block: clean up cmdfilter sysfs interface

This patch changes the interface of the cmd filter to use a +/-
notation like:

echo -- +0x02 +0x03 -0x08

If neither + or - is given it defaults to + (allow command).

Note: The interface was added in 2.6.17-rc1 and is unused and
undocumented so far so it's safe to change it.

Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: jens.axboe@oracle.com
Cc: James.Bottomley@hansenpartnership.com
Cc: dan.j.williams@intel.com
Cc: pjones@redhat.com
Cc: viro@zeniv.linux.org.uk
Cc: dougg@torque.net
Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 30 insertions, 24 deletions

diff --git a/block/cmd-filter.c b/block/cmd-filter.c
index 0e3a123944a..1d4026206ac 100644
--- a/block/cmd-filter.c
+++ b/block/cmd-filter.c
@@ -20,7 +20,6 @@
 #include <linux/list.h>
 #include <linux/genhd.h>
 #include <linux/spinlock.h>
-#include <linux/parser.h>
 #include <linux/capability.h>
 #include <linux/bitops.h>
 
@@ -65,8 +64,7 @@ static ssize_t rcf_cmds_show(struct blk_cmd_filter *filter, char *page,
 
         for (i = 0; i < BLK_SCSI_MAX_CMDS; i++) {
                 if (test_bit(i, okbits)) {
-                        sprintf(npage, "%02x", i);
-                        npage += 2;
+                        npage += sprintf(npage, "0x%02x", i);
                         if (i < BLK_SCSI_MAX_CMDS - 1)
                                 sprintf(npage++, " ");
                 }
@@ -92,33 +90,41 @@ static ssize_t rcf_writecmds_show(struct blk_cmd_filter *filter,
 static ssize_t rcf_cmds_store(struct blk_cmd_filter *filter,
                               const char *page, size_t count, int rw)
 {
-        ssize_t ret = 0;
         unsigned long okbits[BLK_SCSI_CMD_PER_LONG], *target_okbits;
-        int cmd, status, len;
-        substring_t ss;
-
-        memset(&okbits, 0, sizeof(okbits));
-
-        for (len = strlen(page); len > 0; len -= 3) {
-                if (len < 2)
-                        break;
-                ss.from = (char *) page + ret;
-                ss.to = (char *) page + ret + 2;
-                ret += 3;
-                status = match_hex(&ss, &cmd);
+        int cmd, set;
+        char *p, *status;
+
+        if (rw == READ) {
+                memcpy(&okbits, filter->read_ok, sizeof(okbits));
+                target_okbits = filter->read_ok;
+        } else {
+                memcpy(&okbits, filter->write_ok, sizeof(okbits));
+                target_okbits = filter->write_ok;
+        }
+
+        while ((p = strsep((char **)&page, " ")) != NULL) {
+                set = 1;
+
+                if (p[0] == '+') {
+                        p++;
+                } else if (p[0] == '-') {
+                        set = 0;
+                        p++;
+                }
+
+                cmd = simple_strtol(p, &status, 16);
+
                 /* either of these cases means invalid input, so do nothing. */
-                if (status || cmd >= BLK_SCSI_MAX_CMDS)
+                if ((status == p) || cmd >= BLK_SCSI_MAX_CMDS)
                         return -EINVAL;
 
-                __set_bit(cmd, okbits);
+                if (set)
+                        __set_bit(cmd, okbits);
+                else
+                        __clear_bit(cmd, okbits);
         }
 
-        if (rw == READ)
-                target_okbits = filter->read_ok;
-        else
-                target_okbits = filter->write_ok;
-
-        memmove(target_okbits, okbits, sizeof(okbits));
+        memcpy(target_okbits, okbits, sizeof(okbits));
         return count;
 }