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authorEric Paris <eparis@redhat.com>2009-05-21 17:01:20 -0400
committerEric Paris <eparis@redhat.com>2009-06-11 14:57:52 -0400
commit90586523eb4b349806887c62ee70685a49415124 (patch)
tree2ba6da637f897bbb2309b141b81801e4151d87b0 /include/linux/fsnotify.h
parentc9059598ea8981d02356eead3188bf7fa4d717b8 (diff)
downloadop-kernel-dev-90586523eb4b349806887c62ee70685a49415124.zip
op-kernel-dev-90586523eb4b349806887c62ee70685a49415124.tar.gz
fsnotify: unified filesystem notification backend
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. fsnotify can be extended to be the backend for inotify or the upcoming fanotify. fsnotify provides a mechanism for "groups" to register for some set of filesystem events and to then deliver those events to those groups for processing. fsnotify has a number of benefits, the first being actually shrinking the size of an inode. Before fsnotify to support both dnotify and inotify an inode had unsigned long i_dnotify_mask; /* Directory notify events */ struct dnotify_struct *i_dnotify; /* for directory notifications */ struct list_head inotify_watches; /* watches on this inode */ struct mutex inotify_mutex; /* protects the watches list But with fsnotify this same functionallity (and more) is done with just __u32 i_fsnotify_mask; /* all events for this inode */ struct hlist_head i_fsnotify_mark_entries; /* marks on this inode */ That's right, inotify, dnotify, and fanotify all in 64 bits. We used that much space just in inotify_watches alone, before this patch set. fsnotify object lifetime and locking is MUCH better than what we have today. inotify locking is incredibly complex. See 8f7b0ba1c8539 as an example of what's been busted since inception. inotify needs to know internal semantics of superblock destruction and unmounting to function. The inode pinning and vfs contortions are horrible. no fsnotify implementers do allocation under locks. This means things like f04b30de3 which (due to an overabundance of caution) changes GFP_KERNEL to GFP_NOFS can be reverted. There are no longer any allocation rules when using or implementing your own fsnotify listener. fsnotify paves the way for fanotify. In brief fanotify is a notification mechanism that delivers the lisener both an 'event' and an open file descriptor to the object in question. This means that fanotify is pathname agnostic. Some on lkml may not care for the original companies or users that pushed for TALPA, but fanotify was designed with flexibility and input for other users in mind. The readahead group expressed interest in fanotify as it could be used to profile disk access on boot without breaking the audit system. The desktop search groups have also expressed interest in fanotify as it solves a number of the race conditions and problems present with managing inotify when more than a limited number of specific files are of interest. fanotify can provide for a userspace access control system which makes it a clean interface for AV vendors to hook without trying to do binary patching on the syscall table, LSM, and everywhere else they do their things today. With this patch series fanotify can be implemented in less than 1200 lines of easy to review code. Almost all of which is the socket based user interface. This patch series builds fsnotify to the point that it can implement dnotify and inotify_user. Patches exist and will be sent soon after acceptance to finish the in kernel inotify conversion (audit) and implement fanotify. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'include/linux/fsnotify.h')
-rw-r--r--include/linux/fsnotify.h115
1 files changed, 80 insertions, 35 deletions
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index 00fbd5b..6c9ebef 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -13,6 +13,7 @@
#include <linux/dnotify.h>
#include <linux/inotify.h>
+#include <linux/fsnotify_backend.h>
#include <linux/audit.h>
/*
@@ -35,6 +36,16 @@ static inline void fsnotify_d_move(struct dentry *entry)
}
/*
+ * fsnotify_link_count - inode's link count changed
+ */
+static inline void fsnotify_link_count(struct inode *inode)
+{
+ inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL);
+
+ fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE);
+}
+
+/*
* fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
*/
static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
@@ -43,28 +54,47 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
{
struct inode *source = moved->d_inode;
u32 cookie = inotify_get_cookie();
+ __u32 old_dir_mask = 0;
+ __u32 new_dir_mask = 0;
- if (old_dir == new_dir)
+ if (old_dir == new_dir) {
inode_dir_notify(old_dir, DN_RENAME);
- else {
+ old_dir_mask = FS_DN_RENAME;
+ } else {
inode_dir_notify(old_dir, DN_DELETE);
+ old_dir_mask = FS_DELETE;
inode_dir_notify(new_dir, DN_CREATE);
+ new_dir_mask = FS_CREATE;
}
- if (isdir)
+ if (isdir) {
isdir = IN_ISDIR;
+ old_dir_mask |= FS_IN_ISDIR;
+ new_dir_mask |= FS_IN_ISDIR;
+ }
+
+ old_dir_mask |= FS_MOVED_FROM;
+ new_dir_mask |= FS_MOVED_TO;
+
inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir,cookie,old_name,
source);
inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name,
source);
+ fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE);
+ fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE);
+
if (target) {
inotify_inode_queue_event(target, IN_DELETE_SELF, 0, NULL, NULL);
inotify_inode_is_dead(target);
+
+ /* this is really a link_count change not a removal */
+ fsnotify_link_count(target);
}
if (source) {
inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL);
+ fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE);
}
audit_inode_child(new_name, moved, new_dir);
}
@@ -74,10 +104,12 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
*/
static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
{
+ __u32 mask = FS_DELETE;
+
if (isdir)
- isdir = IN_ISDIR;
+ mask |= FS_IN_ISDIR;
dnotify_parent(dentry, DN_DELETE);
- inotify_dentry_parent_queue_event(dentry, IN_DELETE|isdir, 0, dentry->d_name.name);
+ inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
}
/*
@@ -87,14 +119,8 @@ static inline void fsnotify_inoderemove(struct inode *inode)
{
inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL, NULL);
inotify_inode_is_dead(inode);
-}
-/*
- * fsnotify_link_count - inode's link count changed
- */
-static inline void fsnotify_link_count(struct inode *inode)
-{
- inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL);
+ fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE);
}
/*
@@ -106,6 +132,8 @@ static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
inotify_inode_queue_event(inode, IN_CREATE, 0, dentry->d_name.name,
dentry->d_inode);
audit_inode_child(dentry->d_name.name, dentry, inode);
+
+ fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE);
}
/*
@@ -120,6 +148,8 @@ static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct
inode);
fsnotify_link_count(inode);
audit_inode_child(new_dentry->d_name.name, new_dentry, dir);
+
+ fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE);
}
/*
@@ -127,10 +157,14 @@ static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct
*/
static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
{
+ __u32 mask = (FS_CREATE | FS_IN_ISDIR);
+ struct inode *d_inode = dentry->d_inode;
+
inode_dir_notify(inode, DN_CREATE);
- inotify_inode_queue_event(inode, IN_CREATE | IN_ISDIR, 0,
- dentry->d_name.name, dentry->d_inode);
+ inotify_inode_queue_event(inode, mask, 0, dentry->d_name.name, d_inode);
audit_inode_child(dentry->d_name.name, dentry, inode);
+
+ fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE);
}
/*
@@ -139,14 +173,16 @@ static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
static inline void fsnotify_access(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
- u32 mask = IN_ACCESS;
+ __u32 mask = FS_ACCESS;
if (S_ISDIR(inode->i_mode))
- mask |= IN_ISDIR;
+ mask |= FS_IN_ISDIR;
dnotify_parent(dentry, DN_ACCESS);
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
+
+ fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
}
/*
@@ -155,14 +191,16 @@ static inline void fsnotify_access(struct dentry *dentry)
static inline void fsnotify_modify(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
- u32 mask = IN_MODIFY;
+ __u32 mask = FS_MODIFY;
if (S_ISDIR(inode->i_mode))
- mask |= IN_ISDIR;
+ mask |= FS_IN_ISDIR;
dnotify_parent(dentry, DN_MODIFY);
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
+
+ fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
}
/*
@@ -171,13 +209,15 @@ static inline void fsnotify_modify(struct dentry *dentry)
static inline void fsnotify_open(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
- u32 mask = IN_OPEN;
+ __u32 mask = FS_OPEN;
if (S_ISDIR(inode->i_mode))
- mask |= IN_ISDIR;
+ mask |= FS_IN_ISDIR;
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
+
+ fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
}
/*
@@ -189,13 +229,15 @@ static inline void fsnotify_close(struct file *file)
struct inode *inode = dentry->d_inode;
const char *name = dentry->d_name.name;
fmode_t mode = file->f_mode;
- u32 mask = (mode & FMODE_WRITE) ? IN_CLOSE_WRITE : IN_CLOSE_NOWRITE;
+ __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
if (S_ISDIR(inode->i_mode))
- mask |= IN_ISDIR;
+ mask |= FS_IN_ISDIR;
inotify_dentry_parent_queue_event(dentry, mask, 0, name);
inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
+
+ fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE);
}
/*
@@ -204,13 +246,15 @@ static inline void fsnotify_close(struct file *file)
static inline void fsnotify_xattr(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
- u32 mask = IN_ATTRIB;
+ __u32 mask = FS_ATTRIB;
if (S_ISDIR(inode->i_mode))
- mask |= IN_ISDIR;
+ mask |= FS_IN_ISDIR;
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
+
+ fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
}
/*
@@ -221,34 +265,34 @@ static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
{
struct inode *inode = dentry->d_inode;
int dn_mask = 0;
- u32 in_mask = 0;
+ __u32 in_mask = 0;
if (ia_valid & ATTR_UID) {
- in_mask |= IN_ATTRIB;
+ in_mask |= FS_ATTRIB;
dn_mask |= DN_ATTRIB;
}
if (ia_valid & ATTR_GID) {
- in_mask |= IN_ATTRIB;
+ in_mask |= FS_ATTRIB;
dn_mask |= DN_ATTRIB;
}
if (ia_valid & ATTR_SIZE) {
- in_mask |= IN_MODIFY;
+ in_mask |= FS_MODIFY;
dn_mask |= DN_MODIFY;
}
/* both times implies a utime(s) call */
if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
{
- in_mask |= IN_ATTRIB;
+ in_mask |= FS_ATTRIB;
dn_mask |= DN_ATTRIB;
} else if (ia_valid & ATTR_ATIME) {
- in_mask |= IN_ACCESS;
+ in_mask |= FS_ACCESS;
dn_mask |= DN_ACCESS;
} else if (ia_valid & ATTR_MTIME) {
- in_mask |= IN_MODIFY;
+ in_mask |= FS_MODIFY;
dn_mask |= DN_MODIFY;
}
if (ia_valid & ATTR_MODE) {
- in_mask |= IN_ATTRIB;
+ in_mask |= FS_ATTRIB;
dn_mask |= DN_ATTRIB;
}
@@ -256,14 +300,15 @@ static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
dnotify_parent(dentry, dn_mask);
if (in_mask) {
if (S_ISDIR(inode->i_mode))
- in_mask |= IN_ISDIR;
+ in_mask |= FS_IN_ISDIR;
inotify_inode_queue_event(inode, in_mask, 0, NULL, NULL);
inotify_dentry_parent_queue_event(dentry, in_mask, 0,
dentry->d_name.name);
+ fsnotify(inode, in_mask, inode, FSNOTIFY_EVENT_INODE);
}
}
-#ifdef CONFIG_INOTIFY /* inotify helpers */
+#if defined(CONFIG_INOTIFY) || defined(CONFIG_FSNOTIFY) /* notify helpers */
/*
* fsnotify_oldname_init - save off the old filename before we change it
@@ -281,7 +326,7 @@ static inline void fsnotify_oldname_free(const char *old_name)
kfree(old_name);
}
-#else /* CONFIG_INOTIFY */
+#else /* CONFIG_INOTIFY || CONFIG_FSNOTIFY */
static inline const char *fsnotify_oldname_init(const char *name)
{
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