cifs_mark_tcp_ses_conns_for_reconnect helper function is now
meant to be used by any of the threads to mark a channel
(or all the channels) for reconnect.
Replace all such manual changes to tcpStatus to use this
helper function, which takes care that the right channels,
smb sessions and tcons are marked for reconnect.
Also includes one line minor change
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Recent restructuring of cifs_reconnect introduced a helper func
named cifs_ses_mark_for_reconnect, which updates the state of tcp
session for all the channels of a session for reconnect.
However, this does not update the session state and chans_need_reconnect
bitmask. This change fixes that.
Also, cifs_mark_tcp_sess_for_reconnect should mark set the bitmask
for all channels when the whole session is marked for reconnect.
Fixed that here too.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Use new cifs_ses_mark_for_reconnect() helper to mark all session
channels for reconnect instead of duplicating it in different places.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Mounting a dfs link that has nested links was already supported at
mount(2), so make it work over reconnect as well.
Make the following case work:
* mount //root/dfs/link /mnt -o ...
- final share: /server/share
* in server settings
- change target folder of /root/dfs/link3 to /server/share2
- change target folder of /root/dfs/link2 to /root/dfs/link3
- change target folder of /root/dfs/link to /root/dfs/link2
* mount -o remount,... /mnt
- refresh all dfs referrals
- mark current connection for failover
- cifs_reconnect() reconnects to root server
- tree_connect()
* checks that /root/dfs/link2 is a link, then chase it
* checks that root/dfs/link3 is a link, then chase it
* finally tree connect to /server/share2
If the mounted share is no longer accessible and a reconnect had been
triggered, the client will retry it from both last referral
path (/root/dfs/link3) and original referral path (/root/dfs/link).
Any new referral paths found while chasing dfs links over reconnect,
it will be updated to TCP_Server_Info::leaf_fullpath, accordingly.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reorder the parameters in seq_printf() to correctly print header
flags.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When remouting a DFS share, force a new DFS referral of the path and
if the currently cached targets do not match any of the new targets or
there was no cached targets, then mark it for reconnect.
For example:
$ mount //dom/dfs/link /mnt -o username=foo,password=bar
$ ls /mnt
oldfile.txt
change target share of 'link' in server settings
$ mount /mnt -o remount,username=foo,password=bar
$ ls /mnt
newfile.txt
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Interlink is a special type of DFS link that resolves to a different
DFS domain-based namespace. To determine whether it is an interlink
or not, check if ReferralServers and StorageServers bits are set to 1
and 0 respectively in ReferralHeaderFlags, as specified in MS-DFSC
3.1.5.4.5 Determining Whether a Referral Response is an Interlink.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When refreshing the DFS cache, keep SMB2 IOCTL calls as much outside
critical sections as possible and avoid read/write starvation when
getting new DFS referrals by using broken or slow connections.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We don't want to refresh the dfs cache in very short intervals, so
setting a minimum interval of 2 minutes is OK.
If it needs to be refreshed immediately, one could have the cache
cleared with
$ echo 0 > /proc/fs/cifs/dfscache
and then remounting the dfs share.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Fix cache lookup and hash calculations when handling paths with
different cases.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Convert all dfs paths to dfs cache's local codepage (@cache_cp) and
avoid mixing them with different charsets.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
At every mount, keep all sessions alive that were used for chasing the
DFS referrals as long as the dfs mounts are active.
Use those sessions in DFS cache to refresh all active tcons as well as
cached entries. They will be managed by a list of mount_group
structures that will be indexed by a randomly generated uuid at mount
time, so we can put all the sessions related to specific dfs mounts
and avoid leaking them.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
@noreq param isn't used anywhere, so just remove it.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
is_sysvol_or_netlogon() is never used, so can remove it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
As it is, it takes const char * and, in some cases, stores it in
caller's variable that is plain char *. Fortunately, none of the
callers actually proceeded to modify the string via now-non-const
alias, but that's trouble waiting to happen.
It's easy to do properly, anyway...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steve French <stfrench@microsoft.com>
strndup(s, strlen(s)) is a highly unidiomatic way to spell strdup(s);
it's *NOT* safer in any way, since strlen() is just as sensitive to
NUL-termination as strdup() is.
strndup() is for situations when you need a copy of a known-sized
substring, not a magic security juju to drive the bad spirits away.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steve French <stfrench@microsoft.com>
Some servers seem to mistakenly report different values for
capabilities and share flags, so we can't always rely on those values
to decide whether the resolved target can handle any new DFS
referrals.
Add a new helper is_referral_server() to check if all resolved targets
can handle new DFS referrals by directly looking at the
GET_DFS_REFERRAL.ReferralHeaderFlags value as specified in MS-DFSC
2.2.4 RESP_GET_DFS_REFERRAL in addition to is_tcon_dfs().
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org # 5.11
Signed-off-by: Steve French <stfrench@microsoft.com>
The new mount API requires additional changes to how DFS
is handled. Additional testing of DFS uncovered problems
with domain based DFS referrals (a follow on patch addresses
DFS links) which this patch addresses.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
clang static analysis reports this problem
dfs_cache.c:591:2: warning: Argument to kfree() is a constant address
(18446744073709551614), which is not memory allocated by malloc()
kfree(vi);
^~~~~~~~~
In dfs_cache_del_vol() the volume info pointer 'vi' being freed
is the return of a call to find_vol(). The large constant address
is find_vol() returning an error.
Add an error check to dfs_cache_del_vol() similar to the one done
in dfs_cache_update_vol().
Fixes: 54be1f6c1c ("cifs: Add DFS cache routines")
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
CC: <stable@vger.kernel.org> # v5.0+
Signed-off-by: Steve French <stfrench@microsoft.com>
and rename it to smb3_cleanup_fs_context[_content]
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
none of the callers use this argument any more.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
See Documentation/filesystems/mount_api.rst for details on new mount API
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Continue restructuring needed for support of new mount API
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Harmonize and change all such variables to 'ctx', where possible.
No changes to actual logic.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Merge misc updates from Andrew Morton:
- a few MM hotfixes
- kthread, tools, scripts, ntfs and ocfs2
- some of MM
Subsystems affected by this patch series: kthread, tools, scripts, ntfs,
ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan,
debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore,
sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
mm: vmscan: consistent update to pgrefill
mm/vmscan.c: fix typo
khugepaged: khugepaged_test_exit() check mmget_still_valid()
khugepaged: retract_page_tables() remember to test exit
khugepaged: collapse_pte_mapped_thp() protect the pmd lock
khugepaged: collapse_pte_mapped_thp() flush the right range
mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible
mm: thp: replace HTTP links with HTTPS ones
mm/page_alloc: fix memalloc_nocma_{save/restore} APIs
mm/page_alloc.c: skip setting nodemask when we are in interrupt
mm/page_alloc: fallbacks at most has 3 elements
mm/page_alloc: silence a KASAN false positive
mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask()
mm/page_alloc.c: simplify pageblock bitmap access
mm/page_alloc.c: extract the common part in pfn_to_bitidx()
mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits
mm/shuffle: remove dynamic reconfiguration
mm/memory_hotplug: document why shuffle_zone() is relevant
mm/page_alloc: remove nr_free_pagecache_pages()
mm: remove vm_total_pages
...
As said by Linus:
A symmetric naming is only helpful if it implies symmetries in use.
Otherwise it's actively misleading.
In "kzalloc()", the z is meaningful and an important part of what the
caller wants.
In "kzfree()", the z is actively detrimental, because maybe in the
future we really _might_ want to use that "memfill(0xdeadbeef)" or
something. The "zero" part of the interface isn't even _relevant_.
The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.
Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.
The renaming is done by using the command sequence:
git grep -w --name-only kzfree |\
xargs sed -i 's/kzfree/kfree_sensitive/'
followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.
[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use PathConsumed field when parsing prefixes of referral paths that
either match a cache entry or are a complete prefix path of an
existing entry.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When looking up the DFS cache with a referral path that has more than
two path components, and is a complete prefix of an existing cache
entry, do not request another referral and just return the matched
entry as specified in MS-DFSC 3.2.5.5 Receiving a Root Referral
Request or Link Referral Request.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Use pr_fmt to standardize all logging for fs/cifs.
Some logging output had no CIFS: specific prefix.
Now all output has one of three prefixes:
o CIFS:
o CIFS: VFS:
o Root-CIFS:
Miscellanea:
o Convert printks to pr_<level>
o Neaten macro definitions
o Remove embedded CIFS: prefixes from formats
o Convert "illegal" to "invalid"
o Coalesce formats
o Add missing '\n' format terminations
o Consolidate multiple cifs_dbg continuations into single calls
o More consistent use of upper case first word output logging
o Multiline statement argument alignment and wrapping
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
For the case where we have a DFS path like below and we're currently
connected to targetA:
//dfsroot/link -> //targetA/share/foo, //targetB/share/bar
after failover, we should make sure to update cifs_sb->prepath so the
next operations will use the new prefix path "/bar".
Besides, in order to simplify the use of different prefix paths,
enforce CIFS_MOUNT_USE_PREFIX_PATH for DFS mounts so we don't have to
revalidate the root dentry every time we set a new prefix path.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
PTR_ERR_OR_ZERO contains if(IS_ERR(...)) + PTR_ERR, just use
PTR_ERR_OR_ZERO directly.
Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
static analysis with Coverity detected an issue with the following
commit:
Author: Paulo Alcantara (SUSE) <pc@cjr.nz>
Date: Wed Dec 4 17:38:03 2019 -0300
cifs: Avoid doing network I/O while holding cache lock
Addresses-Coverity: ("Uninitialized pointer read")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
copy_ref_data() may return error, it should be
returned to upstream caller.
Fixes: 03535b72873b ("cifs: Avoid doing network I/O while holding cache lock")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When creating or updating a cache entry, we need to get an DFS
referral (get_dfs_referral), so avoid holding any locks during such
network operation.
To prevent that, do the following:
* change cache hashtable sync method from RCU sync to a read/write
lock.
* use GFP_ATOMIC in memory allocations.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
We can't acquire volume lock while refreshing the DFS cache because
cifs_reconnect() may call dfs_cache_update_vol() while we are walking
through the volume list.
To prevent that, make vol_info refcounted, create a temp list with all
volumes eligible for refreshing, and then use it without any locks
held.
Besides, replace vol_lock with a spinlock and protect cache_ttl from
concurrent accesses or changes.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Just do the trivial path validation in get_normalized_path().
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Add helpers for finding TCP connections that are good candidates for
being used by DFS refresh worker.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The DFS cache API is mostly used with heap allocated strings.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Do some renaming and code cleanup.
No functional changes.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We don't care about module aliasing validation in
cifs_compose_mount_options(..., is_smb3) when finding the root SMB
session of an DFS namespace in order to refresh DFS referral cache.
The following issue has been observed when mounting with '-t smb3' and
then specifying 'vers=2.0':
...
Nov 08 15:27:08 tw kernel: address conversion returned 0 for FS0.WIN.LOCAL
Nov 08 15:27:08 tw kernel: [kworke] ==> dns_query((null),FS0.WIN.LOCAL,13,(null))
Nov 08 15:27:08 tw kernel: [kworke] call request_key(,FS0.WIN.LOCAL,)
Nov 08 15:27:08 tw kernel: [kworke] ==> dns_resolver_cmp(FS0.WIN.LOCAL,FS0.WIN.LOCAL)
Nov 08 15:27:08 tw kernel: [kworke] <== dns_resolver_cmp() = 1
Nov 08 15:27:08 tw kernel: [kworke] <== dns_query() = 13
Nov 08 15:27:08 tw kernel: fs/cifs/dns_resolve.c: dns_resolve_server_name_to_ip: resolved: FS0.WIN.LOCAL to 192.168.30.26
===> Nov 08 15:27:08 tw kernel: CIFS VFS: vers=2.0 not permitted when mounting with smb3
Nov 08 15:27:08 tw kernel: fs/cifs/dfs_cache.c: CIFS VFS: leaving refresh_tcon (xid = 26) rc = -22
...
Fixes: 5072010ccf ("cifs: Fix DFS cache refresher for DFS links")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag,
so no need to do that again from its callers. Drop it.
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
In flush_cache_ent(), 'ce->ce_path' is allocated by kstrdup_const().
It should be freed by kfree_const(), rather than kfree().
Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
As per MS-DFSC, when a DFS cache entry is expired and it is a DFS
link, then a new DFS referral must be sent to root server in order to
refresh the expired entry.
This patch ensures that all new DFS referrals for refreshing the cache
are sent to DFS root.
Signed-off-by: Paulo Alcantara (SUSE) <paulo@paulo.ac>
Signed-off-by: Steve French <stfrench@microsoft.com>
The most recent "it" allocation is leaked on this error path. I
believe that small allocations always succeed in current kernels so
this doesn't really affect run time.
Fixes: 54be1f6c1c ("cifs: Add DFS cache routines")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We should zero out the password before we free it.
Fixes: 3d6cacbb5310 ("cifs: Add DFS cache routines")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
memory allocated by kmem_cache_alloc() in alloc_cache_entry()
should be freed using kmem_cache_free(), not kfree().
Fixes: 34a44fb160f9 ("cifs: Add DFS cache routines")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Fixes cifs build failure after merge of the y2038 tree
After merging the y2038 tree, today's linux-next build (x86_64
allmodconfig) failed like this:
fs/cifs/dfs_cache.c: In function 'cache_entry_expired':
fs/cifs/dfs_cache.c:106:7: error: implicit declaration of function 'current_kernel_time64'; did you mean 'core_kernel_text'? [-Werror=implicit-function-declaration]
ts = current_kernel_time64();
^~~~~~~~~~~~~~~~~~~~~
core_kernel_text
fs/cifs/dfs_cache.c:106:5: error: incompatible types when assigning to type 'struct timespec64' from type 'int'
ts = current_kernel_time64();
^
fs/cifs/dfs_cache.c: In function 'get_expire_time':
fs/cifs/dfs_cache.c:342:24: error: incompatible type for argument 1 of 'timespec64_add'
return timespec64_add(current_kernel_time64(), ts);
^~~~~~~~~~~~~~~~~~~~~~~
In file included from include/linux/restart_block.h:10,
from include/linux/thread_info.h:13,
from arch/x86/include/asm/preempt.h:7,
from include/linux/preempt.h:78,
from include/linux/rcupdate.h:40,
from fs/cifs/dfs_cache.c:8:
include/linux/time64.h:66:66: note: expected 'struct timespec64' but argument is of type 'int'
static inline struct timespec64 timespec64_add(struct timespec64 lhs,
~~~~~~~~~~~~~~~~~~^~~
fs/cifs/dfs_cache.c:343:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
Caused by:
commit ccea641b6742 ("timekeeping: remove obsolete time accessors")
interacting with:
commit 34a44fb160f9 ("cifs: Add DFS cache routines")
from the cifs tree.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
* Add new dfs_cache.[ch] files
* Add new /proc/fs/cifs/dfscache file
- dump current cache when read
- clear current cache when writing "0" to it
* Add delayed_work to periodically refresh cache entries
The new interface will be used for caching DFS referrals, as well as
supporting client target failover.
The DFS cache is a hashtable that maps UNC paths to cache entries.
A cache entry contains:
- the UNC path it is mapped on
- how much the the UNC path the entry consumes
- flags
- a Time-To-Live after which the entry expires
- a list of possible targets (linked lists of UNC paths)
- a "hint target" pointing the last known working target or the first
target if none were tried. This hint lets cifs.ko remember and try
working targets first.
* Looking for an entry in the cache is done with dfs_cache_find()
- if no valid entries are found, a DFS query is made, stored in the
cache and returned
- the full target list can be copied and returned to avoid race
conditions and looped on with the help with the
dfs_cache_tgt_iterator
* Updating the target hint to the next target is done with
dfs_cache_update_tgthint()
These functions have a dfs_cache_noreq_XXX() version that doesn't
fetches referrals if no entries are found. These versions don't
require the tcp/ses/tcon/cifs_sb parameters as a result.
Expired entries cannot be used and since they have a pretty short TTL
[1] in order for them to be useful for failover the DFS cache adds a
delayed work called periodically to keep them fresh.
Since we might not have available connections to issue the referral
request when refreshing we need to store volume_info structs with
credentials and other needed info to be able to connect to the right
server.
1: Windows defaults: 5mn for domain-based referrals, 30mn for regular
links
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
