[PATCH] ocfs2: fix mount option parsing

For some mount option types, ocfs2_parse_options() will try to access
sb->s_fs_info to get at the ocfs2 private superblock. Unfortunately, that
hasn't been allocated yet and will cause a kernel crash.

Fix this by storing options in a struct which can then get pushed into the
ocfs2_super once it's been allocated later. If we need more options which
store to the ocfs2_super in the future, we can just fields to this struct.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index f2fc9a7..c034b51 100644 (file)
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -81,8 +81,15 @@ static struct dentry *ocfs2_debugfs_root = NULL;
 MODULE_AUTHOR("Oracle");
 MODULE_LICENSE("GPL");
 
+struct mount_options
+{
+       unsigned long   mount_opt;
+       unsigned int    atime_quantum;
+       signed short    slot;
+};
+
 static int ocfs2_parse_options(struct super_block *sb, char *options,
-                              unsigned long *mount_opt, s16 *slot,
+                              struct mount_options *mopt,
                               int is_remount);
 static void ocfs2_put_super(struct super_block *sb);
 static int ocfs2_mount_volume(struct super_block *sb);
@@ -367,24 +374,23 @@ static int ocfs2_remount(struct super_block *sb, int *flags, char *data)
 {
        int incompat_features;
        int ret = 0;
-       unsigned long parsed_options;
-       s16 slot;
+       struct mount_options parsed_options;
        struct ocfs2_super *osb = OCFS2_SB(sb);
 
-       if (!ocfs2_parse_options(sb, data, &parsed_options, &slot, 1)) {
+       if (!ocfs2_parse_options(sb, data, &parsed_options, 1)) {
                ret = -EINVAL;
                goto out;
        }
 
        if ((osb->s_mount_opt & OCFS2_MOUNT_HB_LOCAL) !=
-           (parsed_options & OCFS2_MOUNT_HB_LOCAL)) {
+           (parsed_options.mount_opt & OCFS2_MOUNT_HB_LOCAL)) {
                ret = -EINVAL;
                mlog(ML_ERROR, "Cannot change heartbeat mode on remount\n");
                goto out;
        }
 
        if ((osb->s_mount_opt & OCFS2_MOUNT_DATA_WRITEBACK) !=
-           (parsed_options & OCFS2_MOUNT_DATA_WRITEBACK)) {
+           (parsed_options.mount_opt & OCFS2_MOUNT_DATA_WRITEBACK)) {
                ret = -EINVAL;
                mlog(ML_ERROR, "Cannot change data mode on remount\n");
                goto out;
@@ -435,7 +441,9 @@ unlock_osb:
 
                /* Only save off the new mount options in case of a successful
                 * remount. */
-               osb->s_mount_opt = parsed_options;
+               osb->s_mount_opt = parsed_options.mount_opt;
+               osb->s_atime_quantum = parsed_options.atime_quantum;
+               osb->preferred_slot = parsed_options.slot;
        }
 out:
        return ret;
@@ -547,8 +555,7 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
 {
        struct dentry *root;
        int status, sector_size;
-       unsigned long parsed_opt;
-       s16 slot;
+       struct mount_options parsed_options;
        struct inode *inode = NULL;
        struct ocfs2_super *osb = NULL;
        struct buffer_head *bh = NULL;
@@ -556,14 +563,14 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
 
        mlog_entry("%p, %p, %i", sb, data, silent);
 
-       if (!ocfs2_parse_options(sb, data, &parsed_opt, &slot, 0)) {
+       if (!ocfs2_parse_options(sb, data, &parsed_options, 0)) {
                status = -EINVAL;
                goto read_super_error;
        }
 
        /* for now we only have one cluster/node, make sure we see it
         * in the heartbeat universe */
-       if (parsed_opt & OCFS2_MOUNT_HB_LOCAL) {
+       if (parsed_options.mount_opt & OCFS2_MOUNT_HB_LOCAL) {
                if (!o2hb_check_local_node_heartbeating()) {
                        status = -EINVAL;
                        goto read_super_error;
@@ -585,8 +592,9 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
        }
        brelse(bh);
        bh = NULL;
-       osb->s_mount_opt = parsed_opt;
-       osb->preferred_slot = slot;
+       osb->s_mount_opt = parsed_options.mount_opt;
+       osb->s_atime_quantum = parsed_options.atime_quantum;
+       osb->preferred_slot = parsed_options.slot;
 
        sb->s_magic = OCFS2_SUPER_MAGIC;
 
@@ -728,8 +736,7 @@ static struct file_system_type ocfs2_fs_type = {
 
 static int ocfs2_parse_options(struct super_block *sb,
                               char *options,
-                              unsigned long *mount_opt,
-                              s16 *slot,
+                              struct mount_options *mopt,
                               int is_remount)
 {
        int status;
@@ -738,8 +745,9 @@ static int ocfs2_parse_options(struct super_block *sb,
        mlog_entry("remount: %d, options: \"%s\"\n", is_remount,
                   options ? options : "(none)");
 
-       *mount_opt = 0;
-       *slot = OCFS2_INVALID_SLOT;
+       mopt->mount_opt = 0;
+       mopt->atime_quantum = OCFS2_DEFAULT_ATIME_QUANTUM;
+       mopt->slot = OCFS2_INVALID_SLOT;
 
        if (!options) {
                status = 1;
@@ -749,7 +757,6 @@ static int ocfs2_parse_options(struct super_block *sb,
        while ((p = strsep(&options, ",")) != NULL) {
                int token, option;
                substring_t args[MAX_OPT_ARGS];
-               struct ocfs2_super * osb = OCFS2_SB(sb);
 
                if (!*p)
                        continue;
@@ -757,10 +764,10 @@ static int ocfs2_parse_options(struct super_block *sb,
                token = match_token(p, tokens, args);
                switch (token) {
                case Opt_hb_local:
-                       *mount_opt |= OCFS2_MOUNT_HB_LOCAL;
+                       mopt->mount_opt |= OCFS2_MOUNT_HB_LOCAL;
                        break;
                case Opt_hb_none:
-                       *mount_opt &= ~OCFS2_MOUNT_HB_LOCAL;
+                       mopt->mount_opt &= ~OCFS2_MOUNT_HB_LOCAL;
                        break;
                case Opt_barrier:
                        if (match_int(&args[0], &option)) {
@@ -768,27 +775,27 @@ static int ocfs2_parse_options(struct super_block *sb,
                                goto bail;
                        }
                        if (option)
-                               *mount_opt |= OCFS2_MOUNT_BARRIER;
+                               mopt->mount_opt |= OCFS2_MOUNT_BARRIER;
                        else
-                               *mount_opt &= ~OCFS2_MOUNT_BARRIER;
+                               mopt->mount_opt &= ~OCFS2_MOUNT_BARRIER;
                        break;
                case Opt_intr:
-                       *mount_opt &= ~OCFS2_MOUNT_NOINTR;
+                       mopt->mount_opt &= ~OCFS2_MOUNT_NOINTR;
                        break;
                case Opt_nointr:
-                       *mount_opt |= OCFS2_MOUNT_NOINTR;
+                       mopt->mount_opt |= OCFS2_MOUNT_NOINTR;
                        break;
                case Opt_err_panic:
-                       *mount_opt |= OCFS2_MOUNT_ERRORS_PANIC;
+                       mopt->mount_opt |= OCFS2_MOUNT_ERRORS_PANIC;
                        break;
                case Opt_err_ro:
-                       *mount_opt &= ~OCFS2_MOUNT_ERRORS_PANIC;
+                       mopt->mount_opt &= ~OCFS2_MOUNT_ERRORS_PANIC;
                        break;
                case Opt_data_ordered:
-                       *mount_opt &= ~OCFS2_MOUNT_DATA_WRITEBACK;
+                       mopt->mount_opt &= ~OCFS2_MOUNT_DATA_WRITEBACK;
                        break;
                case Opt_data_writeback:
-                       *mount_opt |= OCFS2_MOUNT_DATA_WRITEBACK;
+                       mopt->mount_opt |= OCFS2_MOUNT_DATA_WRITEBACK;
                        break;
                case Opt_atime_quantum:
                        if (match_int(&args[0], &option)) {
@@ -796,9 +803,7 @@ static int ocfs2_parse_options(struct super_block *sb,
                                goto bail;
                        }
                        if (option >= 0)
-                               osb->s_atime_quantum = option;
-                       else
-                               osb->s_atime_quantum = OCFS2_DEFAULT_ATIME_QUANTUM;
+                               mopt->atime_quantum = option;
                        break;
                case Opt_slot:
                        option = 0;
@@ -807,7 +812,7 @@ static int ocfs2_parse_options(struct super_block *sb,
                                goto bail;
                        }
                        if (option)
-                               *slot = (s16)option;
+                               mopt->slot = (s16)option;
                        break;
                default:
                        mlog(ML_ERROR,