1 files changed, 14 insertions, 16 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 0645ec428b4f..78de9d5d80c6 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -42,6 +42,7 @@
 #include "dev-replace.h"
 #include "free-space-cache.h"
 #include "backref.h"
+#include "space-info.h"
 #include "tests/btrfs-tests.h"
 
 #include "qgroup.h"
@@ -1553,6 +1554,8 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
         } else {
                 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
                 btrfs_sb(s)->bdev_holder = fs_type;
+                if (!strstr(crc32c_impl(), "generic"))
+                        set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
                 error = btrfs_fill_super(s, fs_devices, data);
         }
         if (!error)
@@ -1601,14 +1604,10 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 {
         struct vfsmount *mnt_root;
         struct dentry *root;
-        fmode_t mode = FMODE_READ;
         char *subvol_name = NULL;
         u64 subvol_objectid = 0;
         int error = 0;
 
-        if (!(flags & SB_RDONLY))
-                mode |= FMODE_WRITE;
-
         error = btrfs_parse_subvol_options(data, &subvol_name,
                                         &subvol_objectid);
         if (error) {
@@ -1904,8 +1903,9 @@ static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
         u64 type;
         u64 avail_space;
         u64 min_stripe_size;
-        int min_stripes = 1, num_stripes = 1;
+        int min_stripes, num_stripes = 1;
         int i = 0, nr_devices;
+        const struct btrfs_raid_attr *rattr;
 
         /*
          * We aren't under the device list lock, so this is racy-ish, but good
@@ -1929,21 +1929,18 @@ static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
 
         /* calc min stripe number for data space allocation */
         type = btrfs_data_alloc_profile(fs_info);
-        if (type & BTRFS_BLOCK_GROUP_RAID0) {
-                min_stripes = 2;
+        rattr = &btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)];
+        min_stripes = rattr->devs_min;
+
+        if (type & BTRFS_BLOCK_GROUP_RAID0)
                 num_stripes = nr_devices;
-        } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
-                min_stripes = 2;
+        else if (type & BTRFS_BLOCK_GROUP_RAID1)
                 num_stripes = 2;
-        } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
-                min_stripes = 4;
+        else if (type & BTRFS_BLOCK_GROUP_RAID10)
                 num_stripes = 4;
-        }
 
-        if (type & BTRFS_BLOCK_GROUP_DUP)
-                min_stripe_size = 2 * BTRFS_STRIPE_LEN;
-        else
-                min_stripe_size = BTRFS_STRIPE_LEN;
+        /* Adjust for more than 1 stripe per device */
+        min_stripe_size = rattr->dev_stripes * BTRFS_STRIPE_LEN;
 
         rcu_read_lock();
         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
@@ -2466,3 +2463,4 @@ late_initcall(init_btrfs_fs);
 module_exit(exit_btrfs_fs)
 
 MODULE_LICENSE("GPL");
+MODULE_SOFTDEP("pre: crc32c");