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authorRobert Love <rml@novell.com>2005-07-12 17:06:03 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2005-07-12 20:38:38 -0700
commit0eeca28300df110bd6ed54b31193c83b87921443 (patch)
tree7db42d8a18d80eca538f5b7d25e0532b8fa38b85 /include/linux/fsnotify.h
parentbd4c625c061c2a38568d0add3478f59172455159 (diff)
downloadop-kernel-dev-0eeca28300df110bd6ed54b31193c83b87921443.zip
op-kernel-dev-0eeca28300df110bd6ed54b31193c83b87921443.tar.gz
[PATCH] inotify
inotify is intended to correct the deficiencies of dnotify, particularly its inability to scale and its terrible user interface: * dnotify requires the opening of one fd per each directory that you intend to watch. This quickly results in too many open files and pins removable media, preventing unmount. * dnotify is directory-based. You only learn about changes to directories. Sure, a change to a file in a directory affects the directory, but you are then forced to keep a cache of stat structures. * dnotify's interface to user-space is awful. Signals? inotify provides a more usable, simple, powerful solution to file change notification: * inotify's interface is a system call that returns a fd, not SIGIO. You get a single fd, which is select()-able. * inotify has an event that says "the filesystem that the item you were watching is on was unmounted." * inotify can watch directories or files. Inotify is currently used by Beagle (a desktop search infrastructure), Gamin (a FAM replacement), and other projects. See Documentation/filesystems/inotify.txt. Signed-off-by: Robert Love <rml@novell.com> Cc: John McCutchan <ttb@tentacle.dhs.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/fsnotify.h')
-rw-r--r--include/linux/fsnotify.h248
1 files changed, 248 insertions, 0 deletions
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
new file mode 100644
index 0000000..eb581b6
--- /dev/null
+++ b/include/linux/fsnotify.h
@@ -0,0 +1,248 @@
+#ifndef _LINUX_FS_NOTIFY_H
+#define _LINUX_FS_NOTIFY_H
+
+/*
+ * include/linux/fsnotify.h - generic hooks for filesystem notification, to
+ * reduce in-source duplication from both dnotify and inotify.
+ *
+ * We don't compile any of this away in some complicated menagerie of ifdefs.
+ * Instead, we rely on the code inside to optimize away as needed.
+ *
+ * (C) Copyright 2005 Robert Love
+ */
+
+#ifdef __KERNEL__
+
+#include <linux/dnotify.h>
+#include <linux/inotify.h>
+
+/*
+ * 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,
+ const char *old_name, const char *new_name,
+ int isdir)
+{
+ u32 cookie = inotify_get_cookie();
+
+ if (old_dir == new_dir)
+ inode_dir_notify(old_dir, DN_RENAME);
+ else {
+ inode_dir_notify(old_dir, DN_DELETE);
+ inode_dir_notify(new_dir, DN_CREATE);
+ }
+
+ if (isdir)
+ isdir = IN_ISDIR;
+ inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir,cookie,old_name);
+ inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name);
+}
+
+/*
+ * fsnotify_unlink - file was unlinked
+ */
+static inline void fsnotify_unlink(struct dentry *dentry, struct inode *dir)
+{
+ struct inode *inode = dentry->d_inode;
+
+ inode_dir_notify(dir, DN_DELETE);
+ inotify_inode_queue_event(dir, IN_DELETE, 0, dentry->d_name.name);
+ inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL);
+
+ inotify_inode_is_dead(inode);
+}
+
+/*
+ * fsnotify_rmdir - directory was removed
+ */
+static inline void fsnotify_rmdir(struct dentry *dentry, struct inode *inode,
+ struct inode *dir)
+{
+ inode_dir_notify(dir, DN_DELETE);
+ inotify_inode_queue_event(dir,IN_DELETE|IN_ISDIR,0,dentry->d_name.name);
+ inotify_inode_queue_event(inode, IN_DELETE_SELF | IN_ISDIR, 0, NULL);
+ inotify_inode_is_dead(inode);
+}
+
+/*
+ * fsnotify_create - 'name' was linked in
+ */
+static inline void fsnotify_create(struct inode *inode, const char *name)
+{
+ inode_dir_notify(inode, DN_CREATE);
+ inotify_inode_queue_event(inode, IN_CREATE, 0, name);
+}
+
+/*
+ * fsnotify_mkdir - directory 'name' was created
+ */
+static inline void fsnotify_mkdir(struct inode *inode, const char *name)
+{
+ inode_dir_notify(inode, DN_CREATE);
+ inotify_inode_queue_event(inode, IN_CREATE | IN_ISDIR, 0, name);
+}
+
+/*
+ * fsnotify_access - file was read
+ */
+static inline void fsnotify_access(struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ u32 mask = IN_ACCESS;
+
+ if (S_ISDIR(inode->i_mode))
+ mask |= 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);
+}
+
+/*
+ * fsnotify_modify - file was modified
+ */
+static inline void fsnotify_modify(struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ u32 mask = IN_MODIFY;
+
+ if (S_ISDIR(inode->i_mode))
+ mask |= 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);
+}
+
+/*
+ * fsnotify_open - file was opened
+ */
+static inline void fsnotify_open(struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ u32 mask = IN_OPEN;
+
+ if (S_ISDIR(inode->i_mode))
+ mask |= IN_ISDIR;
+
+ inotify_inode_queue_event(inode, mask, 0, NULL);
+ inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
+}
+
+/*
+ * fsnotify_close - file was closed
+ */
+static inline void fsnotify_close(struct file *file)
+{
+ struct dentry *dentry = file->f_dentry;
+ struct inode *inode = dentry->d_inode;
+ const char *name = dentry->d_name.name;
+ mode_t mode = file->f_mode;
+ u32 mask = (mode & FMODE_WRITE) ? IN_CLOSE_WRITE : IN_CLOSE_NOWRITE;
+
+ if (S_ISDIR(inode->i_mode))
+ mask |= IN_ISDIR;
+
+ inotify_dentry_parent_queue_event(dentry, mask, 0, name);
+ inotify_inode_queue_event(inode, mask, 0, NULL);
+}
+
+/*
+ * fsnotify_xattr - extended attributes were changed
+ */
+static inline void fsnotify_xattr(struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ u32 mask = IN_ATTRIB;
+
+ if (S_ISDIR(inode->i_mode))
+ mask |= IN_ISDIR;
+
+ inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
+ inotify_inode_queue_event(inode, mask, 0, NULL);
+}
+
+/*
+ * fsnotify_change - notify_change event. file was modified and/or metadata
+ * was changed.
+ */
+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;
+
+ if (ia_valid & ATTR_UID) {
+ in_mask |= IN_ATTRIB;
+ dn_mask |= DN_ATTRIB;
+ }
+ if (ia_valid & ATTR_GID) {
+ in_mask |= IN_ATTRIB;
+ dn_mask |= DN_ATTRIB;
+ }
+ if (ia_valid & ATTR_SIZE) {
+ in_mask |= IN_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;
+ dn_mask |= DN_ATTRIB;
+ } else if (ia_valid & ATTR_ATIME) {
+ in_mask |= IN_ACCESS;
+ dn_mask |= DN_ACCESS;
+ } else if (ia_valid & ATTR_MTIME) {
+ in_mask |= IN_MODIFY;
+ dn_mask |= DN_MODIFY;
+ }
+ if (ia_valid & ATTR_MODE) {
+ in_mask |= IN_ATTRIB;
+ dn_mask |= DN_ATTRIB;
+ }
+
+ if (dn_mask)
+ dnotify_parent(dentry, dn_mask);
+ if (in_mask) {
+ if (S_ISDIR(inode->i_mode))
+ in_mask |= IN_ISDIR;
+ inotify_inode_queue_event(inode, in_mask, 0, NULL);
+ inotify_dentry_parent_queue_event(dentry, in_mask, 0,
+ dentry->d_name.name);
+ }
+}
+
+#ifdef CONFIG_INOTIFY /* inotify helpers */
+
+/*
+ * fsnotify_oldname_init - save off the old filename before we change it
+ */
+static inline const char *fsnotify_oldname_init(const char *name)
+{
+ return kstrdup(name, GFP_KERNEL);
+}
+
+/*
+ * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
+ */
+static inline void fsnotify_oldname_free(const char *old_name)
+{
+ kfree(old_name);
+}
+
+#else /* CONFIG_INOTIFY */
+
+static inline const char *fsnotify_oldname_init(const char *name)
+{
+ return NULL;
+}
+
+static inline void fsnotify_oldname_free(const char *old_name)
+{
+}
+
+#endif /* ! CONFIG_INOTIFY */
+
+#endif /* __KERNEL__ */
+
+#endif /* _LINUX_FS_NOTIFY_H */
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