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 --- fs/sysfs/file.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index d72c1ce4855..335288b9be0 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -3,7 +3,7 @@ */ #include -#include +#include #include #include #include @@ -391,9 +391,6 @@ int sysfs_create_file(struct kobject * kobj, const struct attribute * attr) * sysfs_update_file - update the modified timestamp on an object attribute. * @kobj: object we're acting for. * @attr: attribute descriptor. - * - * Also call dnotify for the dentry, which lots of userspace programs - * use. */ int sysfs_update_file(struct kobject * kobj, const struct attribute * attr) { @@ -408,7 +405,7 @@ int sysfs_update_file(struct kobject * kobj, const struct attribute * attr) if (victim->d_inode && (victim->d_parent->d_inode == dir->d_inode)) { victim->d_inode->i_mtime = CURRENT_TIME; - dnotify_parent(victim, DN_MODIFY); + fsnotify_modify(victim); /** * Drop reference from initial sysfs_get_dentry(). -- cgit v1.2.3 From bc062b1b5c6bef4e3a29c7fda57967251d12beb0 Mon Sep 17 00:00:00 2001 From: Maneesh Soni Date: Fri, 29 Jul 2005 12:13:35 -0700 Subject: [PATCH] sysfs: fix sysfs_chmod_file o sysfs_chmod_file() must update the new iattr field in sysfs_dirent else the mode change will not be persistent in case of inode evacuation from cache. Signed-off-by: Maneesh Soni Signed-off-by: Greg Kroah-Hartman Signed-off-by: Linus Torvalds --- fs/sysfs/file.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 335288b9be0..4013d7905e8 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -437,8 +437,8 @@ int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode) { struct dentry *dir = kobj->dentry; struct dentry *victim; - struct sysfs_dirent *sd; - umode_t umode = (mode & S_IALLUGO) | S_IFREG; + struct inode * inode; + struct iattr newattrs; int res = -ENOENT; down(&dir->d_inode->i_sem); @@ -446,13 +446,15 @@ int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode) if (!IS_ERR(victim)) { if (victim->d_inode && (victim->d_parent->d_inode == dir->d_inode)) { - sd = victim->d_fsdata; - attr->mode = mode; - sd->s_mode = umode; - victim->d_inode->i_mode = umode; - dput(victim); - res = 0; + inode = victim->d_inode; + down(&inode->i_sem); + newattrs.ia_mode = (mode & S_IALLUGO) | + (inode->i_mode & ~S_IALLUGO); + newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; + res = notify_change(victim, &newattrs); + up(&inode->i_sem); } + dput(victim); } up(&dir->d_inode->i_sem); -- cgit v1.2.3