linux-stable.git/fs/cifs/dfs_cache.c, branch linux-5.7.y

cifs: handle prefix paths in reconnect

2020-03-23T03:49:09+00:00

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) 
Acked-by: Ronnie Sahlberg 
Reviewed-by: Aurelien Aptel 
Signed-off-by: Steve French

proc: convert everything to "struct proc_ops"

2020-02-04T03:05:26+00:00

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 
Signed-off-by: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cifs: use PTR_ERR_OR_ZERO() to simplify code

2020-01-27T01:24:17+00:00

PTR_ERR_OR_ZERO contains if(IS_ERR(...)) + PTR_ERR, just use
PTR_ERR_OR_ZERO directly.

Signed-off-by: Chen Zhou 
Signed-off-by: Steve French 
Reviewed-by: Paulo Alcantara (SUSE)

cifs: fix unitialized variable poential problem with network I/O cache lock patch

2020-01-27T01:24:16+00:00

static analysis with Coverity detected an issue with the following
commit:

 Author: Paulo Alcantara (SUSE) 
 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 
Signed-off-by: Paulo Alcantara (SUSE) 
Signed-off-by: Steve French

cifs: Fix return value in __update_cache_entry

2020-01-27T01:24:16+00:00

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 
Signed-off-by: Steve French

cifs: Avoid doing network I/O while holding cache lock

2020-01-27T01:24:16+00:00

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) 
Signed-off-by: Steve French

cifs: Fix potential deadlock when updating vol in cifs_reconnect()

2020-01-27T01:24:16+00:00

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) 
Signed-off-by: Steve French

cifs: Merge is_path_valid() into get_normalized_path()

2020-01-27T01:24:16+00:00

Just do the trivial path validation in get_normalized_path().

Signed-off-by: Paulo Alcantara (SUSE) 
Reviewed-by: Aurelien Aptel 
Signed-off-by: Steve French

cifs: Introduce helpers for finding TCP connection

2020-01-27T01:24:16+00:00

Add helpers for finding TCP connections that are good candidates for
being used by DFS refresh worker.

Signed-off-by: Paulo Alcantara (SUSE) 
Reviewed-by: Aurelien Aptel 
Signed-off-by: Steve French

cifs: Get rid of kstrdup_const()'d paths

2020-01-27T01:24:16+00:00

The DFS cache API is mostly used with heap allocated strings.

Signed-off-by: Paulo Alcantara (SUSE) 
Reviewed-by: Aurelien Aptel 
Signed-off-by: Steve French