| Message ID | 20200716084230.30611-18-amir73il@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fanotify events with name info | expand |
On Thu 16-07-20 11:42:25, Amir Goldstein wrote: > MOVE_SELF event does not get reported to a parent watching children > when a child is moved, but it can be reported to sb/mount mark or to > the moved inode itself with parent/name info if group is interested > in parent/name info. > > Use the fsnotify_parent() helper to send a MOVE_SELF event and adjust > fsnotify() to handle the case of an event "on child" that should not > be sent to the watching parent's inode mark. > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> What I find strange about this is that the MOVE_SELF event will be reported to the new parent under the new name (just due to the way how dentry handling in vfs_rename() works). That seems rather arbitrary and I'm not sure it would be useful? I guess anybody needing dir info with renames will rather use FS_MOVED_FROM / FS_MOVED_TO where it is well defined? So can we leave FS_MOVE_SELF as one of those cases that doesn't report parent + name info? Honza > --- > fs/notify/fsnotify.c | 22 ++++++++++++++++++---- > include/linux/fsnotify.h | 4 +--- > include/linux/fsnotify_backend.h | 2 +- > 3 files changed, 20 insertions(+), 8 deletions(-) > > diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c > index efa5c1c4908a..fa84aea47b20 100644 > --- a/fs/notify/fsnotify.c > +++ b/fs/notify/fsnotify.c > @@ -367,6 +367,7 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, > struct super_block *sb = to_tell->i_sb; > struct inode *dir = S_ISDIR(to_tell->i_mode) ? to_tell : NULL; > struct mount *mnt = NULL; > + struct inode *inode = NULL; > struct inode *child = NULL; > int ret = 0; > __u32 test_mask, marks_mask; > @@ -377,6 +378,14 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, > if (mask & FS_EVENT_ON_CHILD) > child = fsnotify_data_inode(data, data_type); > > + /* > + * If event is "on child" then to_tell is a watching parent. > + * An event "on child" may be sent to mount/sb mark with parent/name > + * info, but not appropriate for watching parent (e.g. FS_MOVE_SELF). > + */ > + if (!child || (mask & FS_EVENTS_POSS_ON_CHILD)) > + inode = to_tell; > + > /* > * Optimization: srcu_read_lock() has a memory barrier which can > * be expensive. It protects walking the *_fsnotify_marks lists. > @@ -384,14 +393,17 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, > * SRCU because we have no references to any objects and do not > * need SRCU to keep them "alive". > */ > - if (!to_tell->i_fsnotify_marks && !sb->s_fsnotify_marks && > + if (!sb->s_fsnotify_marks && > (!mnt || !mnt->mnt_fsnotify_marks) && > + (!inode || !inode->i_fsnotify_marks) && > (!child || !child->i_fsnotify_marks)) > return 0; > > - marks_mask = to_tell->i_fsnotify_mask | sb->s_fsnotify_mask; > + marks_mask = sb->s_fsnotify_mask; > if (mnt) > marks_mask |= mnt->mnt_fsnotify_mask; > + if (inode) > + marks_mask |= inode->i_fsnotify_mask; > if (child) > marks_mask |= child->i_fsnotify_mask; > > @@ -406,14 +418,16 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, > > iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu); > > - iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] = > - fsnotify_first_mark(&to_tell->i_fsnotify_marks); > iter_info.marks[FSNOTIFY_OBJ_TYPE_SB] = > fsnotify_first_mark(&sb->s_fsnotify_marks); > if (mnt) { > iter_info.marks[FSNOTIFY_OBJ_TYPE_VFSMOUNT] = > fsnotify_first_mark(&mnt->mnt_fsnotify_marks); > } > + if (inode) { > + iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] = > + fsnotify_first_mark(&inode->i_fsnotify_marks); > + } > if (child) { > iter_info.marks[FSNOTIFY_OBJ_TYPE_CHILD] = > fsnotify_first_mark(&child->i_fsnotify_marks); > diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h > index fe4f2bc5b4c2..61dccaf21e7b 100644 > --- a/include/linux/fsnotify.h > +++ b/include/linux/fsnotify.h > @@ -131,7 +131,6 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, > u32 fs_cookie = fsnotify_get_cookie(); > __u32 old_dir_mask = FS_MOVED_FROM; > __u32 new_dir_mask = FS_MOVED_TO; > - __u32 mask = FS_MOVE_SELF; > const struct qstr *new_name = &moved->d_name; > > if (old_dir == new_dir) > @@ -140,7 +139,6 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, > if (isdir) { > old_dir_mask |= FS_ISDIR; > new_dir_mask |= FS_ISDIR; > - mask |= FS_ISDIR; > } > > fsnotify_name(old_dir, old_dir_mask, source, old_name, fs_cookie); > @@ -149,7 +147,7 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, > if (target) > fsnotify_link_count(target); > > - fsnotify(source, mask, source, FSNOTIFY_EVENT_INODE, NULL, 0); > + fsnotify_dentry(moved, FS_MOVE_SELF); > audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE); > } > > diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h > index 6f0df110e9f8..acce2ec17edf 100644 > --- a/include/linux/fsnotify_backend.h > +++ b/include/linux/fsnotify_backend.h > @@ -89,7 +89,7 @@ > * It may include events that can be sent to an inode/sb/mount mark, but cannot > * be sent to a parent watching children. > */ > -#define FS_EVENTS_POSS_TO_PARENT (FS_EVENTS_POSS_ON_CHILD) > +#define FS_EVENTS_POSS_TO_PARENT (FS_EVENTS_POSS_ON_CHILD | FS_MOVE_SELF) > > /* Events that can be reported to backends */ > #define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \ > -- > 2.17.1 >
On Thu, Jul 16, 2020 at 4:45 PM Jan Kara <jack@suse.cz> wrote: > > On Thu 16-07-20 11:42:25, Amir Goldstein wrote: > > MOVE_SELF event does not get reported to a parent watching children > > when a child is moved, but it can be reported to sb/mount mark or to > > the moved inode itself with parent/name info if group is interested > > in parent/name info. > > > > Use the fsnotify_parent() helper to send a MOVE_SELF event and adjust > > fsnotify() to handle the case of an event "on child" that should not > > be sent to the watching parent's inode mark. > > > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > > What I find strange about this is that the MOVE_SELF event will be reported > to the new parent under the new name (just due to the way how dentry > handling in vfs_rename() works). That seems rather arbitrary and I'm not > sure it would be useful? I guess anybody needing dir info with renames > will rather use FS_MOVED_FROM / FS_MOVED_TO where it is well defined? > > So can we leave FS_MOVE_SELF as one of those cases that doesn't report > parent + name info? > I can live with that. I didn't have a use case for it. This patch may be dropped from the series without affecting the rest. Thanks, Amir.
On Thu, Jul 16, 2020 at 4:59 PM Amir Goldstein <amir73il@gmail.com> wrote: > > On Thu, Jul 16, 2020 at 4:45 PM Jan Kara <jack@suse.cz> wrote: > > > > On Thu 16-07-20 11:42:25, Amir Goldstein wrote: > > > MOVE_SELF event does not get reported to a parent watching children > > > when a child is moved, but it can be reported to sb/mount mark or to > > > the moved inode itself with parent/name info if group is interested > > > in parent/name info. > > > > > > Use the fsnotify_parent() helper to send a MOVE_SELF event and adjust > > > fsnotify() to handle the case of an event "on child" that should not > > > be sent to the watching parent's inode mark. > > > > > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > > > > What I find strange about this is that the MOVE_SELF event will be reported > > to the new parent under the new name (just due to the way how dentry > > handling in vfs_rename() works). That seems rather arbitrary and I'm not > > sure it would be useful? I guess anybody needing dir info with renames > > will rather use FS_MOVED_FROM / FS_MOVED_TO where it is well defined? > > > > So can we leave FS_MOVE_SELF as one of those cases that doesn't report > > parent + name info? > > > > I can live with that. > I didn't have a use case for it. > This patch may be dropped from the series without affecting the rest. > BTW, I checked my man page and it doesn't say anything about whether parent fid and child fid can be reported together with MOVE_SELF. The language is generic enough on that part. Thanks, Amir.
On Thu, Jul 16, 2020 at 5:10 PM Amir Goldstein <amir73il@gmail.com> wrote: > > On Thu, Jul 16, 2020 at 4:59 PM Amir Goldstein <amir73il@gmail.com> wrote: > > > > On Thu, Jul 16, 2020 at 4:45 PM Jan Kara <jack@suse.cz> wrote: > > > > > > On Thu 16-07-20 11:42:25, Amir Goldstein wrote: > > > > MOVE_SELF event does not get reported to a parent watching children > > > > when a child is moved, but it can be reported to sb/mount mark or to > > > > the moved inode itself with parent/name info if group is interested > > > > in parent/name info. > > > > > > > > Use the fsnotify_parent() helper to send a MOVE_SELF event and adjust > > > > fsnotify() to handle the case of an event "on child" that should not > > > > be sent to the watching parent's inode mark. > > > > > > > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > > > > > > What I find strange about this is that the MOVE_SELF event will be reported > > > to the new parent under the new name (just due to the way how dentry > > > handling in vfs_rename() works). That seems rather arbitrary and I'm not > > > sure it would be useful? I guess anybody needing dir info with renames > > > will rather use FS_MOVED_FROM / FS_MOVED_TO where it is well defined? > > > > > > So can we leave FS_MOVE_SELF as one of those cases that doesn't report > > > parent + name info? > > > > > > > I can live with that. > > I didn't have a use case for it. > > This patch may be dropped from the series without affecting the rest. > > > > BTW, I checked my man page and it doesn't say anything about whether > parent fid and child fid can be reported together with MOVE_SELF. > The language is generic enough on that part. > FYI, I pushed a commit to the LTP branch that adapts the test to MOVE_SELF that does not report name and tested with this patch reverted. The test now has less special cases when setting expected values, which is generally a good sign ;-) Thanks, Amir.
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index efa5c1c4908a..fa84aea47b20 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -367,6 +367,7 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, struct super_block *sb = to_tell->i_sb; struct inode *dir = S_ISDIR(to_tell->i_mode) ? to_tell : NULL; struct mount *mnt = NULL; + struct inode *inode = NULL; struct inode *child = NULL; int ret = 0; __u32 test_mask, marks_mask; @@ -377,6 +378,14 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, if (mask & FS_EVENT_ON_CHILD) child = fsnotify_data_inode(data, data_type); + /* + * If event is "on child" then to_tell is a watching parent. + * An event "on child" may be sent to mount/sb mark with parent/name + * info, but not appropriate for watching parent (e.g. FS_MOVE_SELF). + */ + if (!child || (mask & FS_EVENTS_POSS_ON_CHILD)) + inode = to_tell; + /* * Optimization: srcu_read_lock() has a memory barrier which can * be expensive. It protects walking the *_fsnotify_marks lists. @@ -384,14 +393,17 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, * SRCU because we have no references to any objects and do not * need SRCU to keep them "alive". */ - if (!to_tell->i_fsnotify_marks && !sb->s_fsnotify_marks && + if (!sb->s_fsnotify_marks && (!mnt || !mnt->mnt_fsnotify_marks) && + (!inode || !inode->i_fsnotify_marks) && (!child || !child->i_fsnotify_marks)) return 0; - marks_mask = to_tell->i_fsnotify_mask | sb->s_fsnotify_mask; + marks_mask = sb->s_fsnotify_mask; if (mnt) marks_mask |= mnt->mnt_fsnotify_mask; + if (inode) + marks_mask |= inode->i_fsnotify_mask; if (child) marks_mask |= child->i_fsnotify_mask; @@ -406,14 +418,16 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu); - iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] = - fsnotify_first_mark(&to_tell->i_fsnotify_marks); iter_info.marks[FSNOTIFY_OBJ_TYPE_SB] = fsnotify_first_mark(&sb->s_fsnotify_marks); if (mnt) { iter_info.marks[FSNOTIFY_OBJ_TYPE_VFSMOUNT] = fsnotify_first_mark(&mnt->mnt_fsnotify_marks); } + if (inode) { + iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] = + fsnotify_first_mark(&inode->i_fsnotify_marks); + } if (child) { iter_info.marks[FSNOTIFY_OBJ_TYPE_CHILD] = fsnotify_first_mark(&child->i_fsnotify_marks); diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index fe4f2bc5b4c2..61dccaf21e7b 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -131,7 +131,6 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, u32 fs_cookie = fsnotify_get_cookie(); __u32 old_dir_mask = FS_MOVED_FROM; __u32 new_dir_mask = FS_MOVED_TO; - __u32 mask = FS_MOVE_SELF; const struct qstr *new_name = &moved->d_name; if (old_dir == new_dir) @@ -140,7 +139,6 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, if (isdir) { old_dir_mask |= FS_ISDIR; new_dir_mask |= FS_ISDIR; - mask |= FS_ISDIR; } fsnotify_name(old_dir, old_dir_mask, source, old_name, fs_cookie); @@ -149,7 +147,7 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, if (target) fsnotify_link_count(target); - fsnotify(source, mask, source, FSNOTIFY_EVENT_INODE, NULL, 0); + fsnotify_dentry(moved, FS_MOVE_SELF); audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE); } diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 6f0df110e9f8..acce2ec17edf 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -89,7 +89,7 @@ * It may include events that can be sent to an inode/sb/mount mark, but cannot * be sent to a parent watching children. */ -#define FS_EVENTS_POSS_TO_PARENT (FS_EVENTS_POSS_ON_CHILD) +#define FS_EVENTS_POSS_TO_PARENT (FS_EVENTS_POSS_ON_CHILD | FS_MOVE_SELF) /* Events that can be reported to backends */ #define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \
MOVE_SELF event does not get reported to a parent watching children when a child is moved, but it can be reported to sb/mount mark or to the moved inode itself with parent/name info if group is interested in parent/name info. Use the fsnotify_parent() helper to send a MOVE_SELF event and adjust fsnotify() to handle the case of an event "on child" that should not be sent to the watching parent's inode mark. Signed-off-by: Amir Goldstein <amir73il@gmail.com> --- fs/notify/fsnotify.c | 22 ++++++++++++++++++---- include/linux/fsnotify.h | 4 +--- include/linux/fsnotify_backend.h | 2 +- 3 files changed, 20 insertions(+), 8 deletions(-)