Stable team,
J. Pablo González <disablez@xxxxxxxxxxxx> writes:
> On Mon, Jan 16, 2023 at 2:02 PM Paulo Alcantara <pc@xxxxxx> wrote:
>>
>> J. Pablo González <disablez@xxxxxxxxxxxx> writes:
>>
>> > We’re experiencing some issues when accessing some mounts in a DFS
>> > share, which seem to happen since kernel 5.17.
>> >
>> > After some investigation, we’ve pinpointed the origin to commit
>> > a2809d0e16963fdf3984409e47f145
>> > cccb0c6821
>> > - Original BZ for that is https://bugzilla.kernel.org/show_bug.cgi?id=215440
>> > - Patch discussion is at
>> > https://patchwork.kernel.org/project/cifs-client/patch/YeHUxJ9zTVNrKveF@xxxxxxxxxxx/
>> > - Similar issues referenced in https://bugzilla.suse.com/show_bug.cgi?id=1198753
>>
>> 6.2-rc4 has
>>
>> c877ce47e137 ("cifs: reduce roundtrips on create/qinfo requests")
>>
>> which should fix your issue.
>>
>> Could you try it? Thanks.
>
> I'll still need to test it more thoroughly, but for now, this patch
> seems to have fixed all issues, including the "-o nodfs ones." Thank
> you!
> Any chance this could be formally backported to 6.1.x ? I see it's
> only tagged for 6.2-rc for now.
Could you please queue
c877ce47e137 ("cifs: reduce roundtrips on create/qinfo requests")
for 6.1.y as a fix for
a2809d0e1696 ("cifs: quirk for STATUS_OBJECT_NAME_INVALID returned for non-ASCII dfs refs")
Find attached a backportable version of such commit. Thanks.
>From c877ce47e1378dbafa6f1bf84c0c83a05ca8972a Mon Sep 17 00:00:00 2001
From: Paulo Alcantara <pc@xxxxxx>
Date: Mon, 12 Dec 2022 23:39:37 -0300
Subject: [PATCH] cifs: reduce roundtrips on create/qinfo requests
To work around some Window servers that return
STATUS_OBJECT_NAME_INVALID on query infos under DFS namespaces that
contain non-ASCII characters, we started checking for -ENOENT on every
file open, and if so, then send additional requests to figure out
whether it is a DFS link or not. It means that all those requests
will be sent to every non-existing file.
So, in order to reduce the number of roundtrips, check earlier whether
status code is STATUS_OBJECT_NAME_INVALID and tcon supports dfs, and
if so, then map -ENOENT to -EREMOTE so mount or automount will take
care of chasing the DFS link -- if it isn't an DFS link, then -ENOENT
will be returned appropriately.
Before patch
SMB2 438 Create Request File: ada.test\dfs\foo;GetInfo Request...
SMB2 310 Create Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;...
SMB2 228 Ioctl Request FSCTL_DFS_GET_REFERRALS, File: \ada.test\dfs\foo
SMB2 143 Ioctl Response, Error: STATUS_OBJECT_PATH_NOT_FOUND
SMB2 438 Create Request File: ada.test\dfs\foo;GetInfo Request...
SMB2 310 Create Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;...
SMB2 228 Ioctl Request FSCTL_DFS_GET_REFERRALS, File: \ada.test\dfs\foo
SMB2 143 Ioctl Response, Error: STATUS_OBJECT_PATH_NOT_FOUND
After patch
SMB2 438 Create Request File: ada.test\dfs\foo;GetInfo Request...
SMB2 310 Create Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;...
SMB2 438 Create Request File: ada.test\dfs\foo;GetInfo Request...
SMB2 310 Create Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;...
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/cifs/connect.c | 16 ----------------
fs/cifs/inode.c | 6 ------
fs/cifs/misc.c | 45 ---------------------------------------------
fs/cifs/smb2inode.c | 45 ++++++++++++++++++++++++++++++++-------------
fs/cifs/smb2ops.c | 28 ++++++++++++++++++++++++----
5 files changed, 56 insertions(+), 84 deletions(-)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index fde1c371605a..eab36e4ea130 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3554,9 +3554,6 @@ static int is_path_remote(struct mount_ctx *mnt_ctx)
struct cifs_tcon *tcon = mnt_ctx->tcon;
struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
char *full_path;
-#ifdef CONFIG_CIFS_DFS_UPCALL
- bool nodfs = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS;
-#endif
if (!server->ops->is_path_accessible)
return -EOPNOTSUPP;
@@ -3573,19 +3570,6 @@ static int is_path_remote(struct mount_ctx *mnt_ctx)
rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
full_path);
-#ifdef CONFIG_CIFS_DFS_UPCALL
- if (nodfs) {
- if (rc == -EREMOTE)
- rc = -EOPNOTSUPP;
- goto out;
- }
-
- /* path *might* exist with non-ASCII characters in DFS root
- * try again with full path (only if nodfs is not set) */
- if (rc == -ENOENT && is_tcon_dfs(tcon))
- rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb,
- full_path);
-#endif
if (rc != 0 && rc != -EREMOTE)
goto out;
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 4e2ca3c6e5c0..0c9b619e4386 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -991,12 +991,6 @@ int cifs_get_inode_info(struct inode **inode, const char *full_path,
}
rc = server->ops->query_path_info(xid, tcon, cifs_sb, full_path, &tmp_data,
&adjust_tz, &is_reparse_point);
-#ifdef CONFIG_CIFS_DFS_UPCALL
- if (rc == -ENOENT && is_tcon_dfs(tcon))
- rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon,
- cifs_sb,
- full_path);
-#endif
data = &tmp_data;
}
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 1cbecd64d697..062175994e87 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -1314,49 +1314,4 @@ int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix)
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
return 0;
}
-
-/** cifs_dfs_query_info_nonascii_quirk
- * Handle weird Windows SMB server behaviour. It responds with
- * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request
- * for "\<server>\<dfsname>\<linkpath>" DFS reference,
- * where <dfsname> contains non-ASCII unicode symbols.
- *
- * Check such DFS reference.
- */
-int cifs_dfs_query_info_nonascii_quirk(const unsigned int xid,
- struct cifs_tcon *tcon,
- struct cifs_sb_info *cifs_sb,
- const char *linkpath)
-{
- char *treename, *dfspath, sep;
- int treenamelen, linkpathlen, rc;
-
- treename = tcon->tree_name;
- /* MS-DFSC: All paths in REQ_GET_DFS_REFERRAL and RESP_GET_DFS_REFERRAL
- * messages MUST be encoded with exactly one leading backslash, not two
- * leading backslashes.
- */
- sep = CIFS_DIR_SEP(cifs_sb);
- if (treename[0] == sep && treename[1] == sep)
- treename++;
- linkpathlen = strlen(linkpath);
- treenamelen = strnlen(treename, MAX_TREE_SIZE + 1);
- dfspath = kzalloc(treenamelen + linkpathlen + 1, GFP_KERNEL);
- if (!dfspath)
- return -ENOMEM;
- if (treenamelen)
- memcpy(dfspath, treename, treenamelen);
- memcpy(dfspath + treenamelen, linkpath, linkpathlen);
- rc = dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls,
- cifs_remap(cifs_sb), dfspath, NULL, NULL);
- if (rc == 0) {
- cifs_dbg(FYI, "DFS ref '%s' is found, emulate -EREMOTE\n",
- dfspath);
- rc = -EREMOTE;
- } else {
- cifs_dbg(FYI, "%s: dfs_cache_find returned %d\n", __func__, rc);
- }
- kfree(dfspath);
- return rc;
-}
#endif
diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
index 68e08c85fbb8..6c84d2983166 100644
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -540,22 +540,41 @@ int smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
rc = smb2_compound_op(xid, tcon, cifs_sb, full_path, FILE_READ_ATTRIBUTES, FILE_OPEN,
create_options, ACL_NO_MODE, data, SMB2_OP_QUERY_INFO, cfile,
err_iov, err_buftype);
- if (rc == -EOPNOTSUPP) {
- if (err_iov[0].iov_base && err_buftype[0] != CIFS_NO_BUFFER &&
- ((struct smb2_hdr *)err_iov[0].iov_base)->Command == SMB2_CREATE &&
- ((struct smb2_hdr *)err_iov[0].iov_base)->Status == STATUS_STOPPED_ON_SYMLINK) {
- rc = smb2_parse_symlink_response(cifs_sb, err_iov, &data->symlink_target);
+ if (rc) {
+ struct smb2_hdr *hdr = err_iov[0].iov_base;
+
+ if (unlikely(!hdr || err_buftype[0] == CIFS_NO_BUFFER))
+ goto out;
+ if (rc == -EOPNOTSUPP && hdr->Command == SMB2_CREATE &&
+ hdr->Status == STATUS_STOPPED_ON_SYMLINK) {
+ rc = smb2_parse_symlink_response(cifs_sb, err_iov,
+ &data->symlink_target);
if (rc)
goto out;
+
+ *reparse = true;
+ create_options |= OPEN_REPARSE_POINT;
+
+ /* Failed on a symbolic link - query a reparse point info */
+ cifs_get_readable_path(tcon, full_path, &cfile);
+ rc = smb2_compound_op(xid, tcon, cifs_sb, full_path,
+ FILE_READ_ATTRIBUTES, FILE_OPEN,
+ create_options, ACL_NO_MODE, data,
+ SMB2_OP_QUERY_INFO, cfile, NULL, NULL);
+ goto out;
+ } else if (rc != -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) &&
+ hdr->Status == STATUS_OBJECT_NAME_INVALID) {
+ /*
+ * Handle weird Windows SMB server behaviour. It responds with
+ * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request
+ * for "\<server>\<dfsname>\<linkpath>" DFS reference,
+ * where <dfsname> contains non-ASCII unicode symbols.
+ */
+ rc = -EREMOTE;
}
- *reparse = true;
- create_options |= OPEN_REPARSE_POINT;
-
- /* Failed on a symbolic link - query a reparse point info */
- cifs_get_readable_path(tcon, full_path, &cfile);
- rc = smb2_compound_op(xid, tcon, cifs_sb, full_path, FILE_READ_ATTRIBUTES,
- FILE_OPEN, create_options, ACL_NO_MODE, data,
- SMB2_OP_QUERY_INFO, cfile, NULL, NULL);
+ if (rc == -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && cifs_sb &&
+ (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS))
+ rc = -EOPNOTSUPP;
}
out:
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 8da98918cf86..1ff5b6b0e07a 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -797,7 +797,9 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon,
int rc;
__le16 *utf16_path;
__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
+ int err_buftype = CIFS_NO_BUFFER;
struct cifs_open_parms oparms;
+ struct kvec err_iov = {};
struct cifs_fid fid;
struct cached_fid *cfid;
@@ -821,14 +823,32 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon,
oparms.fid = &fid;
oparms.reconnect = false;
- rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL, NULL,
- NULL);
+ rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
+ &err_iov, &err_buftype);
if (rc) {
- kfree(utf16_path);
- return rc;
+ struct smb2_hdr *hdr = err_iov.iov_base;
+
+ if (unlikely(!hdr || err_buftype == CIFS_NO_BUFFER))
+ goto out;
+ /*
+ * Handle weird Windows SMB server behaviour. It responds with
+ * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request
+ * for "\<server>\<dfsname>\<linkpath>" DFS reference,
+ * where <dfsname> contains non-ASCII unicode symbols.
+ */
+ if (rc != -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) &&
+ hdr->Status == STATUS_OBJECT_NAME_INVALID)
+ rc = -EREMOTE;
+ if (rc == -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && cifs_sb &&
+ (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS))
+ rc = -EOPNOTSUPP;
+ goto out;
}
rc = SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
+
+out:
+ free_rsp_buf(err_buftype, err_iov.iov_base);
kfree(utf16_path);
return rc;
}
--
2.39.0
