Commit 03a143c9 authored by Steve French's avatar Steve French
Browse files

[CIFS] fixup prefixpaths which contain multiple path components 



Currently, when we get a prefixpath as part of mount, the kernel only
changes the first character to be a '/' or '\' depending on whether
posix extensions are enabled. This is problematic as it expects
mount.cifs to pass in the correct delimiter in the rest of the
prefixpath. But, mount.cifs may not know *what* the correct delimiter
is. It's a chicken and egg problem.

Note that mount.cifs should not do conversion of the
prefixpath - if we want posix behavior then '\' is legal in a path
(and we have had bugs in the distant path to prove to me that
customers sometimes have apps that require '\').  The kernel code
assumes that the path passed in is posix (and current code will handle
the first path component fine but was broken for Windows mounts
for "deep" prefixpaths unless the user specified a prefixpath with '\'
deep in it.   So e.g. with current kernel code:

1) mount to //server/share/dir1 will work to all server types
2) mount to //server/share/dir1/subdir1 will work to Samba
3) mount to //server/share/dir1\\subdir1 will work to Windows

But case two would fail to Windows without the fix.
With the kernel cifs module fix case two now works.

First analyzed by Jeff Layton and Simo Sorce

CC: Jeff Layton <jlayton@redhat.com>
CC: Simo Sorce <simo@samba.org>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent c1ce2644

fs/cifs/CHANGES

+3 −1
Original line number Diff line number Diff line
@@ -6,7 +6,9 @@ and sync so that events like out of disk space get reported properly on 
cached files. Fix setxattr failure to certain Samba versions. Fix mount

of second share to disconnected server session (autoreconnect on this).

Add ability to modify cifs acls for handling chmod (when mounted with

cifsacl flag).

cifsacl flag). Fix prefixpath path separator so we can handle mounts

with prefixpaths longer than one directory (one path component) when

mounted to Windows servers.



Version 1.51

------------

fs/cifs/connect.c

+22 −1
Original line number Diff line number Diff line
@@ -1791,6 +1791,20 @@ void reset_cifs_unix_caps(int xid, struct cifsTconInfo *tcon, 
	}

}



static void

convert_delimiter(char *path, char delim)

{

	int i;



	if (path == NULL)

		return;



	for (i = 0; path[i] != '\0'; i++) {

		if ((path[i] == '/') || (path[i] == '\\'))

			path[i] = delim;

	}

}



int

cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,

	   char *mount_data, const char *devname)
@@ -2056,7 +2070,11 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb, 
		cifs_sb->prepath = volume_info.prepath;

		if (cifs_sb->prepath) {

			cifs_sb->prepathlen = strlen(cifs_sb->prepath);

			cifs_sb->prepath[0] = CIFS_DIR_SEP(cifs_sb);

			/* we can not convert the / to \ in the path

			separators in the prefixpath yet because we do not

			know (until reset_cifs_unix_caps is called later)

			whether POSIX PATH CAP is available. We normalize

			the / to \ after reset_cifs_unix_caps is called */

			volume_info.prepath = NULL;

		} else

			cifs_sb->prepathlen = 0;
@@ -2224,6 +2242,9 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb, 
		else

			tcon->unix_ext = 0; /* server does not support them */



		/* convert forward to back slashes in prepath here if needed */

		convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));



		if ((tcon->unix_ext == 0) && (cifs_sb->rsize > (1024 * 127))) {

			cifs_sb->rsize = 1024 * 127;

			cFYI(DBG2,

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