From 0eeca28300df110bd6ed54b31193c83b87921443 Mon Sep 17 00:00:00 2001 From: Robert Love Date: Tue, 12 Jul 2005 17:06:03 -0400 Subject: [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 Cc: John McCutchan Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/fsnotify.h | 248 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 248 insertions(+) create mode 100644 include/linux/fsnotify.h (limited to 'include/linux/fsnotify.h') diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h new file mode 100644 index 000000000000..eb581b6cfca9 --- /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 +#include + +/* + * 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 */ -- cgit v1.2.3