diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-10 11:39:13 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-10 11:39:13 -0700 |
commit | 8c8946f509a494769a8c602b5ed189df01917d39 (patch) | |
tree | dfd96bd6ca5ea6803c6d77f65ba37e04f78b2d3b /fs/notify | |
parent | 5f248c9c251c60af3403902b26e08de43964ea0b (diff) | |
parent | 1968f5eed54ce47bde488fd9a450912e4a2d7138 (diff) |
Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify
* 'for-linus' of git://git.infradead.org/users/eparis/notify: (132 commits)
fanotify: use both marks when possible
fsnotify: pass both the vfsmount mark and inode mark
fsnotify: walk the inode and vfsmount lists simultaneously
fsnotify: rework ignored mark flushing
fsnotify: remove global fsnotify groups lists
fsnotify: remove group->mask
fsnotify: remove the global masks
fsnotify: cleanup should_send_event
fanotify: use the mark in handler functions
audit: use the mark in handler functions
dnotify: use the mark in handler functions
inotify: use the mark in handler functions
fsnotify: send fsnotify_mark to groups in event handling functions
fsnotify: Exchange list heads instead of moving elements
fsnotify: srcu to protect read side of inode and vfsmount locks
fsnotify: use an explicit flag to indicate fsnotify_destroy_mark has been called
fsnotify: use _rcu functions for mark list traversal
fsnotify: place marks on object in order of group memory address
vfs/fsnotify: fsnotify_close can delay the final work in fput
fsnotify: store struct file not struct path
...
Fix up trivial delete/modify conflict in fs/notify/inotify/inotify.c.
Diffstat (limited to 'fs/notify')
-rw-r--r-- | fs/notify/Kconfig | 1 | ||||
-rw-r--r-- | fs/notify/Makefile | 4 | ||||
-rw-r--r-- | fs/notify/dnotify/dnotify.c | 213 | ||||
-rw-r--r-- | fs/notify/fanotify/Kconfig | 26 | ||||
-rw-r--r-- | fs/notify/fanotify/Makefile | 1 | ||||
-rw-r--r-- | fs/notify/fanotify/fanotify.c | 212 | ||||
-rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 760 | ||||
-rw-r--r-- | fs/notify/fsnotify.c | 201 | ||||
-rw-r--r-- | fs/notify/fsnotify.h | 27 | ||||
-rw-r--r-- | fs/notify/group.c | 182 | ||||
-rw-r--r-- | fs/notify/inode_mark.c | 331 | ||||
-rw-r--r-- | fs/notify/inotify/Kconfig | 15 | ||||
-rw-r--r-- | fs/notify/inotify/Makefile | 1 | ||||
-rw-r--r-- | fs/notify/inotify/inotify.c | 872 | ||||
-rw-r--r-- | fs/notify/inotify/inotify.h | 7 | ||||
-rw-r--r-- | fs/notify/inotify/inotify_fsnotify.c | 151 | ||||
-rw-r--r-- | fs/notify/inotify/inotify_user.c | 369 | ||||
-rw-r--r-- | fs/notify/mark.c | 371 | ||||
-rw-r--r-- | fs/notify/notification.c | 236 | ||||
-rw-r--r-- | fs/notify/vfsmount_mark.c | 187 |
20 files changed, 2440 insertions, 1727 deletions
diff --git a/fs/notify/Kconfig b/fs/notify/Kconfig index dffbb0911d02..22c629eedd82 100644 --- a/fs/notify/Kconfig +++ b/fs/notify/Kconfig @@ -3,3 +3,4 @@ config FSNOTIFY source "fs/notify/dnotify/Kconfig" source "fs/notify/inotify/Kconfig" +source "fs/notify/fanotify/Kconfig" diff --git a/fs/notify/Makefile b/fs/notify/Makefile index 0922cc826c46..ae5f33a6d868 100644 --- a/fs/notify/Makefile +++ b/fs/notify/Makefile @@ -1,4 +1,6 @@ -obj-$(CONFIG_FSNOTIFY) += fsnotify.o notification.o group.o inode_mark.o +obj-$(CONFIG_FSNOTIFY) += fsnotify.o notification.o group.o inode_mark.o \ + mark.o vfsmount_mark.o obj-y += dnotify/ obj-y += inotify/ +obj-y += fanotify/ diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c index 7e54e52964dd..3344bdd5506e 100644 --- a/fs/notify/dnotify/dnotify.c +++ b/fs/notify/dnotify/dnotify.c @@ -29,17 +29,17 @@ int dir_notify_enable __read_mostly = 1; static struct kmem_cache *dnotify_struct_cache __read_mostly; -static struct kmem_cache *dnotify_mark_entry_cache __read_mostly; +static struct kmem_cache *dnotify_mark_cache __read_mostly; static struct fsnotify_group *dnotify_group __read_mostly; static DEFINE_MUTEX(dnotify_mark_mutex); /* - * dnotify will attach one of these to each inode (i_fsnotify_mark_entries) which + * dnotify will attach one of these to each inode (i_fsnotify_marks) which * is being watched by dnotify. If multiple userspace applications are watching * the same directory with dnotify their information is chained in dn */ -struct dnotify_mark_entry { - struct fsnotify_mark_entry fsn_entry; +struct dnotify_mark { + struct fsnotify_mark fsn_mark; struct dnotify_struct *dn; }; @@ -51,27 +51,27 @@ struct dnotify_mark_entry { * it calls the fsnotify function so it can update the set of all events relevant * to this inode. */ -static void dnotify_recalc_inode_mask(struct fsnotify_mark_entry *entry) +static void dnotify_recalc_inode_mask(struct fsnotify_mark *fsn_mark) { __u32 new_mask, old_mask; struct dnotify_struct *dn; - struct dnotify_mark_entry *dnentry = container_of(entry, - struct dnotify_mark_entry, - fsn_entry); + struct dnotify_mark *dn_mark = container_of(fsn_mark, + struct dnotify_mark, + fsn_mark); - assert_spin_locked(&entry->lock); + assert_spin_locked(&fsn_mark->lock); - old_mask = entry->mask; + old_mask = fsn_mark->mask; new_mask = 0; - for (dn = dnentry->dn; dn != NULL; dn = dn->dn_next) + for (dn = dn_mark->dn; dn != NULL; dn = dn->dn_next) new_mask |= (dn->dn_mask & ~FS_DN_MULTISHOT); - entry->mask = new_mask; + fsnotify_set_mark_mask_locked(fsn_mark, new_mask); if (old_mask == new_mask) return; - if (entry->inode) - fsnotify_recalc_inode_mask(entry->inode); + if (fsn_mark->i.inode) + fsnotify_recalc_inode_mask(fsn_mark->i.inode); } /* @@ -83,29 +83,25 @@ static void dnotify_recalc_inode_mask(struct fsnotify_mark_entry *entry) * events. */ static int dnotify_handle_event(struct fsnotify_group *group, + struct fsnotify_mark *inode_mark, + struct fsnotify_mark *vfsmount_mark, struct fsnotify_event *event) { - struct fsnotify_mark_entry *entry = NULL; - struct dnotify_mark_entry *dnentry; + struct dnotify_mark *dn_mark; struct inode *to_tell; struct dnotify_struct *dn; struct dnotify_struct **prev; struct fown_struct *fown; __u32 test_mask = event->mask & ~FS_EVENT_ON_CHILD; - to_tell = event->to_tell; + BUG_ON(vfsmount_mark); - spin_lock(&to_tell->i_lock); - entry = fsnotify_find_mark_entry(group, to_tell); - spin_unlock(&to_tell->i_lock); + to_tell = event->to_tell; - /* unlikely since we alreay passed dnotify_should_send_event() */ - if (unlikely(!entry)) - return 0; - dnentry = container_of(entry, struct dnotify_mark_entry, fsn_entry); + dn_mark = container_of(inode_mark, struct dnotify_mark, fsn_mark); - spin_lock(&entry->lock); - prev = &dnentry->dn; + spin_lock(&inode_mark->lock); + prev = &dn_mark->dn; while ((dn = *prev) != NULL) { if ((dn->dn_mask & test_mask) == 0) { prev = &dn->dn_next; @@ -118,12 +114,11 @@ static int dnotify_handle_event(struct fsnotify_group *group, else { *prev = dn->dn_next; kmem_cache_free(dnotify_struct_cache, dn); - dnotify_recalc_inode_mask(entry); + dnotify_recalc_inode_mask(inode_mark); } } - spin_unlock(&entry->lock); - fsnotify_put_mark(entry); + spin_unlock(&inode_mark->lock); return 0; } @@ -133,44 +128,27 @@ static int dnotify_handle_event(struct fsnotify_group *group, * userspace notification for that pair. */ static bool dnotify_should_send_event(struct fsnotify_group *group, - struct inode *inode, __u32 mask) + struct inode *inode, + struct fsnotify_mark *inode_mark, + struct fsnotify_mark *vfsmount_mark, + __u32 mask, void *data, int data_type) { - struct fsnotify_mark_entry *entry; - bool send; - - /* !dir_notify_enable should never get here, don't waste time checking - if (!dir_notify_enable) - return 0; */ - /* not a dir, dnotify doesn't care */ if (!S_ISDIR(inode->i_mode)) return false; - spin_lock(&inode->i_lock); - entry = fsnotify_find_mark_entry(group, inode); - spin_unlock(&inode->i_lock); - - /* no mark means no dnotify watch */ - if (!entry) - return false; - - mask = (mask & ~FS_EVENT_ON_CHILD); - send = (mask & entry->mask); - - fsnotify_put_mark(entry); /* matches fsnotify_find_mark_entry */ - - return send; + return true; } -static void dnotify_free_mark(struct fsnotify_mark_entry *entry) +static void dnotify_free_mark(struct fsnotify_mark *fsn_mark) { - struct dnotify_mark_entry *dnentry = container_of(entry, - struct dnotify_mark_entry, - fsn_entry); + struct dnotify_mark *dn_mark = container_of(fsn_mark, + struct dnotify_mark, + fsn_mark); - BUG_ON(dnentry->dn); + BUG_ON(dn_mark->dn); - kmem_cache_free(dnotify_mark_entry_cache, dnentry); + kmem_cache_free(dnotify_mark_cache, dn_mark); } static struct fsnotify_ops dnotify_fsnotify_ops = { @@ -183,15 +161,15 @@ static struct fsnotify_ops dnotify_fsnotify_ops = { /* * Called every time a file is closed. Looks first for a dnotify mark on the - * inode. If one is found run all of the ->dn entries attached to that + * inode. If one is found run all of the ->dn structures attached to that * mark for one relevant to this process closing the file and remove that * dnotify_struct. If that was the last dnotify_struct also remove the - * fsnotify_mark_entry. + * fsnotify_mark. */ void dnotify_flush(struct file *filp, fl_owner_t id) { - struct fsnotify_mark_entry *entry; - struct dnotify_mark_entry *dnentry; + struct fsnotify_mark *fsn_mark; + struct dnotify_mark *dn_mark; struct dnotify_struct *dn; struct dnotify_struct **prev; struct inode *inode; @@ -200,38 +178,34 @@ void dnotify_flush(struct file *filp, fl_owner_t id) if (!S_ISDIR(inode->i_mode)) return; - spin_lock(&inode->i_lock); - entry = fsnotify_find_mark_entry(dnotify_group, inode); - spin_unlock(&inode->i_lock); - if (!entry) + fsn_mark = fsnotify_find_inode_mark(dnotify_group, inode); + if (!fsn_mark) return; - dnentry = container_of(entry, struct dnotify_mark_entry, fsn_entry); + dn_mark = container_of(fsn_mark, struct dnotify_mark, fsn_mark); mutex_lock(&dnotify_mark_mutex); - spin_lock(&entry->lock); - prev = &dnentry->dn; + spin_lock(&fsn_mark->lock); + prev = &dn_mark->dn; while ((dn = *prev) != NULL) { if ((dn->dn_owner == id) && (dn->dn_filp == filp)) { *prev = dn->dn_next; kmem_cache_free(dnotify_struct_cache, dn); - dnotify_recalc_inode_mask(entry); + dnotify_recalc_inode_mask(fsn_mark); break; } prev = &dn->dn_next; } - spin_unlock(&entry->lock); + spin_unlock(&fsn_mark->lock); /* nothing else could have found us thanks to the dnotify_mark_mutex */ - if (dnentry->dn == NULL) - fsnotify_destroy_mark_by_entry(entry); - - fsnotify_recalc_group_mask(dnotify_group); + if (dn_mark->dn == NULL) + fsnotify_destroy_mark(fsn_mark); mutex_unlock(&dnotify_mark_mutex); - fsnotify_put_mark(entry); + fsnotify_put_mark(fsn_mark); } /* this conversion is done only at watch creation */ @@ -259,16 +233,16 @@ static __u32 convert_arg(unsigned long arg) /* * If multiple processes watch the same inode with dnotify there is only one - * dnotify mark in inode->i_fsnotify_mark_entries but we chain a dnotify_struct + * dnotify mark in inode->i_fsnotify_marks but we chain a dnotify_struct * onto that mark. This function either attaches the new dnotify_struct onto * that list, or it |= the mask onto an existing dnofiy_struct. */ -static int attach_dn(struct dnotify_struct *dn, struct dnotify_mark_entry *dnentry, +static int attach_dn(struct dnotify_struct *dn, struct dnotify_mark *dn_mark, fl_owner_t id, int fd, struct file *filp, __u32 mask) { struct dnotify_struct *odn; - odn = dnentry->dn; + odn = dn_mark->dn; while (odn != NULL) { /* adding more events to existing dnofiy_struct? */ if ((odn->dn_owner == id) && (odn->dn_filp == filp)) { @@ -283,8 +257,8 @@ static int attach_dn(struct dnotify_struct *dn, struct dnotify_mark_entry *dnent dn->dn_fd = fd; dn->dn_filp = filp; dn->dn_owner = id; - dn->dn_next = dnentry->dn; - dnentry->dn = dn; + dn->dn_next = dn_mark->dn; + dn_mark->dn = dn; return 0; } @@ -296,8 +270,8 @@ static int attach_dn(struct dnotify_struct *dn, struct dnotify_mark_entry *dnent */ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) { - struct dnotify_mark_entry *new_dnentry, *dnentry; - struct fsnotify_mark_entry *new_entry, *entry; + struct dnotify_mark *new_dn_mark, *dn_mark; + struct fsnotify_mark *new_fsn_mark, *fsn_mark; struct dnotify_struct *dn; struct inode *inode; fl_owner_t id = current->files; @@ -306,7 +280,7 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) __u32 mask; /* we use these to tell if we need to kfree */ - new_entry = NULL; + new_fsn_mark = NULL; dn = NULL; if (!dir_notify_enable) { @@ -336,8 +310,8 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) } /* new fsnotify mark, we expect most fcntl calls to add a new mark */ - new_dnentry = kmem_cache_alloc(dnotify_mark_entry_cache, GFP_KERNEL); - if (!new_dnentry) { + new_dn_mark = kmem_cache_alloc(dnotify_mark_cache, GFP_KERNEL); + if (!new_dn_mark) { error = -ENOMEM; goto out_err; } @@ -345,29 +319,27 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) /* convert the userspace DN_* "arg" to the internal FS_* defines in fsnotify */ mask = convert_arg(arg); - /* set up the new_entry and new_dnentry */ - new_entry = &new_dnentry->fsn_entry; - fsnotify_init_mark(new_entry, dnotify_free_mark); - new_entry->mask = mask; - new_dnentry->dn = NULL; + /* set up the new_fsn_mark and new_dn_mark */ + new_fsn_mark = &new_dn_mark->fsn_mark; + fsnotify_init_mark(new_fsn_mark, dnotify_free_mark); + new_fsn_mark->mask = mask; + new_dn_mark->dn = NULL; /* this is needed to prevent the fcntl/close race described below */ mutex_lock(&dnotify_mark_mutex); - /* add the new_entry or find an old one. */ - spin_lock(&inode->i_lock); - entry = fsnotify_find_mark_entry(dnotify_group, inode); - spin_unlock(&inode->i_lock); - if (entry) { - dnentry = container_of(entry, struct dnotify_mark_entry, fsn_entry); - spin_lock(&entry->lock); + /* add the new_fsn_mark or find an old one. */ + fsn_mark = fsnotify_find_inode_mark(dnotify_group, inode); + if (fsn_mark) { + dn_mark = container_of(fsn_mark, struct dnotify_mark, fsn_mark); + spin_lock(&fsn_mark->lock); } else { - fsnotify_add_mark(new_entry, dnotify_group, inode); - spin_lock(&new_entry->lock); - entry = new_entry; - dnentry = new_dnentry; - /* we used new_entry, so don't free it */ - new_entry = NULL; + fsnotify_add_mark(new_fsn_mark, dnotify_group, inode, NULL, 0); + spin_lock(&new_fsn_mark->lock); + fsn_mark = new_fsn_mark; + dn_mark = new_dn_mark; + /* we used new_fsn_mark, so don't free it */ + new_fsn_mark = NULL; } rcu_read_lock(); @@ -376,17 +348,17 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) /* if (f != filp) means that we lost a race and another task/thread * actually closed the fd we are still playing with before we grabbed - * the dnotify_mark_mutex and entry->lock. Since closing the fd is the - * only time we clean up the mark entries we need to get our mark off + * the dnotify_mark_mutex and fsn_mark->lock. Since closing the fd is the + * only time we clean up the marks we need to get our mark off * the list. */ if (f != filp) { /* if we added ourselves, shoot ourselves, it's possible that - * the flush actually did shoot this entry. That's fine too + * the flush actually did shoot this fsn_mark. That's fine too * since multiple calls to destroy_mark is perfectly safe, if - * we found a dnentry already attached to the inode, just sod + * we found a dn_mark already attached to the inode, just sod * off silently as the flush at close time dealt with it. */ - if (dnentry == new_dnentry) + if (dn_mark == new_dn_mark) destroy = 1; goto out; } @@ -394,13 +366,13 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0); if (error) { /* if we added, we must shoot */ - if (dnentry == new_dnentry) + if (dn_mark == new_dn_mark) destroy = 1; goto out; } - error = attach_dn(dn, dnentry, id, fd, filp, mask); - /* !error means that we attached the dn to the dnentry, so don't free it */ + error = attach_dn(dn, dn_mark, id, fd, filp, mask); + /* !error means that we attached the dn to the dn_mark, so don't free it */ if (!error) dn = NULL; /* -EEXIST means that we didn't add this new dn and used an old one. @@ -408,20 +380,18 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) else if (error == -EEXIST) error = 0; - dnotify_recalc_inode_mask(entry); + dnotify_recalc_inode_mask(fsn_mark); out: - spin_unlock(&entry->lock); + spin_unlock(&fsn_mark->lock); if (destroy) - fsnotify_destroy_mark_by_entry(entry); - - fsnotify_recalc_group_mask(dnotify_group); + fsnotify_destroy_mark(fsn_mark); mutex_unlock(&dnotify_mark_mutex); - fsnotify_put_mark(entry); + fsnotify_put_mark(fsn_mark); out_err: - if (new_entry) - fsnotify_put_mark(new_entry); + if (new_fsn_mark) + fsnotify_put_mark(new_fsn_mark); if (dn) kmem_cache_free(dnotify_struct_cache, dn); return error; @@ -430,10 +400,9 @@ out_err: static int __init dnotify_init(void) { dnotify_struct_cache = KMEM_CACHE(dnotify_struct, SLAB_PANIC); - dnotify_mark_entry_cache = KMEM_CACHE(dnotify_mark_entry, SLAB_PANIC); + dnotify_mark_cache = KMEM_CACHE(dnotify_mark, SLAB_PANIC); - dnotify_group = fsnotify_obtain_group(DNOTIFY_GROUP_NUM, - 0, &dnotify_fsnotify_ops); + dnotify_group = fsnotify_alloc_group(&dnotify_fsnotify_ops); if (IS_ERR(dnotify_group)) panic("unable to allocate fsnotify group for dnotify\n"); return 0; diff --git a/fs/notify/fanotify/Kconfig b/fs/notify/fanotify/Kconfig new file mode 100644 index 000000000000..3ac36b7bf6b9 --- /dev/null +++ b/fs/notify/fanotify/Kconfig @@ -0,0 +1,26 @@ +config FANOTIFY + bool "Filesystem wide access notification" + select FSNOTIFY + select ANON_INODES + default n + ---help--- + Say Y here to enable fanotify suport. fanotify is a file access + notification system which differs from inotify in that it sends + and open file descriptor to the userspace listener along with + the event. + + If unsure, say Y. + +config FANOTIFY_ACCESS_PERMISSIONS + bool "fanotify permissions checking" + depends on FANOTIFY + depends on SECURITY + default n + ---help--- + Say Y here is you want fanotify listeners to be able to make permissions + decisions concerning filesystem events. This is used by some fanotify + listeners which need to scan files before allowing the system access to + use those files. This is used by some anti-malware vendors and by some + hierarchical storage managent systems. + + If unsure, say N. diff --git a/fs/notify/fanotify/Makefile b/fs/notify/fanotify/Makefile new file mode 100644 index 000000000000..0999213e7e6e --- /dev/null +++ b/fs/notify/fanotify/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_FANOTIFY) += fanotify.o fanotify_user.o diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c new file mode 100644 index 000000000000..eb8f73c9c131 --- /dev/null +++ b/fs/notify/fanotify/fanotify.c @@ -0,0 +1,212 @@ +#include <linux/fanotify.h> +#include <linux/fdtable.h> +#include <linux/fsnotify_backend.h> +#include <linux/init.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> /* UINT_MAX */ +#include <linux/mount.h> +#include <linux/sched.h> +#include <linux/types.h> +#include <linux/wait.h> + +static bool should_merge(struct fsnotify_event *old, struct fsnotify_event *new) +{ + pr_debug("%s: old=%p new=%p\n", __func__, old, new); + + if (old->to_tell == new->to_tell && + old->data_type == new->data_type && + old->tgid == new->tgid) { + switch (old->data_type) { + case (FSNOTIFY_EVENT_FILE): + if ((old->file->f_path.mnt == new->file->f_path.mnt) && + (old->file->f_path.dentry == new->file->f_path.dentry)) + return true; + case (FSNOTIFY_EVENT_NONE): + return true; + default: + BUG(); + }; + } + return false; +} + +/* and the list better be locked by something too! */ +static struct fsnotify_event *fanotify_merge(struct list_head *list, + struct fsnotify_event *event) +{ + struct fsnotify_event_holder *test_holder; + struct fsnotify_event *test_event = NULL; + struct fsnotify_event *new_event; + + pr_debug("%s: list=%p event=%p\n", __func__, list, event); + + + list_for_each_entry_reverse(test_holder, list, event_list) { + if (should_merge(test_holder->event, event)) { + test_event = test_holder->event; + break; + } + } + + if (!test_event) + return NULL; + + fsnotify_get_event(test_event); + + /* if they are exactly the same we are done */ + if (test_event->mask == event->mask) + return test_event; + + /* + * if the refcnt == 2 this is the only queue + * for this event and so we can update the mask + * in place. + */ + if (atomic_read(&test_event->refcnt) == 2) { + test_event->mask |= event->mask; + return test_event; + } + + new_event = fsnotify_clone_event(test_event); + + /* done with test_event */ + fsnotify_put_event(test_event); + + /* couldn't allocate memory, merge was not possible */ + if (unlikely(!new_event)) + return ERR_PTR(-ENOMEM); + + /* build new event and replace it on the list */ + new_event->mask = (test_event->mask | event->mask); + fsnotify_replace_event(test_holder, new_event); + + /* we hold a reference on new_event from clone_event */ + return new_event; +} + +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS +static int fanotify_get_response_from_access(struct fsnotify_group *group, + struct fsnotify_event *event) +{ + int ret; + + pr_debug("%s: group=%p event=%p\n", __func__, group, event); + + wait_event(group->fanotify_data.access_waitq, event->response); + + /* userspace responded, convert to something usable */ + spin_lock(&event->lock); + switch (event->response) { + case FAN_ALLOW: + ret = 0; + break; + case FAN_DENY: + default: + ret = -EPERM; + } + event->response = 0; + spin_unlock(&event->lock); + + pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__, + group, event, ret); + + return ret; +} +#endif + +static int fanotify_handle_event(struct fsnotify_group *group, + struct fsnotify_mark *inode_mark, + struct fsnotify_mark *fanotify_mark, + struct fsnotify_event *event) +{ + int ret = 0; + struct fsnotify_event *notify_event = NULL; + + BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS); + BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY); + BUILD_BUG_ON(FAN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE); + BUILD_BUG_ON(FAN_CLOSE_WRITE != FS_CLOSE_WRITE); + BUILD_BUG_ON(FAN_OPEN != FS_OPEN); + BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD); + BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW); + BUILD_BUG_ON(FAN_OPEN_PERM != FS_OPEN_PERM); + BUILD_BUG_ON(FAN_ACCESS_PERM != FS_ACCESS_PERM); + + pr_debug("%s: group=%p event=%p\n", __func__, group, event); + + notify_event = fsnotify_add_notify_event(group, event, NULL, fanotify_merge); + if (IS_ERR(notify_event)) + return PTR_ERR(notify_event); + +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + if (event->mask & FAN_ALL_PERM_EVENTS) { + /* if we merged we need to wait on the new event */ + if (notify_event) + event = notify_event; + ret = fanotify_get_response_from_access(group, event); + } +#endif + + if (notify_event) + fsnotify_put_event(notify_event); + + return ret; +} + +static bool fanotify_should_send_event(struct fsnotify_group *group, + struct inode *to_tell, + struct fsnotify_mark *inode_mark, + struct fsnotify_mark *vfsmnt_mark, + __u32 event_mask, void *data, int data_type) +{ + __u32 marks_mask, marks_ignored_mask; + + pr_debug("%s: group=%p to_tell=%p inode_mark=%p vfsmnt_mark=%p " + "mask=%x data=%p data_type=%d\n", __func__, group, to_tell, + inode_mark, vfsmnt_mark, event_mask, data, data_type); + + pr_debug("%s: group=%p vfsmount_mark=%p inode_mark=%p mask=%x\n", + __func__, group, vfsmnt_mark, inode_mark, event_mask); + + /* sorry, fanotify only gives a damn about files and dirs */ + if (!S_ISREG(to_tell->i_mode) && + !S_ISDIR(to_tell->i_mode)) + return false; + + /* if we don't have enough info to send an event to userspace say no */ + if (data_type != FSNOTIFY_EVENT_FILE) + return false; + + if (inode_mark && vfsmnt_mark) { + marks_mask = (vfsmnt_mark->mask | inode_mark->mask); + marks_ignored_mask = (vfsmnt_mark->ignored_mask | inode_mark->ignored_mask); + } else if (inode_mark) { + /* + * if the event is for a child and this inode doesn't care about + * events on the child, don't send it! + */ + if ((event_mask & FS_EVENT_ON_CHILD) && + !(inode_mark->mask & FS_EVENT_ON_CHILD)) + return false; + marks_mask = inode_mark->mask; + marks_ignored_mask = inode_mark->ignored_mask; + } else if (vfsmnt_mark) { + marks_mask = vfsmnt_mark->mask; + marks_ignored_mask = vfsmnt_mark->ignored_mask; + } else { + BUG(); + } + + if (event_mask & marks_mask & ~marks_ignored_mask) + return true; + + return false; +} + +const struct fsnotify_ops fanotify_fsnotify_ops = { + .handle_event = fanotify_handle_event, + .should_send_event = fanotify_should_send_event, + .free_group_priv = NULL, + .free_event_priv = NULL, + .freeing_mark = NULL, +}; diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c new file mode 100644 index 000000000000..25a3b4dfcf61 --- /dev/null +++ b/fs/notify/fanotify/fanotify_user.c @@ -0,0 +1,760 @@ +#include <linux/fanotify.h> +#include <linux/fcntl.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/anon_inodes.h> +#include <linux/fsnotify_backend.h> +#include <linux/init.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/poll.h> +#include <linux/security.h> +#include <linux/syscalls.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/uaccess.h> + +#include <asm/ioctls.h> + +extern const struct fsnotify_ops fanotify_fsnotify_ops; + +static struct kmem_cache *fanotify_mark_cache __read_mostly; +static struct kmem_cache *fanotify_response_event_cache __read_mostly; + +struct fanotify_response_event { + struct list_head list; + __s32 fd; + struct fsnotify_event *event; +}; + +/* + * Get an fsnotify notification event if one exists and is small + * enough to fit in "count". Return an error pointer if the count + * is not large enough. + * + * Called with the group->notification_mutex held. + */ +static struct fsnotify_event *get_one_event(struct fsnotify_group *group, + size_t count) +{ + BUG_ON(!mutex_is_locked(&group->notification_mutex)); + + pr_debug("%s: group=%p count=%zd\n", __func__, group, count); + + if (fsnotify_notify_queue_is_empty(group)) + return NULL; + + if (FAN_EVENT_METADATA_LEN > count) + return ERR_PTR(-EINVAL); + + /* held the notification_mutex the whole time, so this is the + * same event we peeked above */ + return fsnotify_remove_notify_event(group); +} + +static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event) +{ + int client_fd; + struct dentry *dentry; + struct vfsmount *mnt; + struct file *new_file; + + pr_debug("%s: group=%p event=%p\n", __func__, group, event); + + client_fd = get_unused_fd(); + if (client_fd < 0) + return client_fd; + + if (event->data_type != FSNOTIFY_EVENT_FILE) { + WARN_ON(1); + put_unused_fd(client_fd); + return -EINVAL; + } + + /* + * we need a new file handle for the userspace program so it can read even if it was + * originally opened O_WRONLY. + */ + dentry = dget(event->file->f_path.dentry); + mnt = mntget(event->file->f_path.mnt); + /* it's possible this event was an overflow event. in that case dentry and mnt + * are NULL; That's fine, just don't call dentry open */ + if (dentry && mnt) + new_file = dentry_open(dentry, mnt, + group->fanotify_data.f_flags | FMODE_NONOTIFY, + current_cred()); + else + new_file = ERR_PTR(-EOVERFLOW); + if (IS_ERR(new_file)) { + /* + * we still send an event even if we can't open the file. this + * can happen when say tasks are gone and we try to open their + * /proc files or we try to open a WRONLY file like in sysfs + * we just send the errno to userspace since there isn't much + * else we can do. + */ + put_unused_fd(client_fd); + client_fd = PTR_ERR(new_file); + } else { + fd_install(client_fd, new_file); + } + + return client_fd; +} + +static ssize_t fill_event_metadata(struct fsnotify_group *group, + struct fanotify_event_metadata *metadata, + struct fsnotify_event *event) +{ + pr_debug("%s: group=%p metadata=%p event=%p\n", __func__, + group, metadata, event); + + metadata->event_len = FAN_EVENT_METADATA_LEN; + metadata->vers = FANOTIFY_METADATA_VERSION; + metadata->mask = event->mask & FAN_ALL_OUTGOING_EVENTS; + metadata->pid = pid_vnr(event->tgid); + metadata->fd = create_fd(group, event); + + return metadata->fd; +} + +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS +static struct fanotify_response_event *dequeue_re(struct fsnotify_group *group, + __s32 fd) +{ + struct fanotify_response_event *re, *return_re = NULL; + + mutex_lock(&group->fanotify_data.access_mutex); + list_for_each_entry(re, &group->fanotify_data.access_list, list) { + if (re->fd != fd) + continue; + + list_del_init(&re->list); + return_re = re; + break; + } + mutex_unlock(&group->fanotify_data.access_mutex); + + pr_debug("%s: found return_re=%p\n", __func__, return_re); + + return return_re; +} + +static int process_access_response(struct fsnotify_group *group, + struct fanotify_response *response_struct) +{ + struct fanotify_response_event *re; + __s32 fd = response_struct->fd; + __u32 response = response_struct->response; + + pr_debug("%s: group=%p fd=%d response=%d\n", __func__, group, + fd, response); + /* + * make sure the response is valid, if invalid we do nothing and either + * userspace can send a valid responce or we will clean it up after the + * timeout + */ + switch (response) { + case FAN_ALLOW: + case FAN_DENY: + break; + default: + return -EINVAL; + } + + if (fd < 0) + return -EINVAL; + + re = dequeue_re(group, fd); + if (!re) + return -ENOENT; + + re->event->response = response; + + wake_up(&group->fanotify_data.access_waitq); + + kmem_cache_free(fanotify_response_event_cache, re); + + return 0; +} + +static int prepare_for_access_response(struct fsnotify_group *group, + struct fsnotify_event *event, + __s32 fd) +{ + struct fanotify_response_event *re; + + if (!(event->mask & FAN_ALL_PERM_EVENTS)) + return 0; + + re = kmem_cache_alloc(fanotify_response_event_cache, GFP_KERNEL); + if (!re) + return -ENOMEM; + + re->event = event; + re->fd = fd; + + mutex_lock(&group->fanotify_data.access_mutex); + list_add_tail(&re->list, &group->fanotify_data.access_list); + mutex_unlock(&group->fanotify_data.access_m |