afs: Split the dynroot stuff out and give it its own ops tables

Split the AFS dynamic root stuff out of the main directory handling file
and into its own file as they share little in com

afs: Split the dynroot stuff out and give it its own ops tables

Split the AFS dynamic root stuff out of the main directory handling file
and into its own file as they share little in common.

The dynamic root code also gets its own dentry and inode ops tables.

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

show more ...

afs: Keep track of invalid-before version for dentry coherency

Each afs dentry is tagged with the version that the parent directory was at
last time it was validated and, currently, if t

afs: Keep track of invalid-before version for dentry coherency

Each afs dentry is tagged with the version that the parent directory was at
last time it was validated and, currently, if this differs, the directory
is scanned and the dentry is refreshed.

However, this leads to an excessive amount of revalidation on directories
that get modified on the client without conflict with another client. We
know there's no conflict because the parent directory's data version number
got incremented by exactly 1 on any create, mkdir, unlink, etc., therefore
we can trust the current state of the unaffected dentries when we perform a
local directory modification.

Optimise by keeping track of the last version of the parent directory that
was changed outside of the client in the parent directory's vnode and using
that to validate the dentries rather than the current version.

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

show more ...

afs: Introduce a statistics proc file

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

Signed-off-by: David How

afs: Introduce a statistics proc file

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

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

show more ...

afs: Implement @cell substitution handling

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 net

afs: Implement @cell substitution handling

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: David Howells <dhowells@redhat.com>

show more ...

afs: Implement @sys substitution handling

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

afs: Implement @sys substitution handling

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: David Howells <dhowells@redhat.com>

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afs: Prospectively look up extra files when doing a single lookup

When afs_lookup() is called, prospectively look up the next 50 uncached
fids also from that same directory and cache the

afs: Prospectively look up extra files when doing a single lookup

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: David Howells <dhowells@redhat.com>

show more ...

afs: Support the AFS dynamic root

Support the AFS dynamic root which is a pseudo-volume that doesn't connect
to any server resource, but rather is just a root directory that
dynamica

afs: Support the AFS dynamic root

Support the AFS dynamic root which is a pseudo-volume that doesn't connect
to any server resource, but rather is just a root directory that
dynamically creates mountpoint directories where the name of such a
directory is the name of the cell.

Such a mount can be created thus:

mount -t afs none /afs -o dyn

Dynamic root superblocks aren't shared except by bind mounts and
propagation. Cell root volumes can then be mounted by referring to them by
name, e.g.:

ls /afs/grand.central.org/
ls /afs/.grand.central.org/

The kernel will upcall to consult the DNS if the address wasn't supplied
directly.

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

show more ...

afs: Fix unlink

Repeating creation and deletion of a file on an afs mount will run the box
out of memory, e.g.:

dd if=/dev/zero of=/afs/scratch/m0 bs=$((1024*1024)) coun

afs: Fix unlink

Repeating creation and deletion of a file on an afs mount will run the box
out of memory, e.g.:

dd if=/dev/zero of=/afs/scratch/m0 bs=$((1024*1024)) count=512
rm /afs/scratch/m0

The problem seems to be that it's not properly decrementing the nlink count
so that the inode can be scrapped.

Note that this doesn't fix local creation followed by remote deletion.
That's harder to handle and will require a separate patch as we're not told
that the file has been deleted - only that the directory has changed.

Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

show more ...

afs: remove redundant assignment of dvnode to itself

The assignment of dvnode to itself is redundant and can be removed.
Cleans up warning detected by cppcheck:

fs/afs/dir.c:975

afs: remove redundant assignment of dvnode to itself

The assignment of dvnode to itself is redundant and can be removed.
Cleans up warning detected by cppcheck:

fs/afs/dir.c:975: (warning) Redundant assignment of 'dvnode' to itself.

Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David Howells <dhowells@redhat.com>

show more ...

afs: Fix signal handling in some file ops

afs_mkdir(), afs_create(), afs_link() and afs_symlink() all need to drop
the target dentry if a signal causes the operation to be killed immedia

afs: Fix signal handling in some file ops

afs_mkdir(), afs_create(), afs_link() and afs_symlink() all need to drop
the target dentry if a signal causes the operation to be killed immediately
before we try to contact the server.

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

show more ...

afs: Fix some dentry handling in dir ops and missing key_puts

Fix some of dentry handling in AFS directory ops:

(1) Do d_drop() on the new_dentry before assigning a new inode to it

afs: Fix some dentry handling in dir ops and missing key_puts

Fix some of dentry handling in AFS directory ops:

(1) Do d_drop() on the new_dentry before assigning a new inode to it in
afs_vnode_new_inode(). It's fine to do this before calling afs_iget()
because the operation has taken place on the server.

(2) Replace d_instantiate()/d_rehash() with d_add().

(3) Don't d_drop() the new_dentry in afs_rename() on error.

Also fix afs_link() and afs_rename() to call key_put() on all error paths
where the key is taken.

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

show more ...

afs: Introduce a file-private data record

Introduce a file-private data record for kAFS and put the key into it
rather than storing the key in file->private_data.

Signed-off-by:

afs: Introduce a file-private data record

Introduce a file-private data record for kAFS and put the key into it
rather than storing the key in file->private_data.

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

show more ...

afs: Fix directory read/modify race

Because parsing of the directory wasn't being done under any sort of lock,
the pages holding the directory content can get invalidated whilst the

afs: Fix directory read/modify race

Because parsing of the directory wasn't being done under any sort of lock,
the pages holding the directory content can get invalidated whilst the
parsing is ongoing.

Further, the directory page check function gets called outside of the page
lock, so if the page gets cleared or updated, this may return reports of
bad magic numbers in the directory page.

Also, the directory may change size whilst checking and parsing are
ongoing, so more care needs to be taken here.

Fix this by:

(1) Perform the page check from the page filling function before we set
PageUptodate and drop the page lock.

(2) Check for the file having shrunk and the page having been abandoned
before checking the page contents.

(3) Lock the page whilst parsing it for the directory iterator.

Whilst we're at it, add a tracepoint to report check failure.

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

show more ...

afs: Overhaul volume and server record caching and fileserver rotation

The current code assumes that volumes and servers are per-cell and are
never shared, but this is not enforced, and,

afs: Overhaul volume and server record caching and fileserver rotation

The current code assumes that volumes and servers are per-cell and are
never shared, but this is not enforced, and, indeed, public cells do exist
that are aliases of each other. Further, an organisation can, say, set up
a public cell and a private cell with overlapping, but not identical, sets
of servers. The difference is purely in the database attached to the VL
servers.

The current code will malfunction if it sees a server in two cells as it
assumes global address -> server record mappings and that each server is in
just one cell.

Further, each server may have multiple addresses - and may have addresses
of different families (IPv4 and IPv6, say).

To this end, the following structural changes are made:

(1) Server record management is overhauled:

(a) Server records are made independent of cell. The namespace keeps
track of them, volume records have lists of them and each vnode
has a server on which its callback interest currently resides.

(b) The cell record no longer keeps a list of servers known to be in
that cell.

(c) The server records are now kept in a flat list because there's no
single address to sort on.

(d) Server records are now keyed by their UUID within the namespace.

(e) The addresses for a server are obtained with the VL.GetAddrsU
rather than with VL.GetEntryByName, using the server's UUID as a
parameter.

(f) Cached server records are garbage collected after a period of
non-use and are counted out of existence before purging is allowed
to complete. This protects the work functions against rmmod.

(g) The servers list is now in /proc/fs/afs/servers.

(2) Volume record management is overhauled:

(a) An RCU-replaceable server list is introduced. This tracks both
servers and their coresponding callback interests.

(b) The superblock is now keyed on cell record and numeric volume ID.

(c) The volume record is now tied to the superblock which mounts it,
and is activated when mounted and deactivated when unmounted.
This makes it easier to handle the cache cookie without causing a
double-use in fscache.

(d) The volume record is loaded from the VLDB using VL.GetEntryByNameU
to get the server UUID list.

(e) The volume name is updated if it is seen to have changed when the
volume is updated (the update is keyed on the volume ID).

(3) The vlocation record is got rid of and VLDB records are no longer
cached. Sufficient information is stored in the volume record, though
an update to a volume record is now no longer shared between related
volumes (volumes come in bundles of three: R/W, R/O and backup).

and the following procedural changes are made:

(1) The fileserver cursor introduced previously is now fleshed out and
used to iterate over fileservers and their addresses.

(2) Volume status is checked during iteration, and the server list is
replaced if a change is detected.

(3) Server status is checked during iteration, and the address list is
replaced if a change is detected.

(4) The abort code is saved into the address list cursor and -ECONNABORTED
returned in afs_make_call() if a remote abort happened rather than
translating the abort into an error message. This allows actions to
be taken depending on the abort code more easily.

(a) If a VMOVED abort is seen then this is handled by rechecking the
volume and restarting the iteration.

(b) If a VBUSY, VRESTARTING or VSALVAGING abort is seen then this is
handled by sleeping for a short period and retrying and/or trying
other servers that might serve that volume. A message is also
displayed once until the condition has cleared.

(c) If a VOFFLINE abort is seen, then this is handled as VBUSY for the
moment.

(d) If a VNOVOL abort is seen, the volume is rechecked in the VLDB to
see if it has been deleted; if not, the fileserver is probably
indicating that the volume couldn't be attached and needs
salvaging.

(e) If statfs() sees one of these aborts, it does not sleep, but
rather returns an error, so as not to block the umount program.

(5) The fileserver iteration functions in vnode.c are now merged into
their callers and more heavily macroised around the cursor. vnode.c
is removed.

(6) Operations on a particular vnode are serialised on that vnode because
the server will lock that vnode whilst it operates on it, so a second
op sent will just have to wait.

(7) Fileservers are probed with FS.GetCapabilities before being used.
This is where service upgrade will be done.

(8) A callback interest on a fileserver is set up before an FS operation
is performed and passed through to afs_make_call() so that it can be
set on the vnode if the operation returns a callback. The callback
interest is passed through to afs_iget() also so that it can be set
there too.

In general, record updating is done on an as-needed basis when we try to
access servers, volumes or vnodes rather than offloading it to work items
and special threads.

Notes:

(1) Pre AFS-3.4 servers are no longer supported, though this can be added
back if necessary (AFS-3.4 was released in 1998).

(2) VBUSY is retried forever for the moment at intervals of 1s.

(3) /proc/fs/afs/<cell>/servers no longer exists.

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

show more ...

afs: Overhaul the callback handling

Overhaul the AFS callback handling by the following means:

(1) Don't give up callback promises on vnodes that we are no longer using,
r

afs: Overhaul the callback handling

Overhaul the AFS callback handling by the following means:

(1) Don't give up callback promises on vnodes that we are no longer using,
rather let them just expire on the server or let the server break
them. This is actually more efficient for the server as the callback
lookup is expensive if there are lots of extant callbacks.

(2) Only give up the callback promises we have from a server when the
server record is destroyed. Then we can just give up *all* the
callback promises on it in one go.

(3) Servers can end up being shared between cells if cells are aliased, so
don't add all the vnodes being backed by a particular server into a
big FID-indexed tree on that server as there may be duplicates.

Instead have each volume instance (~= superblock) register an interest
in a server as it starts to make use of it and use this to allow the
processor for callbacks from the server to find the superblock and
thence the inode corresponding to the FID being broken by means of
ilookup_nowait().

(4) Rather than iterating over the entire callback list when a mass-break
comes in from the server, maintain a counter of mass-breaks in
afs_server (cb_seq) and make afs_validate() check it against the copy
in afs_vnode.

It would be nice not to have to take a read_lock whilst doing this,
but that's tricky without using RCU.

(5) Save a ref on the fileserver we're using for a call in the afs_call
struct so that we can access its cb_s_break during call decoding.

(6) Write-lock around callback and status storage in a vnode and read-lock
around getattr so that we don't see the status mid-update.

This has the following consequences:

(1) Data invalidation isn't seen until someone calls afs_validate() on a
vnode. Unfortunately, we need to use a key to query the server, but
getting one from a background thread is tricky without caching loads
of keys all over the place.

(2) Mass invalidation isn't seen until someone calls afs_validate().

(3) Callback breaking is going to hit the inode_hash_lock quite a bit.
Could this be replaced with rcu_read_lock() since inodes are destroyed
under RCU conditions.

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

show more ...

afs: Push the net ns pointer to more places

Push the network namespace pointer to more places in AFS, including the
afs_server structure (which doesn't hold a ref on the netns).

afs: Push the net ns pointer to more places

Push the network namespace pointer to more places in AFS, including the
afs_server structure (which doesn't hold a ref on the netns).

In particular, afs_put_cell() now takes requires a net ns parameter so that
it can safely alter the netns after decrementing the cell usage count - the
cell will be deallocated by a background thread after being cached for a
period, which means that it's not safe to access it after reducing its
usage count.

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

show more ...

afs: Add metadata xattrs

Add xattrs to allow the user to get/set metadata in lieu of having pioctl()
available. The following xattrs are now available:

- "afs.cell"

afs: Add metadata xattrs

Add xattrs to allow the user to get/set metadata in lieu of having pioctl()
available. The following xattrs are now available:

- "afs.cell"

The name of the cell in which the vnode's volume resides.

- "afs.fid"

The volume ID, vnode ID and vnode uniquifier of the file as three hex
numbers separated by colons.

- "afs.volume"

The name of the volume in which the vnode resides.

For example:

# getfattr -d -m ".*" /mnt/scratch
getfattr: Removing leading '/' from absolute path names
# file: mnt/scratch
afs.cell="mycell.myorg.org"
afs.fid="10000b:1:1"
afs.volume="scratch"

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

lib/vsprintf.c: remove %Z support

Now that %z is standartised in C99 there is no reason to support %Z.
Unlike %L it doesn't even make format strings smaller.

Use BUILD_BUG_ON in

lib/vsprintf.c: remove %Z support

Now that %z is standartised in C99 there is no reason to support %Z.
Unlike %L it doesn't even make format strings smaller.

Use BUILD_BUG_ON in a couple ATM drivers.

In case anyone didn't notice lib/vsprintf.o is about half of SLUB which
is in my opinion is quite an achievement. Hopefully this patch inspires
someone else to trim vsprintf.c more.

Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

fs: rename "rename2" i_op to "rename"

Generated patch:

sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2`
sed -i "s/\brename2\b/rename/g" `git grep -wl rename2`

fs: rename "rename2" i_op to "rename"

Generated patch:

sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2`
sed -i "s/\brename2\b/rename/g" `git grep -wl rename2`

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

show more ...

fs: make remaining filesystems use .rename2

This is trivial to do:

- add flags argument to foo_rename()
- check if flags is zero
- assign foo_rename() to .rename2 instead

fs: make remaining filesystems use .rename2

This is trivial to do:

- add flags argument to foo_rename()
- check if flags is zero
- assign foo_rename() to .rename2 instead of .rename

This doesn't mean it's impossible to support RENAME_NOREPLACE for these
filesystems, but it is not trivial, like for local filesystems.
RENAME_NOREPLACE must guarantee atomicity (i.e. it shouldn't be possible
for a file to be created on one host while it is overwritten by rename on
another host).

Filesystems converted:

9p, afs, ceph, coda, ecryptfs, kernfs, lustre, ncpfs, nfs, ocfs2, orangefs.

After this, we can get rid of the duplicate interfaces for rename.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: David Howells <dhowells@redhat.com> [AFS]
Acked-by: Mike Marshall <hubcap@omnibond.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Mark Fasheh <mfasheh@suse.com>

show more ...

afs: switch to ->iterate_shared()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

make ext2_get_page() and friends work without external serialization

Right now ext2_get_page() (and its analogues in a bunch of other filesystems)
relies upon the directory being locked

make ext2_get_page() and friends work without external serialization

Right now ext2_get_page() (and its analogues in a bunch of other filesystems)
relies upon the directory being locked - the way it sets and tests Checked and
Error bits would be racy without that. Switch to a slightly different scheme,
_not_ setting Checked in case of failure. That way the logics becomes
if Checked => OK
else if Error => fail
else if !validate => fail
else => OK
with validation setting Checked or Error on success and failure resp. and
returning which one had happened. Equivalent to the current logics, but unlike
the current logics not sensitive to the order of set_bit, test_bit getting
reordered by CPU, etc.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

show more ...

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possibl

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized. And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special. They are
not.

The changes are pretty straight-forward:

- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

- page_cache_get() -> get_page();

- page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

VFS: normal filesystems (and lustre): d_inode() annotations

that's the bulk of filesystem drivers dealing with inodes of their own

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

VFS: normal filesystems (and lustre): d_inode() annotations

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

show more ...

assorted conversions to %p[dD]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>