1 files changed, 42 insertions, 178 deletions

diff --git a/Documentation/filesystems/sharedsubtree.txt b/Documentation/filesystems/sharedsubtree.txt
index 736540045dc7..23a181074f94 100644
--- a/Documentation/filesystems/sharedsubtree.txt
+++ b/Documentation/filesystems/sharedsubtree.txt
@@ -4,7 +4,7 @@ Shared Subtrees
 Contents:
         1) Overview
         2) Features
-        3) smount command
+        3) Setting mount states
         4) Use-case
         5) Detailed semantics
         6) Quiz
@@ -41,14 +41,14 @@ replicas continue to be exactly same.
 
         Here is an example:
 
-        Lets say /mnt has a mount that is shared.
+        Let's say /mnt has a mount that is shared.
         mount --make-shared /mnt
 
-        note: mount command does not yet support the --make-shared flag.
-        I have included a small C program which does the same by executing
-        'smount /mnt shared'
+        Note: mount(8) command now supports the --make-shared flag,
+        so the sample 'smount' program is no longer needed and has been
+        removed.
 
-        #mount --bind /mnt /tmp
+        # mount --bind /mnt /tmp
         The above command replicates the mount at /mnt to the mountpoint /tmp
         and the contents of both the mounts remain identical.
 
@@ -58,8 +58,8 @@ replicas continue to be exactly same.
         #ls /tmp
         a b c
 
-        Now lets say we mount a device at /tmp/a
-        #mount /dev/sd0  /tmp/a
+        Now let's say we mount a device at /tmp/a
+        # mount /dev/sd0  /tmp/a
 
         #ls /tmp/a
         t1 t2 t2
@@ -80,21 +80,20 @@ replicas continue to be exactly same.
 
         Here is an example:
 
-        Lets say /mnt has a mount which is shared.
-        #mount --make-shared /mnt
+        Let's say /mnt has a mount which is shared.
+        # mount --make-shared /mnt
 
-        Lets bind mount /mnt to /tmp
-        #mount --bind /mnt /tmp
+        Let's bind mount /mnt to /tmp
+        # mount --bind /mnt /tmp
 
         the new mount at /tmp becomes a shared mount and it is a replica of
         the mount at /mnt.
 
-        Now lets make the mount at /tmp; a slave of /mnt
-        #mount --make-slave /tmp
-        [or smount /tmp slave]
+        Now let's make the mount at /tmp; a slave of /mnt
+        # mount --make-slave /tmp
 
-        lets mount /dev/sd0 on /mnt/a
-        #mount /dev/sd0 /mnt/a
+        let's mount /dev/sd0 on /mnt/a
+        # mount /dev/sd0 /mnt/a
 
         #ls /mnt/a
         t1 t2 t3
@@ -104,9 +103,9 @@ replicas continue to be exactly same.
 
         Note the mount event has propagated to the mount at /tmp
 
-        However lets see what happens if we mount something on the mount at /tmp
+        However let's see what happens if we mount something on the mount at /tmp
 
-        #mount /dev/sd1 /tmp/b
+        # mount /dev/sd1 /tmp/b
 
         #ls /tmp/b
         s1 s2 s3
@@ -124,12 +123,11 @@ replicas continue to be exactly same.
 
 2d) A unbindable mount is a unbindable private mount
 
-        lets say we have a mount at /mnt and we make is unbindable
+        let's say we have a mount at /mnt and we make is unbindable
 
-        #mount --make-unbindable /mnt
-         [ smount /mnt  unbindable ]
+        # mount --make-unbindable /mnt
 
-         Lets try to bind mount this mount somewhere else.
+         Let's try to bind mount this mount somewhere else.
          # mount --bind /mnt /tmp
          mount: wrong fs type, bad option, bad superblock on /mnt,
                 or too many mounted file systems
@@ -137,149 +135,15 @@ replicas continue to be exactly same.
         Binding a unbindable mount is a invalid operation.
 
 
-3) smount command
+3) Setting mount states
 
-        Currently the mount command is not aware of shared subtree features.
-        Work is in progress to add the support in mount ( util-linux package ).
-        Till then use the following program.
+        The mount command (util-linux package) can be used to set mount
+        states:
 
-        ------------------------------------------------------------------------
-        //
-        //this code was developed my Miklos Szeredi <miklos@szeredi.hu>
-        //and modified by Ram Pai <linuxram@us.ibm.com>
-        // sample usage:
-        //              smount /tmp shared
-        //
-        #include <stdio.h>
-        #include <stdlib.h>
-        #include <unistd.h>
-        #include <string.h>
-        #include <sys/mount.h>
-        #include <sys/fsuid.h>
-
-        #ifndef MS_REC
-        #define MS_REC          0x4000  /* 16384: Recursive loopback */
-        #endif
-
-        #ifndef MS_SHARED
-        #define MS_SHARED               1<<20   /* Shared */
-        #endif
-
-        #ifndef MS_PRIVATE
-        #define MS_PRIVATE              1<<18   /* Private */
-        #endif
-
-        #ifndef MS_SLAVE
-        #define MS_SLAVE                1<<19   /* Slave */
-        #endif
-
-        #ifndef MS_UNBINDABLE
-        #define MS_UNBINDABLE           1<<17   /* Unbindable */
-        #endif
-
-        int main(int argc, char *argv[])
-        {
-                int type;
-                if(argc != 3) {
-                        fprintf(stderr, "usage: %s dir "
-                        "<rshared|rslave|rprivate|runbindable|shared|slave"
-                        "|private|unbindable>\n" , argv[0]);
-                        return 1;
-                }
-
-                fprintf(stdout, "%s %s %s\n", argv[0], argv[1], argv[2]);
-
-                if (strcmp(argv[2],"rshared")==0)
-                        type=(MS_SHARED|MS_REC);
-                else if (strcmp(argv[2],"rslave")==0)
-                        type=(MS_SLAVE|MS_REC);
-                else if (strcmp(argv[2],"rprivate")==0)
-                        type=(MS_PRIVATE|MS_REC);
-                else if (strcmp(argv[2],"runbindable")==0)
-                        type=(MS_UNBINDABLE|MS_REC);
-                else if (strcmp(argv[2],"shared")==0)
-                        type=MS_SHARED;
-                else if (strcmp(argv[2],"slave")==0)
-                        type=MS_SLAVE;
-                else if (strcmp(argv[2],"private")==0)
-                        type=MS_PRIVATE;
-                else if (strcmp(argv[2],"unbindable")==0)
-                        type=MS_UNBINDABLE;
-                else {
-                        fprintf(stderr, "invalid operation: %s\n", argv[2]);
-                        return 1;
-                }
-                setfsuid(getuid());
-
-                if(mount("", argv[1], "dontcare", type, "") == -1) {
-                        perror("mount");
-                        return 1;
-                }
-                return 0;
-        }
-        -----------------------------------------------------------------------
-
-        Copy the above code snippet into smount.c
-        gcc -o smount smount.c
-
-
-        (i) To mark all the mounts under /mnt as shared execute the following
-        command:
-
-                smount /mnt rshared
-                the corresponding syntax planned for mount command is
-                mount --make-rshared /mnt
-
-            just to mark a mount /mnt as shared, execute the following
-            command:
-                smount /mnt shared
-                the corresponding syntax planned for mount command is
-                mount --make-shared /mnt
-
-        (ii) To mark all the shared mounts under /mnt as slave execute the
-        following
-
-             command:
-                smount /mnt rslave
-                the corresponding syntax planned for mount command is
-                mount --make-rslave /mnt
-
-            just to mark a mount /mnt as slave, execute the following
-            command:
-                smount /mnt slave
-                the corresponding syntax planned for mount command is
-                mount --make-slave /mnt
-
-        (iii) To mark all the mounts under /mnt as private execute the
-        following command:
-
-                smount /mnt rprivate
-                the corresponding syntax planned for mount command is
-                mount --make-rprivate /mnt
-
-            just to mark a mount /mnt as private, execute the following
-            command:
-                smount /mnt private
-                the corresponding syntax planned for mount command is
-                mount --make-private /mnt
-
-              NOTE: by default all the mounts are created as private. But if
-              you want to change some shared/slave/unbindable  mount as
-              private at a later point in time, this command can help.
-
-        (iv) To mark all the mounts under /mnt as unbindable execute the
-        following
-
-             command:
-                smount /mnt runbindable
-                the corresponding syntax planned for mount command is
-                mount --make-runbindable /mnt
-
-            just to mark a mount /mnt as unbindable, execute the following
-            command:
-                smount /mnt unbindable
-                the corresponding syntax planned for mount command is
-                mount --make-unbindable /mnt
+        mount --make-shared mountpoint
+        mount --make-slave mountpoint
+        mount --make-private mountpoint
+        mount --make-unbindable mountpoint
 
 
 4) Use cases
@@ -350,7 +214,7 @@ replicas continue to be exactly same.
                 mount --rbind / /view/v3
                 mount --rbind / /view/v4
 
-                and if /usr has a versioning filesystem mounted, than that
+                and if /usr has a versioning filesystem mounted, then that
                 mount appears at /view/v1/usr, /view/v2/usr, /view/v3/usr and
                 /view/v4/usr too
 
@@ -390,7 +254,7 @@ replicas continue to be exactly same.
 
                 For example:
                         mount --make-shared /mnt
-                        mount --bin /mnt /tmp
+                        mount --bind /mnt /tmp
 
                 The mount at /mnt and that at /tmp are both shared and belong
                 to the same peer group. Anything mounted or unmounted under
@@ -558,7 +422,7 @@ replicas continue to be exactly same.
         then the subtree under the unbindable mount is pruned in the new
         location.
 
-        eg: lets say we have the following mount tree.
+        eg: let's say we have the following mount tree.
 
                 A
               /   \
@@ -566,7 +430,7 @@ replicas continue to be exactly same.
              / \ / \
              D E F G
 
-             Lets say all the mount except the mount C in the tree are
+             Let's say all the mount except the mount C in the tree are
              of a type other than unbindable.
 
              If this tree is rbound to say Z
@@ -683,13 +547,13 @@ replicas continue to be exactly same.
         'b' on mounts that receive propagation from mount 'B' and does not have
         sub-mounts within them are unmounted.
 
-        Example: Lets say 'B1', 'B2', 'B3' are shared mounts that propagate to
+        Example: Let's say 'B1', 'B2', 'B3' are shared mounts that propagate to
         each other.
 
-        lets say 'A1', 'A2', 'A3' are first mounted at dentry 'b' on mount
+        let's say 'A1', 'A2', 'A3' are first mounted at dentry 'b' on mount
         'B1', 'B2' and 'B3' respectively.
 
-        lets say 'C1', 'C2', 'C3' are next mounted at the same dentry 'b' on
+        let's say 'C1', 'C2', 'C3' are next mounted at the same dentry 'b' on
         mount 'B1', 'B2' and 'B3' respectively.
 
         if 'C1' is unmounted, all the mounts that are most-recently-mounted on
@@ -710,7 +574,7 @@ replicas continue to be exactly same.
         A cloned namespace contains all the mounts as that of the parent
         namespace.
 
-        Lets say 'A' and 'B' are the corresponding mounts in the parent and the
+        Let's say 'A' and 'B' are the corresponding mounts in the parent and the
         child namespace.
 
         If 'A' is shared, then 'B' is also shared and 'A' and 'B' propagate to
@@ -759,11 +623,11 @@ replicas continue to be exactly same.
                 mount --make-slave /mnt
 
                 At this point we have the first mount at /tmp and
-                its root dentry is 1. Lets call this mount 'A'
+                its root dentry is 1. Let's call this mount 'A'
                 And then we have a second mount at /tmp1 with root
-                dentry 2. Lets call this mount 'B'
+                dentry 2. Let's call this mount 'B'
                 Next we have a third mount at /mnt with root dentry
-                mnt. Lets call this mount 'C'
+                mnt. Let's call this mount 'C'
 
                 'B' is the slave of 'A' and 'C' is a slave of 'B'
                 A -> B -> C
@@ -794,7 +658,7 @@ replicas continue to be exactly same.
 
         Q3 Why is unbindable mount needed?
 
-                Lets say we want to replicate the mount tree at multiple
+                Let's say we want to replicate the mount tree at multiple
                 locations within the same subtree.
 
                 if one rbind mounts a tree within the same subtree 'n' times
@@ -803,7 +667,7 @@ replicas continue to be exactly same.
                 mounts. Here is a example.
 
                 step 1:
-                   lets say the root tree has just two directories with
+                   let's say the root tree has just two directories with
                    one vfsmount.
                                     root
                                    /    \
@@ -875,7 +739,7 @@ replicas continue to be exactly same.
                 Unclonable mounts come in handy here.
 
                 step 1:
-                   lets say the root tree has just two directories with
+                   let's say the root tree has just two directories with
                    one vfsmount.
                                     root
                                    /    \