pNFS: Fix the pnfs block driver's calculation of layoutget size

[ Upstream commit 8a6291bf3b0eae1bf26621e6419a91682f2d6227 ]

Instead of relying on the value of the 'bytes_left' field, we should
cal

pNFS: Fix the pnfs block driver's calculation of layoutget size

[ Upstream commit 8a6291bf3b0eae1bf26621e6419a91682f2d6227 ]

Instead of relying on the value of the 'bytes_left' field, we should
calculate the layout size based on the offset of the request that is
being written out.

Reported-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Fixes: 954998b60caa ("NFS: Fix error handling for O_DIRECT write scheduling")
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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pNFS: Fix a hang in nfs4_evict_inode()

We are not allowed to call pnfs_mark_matching_lsegs_return() without
also holding a reference to the layout header, since doing so could lead
to the reference

pNFS: Fix a hang in nfs4_evict_inode()

We are not allowed to call pnfs_mark_matching_lsegs_return() without
also holding a reference to the layout header, since doing so could lead
to the reference count going to zero when we call
pnfs_layout_remove_lseg(). This again can lead to a hang when we get to
nfs4_evict_inode() and are unable to clear the layout pointer.

pnfs_layout_return_unused_byserver() is guilty of this behaviour, and
has been seen to trigger the refcount warning prior to a hang.

Fixes: b6d49ecd1081 ("NFSv4: Fix a pNFS layout related use-after-free race when freeing the inode")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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pNFS/filelayout: treat GETDEVICEINFO errors as layout failure

When GETDEVICEINFO call fails, return the layout and fall back to MDS.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-b

pNFS/filelayout: treat GETDEVICEINFO errors as layout failure

When GETDEVICEINFO call fails, return the layout and fall back to MDS.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFSv4/flexfiles: Cancel I/O if the layout is recalled or revoked

If the layout is recalled or revoked, we want to cancel I/O as quickly
as possible so that we can return the layout.

Signed-off-by:

NFSv4/flexfiles: Cancel I/O if the layout is recalled or revoked

If the layout is recalled or revoked, we want to cancel I/O as quickly
as possible so that we can return the layout.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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freezer,sched: Rewrite core freezer logic

Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensu

freezer,sched: Rewrite core freezer logic

Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.

As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).

Specifically; the current scheme works a little like:

freezer_do_not_count();
schedule();
freezer_count();

And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.

However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.

That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.

This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.

As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:

TASK_FREEZABLE -> TASK_FROZEN
__TASK_STOPPED -> TASK_FROZEN
__TASK_TRACED -> TASK_FROZEN

The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).

The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.

With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org

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NFS: Remove a bogus flag setting in pnfs_write_done_resend_to_mds

Since pnfs_write_done_resend_to_mds() does not actually call
end_page_writeback() on the pages that are being redirected to the
meta

NFS: Remove a bogus flag setting in pnfs_write_done_resend_to_mds

Since pnfs_write_done_resend_to_mds() does not actually call
end_page_writeback() on the pages that are being redirected to the
metadata server, callers of fsync() do not see the I/O as complete until
the writeback to the MDS finishes. We therefore do not need to set
NFS_CONTEXT_RESEND_WRITES, since there is nothing to redrive.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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pNFS: Avoid a live lock condition in pnfs_update_layout()

If we're about to send the first layoutget for an empty layout, we want
to make sure that we drain out the existing pending layoutget calls

pNFS: Avoid a live lock condition in pnfs_update_layout()

If we're about to send the first layoutget for an empty layout, we want
to make sure that we drain out the existing pending layoutget calls
first. The reason is that these layouts may have been already implicitly
returned to the server by a recall to which the client gave a
NFS4ERR_NOMATCHING_LAYOUT response.

The problem is that wait_var_event_killable() could in principle see the
plh_outstanding count go back to '1' when the first process to wake up
starts sending a new layoutget. If it fails to get a layout, then this
loop can continue ad infinitum...

Fixes: 0b77f97a7e42 ("NFSv4/pnfs: Fix layoutget behaviour after invalidation")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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pNFS: Don't keep retrying if the server replied NFS4ERR_LAYOUTUNAVAILABLE

If the server tells us that a pNFS layout is not available for a
specific file, then we should not keep pounding it with fur

pNFS: Don't keep retrying if the server replied NFS4ERR_LAYOUTUNAVAILABLE

If the server tells us that a pNFS layout is not available for a
specific file, then we should not keep pounding it with further
layoutget requests.

Fixes: 183d9e7b112a ("pnfs: rework LAYOUTGET retry handling")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFSv4/pNFS: Do not fail I/O when we fail to allocate the pNFS layout

Commit 587f03deb69b caused pnfs_update_layout() to stop returning ENOMEM
when the memory allocation fails, and hence causes it to

NFSv4/pNFS: Do not fail I/O when we fail to allocate the pNFS layout

Commit 587f03deb69b caused pnfs_update_layout() to stop returning ENOMEM
when the memory allocation fails, and hence causes it to fall back to
trying to do I/O through the MDS. There is no guarantee that this will
fare any better. If we're failing the pNFS layout allocation, then we
should just redirty the page and retry later.

Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 587f03deb69b ("pnfs: refactor send_layoutget")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFSv4/pNFS: Fix another issue with a list iterator pointing to the head

In nfs4_callback_devicenotify(), if we don't find a matching entry for
the deviceid, we're left with a pointer to 'struct nfs_

NFSv4/pNFS: Fix another issue with a list iterator pointing to the head

In nfs4_callback_devicenotify(), if we don't find a matching entry for
the deviceid, we're left with a pointer to 'struct nfs_server' that
actually points to the list of super blocks associated with our struct
nfs_client.
Furthermore, even if we have a valid pointer, nothing pins the super
block, and so the struct nfs_server could end up getting freed while
we're using it.

Since all we want is a pointer to the struct pnfs_layoutdriver_type,
let's skip all the iteration over super blocks, and just use APIs to
find the layout driver directly.

Reported-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Fixes: 1be5683b03a7 ("pnfs: CB_NOTIFY_DEVICEID")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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NFSv4/pnfs: Ensure pNFS allocation modes are consistent with nfsiod

Ensure that pNFS allocations that can be called from rpciod/nfsiod
callback can fail in low memory mode, so that the threads don't

NFSv4/pnfs: Ensure pNFS allocation modes are consistent with nfsiod

Ensure that pNFS allocations that can be called from rpciod/nfsiod
callback can fail in low memory mode, so that the threads don't block
and loop forever.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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NFS: Convert GFP_NOFS to GFP_KERNEL

Assume that sections that should not re-enter the filesystem are already
protected with memalloc_nofs_save/restore call, so relax those GFP_NOFS
instances which m

NFS: Convert GFP_NOFS to GFP_KERNEL

Assume that sections that should not re-enter the filesystem are already
protected with memalloc_nofs_save/restore call, so relax those GFP_NOFS
instances which might be used by other contexts.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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pNFS: Avoid a live lock condition in pnfs_update_layout()

[ Upstream commit 880265c77ac415090090d1fe72a188fee71cb458 ]

If we're about to send the first layoutget for an empty layout, we want
to mak

pNFS: Avoid a live lock condition in pnfs_update_layout()

[ Upstream commit 880265c77ac415090090d1fe72a188fee71cb458 ]

If we're about to send the first layoutget for an empty layout, we want
to make sure that we drain out the existing pending layoutget calls
first. The reason is that these layouts may have been already implicitly
returned to the server by a recall to which the client gave a
NFS4ERR_NOMATCHING_LAYOUT response.

The problem is that wait_var_event_killable() could in principle see the
plh_outstanding count go back to '1' when the first process to wake up
starts sending a new layoutget. If it fails to get a layout, then this
loop can continue ad infinitum...

Fixes: 0b77f97a7e42 ("NFSv4/pnfs: Fix layoutget behaviour after invalidation")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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pNFS: Don't keep retrying if the server replied NFS4ERR_LAYOUTUNAVAILABLE

[ Upstream commit fe44fb23d6ccde4c914c44ef74ab8d9d9ba02bea ]

If the server tells us that a pNFS layout is not available for

pNFS: Don't keep retrying if the server replied NFS4ERR_LAYOUTUNAVAILABLE

[ Upstream commit fe44fb23d6ccde4c914c44ef74ab8d9d9ba02bea ]

If the server tells us that a pNFS layout is not available for a
specific file, then we should not keep pounding it with further
layoutget requests.

Fixes: 183d9e7b112a ("pnfs: rework LAYOUTGET retry handling")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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NFS: Convert GFP_NOFS to GFP_KERNEL

[ Upstream commit da48f267f90d9dc9f930fd9a67753643657b404f ]

Assume that sections that should not re-enter the filesystem are already
protected with memalloc_nof

NFS: Convert GFP_NOFS to GFP_KERNEL

[ Upstream commit da48f267f90d9dc9f930fd9a67753643657b404f ]

Assume that sections that should not re-enter the filesystem are already
protected with memalloc_nofs_save/restore call, so relax those GFP_NOFS
instances which might be used by other contexts.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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NFSv4/pNFS: Do not fail I/O when we fail to allocate the pNFS layout

[ Upstream commit 3764a17e31d579cf9b4bd0a69894b577e8d75702 ]

Commit 587f03deb69b caused pnfs_update_layout() to stop returning E

NFSv4/pNFS: Do not fail I/O when we fail to allocate the pNFS layout

[ Upstream commit 3764a17e31d579cf9b4bd0a69894b577e8d75702 ]

Commit 587f03deb69b caused pnfs_update_layout() to stop returning ENOMEM
when the memory allocation fails, and hence causes it to fall back to
trying to do I/O through the MDS. There is no guarantee that this will
fare any better. If we're failing the pNFS layout allocation, then we
should just redirty the page and retry later.

Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 587f03deb69b ("pnfs: refactor send_layoutget")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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pNFS: Avoid a live lock condition in pnfs_update_layout()

[ Upstream commit 880265c77ac415090090d1fe72a188fee71cb458 ]

If we're about to send the first layoutget for an empty layout, we want
to mak

pNFS: Avoid a live lock condition in pnfs_update_layout()

[ Upstream commit 880265c77ac415090090d1fe72a188fee71cb458 ]

If we're about to send the first layoutget for an empty layout, we want
to make sure that we drain out the existing pending layoutget calls
first. The reason is that these layouts may have been already implicitly
returned to the server by a recall to which the client gave a
NFS4ERR_NOMATCHING_LAYOUT response.

The problem is that wait_var_event_killable() could in principle see the
plh_outstanding count go back to '1' when the first process to wake up
starts sending a new layoutget. If it fails to get a layout, then this
loop can continue ad infinitum...

Fixes: 0b77f97a7e42 ("NFSv4/pnfs: Fix layoutget behaviour after invalidation")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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pNFS: Don't keep retrying if the server replied NFS4ERR_LAYOUTUNAVAILABLE

[ Upstream commit fe44fb23d6ccde4c914c44ef74ab8d9d9ba02bea ]

If the server tells us that a pNFS layout is not available for

pNFS: Don't keep retrying if the server replied NFS4ERR_LAYOUTUNAVAILABLE

[ Upstream commit fe44fb23d6ccde4c914c44ef74ab8d9d9ba02bea ]

If the server tells us that a pNFS layout is not available for a
specific file, then we should not keep pounding it with further
layoutget requests.

Fixes: 183d9e7b112a ("pnfs: rework LAYOUTGET retry handling")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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NFS: Convert GFP_NOFS to GFP_KERNEL

[ Upstream commit da48f267f90d9dc9f930fd9a67753643657b404f ]

Assume that sections that should not re-enter the filesystem are already
protected with memalloc_nof

NFS: Convert GFP_NOFS to GFP_KERNEL

[ Upstream commit da48f267f90d9dc9f930fd9a67753643657b404f ]

Assume that sections that should not re-enter the filesystem are already
protected with memalloc_nofs_save/restore call, so relax those GFP_NOFS
instances which might be used by other contexts.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

NFSv4/pNFS: Do not fail I/O when we fail to allocate the pNFS layout

[ Upstream commit 3764a17e31d579cf9b4bd0a69894b577e8d75702 ]

Commit 587f03deb69b caused pnfs_update_layout() to stop returning E

NFSv4/pNFS: Do not fail I/O when we fail to allocate the pNFS layout

[ Upstream commit 3764a17e31d579cf9b4bd0a69894b577e8d75702 ]

Commit 587f03deb69b caused pnfs_update_layout() to stop returning ENOMEM
when the memory allocation fails, and hence causes it to fall back to
trying to do I/O through the MDS. There is no guarantee that this will
fare any better. If we're failing the pNFS layout allocation, then we
should just redirty the page and retry later.

Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 587f03deb69b ("pnfs: refactor send_layoutget")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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NFSv4/pNFS: Fix another issue with a list iterator pointing to the head

[ Upstream commit 7c9d845f0612e5bcd23456a2ec43be8ac43458f1 ]

In nfs4_callback_devicenotify(), if we don't find a matching ent

NFSv4/pNFS: Fix another issue with a list iterator pointing to the head

[ Upstream commit 7c9d845f0612e5bcd23456a2ec43be8ac43458f1 ]

In nfs4_callback_devicenotify(), if we don't find a matching entry for
the deviceid, we're left with a pointer to 'struct nfs_server' that
actually points to the list of super blocks associated with our struct
nfs_client.
Furthermore, even if we have a valid pointer, nothing pins the super
block, and so the struct nfs_server could end up getting freed while
we're using it.

Since all we want is a pointer to the struct pnfs_layoutdriver_type,
let's skip all the iteration over super blocks, and just use APIs to
find the layout driver directly.

Reported-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Fixes: 1be5683b03a7 ("pnfs: CB_NOTIFY_DEVICEID")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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NFSv4/pnfs: The layout barrier indicate a minimal value for the seqid

The intention of the layout barrier is to ensure that we do not update
the layout to match an older value than the current expec

NFSv4/pnfs: The layout barrier indicate a minimal value for the seqid

The intention of the layout barrier is to ensure that we do not update
the layout to match an older value than the current expectation. Fix the
test in pnfs_layout_stateid_blocked() to reflect that it is legal for
the seqid of the stateid to match that of the barrier.

Fixes: aa95edf309ef ("NFSv4/pnfs: Fix the layout barrier update")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFSv4/pNFS: Always allow update of a zero valued layout barrier

A zero value for the layout barrier indicates that it has been cleared
(since seqid '0' is an illegal value), so we should always allo

NFSv4/pNFS: Always allow update of a zero valued layout barrier

A zero value for the layout barrier indicates that it has been cleared
(since seqid '0' is an illegal value), so we should always allow it to
be updated.

Fixes: d29b468da4f9 ("pNFS/NFSv4: Improve rejection of out-of-order layouts")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFSv4/pNFS: Remove dead code

Since commit 2b28a7bee453 ("fs, nfs: convert
pnfs_layout_hdr.plh_refcount from atomic_t to refcount_t") it has not
been legal to bump a zero refcount, so the code that t

NFSv4/pNFS: Remove dead code

Since commit 2b28a7bee453 ("fs, nfs: convert
pnfs_layout_hdr.plh_refcount from atomic_t to refcount_t") it has not
been legal to bump a zero refcount, so the code that tries to allow it
if the NFS_LSEG_VALID flag is still set would cause trouble. Luckily,
NFS_LSEG_VALID has its own refcount so we can never hit this bad code
snippet in practice. Remove it to avoid confusion.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFSv4/pNFS: Fix a layoutget livelock loop

If NFS_LAYOUT_RETURN_REQUESTED is set, but there is no value set for
the layout plh_return_seq, we can end up in a livelock loop in which
every layout segme

NFSv4/pNFS: Fix a layoutget livelock loop

If NFS_LAYOUT_RETURN_REQUESTED is set, but there is no value set for
the layout plh_return_seq, we can end up in a livelock loop in which
every layout segment retrieved by a new call to layoutget is immediately
invalidated by pnfs_layout_need_return().
To get around this, we should just set plh_return_seq to the current
value of the layout stateid's seqid.

Fixes: d474f96104bd ("NFS: Don't return layout segments that are in use")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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