diff mbox series

[v4,14/16] bcachefs: add pre-content fsnotify hook to fault

Message ID 9627e80117638745c2f4341eb8ac94f63ea9acee.1723670362.git.josef@toxicpanda.com (mailing list archive)
State Superseded, archived
Headers show
Series fanotify: add pre-content hooks | expand

Commit Message

Josef Bacik Aug. 14, 2024, 9:25 p.m. UTC
bcachefs has its own locking around filemap_fault, so we have to make
sure we do the fsnotify hook before the locking.  Add the check to emit
the event before the locking and return VM_FAULT_RETRY to retrigger the
fault once the event has been emitted.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/bcachefs/fs-io-pagecache.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Jan Kara Aug. 29, 2024, 11:10 a.m. UTC | #1
On Wed 14-08-24 17:25:32, Josef Bacik wrote:
> bcachefs has its own locking around filemap_fault, so we have to make
> sure we do the fsnotify hook before the locking.  Add the check to emit
> the event before the locking and return VM_FAULT_RETRY to retrigger the
> fault once the event has been emitted.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>

Looks good to me. Would be nice to get ack from bcachefs guys. Kent?

								Honza

> ---
>  fs/bcachefs/fs-io-pagecache.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/fs/bcachefs/fs-io-pagecache.c b/fs/bcachefs/fs-io-pagecache.c
> index a9cc5cad9cc9..1fa1f1ac48c8 100644
> --- a/fs/bcachefs/fs-io-pagecache.c
> +++ b/fs/bcachefs/fs-io-pagecache.c
> @@ -570,6 +570,10 @@ vm_fault_t bch2_page_fault(struct vm_fault *vmf)
>  	if (fdm == mapping)
>  		return VM_FAULT_SIGBUS;
>  
> +	ret = filemap_maybe_emit_fsnotify_event(vmf);
> +	if (unlikely(ret))
> +		return ret;
> +
>  	/* Lock ordering: */
>  	if (fdm > mapping) {
>  		struct bch_inode_info *fdm_host = to_bch_ei(fdm->host);
> -- 
> 2.43.0
>
Kent Overstreet Aug. 29, 2024, 11:26 a.m. UTC | #2
On Thu, Aug 29, 2024 at 01:10:55PM GMT, Jan Kara wrote:
> On Wed 14-08-24 17:25:32, Josef Bacik wrote:
> > bcachefs has its own locking around filemap_fault, so we have to make
> > sure we do the fsnotify hook before the locking.  Add the check to emit
> > the event before the locking and return VM_FAULT_RETRY to retrigger the
> > fault once the event has been emitted.
> > 
> > Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> 
> Looks good to me. Would be nice to get ack from bcachefs guys. Kent?

I said I wanted the bcachefs side tested, and offered Josef CI access
for that - still waiting to hear from him.
Kent Overstreet Aug. 29, 2024, 12:25 p.m. UTC | #3
On Thu, Aug 29, 2024 at 01:10:55PM GMT, Jan Kara wrote:
> On Wed 14-08-24 17:25:32, Josef Bacik wrote:
> > bcachefs has its own locking around filemap_fault, so we have to make
> > sure we do the fsnotify hook before the locking.  Add the check to emit
> > the event before the locking and return VM_FAULT_RETRY to retrigger the
> > fault once the event has been emitted.
> > 
> > Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> 
> Looks good to me. Would be nice to get ack from bcachefs guys. Kent?

btw, happy to give you a CI account as well: just need username and ssh
pubkey
Josef Bacik Aug. 29, 2024, 12:46 p.m. UTC | #4
On Thu, Aug 29, 2024 at 07:26:42AM -0400, Kent Overstreet wrote:
> On Thu, Aug 29, 2024 at 01:10:55PM GMT, Jan Kara wrote:
> > On Wed 14-08-24 17:25:32, Josef Bacik wrote:
> > > bcachefs has its own locking around filemap_fault, so we have to make
> > > sure we do the fsnotify hook before the locking.  Add the check to emit
> > > the event before the locking and return VM_FAULT_RETRY to retrigger the
> > > fault once the event has been emitted.
> > > 
> > > Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> > 
> > Looks good to me. Would be nice to get ack from bcachefs guys. Kent?
> 
> I said I wanted the bcachefs side tested, and offered Josef CI access
> for that - still waiting to hear from him.

My bad I thought I had responded.  I tested bcachefs, xfs, ext4, and btrfs with
my tests.  I'll get those turned into fstests today/tomorrow.  Thanks,

Josef
Kent Overstreet Aug. 29, 2024, 12:55 p.m. UTC | #5
On Thu, Aug 29, 2024 at 08:46:07AM GMT, Josef Bacik wrote:
> On Thu, Aug 29, 2024 at 07:26:42AM -0400, Kent Overstreet wrote:
> > On Thu, Aug 29, 2024 at 01:10:55PM GMT, Jan Kara wrote:
> > > On Wed 14-08-24 17:25:32, Josef Bacik wrote:
> > > > bcachefs has its own locking around filemap_fault, so we have to make
> > > > sure we do the fsnotify hook before the locking.  Add the check to emit
> > > > the event before the locking and return VM_FAULT_RETRY to retrigger the
> > > > fault once the event has been emitted.
> > > > 
> > > > Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> > > 
> > > Looks good to me. Would be nice to get ack from bcachefs guys. Kent?
> > 
> > I said I wanted the bcachefs side tested, and offered Josef CI access
> > for that - still waiting to hear from him.
> 
> My bad I thought I had responded.  I tested bcachefs, xfs, ext4, and btrfs with
> my tests.  I'll get those turned into fstests today/tomorrow.  Thanks,

Acked-by: Kent Overstreet <kent.overstreet@linux.dev>
diff mbox series

Patch

diff --git a/fs/bcachefs/fs-io-pagecache.c b/fs/bcachefs/fs-io-pagecache.c
index a9cc5cad9cc9..1fa1f1ac48c8 100644
--- a/fs/bcachefs/fs-io-pagecache.c
+++ b/fs/bcachefs/fs-io-pagecache.c
@@ -570,6 +570,10 @@  vm_fault_t bch2_page_fault(struct vm_fault *vmf)
 	if (fdm == mapping)
 		return VM_FAULT_SIGBUS;
 
+	ret = filemap_maybe_emit_fsnotify_event(vmf);
+	if (unlikely(ret))
+		return ret;
+
 	/* Lock ordering: */
 	if (fdm > mapping) {
 		struct bch_inode_info *fdm_host = to_bch_ei(fdm->host);