Commit Graph

108 Commits

Author SHA1 Message Date
David Howells
5c0522484e afs: Fix afs_launder_page() to set correct start file position
Fix afs_launder_page() to set the starting position of the StoreData RPC at
the offset into the page at which the modified data starts instead of at
the beginning of the page (the iov_iter is correctly offset).

The offset got lost during the conversion to passing an iov_iter into
afs_store_data().

Changes:
ver #2:
 - Use page_offset() rather than manually calculating it[1].

Fixes: bd80d8a80e ("afs: Use ITER_XARRAY for writing")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/YST/0e92OdSH0zjg@casper.infradead.org/ [1]
Link: https://lore.kernel.org/r/162880783179.3421678.7795105718190440134.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/162937512409.1449272.18441473411207824084.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/162981148752.1901565.3663780601682206026.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163005741670.2472992.2073548908229887941.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163221839087.3143591.14278359695763025231.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163292980654.4004896.7134735179887998551.stgit@warthog.procyon.org.uk/ # v2
2021-10-05 11:22:06 +01:00
David Howells
9d37e1cab2 afs: Fix updating of i_blocks on file/dir extension
When an afs file or directory is modified locally such that the total file
size is extended, i_blocks needs to be recalculated too.

Fix this by making afs_write_end() and afs_edit_dir_add() call
afs_set_i_size() rather than setting inode->i_size directly as that also
recalculates inode->i_blocks.

This can be tested by creating and writing into directories and files and
then examining them with du.  Without this change, directories show a 4
blocks (they start out at 2048 bytes) and files show 0 blocks; with this
change, they should show a number of blocks proportional to the file size
rounded up to 1024.

Fixes: 31143d5d51 ("AFS: implement basic file write support")
Fixes: 63a4681ff3 ("afs: Locally edit directory data for mkdir/create/unlink/...")
Reported-by: Markus Suvanto <markus.suvanto@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/163113612442.352844.11162345591911691150.stgit@warthog.procyon.org.uk/
2021-09-13 09:14:21 +01:00
David Howells
3978d81652 afs: Add missing vnode validation checks
afs_d_revalidate() should only be validating the directory entry it is
given and the directory to which that belongs; it shouldn't be validating
the inode/vnode to which that dentry points.  Besides, validation need to
be done even if we don't call afs_d_revalidate() - which might be the case
if we're starting from a file descriptor.

In order for afs_d_revalidate() to be fixed, validation points must be
added in some other places.  Certain directory operations, such as
afs_unlink(), already check this, but not all and not all file operations
either.

Note that the validation of a vnode not only checks to see if the
attributes we have are correct, but also gets a promise from the server to
notify us if that file gets changed by a third party.

Add the following checks:

 - Check the vnode we're going to make a hard link to.
 - Check the vnode we're going to move/rename.
 - Check the vnode we're going to read from.
 - Check the vnode we're going to write to.
 - Check the vnode we're going to sync.
 - Check the vnode we're going to make a mapped page writable for.

Some of these aren't strictly necessary as we're going to perform a server
operation that might get the attributes anyway from which we can determine
if something changed - though it might not get us a callback promise.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/163111667354.283156.12720698333342917516.stgit@warthog.procyon.org.uk/
2021-09-13 09:10:39 +01:00
David Howells
581b2027af afs: Fix page leak
There's a loop in afs_extend_writeback() that adds extra pages to a write
we want to make to improve the efficiency of the writeback by making it
larger.  This loop stops, however, if we hit a page we can't write back
from immediately, but it doesn't get rid of the page ref we speculatively
acquired.

This was caused by the removal of the cleanup loop when the code switched
from using find_get_pages_contig() to xarray scanning as the latter only
gets a single page at a time, not a batch.

Fix this by putting the page on a ref on an early break from the loop.
Unfortunately, we can't just add that page to the pagevec we're employing
as we'll go through that and add those pages to the RPC call.

This was found by the generic/074 test.  It leaks ~4GiB of RAM each time it
is run - which can be observed with "top".

Fixes: e87b03f583 ("afs: Prepare for use of THPs")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-and-tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/163111666635.283156.177701903478910460.stgit@warthog.procyon.org.uk/
2021-09-10 22:14:51 +01:00
David Howells
5a972474cf afs: Fix setting of writeback_index
Fix afs_writepages() to always set mapping->writeback_index to a page index
and not a byte position[1].

Fixes: 31143d5d51 ("AFS: implement basic file write support")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/CAB9dFdvHsLsw7CMnB+4cgciWDSqVjuij4mH3TaXnHQB8sz5rHw@mail.gmail.com/ [1]
Link: https://lore.kernel.org/r/162610728339.3408253.4604750166391496546.stgit@warthog.procyon.org.uk/ # v2 (no v1)
2021-07-21 15:10:23 +01:00
Tom Rix
afe6949862 afs: check function return
Static analysis reports this problem

write.c:773:29: warning: Assigned value is garbage or undefined
  mapping->writeback_index = next;
                           ^ ~~~~
The call to afs_writepages_region() can return without setting
next.  So check the function return before using next.

Changes:
 ver #2:
   - Need to fix the range_cyclic case also[1].

Fixes: e87b03f583 ("afs: Prepare for use of THPs")
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/20210430155031.3287870-1-trix@redhat.com
Link: https://lore.kernel.org/r/CAB9dFdvHsLsw7CMnB+4cgciWDSqVjuij4mH3TaXnHQB8sz5rHw@mail.gmail.com/ [1]
Link: https://lore.kernel.org/r/162609464716.3133237.10354897554363093252.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/162610727640.3408253.8687445613469681311.stgit@warthog.procyon.org.uk/ # v2
2021-07-21 15:10:23 +01:00
Linus Torvalds
9e736cf7d6 netfslib fixes
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Merge tag 'netfs-fixes-20210621' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull netfs fixes from David Howells:
 "This contains patches to fix netfs_write_begin() and afs_write_end()
  in the following ways:

  (1) In netfs_write_begin(), extract the decision about whether to skip
      a page out to its own helper and have that clear around the region
      to be written, but not clear that region. This requires the
      filesystem to patch it up afterwards if the hole doesn't get
      completely filled.

  (2) Use offset_in_thp() in (1) rather than manually calculating the
      offset into the page.

  (3) Due to (1), afs_write_end() now needs to handle short data write
      into the page by generic_perform_write(). I've adopted an
      analogous approach to ceph of just returning 0 in this case and
      letting the caller go round again.

  It also adds a note that (in the future) the len parameter may extend
  beyond the page allocated. This is because the page allocation is
  deferred to write_begin() and that gets to decide what size of THP to
  allocate."

Jeff Layton points out:
 "The netfs fix in particular fixes a data corruption bug in cephfs"

* tag 'netfs-fixes-20210621' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  netfs: fix test for whether we can skip read when writing beyond EOF
  afs: Fix afs_write_end() to handle short writes
2021-06-25 09:41:29 -07:00
David Howells
66e9c6a86b afs: Fix afs_write_end() to handle short writes
Fix afs_write_end() to correctly handle a short copy into the intended
write region of the page.  Two things are necessary:

 (1) If the page is not up to date, then we should just return 0
     (ie. indicating a zero-length copy).  The loop in
     generic_perform_write() will go around again, possibly breaking up the
     iterator into discrete chunks[1].

     This is analogous to commit b9de313cf0
     for ceph.

 (2) The page should not have been set uptodate if it wasn't completely set
     up by netfs_write_begin() (this will be fixed in the next patch), so
     we need to set uptodate here in such a case.

Also remove the assertion that was checking that the page was set uptodate
since it's now set uptodate if it wasn't already a few lines above.  The
assertion was from when uptodate was set elsewhere.

Changes:
v3: Remove the handling of len exceeding the end of the page.

Fixes: 3003bbd069 ("afs: Use the netfs_write_begin() helper")
Reported-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/YMwVp268KTzTf8cN@zeniv-ca.linux.org.uk/ [1]
Link: https://lore.kernel.org/r/162367682522.460125.5652091227576721609.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/162391825688.1173366.3437507255136307904.stgit@warthog.procyon.org.uk/ # v2
2021-06-21 21:23:36 +01:00
Matthew Wilcox (Oracle)
9620ad86d0 afs: Re-enable freezing once a page fault is interrupted
If a task is killed during a page fault, it does not currently call
sb_end_pagefault(), which means that the filesystem cannot be frozen
at any time thereafter.  This may be reported by lockdep like this:

====================================
WARNING: fsstress/10757 still has locks held!
5.13.0-rc4-build4+ #91 Not tainted
------------------------------------
1 lock held by fsstress/10757:
 #0: ffff888104eac530
 (
sb_pagefaults

as filesystem freezing is modelled as a lock.

Fix this by removing all the direct returns from within the function,
and using 'ret' to indicate whether we were interrupted or successful.

Fixes: 1cf7a1518a ("afs: Implement shared-writeable mmap")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/20210616154900.1958373-1-willy@infradead.org/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-18 13:49:07 -07:00
Marc Dionne
dc2557308e afs: Fix partial writeback of large files on fsync and close
In commit e87b03f583 ("afs: Prepare for use of THPs"), the return
value for afs_write_back_from_locked_page was changed from a number
of pages to a length in bytes.  The loop in afs_writepages_region uses
the return value to compute the index that will be used to find dirty
pages in the next iteration, but treats it as a number of pages and
wrongly multiplies it by PAGE_SIZE.  This gives a very large index value,
potentially skipping any dirty data that was not covered in the first
pass, which is limited to 256M.

This causes fsync(), and indirectly close(), to only do a partial
writeback of a large file's dirty data.  The rest is eventually written
back by background threads after dirty_expire_centisecs.

Fixes: e87b03f583 ("afs: Prepare for use of THPs")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/20210604175504.4055-1-marc.c.dionne@gmail.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-07 12:56:05 -07:00
David Howells
22650f1481 afs: Fix speculative status fetches
The generic/464 xfstest causes kAFS to emit occasional warnings of the
form:

        kAFS: vnode modified {100055:8a} 30->31 YFS.StoreData64 (c=6015)

This indicates that the data version received back from the server did not
match the expected value (the DV should be incremented monotonically for
each individual modification op committed to a vnode).

What is happening is that a lookup call is doing a bulk status fetch
speculatively on a bunch of vnodes in a directory besides getting the
status of the vnode it's actually interested in.  This is racing with a
StoreData operation (though it could also occur with, say, a MakeDir op).

On the client, a modification operation locks the vnode, but the bulk
status fetch only locks the parent directory, so no ordering is imposed
there (thereby avoiding an avenue to deadlock).

On the server, the StoreData op handler doesn't lock the vnode until it's
received all the request data, and downgrades the lock after committing the
data until it has finished sending change notifications to other clients -
which allows the status fetch to occur before it has finished.

This means that:

 - a status fetch can access the target vnode either side of the exclusive
   section of the modification

 - the status fetch could start before the modification, yet finish after,
   and vice-versa.

 - the status fetch and the modification RPCs can complete in either order.

 - the status fetch can return either the before or the after DV from the
   modification.

 - the status fetch might regress the locally cached DV.

Some of these are handled by the previous fix[1], but that's not sufficient
because it checks the DV it received against the DV it cached at the start
of the op, but the DV might've been updated in the meantime by a locally
generated modification op.

Fix this by the following means:

 (1) Keep track of when we're performing a modification operation on a
     vnode.  This is done by marking vnode parameters with a 'modification'
     note that causes the AFS_VNODE_MODIFYING flag to be set on the vnode
     for the duration.

 (2) Alter the speculation race detection to ignore speculative status
     fetches if either the vnode is marked as being modified or the data
     version number is not what we expected.

Note that whilst the "vnode modified" warning does get recovered from as it
causes the client to refetch the status at the next opportunity, it will
also invalidate the pagecache, so changes might get lost.

Fixes: a9e5c87ca7 ("afs: Fix speculative status fetch going out of order wrt to modifications")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-and-reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/160605082531.252452.14708077925602709042.stgit@warthog.procyon.org.uk/ [1]
Link: https://lore.kernel.org/linux-fsdevel/161961335926.39335.2552653972195467566.stgit@warthog.procyon.org.uk/ # v1
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-01 11:55:36 -07:00
David Howells
3003bbd069 afs: Use the netfs_write_begin() helper
Make AFS use the new netfs_write_begin() helper to do the pre-reading
required before the write.  If successful, the helper returns with the
required page filled in and locked.  It may read more than just one page,
expanding the read to meet cache granularity requirements as necessary.

Note: A more advanced version of this could be made that does
generic_perform_write() for a whole cache granule.  This would make it
easier to avoid doing the download/read for the data to be overwritten.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/160588546422.3465195.1546354372589291098.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161539563244.286939.16537296241609909980.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653819291.2770958.406013201547420544.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789102743.6155.17396591236631761195.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:17:28 +01:00
David Howells
5cbf03985c afs: Use new netfs lib read helper API
Make AFS use the new netfs read helpers to implement the VM read
operations:

 - afs_readpage() now hands off responsibility to netfs_readpage().

 - afs_readpages() is gone and replaced with afs_readahead().

 - afs_readahead() just hands off responsibility to netfs_readahead().

These make use of the cache if a cookie is supplied, otherwise just call
the ->issue_op() method a sufficient number of times to complete the entire
request.

Changes:
v5:
- Use proper wait function for PG_fscache in afs_page_mkwrite()[1].
- Use killable wait for PG_writeback in afs_page_mkwrite()[1].

v4:
- Folded in error handling fixes to afs_req_issue_op().
- Added flag to netfs_subreq_terminated() to indicate that the caller may
  have been running async and stuff that might sleep needs punting to a
  workqueue.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/2499407.1616505440@warthog.procyon.org.uk [1]
Link: https://lore.kernel.org/r/160588542733.3465195.7526541422073350302.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118158436.1232039.3884845981224091996.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161053540.2537118.14904446369309535330.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340418739.1303470.5908092911600241280.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539561926.286939.5729036262354802339.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653817977.2770958.17696456811587237197.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789101258.6155.3879271028895121537.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:17:28 +01:00
David Howells
e87b03f583 afs: Prepare for use of THPs
As a prelude to supporting transparent huge pages, use thp_size() and
similar rather than PAGE_SIZE/SHIFT.

Further, try and frame everything in terms of file positions and lengths
rather than page indices and numbers of pages.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/160588540227.3465195.4752143929716269062.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118155821.1232039.540445038028845740.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161051439.2537118.15577827510426326534.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340415869.1303470.6040191748634322355.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539559365.286939.18344613540296085269.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653815142.2770958.454490670311230206.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789098713.6155.16394227991842480300.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:17:27 +01:00
David Howells
810caa3e67 afs: Extract writeback extension into its own function
Extract writeback extension into its own function to break up the writeback
function a bit.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/160588538471.3465195.782513375683399583.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118154610.1232039.1765365632920504822.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161050546.2537118.2202554806419189453.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340414102.1303470.9078891484034668985.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539558417.286939.2879469588895925399.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653813972.2770958.12671731209438112378.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789097132.6155.4916609419912731964.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:17:27 +01:00
David Howells
630f5dda84 afs: Wait on PG_fscache before modifying/releasing a page
PG_fscache is going to be used to indicate that a page is being written to
the cache, and that the page should not be modified or released until it's
finished.

Make afs_invalidatepage() and afs_releasepage() wait for it.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/158861253957.340223.7465334678444521655.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/159465832417.1377938.3571599385208729791.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/160588536286.3465195.13231895135369807920.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118153708.1232039.3535103645871176749.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161049369.2537118.11591934943429117060.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340412903.1303470.6424701655031380012.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539556890.286939.5873470593519458598.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653812726.2770958.18167145829938766503.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789096241.6155.5907241930823579235.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:17:27 +01:00
David Howells
bd80d8a80e afs: Use ITER_XARRAY for writing
Use a single ITER_XARRAY iterator to describe the portion of a file to be
transmitted to the server rather than generating a series of small
ITER_BVEC iterators on the fly.  This will make it easier to implement AIO
in afs.

In theory we could maybe use one giant ITER_BVEC, but that means
potentially allocating a huge array of bio_vec structs (max 256 per page)
when in fact the pagecache already has a structure listing all the relevant
pages (radix_tree/xarray) that can be walked over.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/153685395197.14766.16289516750731233933.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/158861251312.340223.17924900795425422532.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/159465828607.1377938.6903132788463419368.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/160588535018.3465195.14509994354240338307.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118152415.1232039.6452879415814850025.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161048194.2537118.13763612220937637316.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340411602.1303470.4661108879482218408.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539555629.286939.5241869986617154517.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653811456.2770958.7017388543246759245.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789095005.6155.6789055030327407928.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:17:27 +01:00
David Howells
c450846461 afs: Set up the iov_iter before calling afs_extract_data()
afs_extract_data() sets up a temporary iov_iter and passes it to AF_RXRPC
each time it is called to describe the remaining buffer to be filled.

Instead:

 (1) Put an iterator in the afs_call struct.

 (2) Set the iterator for each marshalling stage to load data into the
     appropriate places.  A number of convenience functions are provided to
     this end (eg. afs_extract_to_buf()).

     This iterator is then passed to afs_extract_data().

 (3) Use the new ITER_XARRAY iterator when reading data to load directly
     into the inode's pages without needing to create a list of them.

This will allow O_DIRECT calls to be supported in future patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/152898380012.11616.12094591785228251717.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/153685394431.14766.3178466345696987059.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/153999787395.866.11218209749223643998.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/154033911195.12041.3882700371848894587.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/158861250059.340223.1248231474865140653.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/159465827399.1377938.11181327349704960046.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/160588533776.3465195.3612752083351956948.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118151238.1232039.17015723405750601161.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161047240.2537118.14721975104810564022.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340410333.1303470.16260122230371140878.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539554187.286939.15305559004905459852.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653810525.2770958.4630666029125411789.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789093719.6155.7877160739235087723.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:17:27 +01:00
David Howells
c69bf479ba afs: Move key to afs_read struct
Stash the key used to authenticate read operations in the afs_read struct.
This will be necessary to reissue the operation against the server if a
read from the cache fails in upcoming cache changes.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/158861248336.340223.1851189950710196001.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/159465823899.1377938.11925978022348532049.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/160588529557.3465195.7303323479305254243.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118147693.1232039.13780672951838643842.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161043340.2537118.511899217704140722.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340406678.1303470.12676824086429446370.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539550819.286939.1268332875889175195.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653806683.2770958.11300984379283401542.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789089556.6155.14603302893431820997.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:17:26 +01:00
David Howells
67d78a6f6e afs: Pass page into dirty region helpers to provide THP size
Pass a pointer to the page being accessed into the dirty region helpers so
that the size of the page can be determined in case it's a transparent huge
page.

This also required the page to be passed into the afs_page_dirty trace
point - so there's no need to specifically pass in the index or private
data as these can be retrieved directly from the page struct.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/160588527183.3465195.16107942526481976308.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118144921.1232039.11377711180492625929.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161040747.2537118.11435394902674511430.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340404553.1303470.11414163641767769882.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539548385.286939.8864598314493255313.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653804285.2770958.3497360004849598038.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789087043.6155.16922142208140170528.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:17:26 +01:00
David Howells
03ffae9092 afs: Disable use of the fscache I/O routines
Disable use of the fscache I/O routined by the AFS filesystem.  It's about
to transition to passing iov_iters down and fscache is about to have its
I/O path to use iov_iter, so all that needs to change.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/158861209824.340223.1864211542341758994.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/159465768717.1376105.2229314852486665807.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/160588457929.3465195.1730097418904945578.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118143744.1232039.2727898205333669064.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161039077.2537118.7986870854927176905.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340403323.1303470.8159439948319423431.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539547167.286939.3536238932531122332.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653802797.2770958.547311814861545911.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789085806.6155.2596146255056027428.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:17:25 +01:00
Matthew Wilcox (Oracle)
75b6979961 afs: Use wait_on_page_writeback_killable
Open-coding this function meant it missed out on the recent bugfix
for waiters being woken by a delayed wake event from a previous
instantiation of the page[1].

[DH: Changed the patch to use vmf->page rather than variable page which
 doesn't exist yet upstream]

Fixes: 1cf7a1518a ("afs: Implement shared-writeable mmap")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: kafs-testing@auristor.com
cc: linux-afs@lists.infradead.org
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20210320054104.1300774-4-willy@infradead.org
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c2407cf7d22d0c0d94cf20342b3b8f06f1d904e7 [1]
2021-03-23 20:54:37 +00:00
David Howells
3ad216ee73 afs: Fix afs_write_end() when called with copied == 0 [ver #3]
When afs_write_end() is called with copied == 0, it tries to set the
dirty region, but there's no way to actually encode a 0-length region in
the encoding in page->private.

"0,0", for example, indicates a 1-byte region at offset 0.  The maths
miscalculates this and sets it incorrectly.

Fix it to just do nothing but unlock and put the page in this case.  We
don't actually need to mark the page dirty as nothing presumably
changed.

Fixes: 65dd2d6072 ("afs: Alter dirty range encoding in page->private")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-14 11:51:18 -08:00
David Howells
2d9900f26a afs: Fix dirty-region encoding on ppc32 with 64K pages
The dirty region bounds stored in page->private on an afs page are 15 bits
on a 32-bit box and can, at most, represent a range of up to 32K within a
32K page with a resolution of 1 byte.  This is a problem for powerpc32 with
64K pages enabled.

Further, transparent huge pages may get up to 2M, which will be a problem
for the afs filesystem on all 32-bit arches in the future.

Fix this by decreasing the resolution.  For the moment, a 64K page will
have a resolution determined from PAGE_SIZE.  In the future, the page will
need to be passed in to the helper functions so that the page size can be
assessed and the resolution determined dynamically.

Note that this might not be the ideal way to handle this, since it may
allow some leakage of undirtied zero bytes to the server's copy in the case
of a 3rd-party conflict.  Fixing that would require a separately allocated
record and is a more complicated fix.

Fixes: 4343d00872 ("afs: Get rid of the afs_writeback record")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-10-29 13:53:04 +00:00
David Howells
f86726a69d afs: Fix afs_invalidatepage to adjust the dirty region
Fix afs_invalidatepage() to adjust the dirty region recorded in
page->private when truncating a page.  If the dirty region is entirely
removed, then the private data is cleared and the page dirty state is
cleared.

Without this, if the page is truncated and then expanded again by truncate,
zeros from the expanded, but no-longer dirty region may get written back to
the server if the page gets laundered due to a conflicting 3rd-party write.

It mustn't, however, shorten the dirty region of the page if that page is
still mmapped and has been marked dirty by afs_page_mkwrite(), so a flag is
stored in page->private to record this.

Fixes: 4343d00872 ("afs: Get rid of the afs_writeback record")
Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-29 13:53:04 +00:00
David Howells
65dd2d6072 afs: Alter dirty range encoding in page->private
Currently, page->private on an afs page is used to store the range of
dirtied data within the page, where the range includes the lower bound, but
excludes the upper bound (e.g. 0-1 is a range covering a single byte).

This, however, requires a superfluous bit for the last-byte bound so that
on a 4KiB page, it can say 0-4096 to indicate the whole page, the idea
being that having both numbers the same would indicate an empty range.
This is unnecessary as the PG_private bit is clear if it's an empty range
(as is PG_dirty).

Alter the way the dirty range is encoded in page->private such that the
upper bound is reduced by 1 (e.g. 0-0 is then specified the same single
byte range mentioned above).

Applying this to both bounds frees up two bits, one of which can be used in
a future commit.

This allows the afs filesystem to be compiled on ppc32 with 64K pages;
without this, the following warnings are seen:

../fs/afs/internal.h: In function 'afs_page_dirty_to':
../fs/afs/internal.h:881:15: warning: right shift count >= width of type [-Wshift-count-overflow]
  881 |  return (priv >> __AFS_PAGE_PRIV_SHIFT) & __AFS_PAGE_PRIV_MASK;
      |               ^~
../fs/afs/internal.h: In function 'afs_page_dirty':
../fs/afs/internal.h:886:28: warning: left shift count >= width of type [-Wshift-count-overflow]
  886 |  return ((unsigned long)to << __AFS_PAGE_PRIV_SHIFT) | from;
      |                            ^~

Fixes: 4343d00872 ("afs: Get rid of the afs_writeback record")
Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-29 13:53:04 +00:00
David Howells
185f0c7073 afs: Wrap page->private manipulations in inline functions
The afs filesystem uses page->private to store the dirty range within a
page such that in the event of a conflicting 3rd-party write to the server,
we write back just the bits that got changed locally.

However, there are a couple of problems with this:

 (1) I need a bit to note if the page might be mapped so that partial
     invalidation doesn't shrink the range.

 (2) There aren't necessarily sufficient bits to store the entire range of
     data altered (say it's a 32-bit system with 64KiB pages or transparent
     huge pages are in use).

So wrap the accesses in inline functions so that future commits can change
how this works.

Also move them out of the tracing header into the in-directory header.
There's not really any need for them to be in the tracing header.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-29 13:53:04 +00:00
David Howells
f792e3ac82 afs: Fix where page->private is set during write
In afs, page->private is set to indicate the dirty region of a page.  This
is done in afs_write_begin(), but that can't take account of whether the
copy into the page actually worked.

Fix this by moving the change of page->private into afs_write_end().

Fixes: 4343d00872 ("afs: Get rid of the afs_writeback record")
Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-29 13:53:04 +00:00
David Howells
21db2cdc66 afs: Fix page leak on afs_write_begin() failure
Fix the leak of the target page in afs_write_begin() when it fails.

Fixes: 15b4650e55 ("afs: convert to new aops")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Nick Piggin <npiggin@gmail.com>
2020-10-29 13:53:04 +00:00
David Howells
fa04a40b16 afs: Fix to take ref on page when PG_private is set
Fix afs to take a ref on a page when it sets PG_private on it and to drop
the ref when removing the flag.

Note that in afs_write_begin(), a lot of the time, PG_private is already
set on a page to which we're going to add some data.  In such a case, we
leave the bit set and mustn't increment the page count.

As suggested by Matthew Wilcox, use attach/detach_page_private() where
possible.

Fixes: 31143d5d51 ("AFS: implement basic file write support")
Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-10-29 13:53:04 +00:00
David Howells
d383e346f9 afs: Fix afs_launder_page to not clear PG_writeback
Fix afs_launder_page() to not clear PG_writeback on the page it is
laundering as the flag isn't set in this case.

Fixes: 4343d00872 ("afs: Get rid of the afs_writeback record")
Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-27 22:05:56 +00:00
David Howells
ec0fa0b659 afs: Fix deadlock between writeback and truncate
The afs filesystem has a lock[*] that it uses to serialise I/O operations
going to the server (vnode->io_lock), as the server will only perform one
modification operation at a time on any given file or directory.  This
prevents the the filesystem from filling up all the call slots to a server
with calls that aren't going to be executed in parallel anyway, thereby
allowing operations on other files to obtain slots.

  [*] Note that is probably redundant for directories at least since
      i_rwsem is used to serialise directory modifications and
      lookup/reading vs modification.  The server does allow parallel
      non-modification ops, however.

When a file truncation op completes, we truncate the in-memory copy of the
file to match - but we do it whilst still holding the io_lock, the idea
being to prevent races with other operations.

However, if writeback starts in a worker thread simultaneously with
truncation (whilst notify_change() is called with i_rwsem locked, writeback
pays it no heed), it may manage to set PG_writeback bits on the pages that
will get truncated before afs_setattr_success() manages to call
truncate_pagecache().  Truncate will then wait for those pages - whilst
still inside io_lock:

    # cat /proc/8837/stack
    [<0>] wait_on_page_bit_common+0x184/0x1e7
    [<0>] truncate_inode_pages_range+0x37f/0x3eb
    [<0>] truncate_pagecache+0x3c/0x53
    [<0>] afs_setattr_success+0x4d/0x6e
    [<0>] afs_wait_for_operation+0xd8/0x169
    [<0>] afs_do_sync_operation+0x16/0x1f
    [<0>] afs_setattr+0x1fb/0x25d
    [<0>] notify_change+0x2cf/0x3c4
    [<0>] do_truncate+0x7f/0xb2
    [<0>] do_sys_ftruncate+0xd1/0x104
    [<0>] do_syscall_64+0x2d/0x3a
    [<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

The writeback operation, however, stalls indefinitely because it needs to
get the io_lock to proceed:

    # cat /proc/5940/stack
    [<0>] afs_get_io_locks+0x58/0x1ae
    [<0>] afs_begin_vnode_operation+0xc7/0xd1
    [<0>] afs_store_data+0x1b2/0x2a3
    [<0>] afs_write_back_from_locked_page+0x418/0x57c
    [<0>] afs_writepages_region+0x196/0x224
    [<0>] afs_writepages+0x74/0x156
    [<0>] do_writepages+0x2d/0x56
    [<0>] __writeback_single_inode+0x84/0x207
    [<0>] writeback_sb_inodes+0x238/0x3cf
    [<0>] __writeback_inodes_wb+0x68/0x9f
    [<0>] wb_writeback+0x145/0x26c
    [<0>] wb_do_writeback+0x16a/0x194
    [<0>] wb_workfn+0x74/0x177
    [<0>] process_one_work+0x174/0x264
    [<0>] worker_thread+0x117/0x1b9
    [<0>] kthread+0xec/0xf1
    [<0>] ret_from_fork+0x1f/0x30

and thus deadlock has occurred.

Note that whilst afs_setattr() calls filemap_write_and_wait(), the fact
that the caller is holding i_rwsem doesn't preclude more pages being
dirtied through an mmap'd region.

Fix this by:

 (1) Use the vnode validate_lock to mediate access between afs_setattr()
     and afs_writepages():

     (a) Exclusively lock validate_lock in afs_setattr() around the whole
     	 RPC operation.

     (b) If WB_SYNC_ALL isn't set on entry to afs_writepages(), trying to
     	 shared-lock validate_lock and returning immediately if we couldn't
     	 get it.

     (c) If WB_SYNC_ALL is set, wait for the lock.

     The validate_lock is also used to validate a file and to zap its cache
     if the file was altered by a third party, so it's probably a good fit
     for this.

 (2) Move the truncation outside of the io_lock in setattr, using the same
     hook as is used for local directory editing.

     This requires the old i_size to be retained in the operation record as
     we commit the revised status to the inode members inside the io_lock
     still, but we still need to know if we reduced the file size.

Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-08 10:50:55 -07:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
David Howells
811f04bac1 afs: Fix interruption of operations
The afs filesystem driver allows unstarted operations to be cancelled by
signal, but most of these can easily be restarted (mkdir for example).  The
primary culprits for reproducing this are those applications that use
SIGALRM to display a progress counter.

File lock-extension operation is marked uninterruptible as we have a
limited time in which to do it, and the release op is marked
uninterruptible also as if we fail to unlock a file, we'll have to wait 20
mins before anyone can lock it again.

The store operation logs a warning if it gets interruption, e.g.:

	kAFS: Unexpected error from FS.StoreData -4

because it's run from the background - but it can also be run from
fdatasync()-type things.  However, store options aren't marked
interruptible at the moment.

Fix this in the following ways:

 (1) Mark store operations as uninterruptible.  It might make sense to
     relax this for certain situations, but I'm not sure how to make sure
     that background store ops aren't affected by signals to foreground
     processes that happen to trigger them.

 (2) In afs_get_io_locks(), where we're getting the serialisation lock for
     talking to the fileserver, return ERESTARTSYS rather than EINTR
     because a lot of the operations (e.g. mkdir) are restartable if we
     haven't yet started sending the op to the server.

Fixes: e49c7b2f6d ("afs: Build an abstraction around an "operation" concept")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-15 15:49:04 -07:00
David Howells
793fe82ee3 afs: Fix truncation issues and mmap writeback size
Fix the following issues:

 (1) Fix writeback to reduce the size of a store operation to i_size,
     effectively discarding the extra data.

     The problem comes when afs_page_mkwrite() records that a page is about
     to be modified by mmap().  It doesn't know what bits of the page are
     going to be modified, so it records the whole page as being dirty
     (this is stored in page->private as start and end offsets).

     Without this, the marshalling for the store to the server extends the
     size of the file to the end of the page (in afs_fs_store_data() and
     yfs_fs_store_data()).

 (2) Fix setattr to actually truncate the pagecache, thereby clearing
     the discarded part of a file.

 (3) Fix setattr to check that the new size is okay and to disable
     ATTR_SIZE if i_size wouldn't change.

 (4) Force i_size to be updated as the result of a truncate.

 (5) Don't truncate if ATTR_SIZE is not set.

 (6) Call pagecache_isize_extended() if the file was enlarged.

Note that truncate_set_size() isn't used because the setting of i_size is
done inside afs_vnode_commit_status() under the vnode->cb_lock.

Found with the generic/029 and generic/393 xfstests.

Fixes: 31143d5d51 ("AFS: implement basic file write support")
Fixes: 4343d00872 ("afs: Get rid of the afs_writeback record")
Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-15 15:41:02 +01:00
David Howells
da8d075512 afs: Concoct ctimes
The in-kernel afs filesystem ignores ctime because the AFS fileserver
protocol doesn't support ctimes.  This, however, causes various xfstests to
fail.

Work around this by:

 (1) Setting ctime to attr->ia_ctime in afs_setattr().

 (2) Not ignoring ATTR_MTIME_SET, ATTR_TIMES_SET and ATTR_TOUCH settings.

 (3) Setting the ctime from the server mtime when on the target file when
     creating a hard link to it.

 (4) Setting the ctime on directories from their revised mtimes when
     renaming/moving a file.

Found by the generic/221 and generic/309 xfstests.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-15 15:41:02 +01:00
David Howells
1f32ef7989 afs: afs_write_end() should change i_size under the right lock
Fix afs_write_end() to change i_size under vnode->cb_lock rather than
->wb_lock so that it doesn't race with afs_vnode_commit_status() and
afs_getattr().

The ->wb_lock is only meant to guard access to ->wb_keys which isn't
accessed by that piece of code.

Fixes: 4343d00872 ("afs: Get rid of the afs_writeback record")
Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-15 15:41:02 +01:00
David Howells
bb41348928 afs: Fix non-setting of mtime when writing into mmap
The mtime on an inode needs to be updated when a write is made into an
mmap'ed section.  There are three ways in which this could be done: update
it when page_mkwrite is called, update it when a page is changed from dirty
to writeback or leave it to the server and fix the mtime up from the reply
to the StoreData RPC.

Found with the generic/215 xfstest.

Fixes: 1cf7a1518a ("afs: Implement shared-writeable mmap")
Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-15 15:41:02 +01:00
David Howells
b3597945c8 afs: Fix afs_store_data() to set mtime in new operation descriptor
Fix afs_store_data() so that it sets the mtime in the new operation
descriptor otherwise the mtime on the server gets set to 0 when a write is
stored to the server.

Fixes: e49c7b2f6d ("afs: Build an abstraction around an "operation" concept")
Reported-by: Dave Botsch <botsch@cnf.cornell.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-11 16:04:30 -07:00
David Howells
e49c7b2f6d afs: Build an abstraction around an "operation" concept
Turn the afs_operation struct into the main way that most fileserver
operations are managed.  Various things are added to the struct, including
the following:

 (1) All the parameters and results of the relevant operations are moved
     into it, removing corresponding fields from the afs_call struct.
     afs_call gets a pointer to the op.

 (2) The target volume is made the main focus of the operation, rather than
     the target vnode(s), and a bunch of op->vnode->volume are made
     op->volume instead.

 (3) Two vnode records are defined (op->file[]) for the vnode(s) involved
     in most operations.  The vnode record (struct afs_vnode_param)
     contains:

	- The vnode pointer.

	- The fid of the vnode to be included in the parameters or that was
          returned in the reply (eg. FS.MakeDir).

	- The status and callback information that may be returned in the
     	  reply about the vnode.

	- Callback break and data version tracking for detecting
          simultaneous third-parth changes.

 (4) Pointers to dentries to be updated with new inodes.

 (5) An operations table pointer.  The table includes pointers to functions
     for issuing AFS and YFS-variant RPCs, handling the success and abort
     of an operation and handling post-I/O-lock local editing of a
     directory.

To make this work, the following function restructuring is made:

 (A) The rotation loop that issues calls to fileservers that can be found
     in each function that wants to issue an RPC (such as afs_mkdir()) is
     extracted out into common code, in a new file called fs_operation.c.

 (B) The rotation loops, such as the one in afs_mkdir(), are replaced with
     a much smaller piece of code that allocates an operation, sets the
     parameters and then calls out to the common code to do the actual
     work.

 (C) The code for handling the success and failure of an operation are
     moved into operation functions (as (5) above) and these are called
     from the core code at appropriate times.

 (D) The pseudo inode getting stuff used by the dynamic root code is moved
     over into dynroot.c.

 (E) struct afs_iget_data is absorbed into the operation struct and
     afs_iget() expects to be given an op pointer and a vnode record.

 (F) Point (E) doesn't work for the root dir of a volume, but we know the
     FID in advance (it's always vnode 1, unique 1), so a separate inode
     getter, afs_root_iget(), is provided to special-case that.

 (G) The inode status init/update functions now also take an op and a vnode
     record.

 (H) The RPC marshalling functions now, for the most part, just take an
     afs_operation struct as their only argument.  All the data they need
     is held there.  The result delivery functions write their answers
     there as well.

 (I) The call is attached to the operation and then the operation core does
     the waiting.

And then the new operation code is, for the moment, made to just initialise
the operation, get the appropriate vnode I/O locks and do the same rotation
loop as before.

This lays the foundation for the following changes in the future:

 (*) Overhauling the rotation (again).

 (*) Support for asynchronous I/O, where the fileserver rotation must be
     done asynchronously also.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-04 15:37:17 +01:00
David Howells
a310082f6d afs: Rename struct afs_fs_cursor to afs_operation
As a prelude to implementing asynchronous fileserver operations in the afs
filesystem, rename struct afs_fs_cursor to afs_operation.

This struct is going to form the core of the operation management and is
going to acquire more members in later.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31 15:19:52 +01:00
Linus Torvalds
8dda9957e3 AFS development
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Merge tag 'afs-next-20190628' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull afs updates from David Howells:
 "A set of minor changes for AFS:

   - Remove an unnecessary check in afs_unlink()

   - Add a tracepoint for tracking callback management

   - Add a tracepoint for afs_server object usage

   - Use struct_size()

   - Add mappings for AFS UAE abort codes to Linux error codes, using
     symbolic names rather than hex numbers in the .c file"

* tag 'afs-next-20190628' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Add support for the UAE error table
  fs/afs: use struct_size() in kzalloc()
  afs: Trace afs_server usage
  afs: Add some callback management tracepoints
  afs: afs_unlink() doesn't need to check dentry->d_inode
2019-07-10 20:55:33 -07:00
Zhengyuan Liu
ee102584ef 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>
2019-06-20 18:12:17 +01:00
Thomas Gleixner
2874c5fd28 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>
2019-05-30 11:26:32 -07:00
David Howells
a58823ac45 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: c435ee3455 ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:21 +01:00
David Howells
20b8391fff 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: d2ddc776a4 ("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>
2019-05-16 16:25:20 +01:00
Marc Dionne
21bd68f196 afs: Unlock pages for __pagevec_release()
__pagevec_release() complains loudly if any page in the vector is still
locked.  The pages need to be locked for generic_error_remove_page(), but
that function doesn't actually unlock them.

Unlock the pages afterwards.

Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Jonathan Billings <jsbillin@umich.edu>
2019-04-13 08:37:37 +01:00
David Howells
3b6492df41 afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS
Increase the sizes of the volume ID to 64 bits and the vnode ID (inode
number equivalent) to 96 bits to allow the support of YFS.

This requires the iget comparator to check the vnode->fid rather than i_ino
and i_generation as i_ino is not sufficiently capacious.  It also requires
this data to be placed into the vnode cache key for fscache.

For the moment, just discard the top 32 bits of the vnode ID when returning
it though stat.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
2a0b4f64c9 afs: Don't invoke the server to read data beyond EOF
When writing a new page, clear space in the page rather than attempting to
load it from the server if the space is beyond the EOF.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
f51375cd9e afs: Add a couple of tracepoints to log I/O errors
Add a couple of tracepoints to log the production of I/O errors within the AFS
filesystem.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00