1 files changed, 69 insertions, 48 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index c5f8fca4195f..96eb9fef7bd2 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -188,7 +188,8 @@ void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...)
         va_start(args, fmt);
 
         if (fmt[0] == '<' && isdigit(fmt[1]) && fmt[2] == '>') {
-                strncpy(lvl, fmt, 3);
+                memcpy(lvl, fmt, 3);
+                lvl[3] = '\0';
                 fmt += 3;
                 type = logtypes[fmt[1] - '0'];
         } else
@@ -435,11 +436,8 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                 case Opt_thread_pool:
                         intarg = 0;
                         match_int(&args[0], &intarg);
-                        if (intarg) {
+                        if (intarg)
                                 info->thread_pool_size = intarg;
-                                printk(KERN_INFO "btrfs: thread pool %d\n",
-                                       info->thread_pool_size);
-                        }
                         break;
                 case Opt_max_inline:
                         num = match_strdup(&args[0]);
@@ -769,7 +767,7 @@ static int btrfs_fill_super(struct super_block *sb,
 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
         sb->s_flags |= MS_POSIXACL;
 #endif
-
+        sb->s_flags |= MS_I_VERSION;
         err = open_ctree(sb, fs_devices, (char *)data);
         if (err) {
                 printk("btrfs: open_ctree failed\n");
@@ -925,63 +923,48 @@ static inline int is_subvolume_inode(struct inode *inode)
  */
 static char *setup_root_args(char *args)
 {
-        unsigned copied = 0;
-        unsigned len = strlen(args) + 2;
-        char *pos;
-        char *ret;
+        unsigned len = strlen(args) + 2 + 1;
+        char *src, *dst, *buf;
 
         /*
-         * We need the same args as before, but minus
-         *
-         * subvol=a
-         *
-         * and add
-         *
-         * subvolid=0
+         * We need the same args as before, but with this substitution:
+         * s!subvol=[^,]+!subvolid=0!
          *
-         * which is a difference of 2 characters, so we allocate strlen(args) +
-         * 2 characters.
+         * Since the replacement string is up to 2 bytes longer than the
+         * original, allocate strlen(args) + 2 + 1 bytes.
          */
-        ret = kzalloc(len * sizeof(char), GFP_NOFS);
-        if (!ret)
-                return NULL;
-        pos = strstr(args, "subvol=");
 
+        src = strstr(args, "subvol=");
         /* This shouldn't happen, but just in case.. */
-        if (!pos) {
-                kfree(ret);
+        if (!src)
+                return NULL;
+
+        buf = dst = kmalloc(len, GFP_NOFS);
+        if (!buf)
                 return NULL;
-        }
 
         /*
-         * The subvol=<> arg is not at the front of the string, copy everybody
-         * up to that into ret.
+         * If the subvol= arg is not at the start of the string,
+         * copy whatever precedes it into buf.
          */
-        if (pos != args) {
-                *pos = '\0';
-                strcpy(ret, args);
-                copied += strlen(args);
-                pos++;
+        if (src != args) {
+                *src++ = '\0';
+                strcpy(buf, args);
+                dst += strlen(args);
         }
 
-        strncpy(ret + copied, "subvolid=0", len - copied);
-
-        /* Length of subvolid=0 */
-        copied += 10;
+        strcpy(dst, "subvolid=0");
+        dst += strlen("subvolid=0");
 
         /*
-         * If there is no , after the subvol= option then we know there's no
-         * other options and we can just return.
+         * If there is a "," after the original subvol=... string,
+         * copy that suffix into our buffer.  Otherwise, we're done.
          */
-        pos = strchr(pos, ',');
-        if (!pos)
-                return ret;
+        src = strchr(src, ',');
+        if (src)
+                strcpy(dst, src);
 
-        /* Copy the rest of the arguments into our buffer */
-        strncpy(ret + copied, pos, len - copied);
-        copied += strlen(pos);
-
-        return ret;
+        return buf;
 }
 
 static struct dentry *mount_subvol(const char *subvol_name, int flags,
@@ -1118,6 +1101,40 @@ error_fs_info:
         return ERR_PTR(error);
 }
 
+static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
+{
+        spin_lock_irq(&workers->lock);
+        workers->max_workers = new_limit;
+        spin_unlock_irq(&workers->lock);
+}
+
+static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
+                                     int new_pool_size, int old_pool_size)
+{
+        if (new_pool_size == old_pool_size)
+                return;
+
+        fs_info->thread_pool_size = new_pool_size;
+
+        printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n",
+               old_pool_size, new_pool_size);
+
+        btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
+        btrfs_set_max_workers(&fs_info->workers, new_pool_size);
+        btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
+        btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
+        btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
+        btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
+        btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
+        btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
+        btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
+        btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
+        btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
+        btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
+        btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
+        btrfs_set_max_workers(&fs_info->scrub_workers, new_pool_size);
+}
+
 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 {
         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
@@ -1137,6 +1154,9 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
                 goto restore;
         }
 
+        btrfs_resize_thread_pool(fs_info,
+                fs_info->thread_pool_size, old_thread_pool_size);
+
         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
                 return 0;
 
@@ -1180,7 +1200,8 @@ restore:
         fs_info->compress_type = old_compress_type;
         fs_info->max_inline = old_max_inline;
         fs_info->alloc_start = old_alloc_start;
-        fs_info->thread_pool_size = old_thread_pool_size;
+        btrfs_resize_thread_pool(fs_info,
+                old_thread_pool_size, fs_info->thread_pool_size);
         fs_info->metadata_ratio = old_metadata_ratio;
         return ret;
 }