afs: Fix rename operation status delivery

The afs_deliver_fs_rename() and yfs_deliver_fs_rename() functions both only
decode the second file status returned unless the parent directories are
differe

afs: Fix rename operation status delivery

The afs_deliver_fs_rename() and yfs_deliver_fs_rename() functions both only
decode the second file status returned unless the parent directories are
different - unfortunately, this means that the xdr pointer isn't advanced
and the volsync record will be read incorrectly in such an instance.

Fix this by always decoding the second status into the second
status/callback block which wasn't being used if the dirs were the same.

The afs_update_dentry_version() calls that update the directory data
version numbers on the dentries can then unconditionally use the second
status record as this will always reflect the state of the destination dir
(the two records will be identical if the destination dir is the same as
the source dir)

Fixes: 260a980317da ("[AFS]: Add "directory write" support.")
Fixes: 30062bd13e36 ("afs: Implement YFS support in the fs client")
Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Fix afs_lookup() to not clobber the version on a new dentry

Fix afs_lookup() to not clobber the version set on a new dentry by
afs_do_lookup() - especially as it's using the wrong version of th

afs: Fix afs_lookup() to not clobber the version on a new dentry

Fix afs_lookup() to not clobber the version set on a new dentry by
afs_do_lookup() - especially as it's using the wrong version of the
version (we need to use the one given to us by whatever op the dir
contents correspond to rather than what's in the afs_vnode).

Fixes: 9dd0b82ef530 ("afs: Fix missing dentry data version updating")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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afs: Fix use-after-loss-of-ref

afs_lookup() has a tracepoint to indicate the outcome of
d_splice_alias(), passing it the inode to retrieve the fid from.
However, the function gave up its ref on that

afs: Fix use-after-loss-of-ref

afs_lookup() has a tracepoint to indicate the outcome of
d_splice_alias(), passing it the inode to retrieve the fid from.
However, the function gave up its ref on that inode when it called
d_splice_alias(), which may have failed and dropped the inode.

Fix this by caching the fid.

Fixes: 80548b03991f ("afs: Add more tracepoints")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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afs: Fix race in commit bulk status fetch

When a lookup is done, the afs filesystem will perform a bulk status-fetch
operation on the requested vnode (file) plus the next 49 other vnodes from
the di

afs: Fix race in commit bulk status fetch

When a lookup is done, the afs filesystem will perform a bulk status-fetch
operation on the requested vnode (file) plus the next 49 other vnodes from
the directory list (in AFS, directory contents are downloaded as blobs and
parsed locally). When the results are received, it will speculatively
populate the inode cache from the extra data.

However, if the lookup races with another lookup on the same directory, but
for a different file - one that's in the 49 extra fetches, then if the bulk
status-fetch operation finishes first, it will try and update the inode
from the other lookup.

If this other inode is still in the throes of being created, however, this
will cause an assertion failure in afs_apply_status():

BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));

on or about fs/afs/inode.c:175 because it expects data to be there already
that it can compare to.

Fix this by skipping the update if the inode is being created as the
creator will presumably set up the inode with the same information.

Fixes: 39db9815da48 ("afs: Fix application of the results of a inline bulk status fetch")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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afs: Support RCU pathwalk

Make afs_permission() and afs_d_revalidate() do initial checks in RCU-mode
pathwalk to reduce latency in pathwalk elements that get done multiple
times. We don't need to q

afs: Support RCU pathwalk

Make afs_permission() and afs_d_revalidate() do initial checks in RCU-mode
pathwalk to reduce latency in pathwalk elements that get done multiple
times. We don't need to query the server unless we've received a
notification from it that something has changed or the callback has
expired.

This requires that we can request a key and check permits under RCU
conditions if we need to.

Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Fix possible oops in afs_lookup trace event

The afs_lookup trace event can cause the following:

[ 216.576777] BUG: kernel NULL pointer dereference, address: 000000000000023b
[ 216.576803] #P

afs: Fix possible oops in afs_lookup trace event

The afs_lookup trace event can cause the following:

[ 216.576777] BUG: kernel NULL pointer dereference, address: 000000000000023b
[ 216.576803] #PF: supervisor read access in kernel mode
[ 216.576813] #PF: error_code(0x0000) - not-present page
...
[ 216.576913] RIP: 0010:trace_event_raw_event_afs_lookup+0x9e/0x1c0 [kafs]

If the inode from afs_do_lookup() is an error other than ENOENT, or if it
is ENOENT and afs_try_auto_mntpt() returns an error, the trace event will
try to dereference the error pointer as a valid pointer.

Use IS_ERR_OR_NULL to only pass a valid pointer for the trace, or NULL.

Ideally the trace would include the error value, but for now just avoid
the oops.

Fixes: 80548b03991f ("afs: Add more tracepoints")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Fix missing dentry data version updating

In the in-kernel afs filesystem, the d_fsdata dentry field is used to hold
the data version of the parent directory when it was created or when
d_revali

afs: Fix missing dentry data version updating

In the in-kernel afs filesystem, the d_fsdata dentry field is used to hold
the data version of the parent directory when it was created or when
d_revalidate() last caused it to be updated. This is compared to the
->invalid_before field in the directory inode, rather than the actual data
version number, thereby allowing changes due to local edits to be ignored.
Only if the server data version gets bumped unexpectedly (eg. by a
competing client), do we need to revalidate stuff.

However, the d_fsdata field should also be updated if an rpc op is
performed that modifies that particular dentry. Such ops return the
revised data version of the directory(ies) involved, so we should use that.

This is particularly problematic for rename, since a dentry from one
directory may be moved directly into another directory (ie. mv a/x b/x).
It would then be sporting the wrong data version - and if this is in the
future, for the destination directory, revalidations would be missed,
leading to foreign renames and hard-link deletion being missed.

Fix this by the following means:

(1) Return the data version number from operations that read the directory
contents - if they issue the read. This starts in afs_dir_iterate()
and is used, ignored or passed back by its callers.

(2) In afs_lookup*(), set the dentry version to the version returned by
(1) before d_splice_alias() is called and the dentry published.

(3) In afs_d_revalidate(), set the dentry version to that returned from
(1) if an rpc call was issued. This means that if a parallel
procedure, such as mkdir(), modifies the directory, we won't
accidentally use the data version from that.

(4) In afs_{mkdir,create,link,symlink}(), set the new dentry's version to
the directory data version before d_instantiate() is called.

(5) In afs_{rmdir,unlink}, update the target dentry's version to the
directory data version as soon as we've updated the directory inode.

(6) In afs_rename(), we need to unhash the old dentry before we start so
that we don't get afs_d_revalidate() reverting the version change in
cross-directory renames.

We then need to set both the old and the new dentry versions the data
version of the new directory before we call d_move() as d_move() will
rehash them.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Only update d_fsdata if different in afs_d_revalidate()

In the in-kernel afs filesystem, d_fsdata is set with the data version of
the parent directory. afs_d_revalidate() will update this to t

afs: Only update d_fsdata if different in afs_d_revalidate()

In the in-kernel afs filesystem, d_fsdata is set with the data version of
the parent directory. afs_d_revalidate() will update this to the current
directory version, but it shouldn't do this if it the value it read from
d_fsdata is the same as no lock is held and cmpxchg() is not used.

Fix the code to only change the value if it is different from the current
directory version.

Fixes: 260a980317da ("[AFS]: Add "directory write" support.")
Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Fix off-by-one in afs_rename() expected data version calculation

When afs_rename() calculates the expected data version of the target
directory in a cross-directory rename, it doesn't increment

afs: Fix off-by-one in afs_rename() expected data version calculation

When afs_rename() calculates the expected data version of the target
directory in a cross-directory rename, it doesn't increment it as it
should, so it always thinks that the target inode is unexpectedly modified
on the server.

Fixes: a58823ac4589 ("afs: Fix application of status and callback to be under same lock")
Signed-off-by: David Howells <dhowells@redhat.com>

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fs/afs: use struct_size() in kzalloc()

As Gustavo said in other patches doing the same replace, we can now
use the new struct_size() helper to avoid leaving these open-coded and
prone to type mistak

fs/afs: use struct_size() in kzalloc()

As Gustavo said in other patches doing the same replace, we can now
use the new struct_size() helper to avoid leaving these open-coded and
prone to type mistake.

Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Add some callback management tracepoints

Add a couple of tracepoints to track callback management:

(1) afs_cb_miss - Logs when we were unable to apply a callback, either due
to the inode

afs: Add some callback management tracepoints

Add a couple of tracepoints to track callback management:

(1) afs_cb_miss - Logs when we were unable to apply a callback, either due
to the inode being discarded or due to a competing thread applying a
callback first.

(2) afs_cb_break - Logs when we attempted to clear the noted callback
promise, either due to the server explicitly breaking the callback,
the callback promise lapsing or a local event obsoleting it.

Signed-off-by: David Howells <dhowells@redhat.com>

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afs: afs_unlink() doesn't need to check dentry->d_inode

Don't check that dentry->d_inode is valid in afs_unlink(). We should be
able to take that as given.

This caused Smatch to issue the followin

afs: afs_unlink() doesn't need to check dentry->d_inode

Don't check that dentry->d_inode is valid in afs_unlink(). We should be
able to take that as given.

This caused Smatch to issue the following warning:

fs/afs/dir.c:1392 afs_unlink() error: we previously assumed 'vnode' could be null (see line 1375)

Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of th

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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afs: Fix application of the results of a inline bulk status fetch

Fix afs_do_lookup() such that when it does an inline bulk status fetch op,
it will update inodes that are already extant (something

afs: Fix application of the results of a inline bulk status fetch

Fix afs_do_lookup() such that when it does an inline bulk status fetch op,
it will update inodes that are already extant (something that afs_iget()
doesn't do) and to cache permits for each inode created (thereby avoiding a
follow up FS.FetchStatus call to determine this).

Extant inodes need looking up in advance so that their cb_break counters
before and after the operation can be compared. To this end, the inode
pointers are cached so that they don't need looking up again after the op.

Fixes: 5cf9dd55a0ec ("afs: Prospectively look up extra files when doing a single lookup")
Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Pass pre-fetch server and volume break counts into afs_iget5_set()

Pass the server and volume break counts from before the status fetch
operation that queried the attributes of a file into afs_

afs: Pass pre-fetch server and volume break counts into afs_iget5_set()

Pass the server and volume break counts from before the status fetch
operation that queried the attributes of a file into afs_iget5_set() so
that the new vnode's break counters can be initialised appropriately.

This allows detection of a volume or server break that happened whilst we
were fetching the status or setting up the vnode.

Fixes: c435ee34551e ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Fix unlink to handle YFS.RemoveFile2 better

Make use of the status update for the target file that the YFS.RemoveFile2
RPC op returns to correctly update the vnode as to whether the file was
ac

afs: Fix unlink to handle YFS.RemoveFile2 better

Make use of the status update for the target file that the YFS.RemoveFile2
RPC op returns to correctly update the vnode as to whether the file was
actually deleted or just had nlink reduced.

Fixes: 30062bd13e36 ("afs: Implement YFS support in the fs client")
Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Make vnode->cb_interest RCU safe

Use RCU-based freeing for afs_cb_interest struct objects and use RCU on
vnode->cb_interest. Use that change to allow afs_check_validity() to use
read_seqbegin_

afs: Make vnode->cb_interest RCU safe

Use RCU-based freeing for afs_cb_interest struct objects and use RCU on
vnode->cb_interest. Use that change to allow afs_check_validity() to use
read_seqbegin_or_lock() instead of read_seqlock_excl().

This also requires the caller of afs_check_validity() to hold the RCU read
lock across the call.

Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Fix application of status and callback to be under same lock

When applying the status and callback in the response of an operation,
apply them in the same critical section so that there's no ra

afs: Fix application of status and callback to be under same lock

When applying the status and callback in the response of an operation,
apply them in the same critical section so that there's no race between
checking the callback state and checking status-dependent state (such as
the data version).

Fix this by:

(1) Allocating a joint {status,callback} record (afs_status_cb) before
calling the RPC function for each vnode for which the RPC reply
contains a status or a status plus a callback. A flag is set in the
record to indicate if a callback was actually received.

(2) These records are passed into the RPC functions to be filled in. The
afs_decode_status() and yfs_decode_status() functions are removed and
the cb_lock is no longer taken.

(3) xdr_decode_AFSFetchStatus() and xdr_decode_YFSFetchStatus() no longer
update the vnode.

(4) xdr_decode_AFSCallBack() and xdr_decode_YFSCallBack() no longer update
the vnode.

(5) vnodes, expected data-version numbers and callback break counters
(cb_break) no longer need to be passed to the reply delivery
functions.

Note that, for the moment, the file locking functions still need
access to both the call and the vnode at the same time.

(6) afs_vnode_commit_status() is now given the cb_break value and the
expected data_version and the task of applying the status and the
callback to the vnode are now done here.

This is done under a single taking of vnode->cb_lock.

(7) afs_pages_written_back() is now called by afs_store_data() rather than
by the reply delivery function.

afs_pages_written_back() has been moved to before the call point and
is now given the first and last page numbers rather than a pointer to
the call.

(8) The indicator from YFS.RemoveFile2 as to whether the target file
actually got removed (status.abort_code == VNOVNODE) rather than
merely dropping a link is now checked in afs_unlink rather than in
xdr_decode_YFSFetchStatus().

Supplementary fixes:

(*) afs_cache_permit() now gets the caller_access mask from the
afs_status_cb object rather than picking it out of the vnode's status
record. afs_fetch_status() returns caller_access through its argument
list for this purpose also.

(*) afs_inode_init_from_status() now uses a write lock on cb_lock rather
than a read lock and now sets the callback inside the same critical
section.

Fixes: c435ee34551e ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Fix order-1 allocation in afs_do_lookup()

afs_do_lookup() will do an order-1 allocation to allocate status records if
there are more than 39 vnodes to stat.

Fix this by allocating an array of

afs: Fix order-1 allocation in afs_do_lookup()

afs_do_lookup() will do an order-1 allocation to allocate status records if
there are more than 39 vnodes to stat.

Fix this by allocating an array of {status,callback} records for each vnode
we want to examine using vmalloc() if larger than a page.

This not only gets rid of the order-1 allocation, but makes it easier to
grow beyond 50 records for YFS servers. It also allows us to move to
{status,callback} tuples for other calls too and makes it easier to lock
across the application of the status and the callback to the vnode.

Fixes: 5cf9dd55a0ec ("afs: Prospectively look up extra files when doing a single lookup")
Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Make some RPC operations non-interruptible

Make certain RPC operations non-interruptible, including:

(*) Set attributes
(*) Store data

We don't want to get interrupted during a flush o

afs: Make some RPC operations non-interruptible

Make certain RPC operations non-interruptible, including:

(*) Set attributes
(*) Store data

We don't want to get interrupted during a flush on close, flush on
unlock, writeback or an inode update, leaving us in a state where we
still need to do the writeback or update.

(*) Extend lock
(*) Release lock

We don't want to get lock extension interrupted as the file locks on
the server are time-limited. Interruption during lock release is less
of an issue since the lock is time-limited, but it's better to
complete the release to avoid a several-minute wait to recover it.

*Setting* the lock isn't a problem if it's interrupted since we can
just return to the user and tell them they were interrupted - at
which point they can elect to retry.

(*) Silly unlink

We want to remove silly unlink files if we can, rather than leaving
them for the salvager to clear up.

Note that whilst these calls are no longer interruptible, they do have
timeouts on them, so if the server stops responding the call will fail with
something like ETIME or ECONNRESET.

Without this, the following:

kAFS: Unexpected error from FS.StoreData -512

appears in dmesg when a pending store data gets interrupted and some
processes may just hang.

Additionally, make the code that checks/updates the server record ignore
failure due to interruption if the main call is uninterruptible and if the
server has an address list. The next op will check it again since the
expiration time on the old list has past.

Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Jonathan Billings <jsbillings@jsbillings.org>
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Log more information for "kAFS: AFS vnode with undefined type\n"

Log more information when "kAFS: AFS vnode with undefined type\n" is
displayed due to a vnode record being retrieved from the se

afs: Log more information for "kAFS: AFS vnode with undefined type\n"

Log more information when "kAFS: AFS vnode with undefined type\n" is
displayed due to a vnode record being retrieved from the server that
appears to have a duff file type (usually 0). This prints more information
to try and help pin down the problem.

Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Add more tracepoints

Add four more tracepoints:

(1) afs_make_fs_call1 - Split from afs_make_fs_call but takes a filename
to log also.

(2) afs_make_fs_call2 - Like the above but takes t

afs: Add more tracepoints

Add four more tracepoints:

(1) afs_make_fs_call1 - Split from afs_make_fs_call but takes a filename
to log also.

(2) afs_make_fs_call2 - Like the above but takes two filenames to log.

(3) afs_lookup - Log the result of doing a successful lookup, including a
negative result (fid 0:0).

(4) afs_get_tree - Log the set up of a volume for mounting.

It also extends the name buffer on the afs_edit_dir tracepoint to 24 chars
and puts quotes around the filename in the text representation.

Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Implement sillyrename for unlink and rename

Implement sillyrename for AFS unlink and rename, using the NFS variant
implementation as a basis.

Note that the asynchronous file locking extender/r

afs: Implement sillyrename for unlink and rename

Implement sillyrename for AFS unlink and rename, using the NFS variant
implementation as a basis.

Note that the asynchronous file locking extender/releaser has to be
notified with a state change to stop it complaining if there's a race
between that and the actual file deletion.

A tracepoint, afs_silly_rename, is also added to note the silly rename and
the cleanup. The afs_edit_dir tracepoint is given some extra reason
indicators and the afs_flock_ev tracepoint is given a silly-delete file
lock cancellation indicator.

Signed-off-by: David Howells <dhowells@redhat.com>

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afs: Add directory reload tracepoint

Add a tracepoint (afs_reload_dir) to indicate when a directory is being
reloaded.

Signed-off-by: David Howells <dhowells@redhat.com>

afs: Improve dir check failure reports

Improve the content of directory check failure reports from:

kAFS: afs_dir_check_page(6d57): bad magic 1/2 is 0000

to dump more information about the indivi

afs: Improve dir check failure reports

Improve the content of directory check failure reports from:

kAFS: afs_dir_check_page(6d57): bad magic 1/2 is 0000

to dump more information about the individual blocks in a directory page.

Signed-off-by: David Howells <dhowells@redhat.com>

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