From b9e4e3bd0495fea9e8f8e712889c9cd8ffa43c94 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 17 Dec 2009 21:24:33 -0500 Subject: [PATCH] fanotify: allow users to set an ignored_mask Change the sys_fanotify_mark() system call so users can set ignored_masks on inodes. Remember, if a user new sets a real mask, and only sets ignored masks, the ignore will never be pinned in memory. Thus ignored_masks can be lost under memory pressure and the user may again get events they previously thought were ignored. Signed-off-by: Eric Paris --- fs/notify/fanotify/fanotify_user.c | 54 ++++++++++++++++++++---------- include/linux/fanotify.h | 4 ++- 2 files changed, 39 insertions(+), 19 deletions(-) diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 3320f0c57e31..ad02d475770f 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -296,13 +296,20 @@ out: return ret; } -static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark, __u32 mask) +static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark, + __u32 mask, + unsigned int flags) { __u32 oldmask; spin_lock(&fsn_mark->lock); - oldmask = fsn_mark->mask; - fsnotify_set_mark_mask_locked(fsn_mark, (oldmask & ~mask)); + if (!(flags & FAN_MARK_IGNORED_MASK)) { + oldmask = fsn_mark->mask; + fsnotify_set_mark_mask_locked(fsn_mark, (oldmask & ~mask)); + } else { + oldmask = fsn_mark->ignored_mask; + fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask & ~mask)); + } spin_unlock(&fsn_mark->lock); if (!(oldmask & ~mask)) @@ -312,7 +319,8 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark, __u3 } static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group, - struct vfsmount *mnt, __u32 mask) + struct vfsmount *mnt, __u32 mask, + unsigned int flags) { struct fsnotify_mark *fsn_mark = NULL; __u32 removed; @@ -321,7 +329,7 @@ static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group, if (!fsn_mark) return -ENOENT; - removed = fanotify_mark_remove_from_mask(fsn_mark, mask); + removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags); fsnotify_put_mark(fsn_mark); if (removed & group->mask) fsnotify_recalc_group_mask(group); @@ -332,7 +340,8 @@ static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group, } static int fanotify_remove_inode_mark(struct fsnotify_group *group, - struct inode *inode, __u32 mask) + struct inode *inode, __u32 mask, + unsigned int flags) { struct fsnotify_mark *fsn_mark = NULL; __u32 removed; @@ -341,7 +350,7 @@ static int fanotify_remove_inode_mark(struct fsnotify_group *group, if (!fsn_mark) return -ENOENT; - removed = fanotify_mark_remove_from_mask(fsn_mark, mask); + removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags); /* matches the fsnotify_find_inode_mark() */ fsnotify_put_mark(fsn_mark); @@ -353,20 +362,28 @@ static int fanotify_remove_inode_mark(struct fsnotify_group *group, return 0; } -static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark, __u32 mask) +static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark, + __u32 mask, + unsigned int flags) { __u32 oldmask; spin_lock(&fsn_mark->lock); - oldmask = fsn_mark->mask; - fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask)); + if (!(flags & FAN_MARK_IGNORED_MASK)) { + oldmask = fsn_mark->mask; + fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask)); + } else { + oldmask = fsn_mark->ignored_mask; + fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask | mask)); + } spin_unlock(&fsn_mark->lock); return mask & ~oldmask; } static int fanotify_add_vfsmount_mark(struct fsnotify_group *group, - struct vfsmount *mnt, __u32 mask) + struct vfsmount *mnt, __u32 mask, + unsigned int flags) { struct fsnotify_mark *fsn_mark; __u32 added; @@ -386,7 +403,7 @@ static int fanotify_add_vfsmount_mark(struct fsnotify_group *group, return ret; } } - added = fanotify_mark_add_to_mask(fsn_mark, mask); + added = fanotify_mark_add_to_mask(fsn_mark, mask, flags); fsnotify_put_mark(fsn_mark); if (added) { if (added & ~group->mask) @@ -398,7 +415,8 @@ static int fanotify_add_vfsmount_mark(struct fsnotify_group *group, } static int fanotify_add_inode_mark(struct fsnotify_group *group, - struct inode *inode, __u32 mask) + struct inode *inode, __u32 mask, + unsigned int flags) { struct fsnotify_mark *fsn_mark; __u32 added; @@ -420,7 +438,7 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group, return ret; } } - added = fanotify_mark_add_to_mask(fsn_mark, mask); + added = fanotify_mark_add_to_mask(fsn_mark, mask, flags); fsnotify_put_mark(fsn_mark); if (added) { if (added & ~group->mask) @@ -528,15 +546,15 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags, switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE)) { case FAN_MARK_ADD: if (flags & FAN_MARK_MOUNT) - ret = fanotify_add_vfsmount_mark(group, mnt, mask); + ret = fanotify_add_vfsmount_mark(group, mnt, mask, flags); else - ret = fanotify_add_inode_mark(group, inode, mask); + ret = fanotify_add_inode_mark(group, inode, mask, flags); break; case FAN_MARK_REMOVE: if (flags & FAN_MARK_MOUNT) - ret = fanotify_remove_vfsmount_mark(group, mnt, mask); + ret = fanotify_remove_vfsmount_mark(group, mnt, mask, flags); else - ret = fanotify_remove_inode_mark(group, inode, mask); + ret = fanotify_remove_inode_mark(group, inode, mask, flags); break; default: ret = -EINVAL; diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h index 90e59b24fd04..b8daa9f9b560 100644 --- a/include/linux/fanotify.h +++ b/include/linux/fanotify.h @@ -30,12 +30,14 @@ #define FAN_MARK_DONT_FOLLOW 0x00000004 #define FAN_MARK_ONLYDIR 0x00000008 #define FAN_MARK_MOUNT 0x00000010 +#define FAN_MARK_IGNORED_MASK 0x00000020 #define FAN_ALL_MARK_FLAGS (FAN_MARK_ADD |\ FAN_MARK_REMOVE |\ FAN_MARK_DONT_FOLLOW |\ FAN_MARK_ONLYDIR |\ - FAN_MARK_MOUNT) + FAN_MARK_MOUNT |\ + FAN_MARK_IGNORED_MASK) /* * All of the events - we build the list by hand so that we can add flags in -- 2.20.1