2014-12-04 04:43:52

by Lino Sanfilippo

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

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 <[email protected]>
---
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

2014-12-04 04:43:46

by Lino Sanfilippo

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

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 <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
---
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

2014-12-04 04:44:12

by Lino Sanfilippo

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

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 <[email protected]>
---
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

2014-12-04 12:22:24

by Jan Kara

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

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 <[email protected]>
Looks good you can add:
Reviewed-by: Jan Kara <[email protected]>

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 <[email protected]>
SUSE Labs, CR

2014-12-04 12:30:50

by Jan Kara

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

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 <[email protected]>

Honza
>
> Signed-off-by: Lino Sanfilippo <[email protected]>
> ---
> 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 <[email protected]>
SUSE Labs, CR