btrfs-progs: update man page for btrfs filesystem label
[platform/upstream/btrfs-progs.git] / volumes.c
index a3acee8..10fdc48 100644 (file)
--- a/volumes.c
+++ b/volumes.c
@@ -29,6 +29,7 @@
 #include "transaction.h"
 #include "print-tree.h"
 #include "volumes.h"
+#include "math.h"
 
 struct stripe {
        struct btrfs_device *dev;
@@ -52,9 +53,6 @@ static inline int nr_data_stripes(struct map_lookup *map)
 
 #define is_parity_stripe(x) ( ((x) == BTRFS_RAID5_P_STRIPE) || ((x) == BTRFS_RAID6_Q_STRIPE) )
 
-#define map_lookup_size(n) (sizeof(struct map_lookup) + \
-                           (sizeof(struct btrfs_bio_stripe) * (n)))
-
 static LIST_HEAD(fs_uuids);
 
 static struct btrfs_device *__find_device(struct list_head *head, u64 devid,
@@ -192,6 +190,10 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int flags)
 
        list_for_each(cur, head) {
                device = list_entry(cur, struct btrfs_device, dev_list);
+               if (!device->name) {
+                       printk("no name for device %llu, skip it now\n", device->devid);
+                       continue;
+               }
 
                fd = open(device->name, flags);
                if (fd < 0) {
@@ -629,14 +631,6 @@ int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
        return 0;
 }
 
-static u64 div_factor(u64 num, int factor)
-{
-       if (factor == 10)
-               return num;
-       num *= factor;
-       return num / 10;
-}
-
 static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
                               int sub_stripes)
 {
@@ -823,7 +817,7 @@ again:
        if (!chunk)
                return -ENOMEM;
 
-       map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+       map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
        if (!map) {
                kfree(chunk);
                return -ENOMEM;
@@ -935,7 +929,7 @@ int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
        if (!chunk)
                return -ENOMEM;
 
-       map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+       map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
        if (!map) {
                kfree(chunk);
                return -ENOMEM;
@@ -1389,16 +1383,15 @@ struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
        return NULL;
 }
 
-struct btrfs_device *btrfs_find_device_by_devid(struct btrfs_root *root,
-                                               u64 devid, int instance)
+struct btrfs_device *
+btrfs_find_device_by_devid(struct btrfs_fs_devices *fs_devices,
+                          u64 devid, int instance)
 {
-       struct list_head *head = &root->fs_info->fs_devices->devices;
+       struct list_head *head = &fs_devices->devices;
        struct btrfs_device *dev;
-       struct list_head *cur;
        int num_found = 0;
 
-       list_for_each(cur, head) {
-               dev = list_entry(cur, struct btrfs_device, dev_list);
+       list_for_each_entry(dev, head, dev_list) {
                if (dev->devid == devid && num_found++ == instance)
                        return dev;
        }
@@ -1420,7 +1413,7 @@ int btrfs_bootstrap_super_map(struct btrfs_mapping_tree *map_tree,
        list_for_each(cur, &fs_devices->devices) {
                num_stripes++;
        }
-       map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+       map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
        if (!map)
                return -ENOMEM;
 
@@ -1517,7 +1510,7 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
        }
 
        num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
-       map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+       map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
        if (!map)
                return -ENOMEM;
 
@@ -1631,10 +1624,10 @@ static int read_one_dev(struct btrfs_root *root,
        if (!device) {
                printk("warning devid %llu not found already\n",
                        (unsigned long long)devid);
-               device = kmalloc(sizeof(*device), GFP_NOFS);
+               device = kzalloc(sizeof(*device), GFP_NOFS);
                if (!device)
                        return -ENOMEM;
-               device->total_ios = 0;
+               device->fd = -1;
                list_add(&device->dev_list,
                         &root->fs_info->fs_devices->devices);
        }
@@ -1773,3 +1766,146 @@ struct list_head *btrfs_scanned_uuids(void)
 {
        return &fs_uuids;
 }
+
+static int rmw_eb(struct btrfs_fs_info *info,
+                 struct extent_buffer *eb, struct extent_buffer *orig_eb)
+{
+       int ret;
+       unsigned long orig_off = 0;
+       unsigned long dest_off = 0;
+       unsigned long copy_len = eb->len;
+
+       ret = read_whole_eb(info, eb, 0);
+       if (ret)
+               return ret;
+
+       if (eb->start + eb->len <= orig_eb->start ||
+           eb->start >= orig_eb->start + orig_eb->len)
+               return 0;
+       /*
+        * | ----- orig_eb ------- |
+        *         | ----- stripe -------  |
+        *         | ----- orig_eb ------- |
+        *              | ----- orig_eb ------- |
+        */
+       if (eb->start > orig_eb->start)
+               orig_off = eb->start - orig_eb->start;
+       if (orig_eb->start > eb->start)
+               dest_off = orig_eb->start - eb->start;
+
+       if (copy_len > orig_eb->len - orig_off)
+               copy_len = orig_eb->len - orig_off;
+       if (copy_len > eb->len - dest_off)
+               copy_len = eb->len - dest_off;
+
+       memcpy(eb->data + dest_off, orig_eb->data + orig_off, copy_len);
+       return 0;
+}
+
+static void split_eb_for_raid56(struct btrfs_fs_info *info,
+                               struct extent_buffer *orig_eb,
+                              struct extent_buffer **ebs,
+                              u64 stripe_len, u64 *raid_map,
+                              int num_stripes)
+{
+       struct extent_buffer *eb;
+       u64 start = orig_eb->start;
+       u64 this_eb_start;
+       int i;
+       int ret;
+
+       for (i = 0; i < num_stripes; i++) {
+               if (raid_map[i] >= BTRFS_RAID5_P_STRIPE)
+                       break;
+
+               eb = malloc(sizeof(struct extent_buffer) + stripe_len);
+               if (!eb)
+                       BUG();
+               memset(eb, 0, sizeof(struct extent_buffer) + stripe_len);
+
+               eb->start = raid_map[i];
+               eb->len = stripe_len;
+               eb->refs = 1;
+               eb->flags = 0;
+               eb->fd = -1;
+               eb->dev_bytenr = (u64)-1;
+
+               this_eb_start = raid_map[i];
+
+               if (start > this_eb_start ||
+                   start + orig_eb->len < this_eb_start + stripe_len) {
+                       ret = rmw_eb(info, eb, orig_eb);
+                       BUG_ON(ret);
+               } else {
+                       memcpy(eb->data, orig_eb->data + eb->start - start, stripe_len);
+               }
+               ebs[i] = eb;
+       }
+}
+
+int write_raid56_with_parity(struct btrfs_fs_info *info,
+                            struct extent_buffer *eb,
+                            struct btrfs_multi_bio *multi,
+                            u64 stripe_len, u64 *raid_map)
+{
+       struct extent_buffer *ebs[multi->num_stripes], *p_eb = NULL, *q_eb = NULL;
+       int i;
+       int j;
+       int ret;
+       int alloc_size = eb->len;
+
+       if (stripe_len > alloc_size)
+               alloc_size = stripe_len;
+
+       split_eb_for_raid56(info, eb, ebs, stripe_len, raid_map,
+                           multi->num_stripes);
+
+       for (i = 0; i < multi->num_stripes; i++) {
+               struct extent_buffer *new_eb;
+               if (raid_map[i] < BTRFS_RAID5_P_STRIPE) {
+                       ebs[i]->dev_bytenr = multi->stripes[i].physical;
+                       ebs[i]->fd = multi->stripes[i].dev->fd;
+                       multi->stripes[i].dev->total_ios++;
+                       BUG_ON(ebs[i]->start != raid_map[i]);
+                       continue;
+               }
+               new_eb = kmalloc(sizeof(*eb) + alloc_size, GFP_NOFS);
+               BUG_ON(!new_eb);
+               new_eb->dev_bytenr = multi->stripes[i].physical;
+               new_eb->fd = multi->stripes[i].dev->fd;
+               multi->stripes[i].dev->total_ios++;
+               new_eb->len = stripe_len;
+
+               if (raid_map[i] == BTRFS_RAID5_P_STRIPE)
+                       p_eb = new_eb;
+               else if (raid_map[i] == BTRFS_RAID6_Q_STRIPE)
+                       q_eb = new_eb;
+       }
+       if (q_eb) {
+               void *pointers[multi->num_stripes];
+               ebs[multi->num_stripes - 2] = p_eb;
+               ebs[multi->num_stripes - 1] = q_eb;
+
+               for (i = 0; i < multi->num_stripes; i++)
+                       pointers[i] = ebs[i]->data;
+
+               raid6_gen_syndrome(multi->num_stripes, stripe_len, pointers);
+       } else {
+               ebs[multi->num_stripes - 1] = p_eb;
+               memcpy(p_eb->data, ebs[0]->data, stripe_len);
+               for (j = 1; j < multi->num_stripes - 1; j++) {
+                       for (i = 0; i < stripe_len; i += sizeof(unsigned long)) {
+                               *(unsigned long *)(p_eb->data + i) ^=
+                                       *(unsigned long *)(ebs[j]->data + i);
+                       }
+               }
+       }
+
+       for (i = 0; i < multi->num_stripes; i++) {
+               ret = write_extent_to_disk(ebs[i]);
+               BUG_ON(ret);
+               if (ebs[i] != eb)
+                       kfree(ebs[i]);
+       }
+       return 0;
+}