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path: root/fs/cifs/dfs_cache.c
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2021-04-25cifs: constify get_normalized_path() properlyAl Viro
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>
2021-04-25cifs: don't cargo-cult strndup()Al Viro
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>
2021-02-25cifs: introduce helper for finding referral server to improve DFS target ↵Paulo Alcantara
resolution 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>
2021-01-28cifs: fix dfs domain referralsRonnie Sahlberg
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>
2021-01-13cifs: check pointer before freeingTom Rix
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: 54be1f6c1c37 ("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>
2020-12-14cifs: move cifs_cleanup_volume_info[_content] to fs_context.cRonnie Sahlberg
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>
2020-12-13cifs: remove the devname argument to cifs_compose_mount_optionsRonnie Sahlberg
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>
2020-12-13cifs: switch to new mount apiRonnie Sahlberg
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>
2020-12-13cifs: rename dup_vol to smb3_fs_context_dup and move it into fs_context.cRonnie Sahlberg
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>
2020-12-13cifs: rename smb_vol as smb3_fs_context and move it to fs_context.hRonnie Sahlberg
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>
2020-08-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds
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 ...
2020-08-07mm, treewide: rename kzfree() to kfree_sensitive()Waiman Long
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>
2020-08-02cifs: handle RESP_GET_DFS_REFERRAL.PathConsumed in reconnectPaulo Alcantara
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>
2020-08-02cifs: reduce number of referral requests in DFS link lookupsPaulo Alcantara
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>
2020-06-01cifs: Standardize logging outputJoe Perches
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>
2020-03-22cifs: handle prefix paths in reconnectPaulo Alcantara (SUSE)
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>
2020-02-04proc: convert everything to "struct proc_ops"Alexey Dobriyan
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c] [sfr@canb.auug.org.au: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-26cifs: use PTR_ERR_OR_ZERO() to simplify codeChen Zhou
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>
2020-01-26cifs: fix unitialized variable poential problem with network I/O cache lock ↵Steve French
patch 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>
2020-01-26cifs: Fix return value in __update_cache_entryYueHaibing
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>
2020-01-26cifs: Avoid doing network I/O while holding cache lockPaulo Alcantara (SUSE)
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>
2020-01-26cifs: Fix potential deadlock when updating vol in cifs_reconnect()Paulo Alcantara (SUSE)
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>
2020-01-26cifs: Merge is_path_valid() into get_normalized_path()Paulo Alcantara (SUSE)
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>
2020-01-26cifs: Introduce helpers for finding TCP connectionPaulo Alcantara (SUSE)
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>
2020-01-26cifs: Get rid of kstrdup_const()'d pathsPaulo Alcantara (SUSE)
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>
2020-01-26cifs: Clean up DFS referral cachePaulo Alcantara (SUSE)
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>
2019-11-25cifs: Fix lookup of root ses in DFS referral cachePaulo Alcantara (SUSE)
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: 5072010ccf05 ("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>
2019-07-07fs: cifs: Drop unlikely before IS_ERR(_OR_NULL)Kefeng Wang
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>
2019-05-28dfs_cache: fix a wrong use of kfree in flush_cache_ent()Gen Zhang
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>
2019-05-07cifs: Fix DFS cache refresher for DFS linksPaulo Alcantara (SUSE)
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>
2019-01-10cifs: Fix a tiny potential memory leakDan Carpenter
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: 54be1f6c1c37 ("cifs: Add DFS cache routines") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2018-12-28cifs: Use kzfree() to free passwordDan Carpenter
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>
2018-12-28cifs: Fix to use kmem_cache_free() instead of kfree()Wei Yongjun
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>
2018-12-28cifs: update for current_kernel_time64() removalStephen Rothwell
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>
2018-12-28cifs: Add DFS cache routinesPaulo Alcantara
* 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>