, &nul_inotify_event, len_to_zero)) + /* fill userspace with 0's */ + if (clear_user(buf, len_to_zero)) return -EFAULT; buf += len_to_zero; event_size += name_len; @@ -296,12 +297,15 @@ static int inotify_fasync(int fd, struct file *file, int on) static int inotify_release(struct inode *ignored, struct file *file) { struct fsnotify_group *group = file->private_data; + struct user_struct *user = group->inotify_data.user; fsnotify_clear_marks_by_group(group); /* free this group, matching get was inotify_init->fsnotify_obtain_group */ fsnotify_put_group(group); + atomic_dec(&user->inotify_devs); + return 0; } @@ -324,8 +328,9 @@ static long inotify_ioctl(struct file *file, unsigned int cmd, list_for_each_entry(holder, &group->notification_list, event_list) { event = holder->event; send_len += sizeof(struct inotify_event); - send_len += roundup(event->name_len, - sizeof(struct inotify_event)); + if (event->name_len) + send_len += roundup(event->name_len + 1, + sizeof(struct inotify_event)); } mutex_unlock(&group->notification_mutex); ret = put_user(send_len, (int __user *) p); @@ -363,20 +368,71 @@ static int inotify_find_inode(const char __user *dirname, struct path *path, uns } /* - * Send IN_IGNORED for this wd, remove this wd from the idr, and drop the - * internal reference help on the mark because it is in the idr. + * Remove the mark from the idr (if present) and drop the reference + * on the mark because it was in the idr. + */ +static void inotify_remove_from_idr(struct fsnotify_group *group, + struct inotify_inode_mark_entry *ientry) +{ + struct idr *idr; + struct fsnotify_mark_entry *entry; + struct inotify_inode_mark_entry *found_ientry; + int wd; + + spin_lock(&group->inotify_data.idr_lock); + idr = &group->inotify_data.idr; + wd = ientry->wd; + + if (wd == -1) + goto out; + + entry = idr_find(&group->inotify_data.idr, wd); + if (unlikely(!entry)) + goto out; + + found_ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); + if (unlikely(found_ientry != ientry)) { + /* We found an entry in the idr with the right wd, but it's + * not the entry we were told to remove. eparis seriously + * fucked up somewhere. */ + WARN_ON(1); + ientry->wd = -1; + goto out; + } + + /* One ref for being in the idr, one ref held by the caller */ + BUG_ON(atomic_read(&entry->refcnt) < 2); + + idr_remove(idr, wd); + ientry->wd = -1; + + /* removed from the idr, drop that ref */ + fsnotify_put_mark(entry); +out: + spin_unlock(&group->inotify_data.idr_lock); +} + +/* + * Send IN_IGNORED for this wd, remove this wd from the idr. */ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry, struct fsnotify_group *group) { struct inotify_inode_mark_entry *ientry; + struct fsnotify_event *ignored_event; struct inotify_event_private_data *event_priv; struct fsnotify_event_private_data *fsn_event_priv; - struct idr *idr; + int ret; + + ignored_event = fsnotify_create_event(NULL, FS_IN_IGNORED, NULL, + FSNOTIFY_EVENT_NONE, NULL, 0, + GFP_NOFS); + if (!ignored_event) + return; ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); - event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL); + event_priv = kmem_cache_alloc(event_priv_cachep, GFP_NOFS); if (unlikely(!event_priv)) goto skip_send_ignore; @@ -385,22 +441,19 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry, fsn_event_priv->group = group; event_priv->wd = ientry->wd; - fsnotify_add_notify_event(group, inotify_ignored_event, fsn_event_priv); - - /* did the private data get added? */ - if (list_empty(&fsn_event_priv->event_list)) + ret = fsnotify_add_notify_event(group, ignored_event, fsn_event_priv); + if (ret) inotify_free_event_priv(fsn_event_priv); skip_send_ignore: + /* matches the reference taken when the event was created */ + fsnotify_put_event(ignored_event); + /* remove this entry from the idr */ - spin_lock(&group->inotify_data.idr_lock); - idr = &group->inotify_data.idr; - idr_remove(idr, ientry->wd); - spin_unlock(&group->inotify_data.idr_lock); + inotify_remove_from_idr(group, ientry); - /* removed from idr, drop that reference */ - fsnotify_put_mark(entry); + atomic_dec(&group->inotify_data.user->inotify_watches); } /* ding dong the mark is dead */ @@ -411,67 +464,29 @@ static void inotify_free_mark(struct fsnotify_mark_entry *entry) kmem_cache_free(inotify_inode_mark_cachep, ientry); } -static int inotify_update_watch(struct fsnotify_group *group, struct inode *inode, u32 arg) +static int inotify_update_existing_watch(struct fsnotify_group *group, + struct inode *inode, + u32 arg) { - struct fsnotify_mark_entry *entry = NULL; + struct fsnotify_mark_entry *entry; struct inotify_inode_mark_entry *ientry; - int ret = 0; - int add = (arg & IN_MASK_ADD); - __u32 mask; __u32 old_mask, new_mask; + __u32 mask; + int add = (arg & IN_MASK_ADD); + int ret; /* don't allow invalid bits: we don't want flags set */ mask = inotify_arg_to_mask(arg); if (unlikely(!mask)) return -EINVAL; - ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL); - if (unlikely(!ientry)) - return -ENOMEM; - /* we set the mask at the end after attaching it */ - fsnotify_init_mark(&ientry->fsn_entry, inotify_free_mark); - ientry->wd = 0; - -find_entry: spin_lock(&inode->i_lock); entry = fsnotify_find_mark_entry(group, inode); spin_unlock(&inode->i_lock); - if (entry) { - kmem_cache_free(inotify_inode_mark_cachep, ientry); - ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); - } else { - if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches) { - ret = -ENOSPC; - goto out_err; - } + if (!entry) + return -ENOENT; - ret = fsnotify_add_mark(&ientry->fsn_entry, group, inode); - if (ret == -EEXIST) - goto find_entry; - else if (ret) - goto out_err; - - entry = &ientry->fsn_entry; -retry: - ret = -ENOMEM; - if (unlikely(!idr_pre_get(&group->inotify_data.idr, GFP_KERNEL))) - goto out_err; - - spin_lock(&group->inotify_data.idr_lock); - /* if entry is added to the idr we keep the reference obtained - * through fsnotify_mark_add. remember to drop this reference - * when entry is removed from idr */ - ret = idr_get_new_above(&group->inotify_data.idr, entry, - ++group->inotify_data.last_wd, - &ientry->wd); - spin_unlock(&group->inotify_data.idr_lock); - if (ret) { - if (ret == -EAGAIN) - goto retry; - goto out_err; - } - atomic_inc(&group->inotify_data.user->inotify_watches); - } + ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); spin_lock(&entry->lock); @@ -503,14 +518,108 @@ retry: fsnotify_recalc_group_mask(group); } - return ientry->wd; + /* return the wd */ + ret = ientry->wd; -out_err: - /* see this isn't supposed to happen, just kill the watch */ - if (entry) { - fsnotify_destroy_mark_by_entry(entry); - fsnotify_put_mark(entry); + /* match the get from fsnotify_find_mark_entry() */ + fsnotify_put_mark(entry); + + return ret; +} + +static int inotify_new_watch(struct fsnotify_group *group, + struct inode *inode, + u32 arg) +{ + struct inotify_inode_mark_entry *tmp_ientry; + __u32 mask; + int ret; + + /* don't allow invalid bits: we don't want flags set */ + mask = inotify_arg_to_mask(arg); + if (unlikely(!mask)) + return -EINVAL; + + tmp_ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL); + if (unlikely(!tmp_ientry)) + return -ENOMEM; + + fsnotify_init_mark(&tmp_ientry->fsn_entry, inotify_free_mark); + tmp_ientry->fsn_entry.mask = mask; + tmp_ientry->wd = -1; + + ret = -ENOSPC; + if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches) + goto out_err; +retry: + ret = -ENOMEM; + if (unlikely(!idr_pre_get(&group->inotify_data.idr, GFP_KERNEL))) + goto out_err; + + spin_lock(&group->inotify_data.idr_lock); + ret = idr_get_new_above(&group->inotify_data.idr, &tmp_ientry->fsn_entry, + group->inotify_data.last_wd, + &tmp_ientry->wd); + spin_unlock(&group->inotify_data.idr_lock); + if (ret) { + /* idr was out of memory allocate and try again */ + if (ret == -EAGAIN) + goto retry; + goto out_err; } + + /* we put the mark on the idr, take a reference */ + fsnotify_get_mark(&tmp_ientry->fsn_entry); + + /* we are on the idr, now get on the inode */ + ret = fsnotify_add_mark(&tmp_ientry->fsn_entry, group, inode); + if (ret) { + /* we failed to get on the inode, get off the idr */ + inotify_remove_from_idr(group, tmp_ientry); + goto out_err; + } + + /* update the idr hint, who cares about races, it's just a hint */ + group->inotify_data.last_wd = tmp_ientry->wd; + + /* increment the number of watches the user has */ + atomic_inc(&group->inotify_data.user->inotify_watches); + + /* return the watch descriptor for this new entry */ + ret = tmp_ientry->wd; + + /* match the ref from fsnotify_init_markentry() */ + fsnotify_put_mark(&tmp_ientry->fsn_entry); + + /* if this mark added a new event update the group mask */ + if (mask & ~group->mask) + fsnotify_recalc_group_mask(group); + +out_err: + if (ret < 0) + kmem_cache_free(inotify_inode_mark_cachep, tmp_ientry); + + return ret; +} + +static int inotify_update_watch(struct fsnotify_group *group, struct inode *inode, u32 arg) +{ + int ret = 0; + +retry: + /* try to update and existing watch with the new arg */ + ret = inotify_update_existing_watch(group, inode, arg); + /* no mark present, try to add a new one */ + if (ret == -ENOENT) + ret = inotify_new_watch(group, inode, arg); + /* + * inotify_new_watch could race with another thread which did an + * inotify_new_watch between the update_existing and the add watch + * here, go back and try to update an existing mark again. + */ + if (ret == -EEXIST) + goto retry; + return ret; } @@ -529,7 +638,7 @@ static struct fsnotify_group *inotify_new_group(struct user_struct *user, unsign spin_lock_init(&group->inotify_data.idr_lock); idr_init(&group->inotify_data.idr); - group->inotify_data.last_wd = 0; + group->inotify_data.last_wd = 1; group->inotify_data.user = user; group->inotify_data.fa = NULL; @@ -718,9 +827,6 @@ static int __init inotify_user_setup(void) inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark_entry, SLAB_PANIC); event_priv_cachep = KMEM_CACHE(inotify_event_private_data, SLAB_PANIC); - inotify_ignored_event = fsnotify_create_event(NULL, FS_IN_IGNORED, NULL, FSNOTIFY_EVENT_NONE, NULL, 0); - if (!inotify_ignored_event) - panic("unable to allocate the inotify ignored event\n"); inotify_max_queued_events = 16384; inotify_max_user_instances = 128; diff --git a/fs/notify/notification.c b/fs/notify/notification.c index 959b73e756f..3816d5750dd 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -136,18 +136,28 @@ static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new { if ((old->mask == new->mask) && (old->to_tell == new->to_tell) && - (old->data_type == new->data_type)) { + (old->data_type == new->data_type) && + (old->name_len == new->name_len)) { switch (old->data_type) { case (FSNOTIFY_EVENT_INODE): - if (old->inode == new->inode) + /* remember, after old was put on the wait_q we aren't + * allowed to look at the inode any more, only thing + * left to check was if the file_name is the same */ + if (old->name_len && + !strcmp(old->file_name, new->file_name)) return true; break; case (FSNOTIFY_EVENT_PATH): if ((old->path.mnt == new->path.mnt) && (old->path.dentry == new->path.dentry)) return true; + break; case (FSNOTIFY_EVENT_NONE): - return true; + if (old->mask & FS_Q_OVERFLOW) + return true; + else if (old->mask & FS_IN_IGNORED) + return false; + return false; }; } return false; @@ -165,9 +175,7 @@ int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_even struct list_head *list = &group->notification_list; struct fsnotify_event_holder *last_holder; struct fsnotify_event *last_event; - - /* easy to tell if priv was attached to the event */ - INIT_LIST_HEAD(&priv->event_list); + int ret = 0; /* * There is one fsnotify_event_holder embedded inside each fsnotify_event. @@ -188,6 +196,7 @@ alloc_holder: if (group->q_len >= group->max_events) { event = &q_overflow_event; + ret = -EOVERFLOW; /* sorry, no private data on the overflow event */ priv = NULL; } @@ -229,7 +238,7 @@ alloc_holder: mutex_unlock(&group->notification_mutex); wake_up(&group->notification_waitq); - return 0; + return ret; } /* @@ -339,18 +348,19 @@ static void initialize_event(struct fsnotify_event *event) * @name the filename, if available */ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, void *data, - int data_type, const char *name, u32 cookie) + int data_type, const char *name, u32 cookie, + gfp_t gfp) { struct fsnotify_event *event; - event = kmem_cache_alloc(fsnotify_event_cachep, GFP_KERNEL); + event = kmem_cache_alloc(fsnotify_event_cachep, gfp); if (!event) return NULL; initialize_event(event); if (name) { - event->file_name = kstrdup(name, GFP_KERNEL); + event->file_name = kstrdup(name, gfp); if (!event->file_name) { kmem_cache_free(fsnotify_event_cachep, event); return NULL; |