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  1. Apr 09, 2018
    • David Howells's avatar
      afs: Rearrange status mapping · dd9fbcb8
      David Howells authored 
      

Rearrange the AFSFetchStatus to inode attribute mapping code in a number of
ways:

 (1) Use an XDR structure rather than a series of incremented pointer
     accesses when decoding an AFSFetchStatus object.  This allows
     out-of-order decode.

 (2) Don't store the if_version value but rather just check it and abort if
     it's not something we can handle.

 (3) Store the owner and group in the status record as raw values rather
     than converting them to kuid/kgid.  Do that when they're mapped into
     i_uid/i_gid.

 (4) Validate the type and abort code up front and abort if they're wrong.

 (5) Split the inode attribute setting out into its own function from the
     XDR decode of an AFSFetchStatus object.  This allows it to be called
     from elsewhere too.

 (6) Differentiate changes to data from changes to metadata.

 (7) Use the split-out attribute mapping function from afs_iget().

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      dd9fbcb8
    • David Howells's avatar
      afs: Make it possible to get the data version in readpage · 0c3a5ac2
      David Howells authored 
      

Store the data version number indicated by an FS.FetchData op into the read
request structure so that it's accessible by the page reader.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      0c3a5ac2
    • David Howells's avatar
      afs: Init inode before accessing cache · 5800db81
      David Howells authored 
      

We no longer parse symlinks when we get the inode to determine if this
symlink is actually a mountpoint as we detect that by examining the mode
instead (symlinks are always 0777 and mountpoints 0644).

Access the cache after mapping the status so that we don't have to manually
set the inode size now.

Note that this may need adjusting if the disconnected operation is
implemented as the file metadata may have to be obtained from the cache.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      5800db81
    • David Howells's avatar
      afs: Introduce a statistics proc file · d55b4da4
      David Howells authored 
      

Introduce a proc file that displays a bunch of statistics for the AFS
filesystem in the current network namespace.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      d55b4da4
    • David Howells's avatar
      afs: Dump bad status record · 888b3384
      David Howells authored 
      

Dump an AFS FileStatus record that is detected as invalid.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      888b3384
    • David Howells's avatar
      afs: Implement @cell substitution handling · 37ab6368
      David Howells authored 
      

Implement @cell substitution handling such that if @cell is seen as a name
in a dynamic root mount, then the name of the root cell for that network
namespace will be substituted for @cell during lookup.

The substitution of @cell for the current net namespace is set by writing
the cell name to /proc/fs/afs/rootcell.  The value can be obtained by
reading the file.

For example:

	# mount -t afs none /kafs -o dyn
	# echo grand.central.org >/proc/fs/afs/rootcell
	# ls /kafs/@cell
	archive/  cvs/  doc/  local/  project/  service/  software/  user/  www/
	# cat /proc/fs/afs/rootcell
	grand.central.org

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      37ab6368
    • David Howells's avatar
      afs: Implement @sys substitution handling · 6f8880d8
      David Howells authored 
      

Implement the AFS feature by which @sys at the end of a pathname component
may be substituted for one of a list of values, typically naming the
operating system.  Up to 16 alternatives may be specified and these are
tried in turn until one works.  Each network namespace has[*] a separate
independent list.

Upon creation of a new network namespace, the list of values is
initialised[*] to a single OpenAFS-compatible string representing arch type
plus "_linux26".  For example, on x86_64, the sysname is "amd64_linux26".

[*] Or will, once network namespace support is finalised in kAFS.

The list may be set by:

	# for i in foo bar linux-x86_64; do echo $i; done >/proc/fs/afs/sysname

for which separate writes to the same fd are amalgamated and applied on
close.  The LF character may be used as a separator to specify multiple
items in the same write() call.

The list may be cleared by:

	# echo >/proc/fs/afs/sysname

and read by:

	# cat /proc/fs/afs/sysname
	foo
	bar
	linux-x86_64

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      6f8880d8
    • David Howells's avatar
      afs: Prospectively look up extra files when doing a single lookup · 5cf9dd55
      David Howells authored 
      

When afs_lookup() is called, prospectively look up the next 50 uncached
fids also from that same directory and cache the results, rather than just
looking up the one file requested.

This allows us to use the FS.InlineBulkStatus RPC op to increase efficiency
by fetching up to 50 file statuses at a time.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      5cf9dd55
    • David Howells's avatar
      afs: Don't over-increment the cell usage count when pinning it · 17814aef
      David Howells authored 
      

AFS cells that are added or set as the workstation cell through /proc are
pinned against removal by setting the AFS_CELL_FL_NO_GC flag on them and
taking a ref.  The ref should be only taken if the flag wasn't already set.

Fix this by making it conditional.

Without this an assertion failure will occur during module removal
indicating that the refcount is too elevated.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      17814aef
    • David Howells's avatar
      afs: Fix checker warnings · fe342cf7
      David Howells authored 
      

Fix warnings raised by checker, including:

 (*) Warnings raised by unequal comparison for the purposes of sorting,
     where the endianness doesn't matter:

fs/afs/addr_list.c:246:21: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:246:30: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:248:21: warning: restricted __be32 degrades to integer
fs/afs/addr_list.c:248:49: warning: restricted __be32 degrades to integer
fs/afs/addr_list.c:283:21: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:283:30: warning: restricted __be16 degrades to integer

 (*) afs_set_cb_interest() is not actually used and can be removed.

 (*) afs_cell_gc_delay() should be provided with a sysctl.

 (*) afs_cell_destroy() needs to use rcu_access_pointer() to read
     cell->vl_addrs.

 (*) afs_init_fs_cursor() should be static.

 (*) struct afs_vnode::permit_cache needs to be marked __rcu.

 (*) afs_server_rcu() needs to use rcu_access_pointer().

 (*) afs_destroy_server() should use rcu_access_pointer() on
     server->addresses as the server object is no longer accessible.

 (*) afs_find_server() casts __be16/__be32 values to int in order to
     directly compare them for the purpose of finding a match in a list,
     but is should also annotate the cast with __force to avoid checker
     warnings.

 (*) afs_check_permit() accesses vnode->permit_cache outside of the RCU
     readlock, though it doesn't then access the value; the extraneous
     access is deleted.

False positives:

 (*) Conditional locking around the code in xdr_decode_AFSFetchStatus.  This
     can be dealt with in a separate patch.

fs/afs/fsclient.c:148:9: warning: context imbalance in 'xdr_decode_AFSFetchStatus' - different lock contexts for basic block

 (*) Incorrect handling of seq-retry lock context balance:

fs/afs/inode.c:455:38: warning: context imbalance in 'afs_getattr' - different
lock contexts for basic block
fs/afs/server.c:52:17: warning: context imbalance in 'afs_find_server' - different lock contexts for basic block
fs/afs/server.c:128:17: warning: context imbalance in 'afs_find_server_by_uuid' - different lock contexts for basic block

Errors:

 (*) afs_lookup_cell_rcu() needs to break out of the seq-retry loop, not go
     round again if it successfully found the workstation cell.

 (*) Fix UUID decode in afs_deliver_cb_probe_uuid().

 (*) afs_cache_permit() has a missing rcu_read_unlock() before one of the
     jumps to the someone_else_changed_it label.  Move the unlock to after
     the label.

 (*) afs_vl_get_addrs_u() is using ntohl() rather than htonl() when
     encoding to XDR.

 (*) afs_deliver_yfsvl_get_endpoints() is using htonl() rather than ntohl()
     when decoding from XDR.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      fe342cf7
  3. Apr 08, 2018
  5. Apr 06, 2018