commit 710a492fda68092a02d6360d7a185f6a4dcaea85

Author: NeilBrown <neilb@suse.de>

Date:   Thu Feb 26 14:10:35 2015 -0500

    exports.man: improve documentation of 'nohide' and 'crossmnt'

    - note that 'nohide' is irrelevant for NFSv4

    - note that children on a 'crossmnt' filesystem cannot be unexported

    - note that 'nocrossmnt' is a valid option, but probably not useful.

    Signed-off-by: NeilBrown <neilb@suse.de>

    Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/utils/exportfs/exports.man b/utils/exportfs/exports.man

index 59358e6..9309246 100644

--- a/utils/exportfs/exports.man

+++ b/utils/exportfs/exports.man

@@ -218,16 +218,46 @@ This option can be very useful in some situations, but it should be

 used with due care, and only after confirming that the client system

 copes with the situation effectively.

-The option can be explicitly disabled with

+The option can be explicitly disabled for NFSv2 and NFSv3 with

 .IR hide .

+

+This option is not relevant when NFSv4 is use.  NFSv4 never hides

+subordinate filesystems.  Any filesystem that is exported will be

+visible where expected when using NFSv4.

 .TP

-.IR crossmnt

+.I crossmnt

 This option is similar to

 .I nohide

-but it makes it possible for clients to move from the filesystem marked

-with crossmnt to exported filesystems mounted on it.  Thus when a child

-filesystem "B" is mounted on a parent "A", setting crossmnt on "A" has

-the same effect as setting "nohide" on B.

+but it makes it possible for clients to access all filesystems mounted

+on a filesystem marked with

+.IR crossmnt .

+Thus when a child filesystem "B" is mounted on a parent "A", setting

+crossmnt on "A" has a similar effect to setting "nohide" on B.

+

+With

+.I nohide

+the child filesystem needs to be explicitly exported.  With

+.I crossmnt

+it need not.  If a child of a

+.I crossmnt

+file is not explicitly exported, then it will be implicitly exported

+with the same export options as the parent, except for

+.IR fsid= .

+This makes it impossible to

+.B not

+export a child of a

+.I crossmnt

+filesystem.  If some but not all subordinate filesystems of a parent

+are to be exported, then they must be explicitly exported and the

+parent should not have

+.I crossmnt

+set.

+

+The

+.I nocrossmnt

+option can explictly disable

+.I crossmnt

+if it was previously set.  This is rarely useful.

 .TP

 .IR no_subtree_check

 This option disables subtree checking, which has mild security

commit b7341b19d62481504f1820414159009535d37809

Author: NeilBrown <neilb@suse.de>

Date:   Wed Feb 25 16:47:56 2015 -0500

    mountd: fix next_mnt handling for "/"

    If the (exported) path passed to next_mnt() is simply "/", next_mnt()

    will not report any children, as none start with "/" followed by a '/'.

    So make a special case for strlen(p)==1.  In that case, return all

    children.

    This gives correct handling if only "/" is exported.

    Signed-off-by: NeilBrown <neilb@suse.de>

    Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c

index 1430aee..23af4a9 100644

--- a/utils/mountd/cache.c

+++ b/utils/mountd/cache.c

@@ -365,7 +365,7 @@ static char *next_mnt(void **v, char *p)

 		*v = f;

 	} else

 		f = *v;

-	while ((me = getmntent(f)) != NULL &&

+	while ((me = getmntent(f)) != NULL && l > 1 &&

 	       (strncmp(me->mnt_dir, p, l) != 0 ||

 		me->mnt_dir[l] != '/'))

 		;

commit 7e27d4a542bf97e0ddc1036010e1b2d218a01c2b

Author: Vivek Trivedi <t.vivek@samsung.com>

Date:   Wed Sep 16 11:14:03 2015 -0400

    mountd: fix mount issue due to comparison with uninitialized uuid

    Fix mount issue due to comparison of uninitialized variable

    u(uuid) with parsed->fhuuid when uuid_by_path return 0.

    /tmp/usb

    192.168.1.0/16(ro,no_root_squash,no_subtree_check,fsid=0)

    /tmp/usb/sda1       192.168.1.0/16(ro,no_root_squash,no_subtree_check)

    /tmp/usb/sdb1       192.168.1.0/16(ro,no_root_squash,no_subtree_check)

    mount -t nfs -o nolock,nfsvers=3 192.168.1.2:/tmp/usb/sda1 /tmp/sda1

    mount -t nfs -o nolock,nfsvers=3 192.168.1.2:/tmp/usb/sdb1 /tmp/sdb1

    results in below mountd error:

    mountd: /tmp/usb and /tmp/usb/sdb1 have same filehandle for

    192.168.1.0/16, using first

    when uuid_by_path returned 0, by chance, garbage value of u was same as

    parsed->fhuuid(of sdb1), and comparison of these resulted in above

    error.

    Signed-off-by: Vivek Trivedi <t.vivek@samsung.com>

    Reviewed-by: Amit Sahrawat <a.sahrawat@samsung.com>

    Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c

index 9a1bb27..1430aee 100644

--- a/utils/mountd/cache.c

+++ b/utils/mountd/cache.c

@@ -547,18 +547,17 @@ static bool match_fsid(struct parsed_fsid *parsed, nfs_export *exp, char *path)

 		if (!is_mountpoint(path))

 			return false;

 	check_uuid:

-		if (exp->m_export.e_uuid)

+		if (exp->m_export.e_uuid) {

 			get_uuid(exp->m_export.e_uuid, parsed->uuidlen, u);

+			if (memcmp(u, parsed->fhuuid, parsed->uuidlen) == 0)

+				return true;

+		}

 		else

 			for (type = 0;

 			     uuid_by_path(path, type, parsed->uuidlen, u);

 			     type++)

 				if (memcmp(u, parsed->fhuuid, parsed->uuidlen) == 0)

 					return true;

-

-		if (memcmp(u, parsed->fhuuid, parsed->uuidlen) != 0)

-			return false;

-		return true;

 	}

 	/* Well, unreachable, actually: */

 	return false;