Was helpful in debug for some recent problems. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> 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>
In order to debug complex problems it is often helpful to have detailed information on the client and server view of the open file information. Add the ability for root to view the list of smb3 open files and dump the persistent handle and other info so that it can be more easily correlated with server logs. Sample output from "cat /proc/fs/cifs/open_files" # Version:1 # Format: # <tree id> <persistent fid> <flags> <count> <pid> <uid> <filename> <mid> 0x5 0x800000378 0x8000 1 7704 0 some-file 0x14 0xcb903c0c 0x84412e67 0x8000 1 7754 1001 rofile 0x1a6d 0xcb903c0c 0x9526b767 0x8000 1 7720 1000 file 0x1a5b 0xcb903c0c 0x9ce41a21 0x8000 1 7715 0 smallfile 0xd67 Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Make the output of /proc/fs/cifs/DebugData a little easier to
read by cleaning up the listing of network interfaces removing
a wasted line break.
Here is a comparison of the network interface information
that from be viewed at the end of output from
"cat /proc/fs/cifs/DebugData"
Before:
Server interfaces: 8
0)
Speed: 10000000000 bps
Capabilities: rss
IPv6: fe80:0000:0000:0000:2cf5:407e:84b0:21dd
1)
Speed: 1000000000 bps
Capabilities:
IPv6: fe80:0000:0000:0000:61cd:6147:3d0c:f484
vs. after:
Server interfaces: 11
0) Speed: 10000000000 bps
Capabilities: rss
IPv6: fe80:0000:0000:0000:2cf5:407e:84b0:21dd
1) Speed: 2000000000 bps
Capabilities:
IPv6: fe80:0000:0000:0000:3d76:2d05:dcf8:ed10
Signed-off-by: Steve French <stfrench@microsoft.com>
Each time we reconnect to the same server, bump an instance counter (and display in /proc/fs/cifs/DebugData) to make it easier to debug. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Currently, "echo 0 > /proc/fs/cifs/Stats" resets all of the stats except the session and share reconnect counts. Fix it to reset those as well. CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
When CONFIG_CIFS_STATS2 is enabled keep counters for slow commands (ie server took longer than 1 second to respond) by SMB2/SMB3 command code. This can help in diagnosing whether performance problems are on server (instead of client) and which commands are causing the problem. Sample output (the new lines contain words "slow responses ...") $ cat /proc/fs/cifs/Stats Resources in use CIFS Session: 1 Share (unique mount targets): 2 SMB Request/Response Buffer: 1 Pool size: 5 SMB Small Req/Resp Buffer: 1 Pool size: 30 Total Large 10 Small 490 Allocations Operations (MIDs): 0 0 session 0 share reconnects Total vfs operations: 67 maximum at one time: 2 4 slow responses from localhost for command 5 1 slow responses from localhost for command 6 1 slow responses from localhost for command 14 1 slow responses from localhost for command 16 1) \\localhost\test SMBs: 243 Bytes read: 1024000 Bytes written: 104857600 TreeConnects: 1 total 0 failed TreeDisconnects: 0 total 0 failed Creates: 40 total 0 failed Closes: 39 total 0 failed ... Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
CONFIG_CIFS_STATS is now always enabled (to simplify the code and since the STATS are important for some common customer use cases and also debugging), but needed one minor change so that STATS shows as enabled in the debug output in /proc/fs/cifs/DebugData, otherwise it could get confusing with STATS no longer showing up in the "Features" list in /proc/fs/cifs/DebugData when basic stats were in fact available. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
echo 0 > /proc/fs/cifs/Stats is supposed to reset the stats but there were four (see example below) that were not reset (bytes read and witten, total vfs ops and max ops at one time). ... 0 session 0 share reconnects Total vfs operations: 100 maximum at one time: 2 1) \\localhost\test SMBs: 0 Bytes read: 502092 Bytes written: 31457286 TreeConnects: 0 total 0 failed TreeDisconnects: 0 total 0 failed ... This patch fixes cifs_stats_proc_write to properly reset those four. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
CONFIG_CIFS_STATS should always be enabled as Pavel recently noted. Simple statistics are not a significant performance hit, and removing the ifdef simplifies the code slightly. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>