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path: root/fs/cifs/dfs_cache.c
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2023-05-25smb: move client and server files to common directory fs/smbSteve French1-1305/+0
Move CIFS/SMB3 related client and server files (cifs.ko and ksmbd.ko and helper modules) to new fs/smb subdirectory: fs/cifs --> fs/smb/client fs/ksmbd --> fs/smb/server fs/smbfs_common --> fs/smb/common Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-05-04cifs: avoid potential races when handling multiple dfs tconsPaulo Alcantara1-77/+60
Now that a DFS tcon manages its own list of DFS referrals and sessions, there is no point in having a single worker to refresh referrals of all DFS tcons. Make it faster and less prone to race conditions when having several mounts by queueing a worker per DFS tcon that will take care of refreshing only the DFS referrals related to it. Cc: stable@vger.kernel.org # v6.2+ Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-05-04cifs: protect access of TCP_Server_Info::{origin,leaf}_fullpathPaulo Alcantara1-1/+5
Protect access of TCP_Server_Info::{origin,leaf}_fullpath when matching DFS connections, and get rid of TCP_Server_Info::current_fullpath while we're at it. Cc: stable@vger.kernel.org # v6.2+ Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-03-17cifs: check only tcon status on tcon related functionsShyam Prasad N1-1/+1
We had a couple of checks for session in cifs_tree_connect and cifs_mark_open_files_invalid, which were unnecessary. And that was done with ses_lock. Changed that to tc_lock too. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-03-15cifs: fix use-after-free bug in refresh_cache_worker()Paulo Alcantara1-140/+0
The UAF bug occurred because we were putting DFS root sessions in cifs_umount() while DFS cache refresher was being executed. Make DFS root sessions have same lifetime as DFS tcons so we can avoid the use-after-free bug is DFS cache refresher and other places that require IPCs to get new DFS referrals on. Also, get rid of mount group handling in DFS cache as we no longer need it. This fixes below use-after-free bug catched by KASAN [ 379.946955] BUG: KASAN: use-after-free in __refresh_tcon.isra.0+0x10b/0xc10 [cifs] [ 379.947642] Read of size 8 at addr ffff888018f57030 by task kworker/u4:3/56 [ 379.948096] [ 379.948208] CPU: 0 PID: 56 Comm: kworker/u4:3 Not tainted 6.2.0-rc7-lku #23 [ 379.948661] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552-rebuilt.opensuse.org 04/01/2014 [ 379.949368] Workqueue: cifs-dfscache refresh_cache_worker [cifs] [ 379.949942] Call Trace: [ 379.950113] <TASK> [ 379.950260] dump_stack_lvl+0x50/0x67 [ 379.950510] print_report+0x16a/0x48e [ 379.950759] ? __virt_addr_valid+0xd8/0x160 [ 379.951040] ? __phys_addr+0x41/0x80 [ 379.951285] kasan_report+0xdb/0x110 [ 379.951533] ? __refresh_tcon.isra.0+0x10b/0xc10 [cifs] [ 379.952056] ? __refresh_tcon.isra.0+0x10b/0xc10 [cifs] [ 379.952585] __refresh_tcon.isra.0+0x10b/0xc10 [cifs] [ 379.953096] ? __pfx___refresh_tcon.isra.0+0x10/0x10 [cifs] [ 379.953637] ? __pfx___mutex_lock+0x10/0x10 [ 379.953915] ? lock_release+0xb6/0x720 [ 379.954167] ? __pfx_lock_acquire+0x10/0x10 [ 379.954443] ? refresh_cache_worker+0x34e/0x6d0 [cifs] [ 379.954960] ? __pfx_wb_workfn+0x10/0x10 [ 379.955239] refresh_cache_worker+0x4ad/0x6d0 [cifs] [ 379.955755] ? __pfx_refresh_cache_worker+0x10/0x10 [cifs] [ 379.956323] ? __pfx_lock_acquired+0x10/0x10 [ 379.956615] ? read_word_at_a_time+0xe/0x20 [ 379.956898] ? lockdep_hardirqs_on_prepare+0x12/0x220 [ 379.957235] process_one_work+0x535/0x990 [ 379.957509] ? __pfx_process_one_work+0x10/0x10 [ 379.957812] ? lock_acquired+0xb7/0x5f0 [ 379.958069] ? __list_add_valid+0x37/0xd0 [ 379.958341] ? __list_add_valid+0x37/0xd0 [ 379.958611] worker_thread+0x8e/0x630 [ 379.958861] ? __pfx_worker_thread+0x10/0x10 [ 379.959148] kthread+0x17d/0x1b0 [ 379.959369] ? __pfx_kthread+0x10/0x10 [ 379.959630] ret_from_fork+0x2c/0x50 [ 379.959879] </TASK> Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Cc: stable@vger.kernel.org # 6.2 Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18cifs: remove unused functionPaulo Alcantara1-60/+0
Remove dfs_cache_update_tgthint() as it is not used anywhere. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18cifs: fix return of uninitialized rc in dfs_cache_update_tgthint()Paulo Alcantara1-3/+3
Fix this by initializing rc to 0 as cache_refresh_path() would not set it in case of success. Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/all/202301190004.bEHvbKG6-lkp@intel.com/ Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18cifs: handle cache lookup errors different than -ENOENTPaulo Alcantara1-2/+9
lookup_cache_entry() might return an error different than -ENOENT (e.g. from ->char2uni), so handle those as well in cache_refresh_path(). Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18cifs: remove duplicate code in __refresh_tcon()Paulo Alcantara1-38/+33
The logic for creating or updating a cache entry in __refresh_tcon() could be simply done with cache_refresh_path(), so use it instead. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18cifs: don't take exclusive lock for updating target hintsPaulo Alcantara1-27/+20
Avoid contention while updating dfs target hints. This should be perfectly fine to update them under shared locks. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18cifs: avoid re-lookups in dfs_cache_find()Paulo Alcantara1-24/+34
Simply downgrade the write lock on cache updates from cache_refresh_path() and avoid unnecessary re-lookup in dfs_cache_find(). Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18cifs: fix potential deadlock in cache_refresh_path()Paulo Alcantara1-19/+23
Avoid getting DFS referral from an exclusive lock in cache_refresh_path() because the tcon IPC used for getting the referral could be disconnected and thus causing a deadlock as shown below: task A task B ====== ====== cifs_demultiplex_thread() dfs_cache_find() cifs_handle_standard() cache_refresh_path() reconnect_dfs_server() down_write() dfs_cache_noreq_find() get_dfs_referral() down_read() <- deadlock smb2_get_dfs_refer() SMB2_ioctl() cifs_send_recv() compound_send_recv() wait_for_response() where task A cannot wake up task B because it is blocked on down_read() due to the exclusive lock held in cache_refresh_path() and therefore not being able to make progress. Fixes: c9f711039905 ("cifs: keep referral server sessions alive") Reviewed-by: Aurélien Aptel <aurelien.aptel@gmail.com> Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-11cifs: remove redundant assignment to the variable matchColin Ian King1-1/+0
The variable match is being assigned a value that is never read, it is being re-assigned a new value later on. The assignment is redundant and can be removed. Cleans up clang scan-build warning: fs/cifs/dfs_cache.c:1302:2: warning: Value stored to 'match' is never read Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19cifs: don't block in dfs_cache_noreq_update_tgthint()Paulo Alcantara1-11/+7
Avoid blocking in dfs_cache_noreq_update_tgthint() while reconnecting servers or tcons as the cache refresh worker or new mounts might already be updating their targets. Move some more dfs related code out of connect.c while at it. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19cifs: refresh root referralsPaulo Alcantara1-18/+22
Also refresh cached root referrals so the other cached referrals may have a better chance to have a working root server to issue the referrals on. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19cifs: fix refresh of cached referralsPaulo Alcantara1-115/+25
We can't rely on cifs_tcon::ses to refresh cached referral as the server target might not respond to referrals, e.g. share is not hosted in a DFS root server. Consider the following mount //dom/dfs/link -> /root1/dfs/link -> /fs0/share where fs0 can't get a referral for "/root1/dfs/link". To simplify and fix the access of dfs root sessions, store the dfs root session pointer directly to new sessions so making it easier to select the appropriate ipc connection and use it for failover or cache refresh. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19cifs: don't refresh cached referrals from unactive mountsPaulo Alcantara1-72/+1
There is no point refreshing cached referrals from unactive mounts as they will no longer be used and new mounts will either create or refresh them anyway. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19cifs: share dfs connections and supersPaulo Alcantara1-11/+3
When matching DFS superblocks we can't rely on either the server's address or tcon's UNC name from mount(2) as the existing servers and tcons might be connected to somewhere else. Instead, check if superblock is dfs, and if so, match its original source pathname with the new mount's source pathname. For DFS connections, instead of checking server's address, match its referral path as it could be connected to different targets. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19cifs: set resolved ip in sockaddrPaulo Alcantara1-12/+5
All callers from dns_resolve_server_name_to_ip() used to convert the ip addr string back to sockaddr, so do that inside dns_resolve_server_name_to_ip() and avoid duplicating code. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-05smb3: add dynamic trace points for tree disconnectSteve French1-1/+1
Needed this for debugging a failing xfstest. Also change camel case for "treeName" to "tree_name" in tcon struct. Example trace output (from "trace-cmd record -e smb3_tdis*"): umount-9718 [006] ..... 5909.780244: smb3_tdis_enter: xid=206 sid=0xcf38894e tid=0x3d0b8cf8 path=\\localhost\test umount-9718 [007] ..... 5909.780878: smb3_tdis_done: xid=206 sid=0xcf38894e tid=0x3d0b8cf8 Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-01cifs: avoid use of global locks for high contention dataShyam Prasad N1-1/+7
During analysis of multichannel perf, it was seen that the global locks cifs_tcp_ses_lock and GlobalMid_Lock, which were shared between various data structures were causing a lot of contention points. With this change, we're breaking down the use of these locks by introducing new locks at more granular levels. i.e. server->srv_lock, ses->ses_lock and tcon->tc_lock to protect the unprotected fields of server, session and tcon structs; and server->mid_lock to protect mid related lists and entries at server level. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-04cifs: fix uninitialized pointer in error case in dfs_cache_get_tgt_shareSteve French1-1/+2
Set default value of ppath to null. Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-03cifs: skip trailing separators of prefix pathsPaulo Alcantara1-36/+49
During DFS failover, prefix paths may change, so make sure to not leave trailing separators when parsing thew in dfs_cache_get_tgt_share(). The separators of prefix paths are already handled by build_path_from_dentry_optional_prefix(). Consider the following DFS link: //dom/dfs/link: [\srv1\share\dir1, \srv2\share\dir1] Before commit: mount.cifs //dom/dfs/link tree connect to \\srv1\share; prefix_path=dir1 disconnect srv1; failover to srv2 tree connect to \\srv2\share; prefix_path=dir1\ mv foo bar ... SMB2 430 Create Request File: dir1\\foo;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request SMB2 582 Create Response File: dir1\\foo;GetInfo Response;Close Response SMB2 430 Create Request File: dir1\\bar;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request SMB2 286 Create Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;GetInfo Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;Close Response, Error: STATUS_OBJECT_NAME_NOT_FOUND SMB2 462 Create Request File: dir1\\foo;SetInfo Request FILE_INFO/SMB2_FILE_RENAME_INFO NewName:dir1\\bar;Close Request SMB2 478 Create Response File: dir1\\foo;SetInfo Response, Error: STATUS_OBJECT_NAME_INVALID;Close Response After commit: mount.cifs //dom/dfs/link tree connect to \\srv1\share; prefix_path=dir1 disconnect srv1; failover to srv2 tree connect to \\srv2\share; prefix_path=dir1 mv foo bar ... SMB2 430 Create Request File: dir1\foo;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request SMB2 582 Create Response File: dir1\foo;GetInfo Response;Close Response SMB2 430 Create Request File: dir1\bar;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request SMB2 286 Create Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;GetInfo Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;Close Response, Error: STATUS_OBJECT_NAME_NOT_FOUND SMB2 462 Create Request File: dir1\foo;SetInfo Request FILE_INFO/SMB2_FILE_RENAME_INFO NewName:dir1\bar;Close Request SMB2 478 Create Response File: dir1\foo;SetInfo Response;Close Response Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-01cifs: fix potential deadlock in direct reclaimVincent Whitchurch1-2/+2
The srv_mutex is used during writeback so cifs should ensure that allocations done when that mutex is held are done with GFP_NOFS, to avoid having direct reclaim ending up waiting for the same mutex and causing a deadlock. This is detected by lockdep with the splat below: ====================================================== WARNING: possible circular locking dependency detected 5.18.0 #70 Not tainted ------------------------------------------------------ kswapd0/49 is trying to acquire lock: ffff8880195782e0 (&tcp_ses->srv_mutex){+.+.}-{3:3}, at: compound_send_recv but task is already holding lock: ffffffffa98e66c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: fs_reclaim_acquire kmem_cache_alloc_trace __request_module crypto_alg_mod_lookup crypto_alloc_tfm_node crypto_alloc_shash cifs_alloc_hash smb311_crypto_shash_allocate smb311_update_preauth_hash compound_send_recv cifs_send_recv SMB2_negotiate smb2_negotiate cifs_negotiate_protocol cifs_get_smb_ses cifs_mount cifs_smb3_do_mount smb3_get_tree vfs_get_tree path_mount __x64_sys_mount do_syscall_64 entry_SYSCALL_64_after_hwframe -> #0 (&tcp_ses->srv_mutex){+.+.}-{3:3}: __lock_acquire lock_acquire __mutex_lock mutex_lock_nested compound_send_recv cifs_send_recv SMB2_write smb2_sync_write cifs_write cifs_writepage_locked cifs_writepage shrink_page_list shrink_lruvec shrink_node balance_pgdat kswapd kthread ret_from_fork other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&tcp_ses->srv_mutex); lock(fs_reclaim); lock(&tcp_ses->srv_mutex); *** DEADLOCK *** 1 lock held by kswapd0/49: #0: ffffffffa98e66c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat stack backtrace: CPU: 2 PID: 49 Comm: kswapd0 Not tainted 5.18.0 #70 Call Trace: <TASK> dump_stack_lvl dump_stack print_circular_bug.cold check_noncircular __lock_acquire lock_acquire __mutex_lock mutex_lock_nested compound_send_recv cifs_send_recv SMB2_write smb2_sync_write cifs_write cifs_writepage_locked cifs_writepage shrink_page_list shrink_lruvec shrink_node balance_pgdat kswapd kthread ret_from_fork </TASK> Fix this by using the memalloc_nofs_save/restore APIs around the places where the srv_mutex is held. Do this in a wrapper function for the lock/unlock of the srv_mutex, and rename the srv_mutex to avoid missing call sites in the conversion. Note that there is another lockdep warning involving internal crypto locks, which was masked by this problem and is visible after this fix, see the discussion in this thread: https://lore.kernel.org/all/20220523123755.GA13668@axis.com/ Link: https://lore.kernel.org/r/CANT5p=rqcYfYMVHirqvdnnca4Mo+JQSw5Qu12v=kPfpk5yhhmg@mail.gmail.com/ Reported-by: Shyam Prasad N <nspmangalore@gmail.com> Suggested-by: Lars Persson <larper@axis.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-21cifs: return ENOENT for DFS lookup_cache_entry()Enzo Matsumiya1-3/+3
EEXIST didn't make sense to use when dfs_cache_find() couldn't find a cache entry nor retrieve a referral target. It also doesn't make sense cifs_dfs_query_info_nonascii_quirk() to emulate ENOENT anymore. Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-04-21cifs: fix NULL ptr dereference in refresh_mounts()Paulo Alcantara1-7/+12
Either mount(2) or automount might not have server->origin_fullpath set yet while refresh_cache_worker() is attempting to refresh DFS referrals. Add missing NULL check and locking around it. This fixes bellow crash: [ 1070.276835] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI [ 1070.277676] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] [ 1070.278219] CPU: 1 PID: 8506 Comm: kworker/u8:1 Not tainted 5.18.0-rc3 #10 [ 1070.278701] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014 [ 1070.279495] Workqueue: cifs-dfscache refresh_cache_worker [cifs] [ 1070.280044] RIP: 0010:strcasecmp+0x34/0x150 [ 1070.280359] Code: 00 00 00 fc ff df 41 54 55 48 89 fd 53 48 83 ec 10 eb 03 4c 89 fe 48 89 ef 48 83 c5 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 bc 00 00 00 0f b6 45 ff 44 [ 1070.281729] RSP: 0018:ffffc90008367958 EFLAGS: 00010246 [ 1070.282114] RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 [ 1070.282691] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 1070.283273] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff873eda27 [ 1070.283857] R10: ffffc900083679a0 R11: 0000000000000001 R12: ffff88812624c000 [ 1070.284436] R13: dffffc0000000000 R14: ffff88810e6e9a88 R15: ffff888119bb9000 [ 1070.284990] FS: 0000000000000000(0000) GS:ffff888151200000(0000) knlGS:0000000000000000 [ 1070.285625] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1070.286100] CR2: 0000561a4d922418 CR3: 000000010aecc000 CR4: 0000000000350ee0 [ 1070.286683] Call Trace: [ 1070.286890] <TASK> [ 1070.287070] refresh_cache_worker+0x895/0xd20 [cifs] [ 1070.287475] ? __refresh_tcon.isra.0+0xfb0/0xfb0 [cifs] [ 1070.287905] ? __lock_acquire+0xcd1/0x6960 [ 1070.288247] ? is_dynamic_key+0x1a0/0x1a0 [ 1070.288591] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 1070.289012] ? lock_downgrade+0x6f0/0x6f0 [ 1070.289318] process_one_work+0x7bd/0x12d0 [ 1070.289637] ? worker_thread+0x160/0xec0 [ 1070.289970] ? pwq_dec_nr_in_flight+0x230/0x230 [ 1070.290318] ? _raw_spin_lock_irq+0x5e/0x90 [ 1070.290619] worker_thread+0x5ac/0xec0 [ 1070.290891] ? process_one_work+0x12d0/0x12d0 [ 1070.291199] kthread+0x2a5/0x350 [ 1070.291430] ? kthread_complete_and_exit+0x20/0x20 [ 1070.291770] ret_from_fork+0x22/0x30 [ 1070.292050] </TASK> [ 1070.292223] Modules linked in: bpfilter cifs cifs_arc4 cifs_md4 [ 1070.292765] ---[ end trace 0000000000000000 ]--- [ 1070.293108] RIP: 0010:strcasecmp+0x34/0x150 [ 1070.293471] Code: 00 00 00 fc ff df 41 54 55 48 89 fd 53 48 83 ec 10 eb 03 4c 89 fe 48 89 ef 48 83 c5 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 bc 00 00 00 0f b6 45 ff 44 [ 1070.297718] RSP: 0018:ffffc90008367958 EFLAGS: 00010246 [ 1070.298622] RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 [ 1070.299428] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 1070.300296] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff873eda27 [ 1070.301204] R10: ffffc900083679a0 R11: 0000000000000001 R12: ffff88812624c000 [ 1070.301932] R13: dffffc0000000000 R14: ffff88810e6e9a88 R15: ffff888119bb9000 [ 1070.302645] FS: 0000000000000000(0000) GS:ffff888151200000(0000) knlGS:0000000000000000 [ 1070.303462] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1070.304131] CR2: 0000561a4d922418 CR3: 000000010aecc000 CR4: 0000000000350ee0 [ 1070.305004] Kernel panic - not syncing: Fatal exception [ 1070.305711] Kernel Offset: disabled [ 1070.305971] ---[ end Kernel panic - not syncing: Fatal exception ]--- Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Cc: stable@vger.kernel.org Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-03-19cifs: use a different reconnect helper for non-cifsd threadsShyam Prasad N1-1/+1
The cifs_demultiplexer_thread should only call cifs_reconnect. If any other thread wants to trigger a reconnect, they can do so by updating the server tcpStatus to CifsNeedReconnect. The last patch attempted to use the same helper function for both types of threads, but that causes other issues with lock dependencies. This patch creates a new helper for non-cifsd threads, that will indicate to cifsd that the server needs reconnect. Fixes: 2a05137a0575 ("cifs: mark sessions for reconnection in helper function") Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-02-09cifs: call helper functions for marking channels for reconnectShyam Prasad N1-1/+1
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>
2022-01-19cifs: cifs_ses_mark_for_reconnect should also update reconnect bitsShyam Prasad N1-1/+1
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>
2021-11-16cifs: introduce cifs_ses_mark_for_reconnect() helperPaulo Alcantara1-6/+1
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>
2021-11-11cifs: support nested dfs links over reconnectPaulo Alcantara1-8/+36
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>
2021-11-10cifs: fix print of hdr_flags in dfscache_proc_show()Paulo Alcantara1-1/+1
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>
2021-07-22cifs: support share failover when remountingPaulo Alcantara1-38/+191
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>
2021-06-21cifs: fix check of dfs interlinksPaulo Alcantara1-4/+3
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>
2021-06-21cifs: avoid starvation when refreshing dfs cachePaulo Alcantara1-40/+105
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>
2021-06-21cifs: set a minimum of 2 minutes for refreshing dfs cachePaulo Alcantara1-1/+2
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>
2021-06-21cifs: fix path comparison and hash calcPaulo Alcantara1-76/+94
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>
2021-06-21cifs: handle different charsets in dfs cachePaulo Alcantara1-88/+77
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>
2021-06-21cifs: keep referral server sessions alivePaulo Alcantara1-427/+250
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>
2021-06-21cifs: get rid of @noreq param in __dfs_cache_find()Paulo Alcantara1-14/+3
@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>
2021-06-21cifs: Remove unused inline function is_sysvol_or_netlogon()YueHaibing1-11/+0
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>
2021-04-26cifs: constify get_normalized_path() properlyAl Viro1-12/+13
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>
2021-04-26cifs: don't cargo-cult strndup()Al Viro1-9/+9
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 Alcantara1-16/+17
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>
2021-01-29cifs: fix dfs domain referralsRonnie Sahlberg1-3/+5
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 Rix1-1/+2
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 Sahlberg1-2/+2
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>
2020-12-14cifs: remove the devname argument to cifs_compose_mount_optionsRonnie Sahlberg1-4/+2
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>
2020-12-14cifs: switch to new mount apiRonnie Sahlberg1-4/+4
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>
2020-12-14cifs: rename dup_vol to smb3_fs_context_dup and move it into fs_context.cRonnie Sahlberg1-59/+1
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>