| Message ID | 3e28d2c7-fbe5-298a-13ba-dcd8fd504666@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V2] uapi: fix statx attribute value overlap for DAX & MOUNT_ROOT | expand |
On Tue, Dec 01, 2020 at 05:21:40PM -0600, Eric Sandeen wrote: > [*] Note: This needs to be merged as soon as possible as it's introducing an incompatible UAPI change... > > STATX_ATTR_MOUNT_ROOT and STATX_ATTR_DAX got merged with the same value, > so one of them needs fixing. Move STATX_ATTR_DAX. > > While we're in here, clarify the value-matching scheme for some of the > attributes, and explain why the value for DAX does not match. > > Fixes: 80340fe3605c ("statx: add mount_root") > Fixes: 712b2698e4c0 ("fs/stat: Define DAX statx attribute") > Reported-by: David Howells <dhowells@redhat.com> > Signed-off-by: Eric Sandeen <sandeen@redhat.com> > Reviewed-by: David Howells <dhowells@redhat.com> Looks fine to me, Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --D > --- > V2: Change flag value per Darrick Wong > Tweak comment per Darrick Wong > Add Fixes: tags & reported-by & RVB per dhowells > > include/uapi/linux/stat.h | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h > index 82cc58fe9368..1500a0f58041 100644 > --- a/include/uapi/linux/stat.h > +++ b/include/uapi/linux/stat.h > @@ -171,9 +171,12 @@ struct statx { > * be of use to ordinary userspace programs such as GUIs or ls rather than > * specialised tools. > * > - * Note that the flags marked [I] correspond to generic FS_IOC_FLAGS > + * Note that the flags marked [I] correspond to the FS_IOC_SETFLAGS flags > * semantically. Where possible, the numerical value is picked to correspond > - * also. > + * also. Note that the DAX attribute indicates that the file is in the CPU > + * direct access state. It does not correspond to the per-inode flag that > + * some filesystems support. > + * > */ > #define STATX_ATTR_COMPRESSED 0x00000004 /* [I] File is compressed by the fs */ > #define STATX_ATTR_IMMUTABLE 0x00000010 /* [I] File is marked immutable */ > @@ -183,7 +186,7 @@ struct statx { > #define STATX_ATTR_AUTOMOUNT 0x00001000 /* Dir: Automount trigger */ > #define STATX_ATTR_MOUNT_ROOT 0x00002000 /* Root of a mount */ > #define STATX_ATTR_VERITY 0x00100000 /* [I] Verity protected file */ > -#define STATX_ATTR_DAX 0x00002000 /* [I] File is DAX */ > +#define STATX_ATTR_DAX 0x00200000 /* File is currently in DAX state */ > > > #endif /* _UAPI_LINUX_STAT_H */ > -- > 2.17.0 >
Looks good for the urgent fix:
Reviewed-by: Christoph Hellwig <hch@lst.de>
We can keep debatting about stx_attributes_mask for a while once this
is sorted out :)
On Tue, Dec 01, 2020 at 05:21:40PM -0600, Eric Sandeen wrote: > [*] Note: This needs to be merged as soon as possible as it's introducing an incompatible UAPI change... > > STATX_ATTR_MOUNT_ROOT and STATX_ATTR_DAX got merged with the same value, > so one of them needs fixing. Move STATX_ATTR_DAX. > > While we're in here, clarify the value-matching scheme for some of the > attributes, and explain why the value for DAX does not match. > > Fixes: 80340fe3605c ("statx: add mount_root") > Fixes: 712b2698e4c0 ("fs/stat: Define DAX statx attribute") > Reported-by: David Howells <dhowells@redhat.com> > Signed-off-by: Eric Sandeen <sandeen@redhat.com> > Reviewed-by: David Howells <dhowells@redhat.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> > --- > V2: Change flag value per Darrick Wong > Tweak comment per Darrick Wong > Add Fixes: tags & reported-by & RVB per dhowells > > include/uapi/linux/stat.h | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h > index 82cc58fe9368..1500a0f58041 100644 > --- a/include/uapi/linux/stat.h > +++ b/include/uapi/linux/stat.h > @@ -171,9 +171,12 @@ struct statx { > * be of use to ordinary userspace programs such as GUIs or ls rather than > * specialised tools. > * > - * Note that the flags marked [I] correspond to generic FS_IOC_FLAGS > + * Note that the flags marked [I] correspond to the FS_IOC_SETFLAGS flags > * semantically. Where possible, the numerical value is picked to correspond > - * also. > + * also. Note that the DAX attribute indicates that the file is in the CPU > + * direct access state. It does not correspond to the per-inode flag that > + * some filesystems support. > + * > */ > #define STATX_ATTR_COMPRESSED 0x00000004 /* [I] File is compressed by the fs */ > #define STATX_ATTR_IMMUTABLE 0x00000010 /* [I] File is marked immutable */ > @@ -183,7 +186,7 @@ struct statx { > #define STATX_ATTR_AUTOMOUNT 0x00001000 /* Dir: Automount trigger */ > #define STATX_ATTR_MOUNT_ROOT 0x00002000 /* Root of a mount */ > #define STATX_ATTR_VERITY 0x00100000 /* [I] Verity protected file */ > -#define STATX_ATTR_DAX 0x00002000 /* [I] File is DAX */ > +#define STATX_ATTR_DAX 0x00200000 /* File is currently in DAX state */ > > > #endif /* _UAPI_LINUX_STAT_H */ > -- > 2.17.0 >
On Wed, Dec 2, 2020 at 5:03 PM Ira Weiny <ira.weiny@intel.com> wrote: > > On Tue, Dec 01, 2020 at 05:21:40PM -0600, Eric Sandeen wrote: > > [*] Note: This needs to be merged as soon as possible as it's introducing an incompatible UAPI change... > > > > STATX_ATTR_MOUNT_ROOT and STATX_ATTR_DAX got merged with the same value, > > so one of them needs fixing. Move STATX_ATTR_DAX. > > > > While we're in here, clarify the value-matching scheme for some of the > > attributes, and explain why the value for DAX does not match. > > > > Fixes: 80340fe3605c ("statx: add mount_root") > > Fixes: 712b2698e4c0 ("fs/stat: Define DAX statx attribute") > > Reported-by: David Howells <dhowells@redhat.com> > > Signed-off-by: Eric Sandeen <sandeen@redhat.com> > > Reviewed-by: David Howells <dhowells@redhat.com> > > Reviewed-by: Ira Weiny <ira.weiny@intel.com> Stable cc also? Cc: <stable@vger.kernel.org> # 5.8 Thanks, Miklos
Miklos Szeredi <miklos@szeredi.hu> wrote: > Stable cc also? > > Cc: <stable@vger.kernel.org> # 5.8 That seems to be unnecessary, provided there's a Fixes: tag. David
On Wed, Dec 2, 2020 at 5:24 PM David Howells <dhowells@redhat.com> wrote: > > Miklos Szeredi <miklos@szeredi.hu> wrote: > > > Stable cc also? > > > > Cc: <stable@vger.kernel.org> # 5.8 > > That seems to be unnecessary, provided there's a Fixes: tag. Is it? Fixes: means it fixes a patch, Cc: stable means it needs to be included in stable kernels. The two are not necessarily the same. Greg? Thanks, Miklos
On Wed, Dec 02, 2020 at 06:41:43PM +0100, Miklos Szeredi wrote: > On Wed, Dec 2, 2020 at 5:24 PM David Howells <dhowells@redhat.com> wrote: > > > > Miklos Szeredi <miklos@szeredi.hu> wrote: > > > > > Stable cc also? > > > > > > Cc: <stable@vger.kernel.org> # 5.8 > > > > That seems to be unnecessary, provided there's a Fixes: tag. > > Is it? > > Fixes: means it fixes a patch, Cc: stable means it needs to be > included in stable kernels. The two are not necessarily the same. > > Greg? You are correct. cc: stable, as is documented in https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html ensures that the patch will get merged into the stable tree. Fixes: is independent of it. It's great to have for stable patches so that I know how far back to backport patches. We do scan all commits for Fixes: tags that do not have cc: stable, and try to pick them up when we can and have the time to do so. But it's not guaranteed at all that this will happen. I don't know why people keep getting confused about this, we don't document the "Fixes: means it goes to stable" anywhere... thanks, greg k-h
On Wed, Dec 02, 2020 at 08:06:01PM +0100, Greg Kroah-Hartman wrote: > On Wed, Dec 02, 2020 at 06:41:43PM +0100, Miklos Szeredi wrote: > > On Wed, Dec 2, 2020 at 5:24 PM David Howells <dhowells@redhat.com> wrote: > > > > > > Miklos Szeredi <miklos@szeredi.hu> wrote: > > > > > > > Stable cc also? > > > > > > > > Cc: <stable@vger.kernel.org> # 5.8 > > > > > > That seems to be unnecessary, provided there's a Fixes: tag. > > > > Is it? > > > > Fixes: means it fixes a patch, Cc: stable means it needs to be > > included in stable kernels. The two are not necessarily the same. > > > > Greg? > > You are correct. cc: stable, as is documented in > https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html > ensures that the patch will get merged into the stable tree. > > Fixes: is independent of it. It's great to have for stable patches so > that I know how far back to backport patches. > > We do scan all commits for Fixes: tags that do not have cc: stable, and > try to pick them up when we can and have the time to do so. But it's > not guaranteed at all that this will happen. > > I don't know why people keep getting confused about this, we don't > document the "Fixes: means it goes to stable" anywhere... Except that is exactly what happens, sometimes within a day of two of a patch with a Fixes tag hitting Linus' kernel. We have had a serious XFS regression in the 5.9.9 stable kernel that should never have happened as a result of exactly this "Fixes = automatically swept immediately into stable kernels" behaviour. See here for post-mortem analysis: https://lore.kernel.org/linux-xfs/20201126071323.GF2842436@dread.disaster.area/T/#m26e14ebd28ad306025f4ebf37e2aae9a304345a5 This happened because these auotmated Fixes scans seem to occur weekly during -rcX release periods, which means there really is *no practical difference* between the way the stable process treats Fixes tags and cc: stable. Hence instead of developers having some control over "urgent, must backport now" fixes versus fixes that still need the -rcX stabilisation and integration testing to shake them out fully, the regular scans result in everything with a fixes tag is treated as an "urgent, must backport now" category of fix. It effectively removes the stabilisation and integration testing process from the changes stable kernel users are being exposed to... That's not right. It gives upstream developers no margin for error, and it exposes stable kernel users to bugs that the normal upstream kernel stabilisation process prevents users from ever seeing in released kernels. And it is exactly this behaviour that lead people to understand that "fixes" and "cc: stable" essentially mean the same thing from a stable kernel perspective. It seems like this can all be avoided simply by scheduling the automated fixes scans once the upstream kernel is released, not while it is still being stabilised by -rc releases. That way stable kernels get better tested fixes, they still get the same quantity of fixes, and upstream developers have some margin to detect and correct regressions in fixes before they get propagated to users. It also creates a clear demarcation between fixes and cc: stable for maintainers and developers: only patches with a cc: stable will be backported immediately to stable. Developers know what patches need urgent backports and, unlike developers, the automated fixes scan does not have the subject matter expertise or background to make that judgement.... Cheers, Dave.
On Thu, Dec 03, 2020 at 07:40:45AM +1100, Dave Chinner wrote: > On Wed, Dec 02, 2020 at 08:06:01PM +0100, Greg Kroah-Hartman wrote: > > On Wed, Dec 02, 2020 at 06:41:43PM +0100, Miklos Szeredi wrote: > > > On Wed, Dec 2, 2020 at 5:24 PM David Howells <dhowells@redhat.com> wrote: > > > > > > > > Miklos Szeredi <miklos@szeredi.hu> wrote: > > > > > > > > > Stable cc also? > > > > > > > > > > Cc: <stable@vger.kernel.org> # 5.8 > > > > > > > > That seems to be unnecessary, provided there's a Fixes: tag. > > > > > > Is it? > > > > > > Fixes: means it fixes a patch, Cc: stable means it needs to be > > > included in stable kernels. The two are not necessarily the same. > > > > > > Greg? > > > > You are correct. cc: stable, as is documented in > > https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html > > ensures that the patch will get merged into the stable tree. > > > > Fixes: is independent of it. It's great to have for stable patches so > > that I know how far back to backport patches. > > > > We do scan all commits for Fixes: tags that do not have cc: stable, and > > try to pick them up when we can and have the time to do so. But it's > > not guaranteed at all that this will happen. > > > > I don't know why people keep getting confused about this, we don't > > document the "Fixes: means it goes to stable" anywhere... > > Except that is exactly what happens, sometimes within a day of two > of a patch with a Fixes tag hitting Linus' kernel. We have had a > serious XFS regression in the 5.9.9 stable kernel that should never > have happened as a result of exactly this "Fixes = automatically > swept immediately into stable kernels" behaviour. See here for > post-mortem analysis: > > https://lore.kernel.org/linux-xfs/20201126071323.GF2842436@dread.disaster.area/T/#m26e14ebd28ad306025f4ebf37e2aae9a304345a5 > > This happened because these auotmated Fixes scans seem to occur > weekly during -rcX release periods, which means there really is *no > practical difference* between the way the stable process treats > Fixes tags and cc: stable. Sometimes, yes, that is true. But as it went into Linus's tree at the same time, we just ended up with "bug compatible" trees :) Not a big deal overall, happens every few releases, we fix it up and move on. The benifits in doing all of this _FAR_ outweigh the very infrequent times that kernel developers get something wrong. As always, if you do NOT want your subsystem to have fixes: tags picked up automatically by us for stable trees, just email us and let us know to not do that and we gladly will. > It seems like this can all be avoided simply by scheduling the > automated fixes scans once the upstream kernel is released, not > while it is still being stabilised by -rc releases. That way stable > kernels get better tested fixes, they still get the same quantity of > fixes, and upstream developers have some margin to detect and > correct regressions in fixes before they get propagated to users. So the "magic" -final release from Linus would cause this to happen? That means that the world would go for 3 months without some known fixes being applied to the tree? That's not acceptable to me, as I started doing this because it was needed to be done, not just because I wanted to do more work... > It also creates a clear demarcation between fixes and cc: stable for > maintainers and developers: only patches with a cc: stable will be > backported immediately to stable. Developers know what patches need > urgent backports and, unlike developers, the automated fixes scan > does not have the subject matter expertise or background to make > that judgement.... Some subsystems do not have such clear demarcation at all. Heck, some subsystems don't even add a cc: stable to known major fixes. And that's ok, the goal of the stable kernel work is to NOT impose additional work on developers or maintainers if they don't want to do that work. thanks, greg k-h
On Wed, Dec 02, 2020 at 10:04:17PM +0100, Greg Kroah-Hartman wrote: > On Thu, Dec 03, 2020 at 07:40:45AM +1100, Dave Chinner wrote: > > On Wed, Dec 02, 2020 at 08:06:01PM +0100, Greg Kroah-Hartman wrote: > > > On Wed, Dec 02, 2020 at 06:41:43PM +0100, Miklos Szeredi wrote: > > > > On Wed, Dec 2, 2020 at 5:24 PM David Howells <dhowells@redhat.com> wrote: > > > > > > > > > > Miklos Szeredi <miklos@szeredi.hu> wrote: > > > > > > > > > > > Stable cc also? > > > > > > > > > > > > Cc: <stable@vger.kernel.org> # 5.8 > > > > > > > > > > That seems to be unnecessary, provided there's a Fixes: tag. > > > > > > > > Is it? > > > > > > > > Fixes: means it fixes a patch, Cc: stable means it needs to be > > > > included in stable kernels. The two are not necessarily the same. > > > > > > > > Greg? > > > > > > You are correct. cc: stable, as is documented in > > > https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html > > > ensures that the patch will get merged into the stable tree. > > > > > > Fixes: is independent of it. It's great to have for stable patches so > > > that I know how far back to backport patches. > > > > > > We do scan all commits for Fixes: tags that do not have cc: stable, and > > > try to pick them up when we can and have the time to do so. But it's > > > not guaranteed at all that this will happen. > > > > > > I don't know why people keep getting confused about this, we don't > > > document the "Fixes: means it goes to stable" anywhere... > > > > Except that is exactly what happens, sometimes within a day of two > > of a patch with a Fixes tag hitting Linus' kernel. We have had a > > serious XFS regression in the 5.9.9 stable kernel that should never > > have happened as a result of exactly this "Fixes = automatically > > swept immediately into stable kernels" behaviour. See here for > > post-mortem analysis: > > > > https://lore.kernel.org/linux-xfs/20201126071323.GF2842436@dread.disaster.area/T/#m26e14ebd28ad306025f4ebf37e2aae9a304345a5 > > > > This happened because these auotmated Fixes scans seem to occur > > weekly during -rcX release periods, which means there really is *no > > practical difference* between the way the stable process treats > > Fixes tags and cc: stable. > > Sometimes, yes, that is true. But as it went into Linus's tree at the > same time, we just ended up with "bug compatible" trees :) > > Not a big deal overall, happens every few releases, we fix it up and > move on. The benifits in doing all of this _FAR_ outweigh the very > infrequent times that kernel developers get something wrong. I'm not debating that users benefit from backports. I'm talking about managing risk profiles and how to prevent an entirely preventable stable kernel regression from happening again. Talking about risk profiles, the issue here is that the regression that slipped through to the stable kernels had a -catastrophic- risk profile. That's exactly the sort of things that the stable kernel is supposed to avoid exposing users to, and that raises the importance and priority of ensuring that *never happens again*. And the cause of this regression slipping through to stable kernel users? It was a result of the automated "fixes" scan done by the stable process that results in "fixes" meaning the same thing as "cc: stable".... > As always, if you do NOT want your subsystem to have fixes: tags picked > up automatically by us for stable trees, just email us and let us know > to not do that and we gladly will. No, that is not an acceptible solution for anyone. The stable maintainers need to stop suggesting this as a solution to any criticism that is raised against the stable process. You may as well just say "shut up, go away, we don't care what you want". > > It seems like this can all be avoided simply by scheduling the > > automated fixes scans once the upstream kernel is released, not > > while it is still being stabilised by -rc releases. That way stable > > kernels get better tested fixes, they still get the same quantity of > > fixes, and upstream developers have some margin to detect and > > correct regressions in fixes before they get propagated to users. > > So the "magic" -final release from Linus would cause this to happen? > That means that the world would go for 3 months without some known fixes > being applied to the tree? That's not acceptable to me, as I started > doing this because it was needed to be done, not just because I wanted > to do more work... I'm not suggesting that all fixes across the entire kernel get held until release. That's just taking things to extremes for no valid reason as the risk profiles of most subsystems don't justify needing a margin of error that large. I'm asking that specific subsystems with catastrophic failure risk profiles be allowed to opt out of the "just merged" fixes scans and instead have them replaced by a less frequent scan. Perhaps we don't even need to wait for the full release. Maybe just increasing the fixes scanning window for those subsystems to pick up changes in -rc(X-2) so that the commits have been exposed to testing for a couple of weeks before being considered a stable backport candidate. That mitigates the immediate risk concern as it gives developers time to catch and fix regressions before stable backports are done. Such a 2 week delay would have avoided exposing stable kernel users to dangerous regression that should never have been released outside developer and test machines exercising the upstream -rcX tree. > > It also creates a clear demarcation between fixes and cc: stable for > > maintainers and developers: only patches with a cc: stable will be > > backported immediately to stable. Developers know what patches need > > urgent backports and, unlike developers, the automated fixes scan > > does not have the subject matter expertise or background to make > > that judgement.... > > Some subsystems do not have such clear demarcation at all. Heck, some > subsystems don't even add a cc: stable to known major fixes. And that's > ok, the goal of the stable kernel work is to NOT impose additional work > on developers or maintainers if they don't want to do that work. Engineering is as much about improving processes as it is about improving the thing that is being built. I'm not asking you to stop backporting fixes or stop improving the stable kernels. All I'm asking for is to increase the latency of backports for some subsystems because a margin of error is needed to minimise the risk profile stable users are exposed to. IOWs, I'm asking for a *minor tweak* to the existing process, not asking you to start all over again. -Dave.
> > It seems like this can all be avoided simply by scheduling the > > automated fixes scans once the upstream kernel is released, not > > while it is still being stabilised by -rc releases. That way stable > > kernels get better tested fixes, they still get the same quantity of > > fixes, and upstream developers have some margin to detect and > > correct regressions in fixes before they get propagated to users. > > So the "magic" -final release from Linus would cause this to happen? > That means that the world would go for 3 months without some known fixes > being applied to the tree? That's not acceptable to me, as I started > doing this because it was needed to be done, not just because I wanted > to do more work... > Nobody was trying to undermine the need for expediting important fixes into stable kernels. Quite the contrary. > > It also creates a clear demarcation between fixes and cc: stable for > > maintainers and developers: only patches with a cc: stable will be > > backported immediately to stable. Developers know what patches need > > urgent backports and, unlike developers, the automated fixes scan > > does not have the subject matter expertise or background to make > > that judgement.... > > Some subsystems do not have such clear demarcation at all. Heck, some > subsystems don't even add a cc: stable to known major fixes. And that's > ok, the goal of the stable kernel work is to NOT impose additional work > on developers or maintainers if they don't want to do that work. > Greg, Please acknowledge that there is something to improve. Saying that some subsystems maintainers don't care is not a great argument for subsystem maintainers that do care and try to improve the process. I am speaking here both as a maintainer of a downstream stable kernel, who cares specifically about xfs fixes and as an upstream developer who "contributes" patches to stable kernels. And I am not a passive contributor to stable kernels. I try to take good care of overlayfs and fsnotify patches being properly routed to stable kernels, as well as prepping the patches for backport-ability during review and occasional backporting. I also try to help with auditing the AUTOSEL patch selection of xfs. The process can improve. This is an indisputable fact, because as contributors we want to improve the quality of the stable kernels but missing the tools to do so. As a downstream user of stable kernels I learned to wait out a few .y releases after xfs fixes have flowed in. This is possible because xfs stable fixes are not flowing that often. Do you see what happened? You did not make the problem go away, but pushed it down to your downstream users. I would not have complained unless I thought that we could do better. Here is a recent example, where during patch review, I requested NOT to include any stable backport triggers [1]: "...We should consider sending this to stable, but maybe let's merge first and let it run in master for a while before because it is not a clear and immediate danger..." This is just one patch and I put a mental trigger to myself to stop it during stable patch review if it gets selected, but you can see how this solution does not scale. As a developer and as a reviewer, I wish (as Dave implied) that I had a way to communicate to AUTOSEL that auto backport of this patch has more risk than the risk of not backporting. I could also use a way to communicate that this patch (although may fix a bug) should be "treated as a feature", meaning that it needs a full release cycle to stabilize should not see the light of day before the upstream .0 release. Some fixes are just like that. The question is how to annotate these changes. Thinking out loud: Cc: stable@vger.kernel.org#v5.9<<v5.10 Cc: stable@vger.kernel.org#v5.9<<v5.10-rc5 For patches that need to soak a few cycles in master or need to linger in master until the .0 release. Thanks, Amir. [1] https://lore.kernel.org/linux-unionfs/CAOQ4uxiUTsXEdQsE275qxTh61tZOB+-wqCp6gaNLkOw5ueUJgw@mail.gmail.com/
On Thu, Dec 03, 2020 at 08:18:23AM +0200, Amir Goldstein wrote: > Here is a recent example, where during patch review, I requested NOT to include > any stable backport triggers [1]: > "...We should consider sending this to stable, but maybe let's merge > first and let it > run in master for a while before because it is not a clear and > immediate danger..." > > As a developer and as a reviewer, I wish (as Dave implied) that I had a way to > communicate to AUTOSEL that auto backport of this patch has more risk than > the risk of not backporting. My suggestion is that we could put something in the MAINTAINERS file which indicates what the preferred delay time should be for (a) patches explicitly cc'ed to stable, and (b) preferred time should be for patches which are AUTOSEL'ed for stable for that subsystem. That time might be either in days/weeks, or "after N -rc releases", "after the next full release", or, "never" (which would be a way for a subsystem to opt out of the AUTOSEL process). It should also be possible specify the delay in the trailer, e.g.: Stable-Defer: <delayspec> Auto-Stable-Defer: <delayspec> The advantage of specifying the delay relative to when they show up in Linus's tree helps deal with the case where the submaintainer might not be sure when their patches will get pushed to Linus by the maintainer. Cheers, - Ted
diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h index 82cc58fe9368..1500a0f58041 100644 --- a/include/uapi/linux/stat.h +++ b/include/uapi/linux/stat.h @@ -171,9 +171,12 @@ struct statx { * be of use to ordinary userspace programs such as GUIs or ls rather than * specialised tools. * - * Note that the flags marked [I] correspond to generic FS_IOC_FLAGS + * Note that the flags marked [I] correspond to the FS_IOC_SETFLAGS flags * semantically. Where possible, the numerical value is picked to correspond - * also. + * also. Note that the DAX attribute indicates that the file is in the CPU + * direct access state. It does not correspond to the per-inode flag that + * some filesystems support. + * */ #define STATX_ATTR_COMPRESSED 0x00000004 /* [I] File is compressed by the fs */ #define STATX_ATTR_IMMUTABLE 0x00000010 /* [I] File is marked immutable */ @@ -183,7 +186,7 @@ struct statx { #define STATX_ATTR_AUTOMOUNT 0x00001000 /* Dir: Automount trigger */ #define STATX_ATTR_MOUNT_ROOT 0x00002000 /* Root of a mount */ #define STATX_ATTR_VERITY 0x00100000 /* [I] Verity protected file */ -#define STATX_ATTR_DAX 0x00002000 /* [I] File is DAX */ +#define STATX_ATTR_DAX 0x00200000 /* File is currently in DAX state */ #endif /* _UAPI_LINUX_STAT_H */
[*] Note: This needs to be merged as soon as possible as it's introducing an incompatible UAPI change... STATX_ATTR_MOUNT_ROOT and STATX_ATTR_DAX got merged with the same value, so one of them needs fixing. Move STATX_ATTR_DAX. While we're in here, clarify the value-matching scheme for some of the attributes, and explain why the value for DAX does not match. Fixes: 80340fe3605c ("statx: add mount_root") Fixes: 712b2698e4c0 ("fs/stat: Define DAX statx attribute") Reported-by: David Howells <dhowells@redhat.com> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> --- V2: Change flag value per Darrick Wong Tweak comment per Darrick Wong Add Fixes: tags & reported-by & RVB per dhowells include/uapi/linux/stat.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)