[PATCH v2 1/3] fanotify: only destroy mark when both mask and ignored_mask are cleared

[PATCH v2 1/3] fanotify: only destroy mark when both mask and ignored_mask are cleared

[Lino Sanfilippo]

In fanotify_mark_remove_from_mask() a mark is destroyed if only one of both
bitmasks (mask or ignored_mask) of a mark is cleared. However the other mask
may still be set and contain information that should not be lost. So only
destroy a mark if both masks are cleared.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
 fs/notify/fanotify/fanotify_user.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index c991616..ba31055 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -497,10 +497,9 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
 		oldmask = fsn_mark->ignored_mask;
 		fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask & ~mask));
 	}
+	*destroy = !(fsn_mark->mask | fsn_mark->ignored_mask);
 	spin_unlock(&fsn_mark->lock);
 
-	*destroy = !(oldmask & ~mask);
-
 	return mask & oldmask;
 }
 
-- 
1.9.1

[PATCH v2 2/3] fanotify: dont recalculate a marks mask if only the ignored mask changed

[Lino Sanfilippo]

If removing bits from a marks ignored mask, the concerning inodes/vfsmounts
mask is not affected. So dont recalculate it.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Reviewed-by: Jan Kara <jack@suse.cz>
---
 fs/notify/fanotify/fanotify_user.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index ba31055..ddc33fb 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -487,15 +487,15 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
 					    unsigned int flags,
 					    int *destroy)
 {
-	__u32 oldmask;
+	__u32 oldmask = 0;
 
 	spin_lock(&fsn_mark->lock);
 	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));
+		__u32 tmask = fsn_mark->ignored_mask & ~mask;
+		fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
 	}
 	*destroy = !(fsn_mark->mask | fsn_mark->ignored_mask);
 	spin_unlock(&fsn_mark->lock);
-- 
1.9.1

[PATCH v2 3/3] fanotify: dont set FAN_ONDIR implicitly on a marks ignored mask

[Lino Sanfilippo]

Currently FAN_ONDIR is always set on a marks ignored mask when the event mask
is extended without FAN_MARK_ONDIR being set. This may result in events for
directories being ignored unexpectedly for call sequences like

fanotify_mark(fd, FAN_MARK_ADD, FAN_OPEN | FAN_ONDIR , AT_FDCWD, "dir");
fanotify_mark(fd, FAN_MARK_ADD, FAN_CLOSE, AT_FDCWD, "dir");

Also FAN_MARK_ONDIR is only honored when adding events to a marks mask, but
not for event removal. Fix both issues.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
 fs/notify/fanotify/fanotify.c      |  2 +-
 fs/notify/fanotify/fanotify_user.c | 24 ++++++++++++++++--------
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 30d3add..51ceb81 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -140,7 +140,7 @@ static bool fanotify_should_send_event(struct fsnotify_mark *inode_mark,
 	}
 
 	if (S_ISDIR(path->dentry->d_inode->i_mode) &&
-	    (marks_ignored_mask & FS_ISDIR))
+	    !(marks_mask & FS_ISDIR & ~marks_ignored_mask))
 		return false;
 
 	if (event_mask & marks_mask & ~marks_ignored_mask)
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index ddc33fb..683d140 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -491,10 +491,17 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
 
 	spin_lock(&fsn_mark->lock);
 	if (!(flags & FAN_MARK_IGNORED_MASK)) {
+		__u32 tmask = fsn_mark->mask & ~mask;
+		if (flags & FAN_MARK_ONDIR)
+			tmask &= ~FAN_ONDIR;
+
 		oldmask = fsn_mark->mask;
-		fsnotify_set_mark_mask_locked(fsn_mark, (oldmask & ~mask));
+		fsnotify_set_mark_mask_locked(fsn_mark, tmask);
 	} else {
 		__u32 tmask = fsn_mark->ignored_mask & ~mask;
+		if (flags & FAN_MARK_ONDIR)
+			tmask &= ~FAN_ONDIR;
+
 		fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
 	}
 	*destroy = !(fsn_mark->mask | fsn_mark->ignored_mask);
@@ -568,20 +575,21 @@ static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
 
 	spin_lock(&fsn_mark->lock);
 	if (!(flags & FAN_MARK_IGNORED_MASK)) {
+		__u32 tmask = fsn_mark->mask | mask;
+		if (flags & FAN_MARK_ONDIR)
+			tmask |= FAN_ONDIR;
+
 		oldmask = fsn_mark->mask;
-		fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask));
+		fsnotify_set_mark_mask_locked(fsn_mark, tmask);
 	} else {
 		__u32 tmask = fsn_mark->ignored_mask | mask;
+		if (flags & FAN_MARK_ONDIR)
+			tmask |= FAN_ONDIR;
+
 		fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
 		if (flags & FAN_MARK_IGNORED_SURV_MODIFY)
 			fsn_mark->flags |= FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY;
 	}
-
-	if (!(flags & FAN_MARK_ONDIR)) {
-		__u32 tmask = fsn_mark->ignored_mask | FAN_ONDIR;
-		fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
-	}
-
 	spin_unlock(&fsn_mark->lock);
 
 	return mask & ~oldmask;
-- 
1.9.1

Re: [PATCH v2 1/3] fanotify: only destroy mark when both mask and ignored_mask are cleared

[Jan Kara]

On Thu 04-12-14 05:43:02, Lino Sanfilippo wrote:
> In fanotify_mark_remove_from_mask() a mark is destroyed if only one of both
> bitmasks (mask or ignored_mask) of a mark is cleared. However the other mask
> may still be set and contain information that should not be lost. So only
> destroy a mark if both masks are cleared.
> 
> Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
  Looks good you can add:
Reviewed-by: Jan Kara <jack@suse.cz>

BTW: Andrew Morton merges notification patches these days so please post
the patches again with reviewed-by tags and CC him as well to make it
easier for him to pick them up.

								Honza
> ---
>  fs/notify/fanotify/fanotify_user.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
> index c991616..ba31055 100644
> --- a/fs/notify/fanotify/fanotify_user.c
> +++ b/fs/notify/fanotify/fanotify_user.c
> @@ -497,10 +497,9 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
>  		oldmask = fsn_mark->ignored_mask;
>  		fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask & ~mask));
>  	}
> +	*destroy = !(fsn_mark->mask | fsn_mark->ignored_mask);
>  	spin_unlock(&fsn_mark->lock);
>  
> -	*destroy = !(oldmask & ~mask);
> -
>  	return mask & oldmask;
>  }
>  
> -- 
> 1.9.1
> 
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

Re: [PATCH v2 3/3] fanotify: dont set FAN_ONDIR implicitly on a marks ignored mask

[Jan Kara]

On Thu 04-12-14 05:43:04, Lino Sanfilippo wrote:
> Currently FAN_ONDIR is always set on a marks ignored mask when the event mask
> is extended without FAN_MARK_ONDIR being set. This may result in events for
> directories being ignored unexpectedly for call sequences like
> 
> fanotify_mark(fd, FAN_MARK_ADD, FAN_OPEN | FAN_ONDIR , AT_FDCWD, "dir");
> fanotify_mark(fd, FAN_MARK_ADD, FAN_CLOSE, AT_FDCWD, "dir");
> 
> Also FAN_MARK_ONDIR is only honored when adding events to a marks mask, but
> not for event removal. Fix both issues.
  Looks good. Changelog is better but please also expand a bit "Fix both
issues" to something like:
Fix both issues by treating FAN_ONDIR as any other event flag and require
FAN_ONDIR to be set on a mark to send events for directories.

Also you can add:
Reviewed-by: Jan Kara <jack@suse.cz>

								Honza
> 
> Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
> ---
>  fs/notify/fanotify/fanotify.c      |  2 +-
>  fs/notify/fanotify/fanotify_user.c | 24 ++++++++++++++++--------
>  2 files changed, 17 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
> index 30d3add..51ceb81 100644
> --- a/fs/notify/fanotify/fanotify.c
> +++ b/fs/notify/fanotify/fanotify.c
> @@ -140,7 +140,7 @@ static bool fanotify_should_send_event(struct fsnotify_mark *inode_mark,
>  	}
>  
>  	if (S_ISDIR(path->dentry->d_inode->i_mode) &&
> -	    (marks_ignored_mask & FS_ISDIR))
> +	    !(marks_mask & FS_ISDIR & ~marks_ignored_mask))
>  		return false;
>  
>  	if (event_mask & marks_mask & ~marks_ignored_mask)
> diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
> index ddc33fb..683d140 100644
> --- a/fs/notify/fanotify/fanotify_user.c
> +++ b/fs/notify/fanotify/fanotify_user.c
> @@ -491,10 +491,17 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
>  
>  	spin_lock(&fsn_mark->lock);
>  	if (!(flags & FAN_MARK_IGNORED_MASK)) {
> +		__u32 tmask = fsn_mark->mask & ~mask;
> +		if (flags & FAN_MARK_ONDIR)
> +			tmask &= ~FAN_ONDIR;
> +
>  		oldmask = fsn_mark->mask;
> -		fsnotify_set_mark_mask_locked(fsn_mark, (oldmask & ~mask));
> +		fsnotify_set_mark_mask_locked(fsn_mark, tmask);
>  	} else {
>  		__u32 tmask = fsn_mark->ignored_mask & ~mask;
> +		if (flags & FAN_MARK_ONDIR)
> +			tmask &= ~FAN_ONDIR;
> +
>  		fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
>  	}
>  	*destroy = !(fsn_mark->mask | fsn_mark->ignored_mask);
> @@ -568,20 +575,21 @@ static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
>  
>  	spin_lock(&fsn_mark->lock);
>  	if (!(flags & FAN_MARK_IGNORED_MASK)) {
> +		__u32 tmask = fsn_mark->mask | mask;
> +		if (flags & FAN_MARK_ONDIR)
> +			tmask |= FAN_ONDIR;
> +
>  		oldmask = fsn_mark->mask;
> -		fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask));
> +		fsnotify_set_mark_mask_locked(fsn_mark, tmask);
>  	} else {
>  		__u32 tmask = fsn_mark->ignored_mask | mask;
> +		if (flags & FAN_MARK_ONDIR)
> +			tmask |= FAN_ONDIR;
> +
>  		fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
>  		if (flags & FAN_MARK_IGNORED_SURV_MODIFY)
>  			fsn_mark->flags |= FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY;
>  	}
> -
> -	if (!(flags & FAN_MARK_ONDIR)) {
> -		__u32 tmask = fsn_mark->ignored_mask | FAN_ONDIR;
> -		fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
> -	}
> -
>  	spin_unlock(&fsn_mark->lock);
>  
>  	return mask & ~oldmask;
> -- 
> 1.9.1
> 
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR