| Message ID | 20210322173944.449469-3-amir73il@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Better fanotify support for tmpfs | expand |
On Mon 22-03-21 19:39:44, Amir Goldstein wrote: > Since kernel v5.1, fanotify_init(2) supports the flag FAN_REPORT_FID > for identifying objects using file handle and fsid in events. > > fanotify_mark(2) fails with -ENODEV when trying to set a mark on > filesystems that report null f_fsid in stasfs(2). > > Use the digest of uuid as f_fsid for tmpfs to uniquely identify tmpfs > objects as best as possible and allow setting an fanotify mark that > reports events with file handles on tmpfs. > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> Hugh, any opinion on this patch? Honza > --- > mm/shmem.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/shmem.c b/mm/shmem.c > index b2db4ed0fbc7..162d8f8993bb 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -2846,6 +2846,9 @@ static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) > buf->f_ffree = sbinfo->free_inodes; > } > /* else leave those fields 0 like simple_statfs */ > + > + buf->f_fsid = uuid_to_fsid(dentry->d_sb->s_uuid.b); > + > return 0; > } > > -- > 2.25.1 >
On Thu, Mar 25, 2021 at 5:00 PM Jan Kara <jack@suse.cz> wrote: > > On Mon 22-03-21 19:39:44, Amir Goldstein wrote: > > Since kernel v5.1, fanotify_init(2) supports the flag FAN_REPORT_FID > > for identifying objects using file handle and fsid in events. > > > > fanotify_mark(2) fails with -ENODEV when trying to set a mark on > > filesystems that report null f_fsid in stasfs(2). > > > > Use the digest of uuid as f_fsid for tmpfs to uniquely identify tmpfs > > objects as best as possible and allow setting an fanotify mark that > > reports events with file handles on tmpfs. > > > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > > Hugh, any opinion on this patch? > > Honza > > > --- > > mm/shmem.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/mm/shmem.c b/mm/shmem.c > > index b2db4ed0fbc7..162d8f8993bb 100644 > > --- a/mm/shmem.c > > +++ b/mm/shmem.c > > @@ -2846,6 +2846,9 @@ static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) > > buf->f_ffree = sbinfo->free_inodes; > > } > > /* else leave those fields 0 like simple_statfs */ > > + > > + buf->f_fsid = uuid_to_fsid(dentry->d_sb->s_uuid.b); > > + > > return 0; > > } > > Ping. Hugh, are you ok with this change? Thanks, Amir.
On Fri, 16 Apr 2021, Amir Goldstein wrote: > On Thu, Mar 25, 2021 at 5:00 PM Jan Kara <jack@suse.cz> wrote: > > > > On Mon 22-03-21 19:39:44, Amir Goldstein wrote: > > > Since kernel v5.1, fanotify_init(2) supports the flag FAN_REPORT_FID > > > for identifying objects using file handle and fsid in events. > > > > > > fanotify_mark(2) fails with -ENODEV when trying to set a mark on > > > filesystems that report null f_fsid in stasfs(2). > > > > > > Use the digest of uuid as f_fsid for tmpfs to uniquely identify tmpfs > > > objects as best as possible and allow setting an fanotify mark that > > > reports events with file handles on tmpfs. > > > > > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > > > > Hugh, any opinion on this patch? > > > > Honza > > > > > --- > > > mm/shmem.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/mm/shmem.c b/mm/shmem.c > > > index b2db4ed0fbc7..162d8f8993bb 100644 > > > --- a/mm/shmem.c > > > +++ b/mm/shmem.c > > > @@ -2846,6 +2846,9 @@ static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) > > > buf->f_ffree = sbinfo->free_inodes; > > > } > > > /* else leave those fields 0 like simple_statfs */ > > > + > > > + buf->f_fsid = uuid_to_fsid(dentry->d_sb->s_uuid.b); > > > + > > > return 0; > > > } > > > > > > Ping. > > Hugh, are you ok with this change? > > Thanks, > Amir. Yes, apologies for my delay to you, Amir and Jan: sure I'm ok with this change, and thank you for taking care of tmpfs. Acked-by: Hugh Dickins <hughd@google.com> But you have more valuable acks on this little series already, so don't bother rebasing some tree to add mine in now. I don't yet see the uuid_to_fsid() 1/2 which this depends on in linux-next, and fear that's my fault for holding you back: sorry, please go ahead now. Hugh
On Fri 16-04-21 20:54:46, Hugh Dickins wrote: > On Fri, 16 Apr 2021, Amir Goldstein wrote: > > On Thu, Mar 25, 2021 at 5:00 PM Jan Kara <jack@suse.cz> wrote: > > > > > > On Mon 22-03-21 19:39:44, Amir Goldstein wrote: > > > > Since kernel v5.1, fanotify_init(2) supports the flag FAN_REPORT_FID > > > > for identifying objects using file handle and fsid in events. > > > > > > > > fanotify_mark(2) fails with -ENODEV when trying to set a mark on > > > > filesystems that report null f_fsid in stasfs(2). > > > > > > > > Use the digest of uuid as f_fsid for tmpfs to uniquely identify tmpfs > > > > objects as best as possible and allow setting an fanotify mark that > > > > reports events with file handles on tmpfs. > > > > > > > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > > > > > > Hugh, any opinion on this patch? > > > > > > Honza > > > > > > > --- > > > > mm/shmem.c | 3 +++ > > > > 1 file changed, 3 insertions(+) > > > > > > > > diff --git a/mm/shmem.c b/mm/shmem.c > > > > index b2db4ed0fbc7..162d8f8993bb 100644 > > > > --- a/mm/shmem.c > > > > +++ b/mm/shmem.c > > > > @@ -2846,6 +2846,9 @@ static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) > > > > buf->f_ffree = sbinfo->free_inodes; > > > > } > > > > /* else leave those fields 0 like simple_statfs */ > > > > + > > > > + buf->f_fsid = uuid_to_fsid(dentry->d_sb->s_uuid.b); > > > > + > > > > return 0; > > > > } > > > > > > > > > > Ping. > > > > Hugh, are you ok with this change? > > > > Thanks, > > Amir. > > Yes, apologies for my delay to you, Amir and Jan: > sure I'm ok with this change, and thank you for taking care of tmpfs. > > Acked-by: Hugh Dickins <hughd@google.com> Thanks for the ack Hugh! > But you have more valuable acks on this little series already, > so don't bother rebasing some tree to add mine in now. I don't yet > see the uuid_to_fsid() 1/2 which this depends on in linux-next, and > fear that's my fault for holding you back: sorry, please go ahead now. Yeah, I was reluctant to push this patch without your ack and honestly I forgot about the first patch while waiting for your ack. Anyway, both patches are now in my tree and since Linus tagged rc8 and they are nobrainers, I plan to push them to Linus for the next merge window. Honza
diff --git a/mm/shmem.c b/mm/shmem.c index b2db4ed0fbc7..162d8f8993bb 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2846,6 +2846,9 @@ static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) buf->f_ffree = sbinfo->free_inodes; } /* else leave those fields 0 like simple_statfs */ + + buf->f_fsid = uuid_to_fsid(dentry->d_sb->s_uuid.b); + return 0; }
Since kernel v5.1, fanotify_init(2) supports the flag FAN_REPORT_FID for identifying objects using file handle and fsid in events. fanotify_mark(2) fails with -ENODEV when trying to set a mark on filesystems that report null f_fsid in stasfs(2). Use the digest of uuid as f_fsid for tmpfs to uniquely identify tmpfs objects as best as possible and allow setting an fanotify mark that reports events with file handles on tmpfs. Signed-off-by: Amir Goldstein <amir73il@gmail.com> --- mm/shmem.c | 3 +++ 1 file changed, 3 insertions(+)