Merge git://git.jan-o-sch.net/btrfs-unstable into integration
authorChris Mason <chris.mason@oracle.com>
Sun, 6 Nov 2011 08:07:10 +0000 (03:07 -0500)
committerChris Mason <chris.mason@oracle.com>
Sun, 6 Nov 2011 08:07:10 +0000 (03:07 -0500)
Conflicts:
fs/btrfs/Makefile
fs/btrfs/extent_io.c
fs/btrfs/extent_io.h
fs/btrfs/scrub.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
14 files changed:
fs/btrfs/Makefile
fs/btrfs/backref.c [new file with mode: 0644]
fs/btrfs/backref.h [new file with mode: 0644]
fs/btrfs/disk-io.c
fs/btrfs/extent-tree.c
fs/btrfs/extent_io.c
fs/btrfs/extent_io.h
fs/btrfs/inode.c
fs/btrfs/ioctl.c
fs/btrfs/ioctl.h
fs/btrfs/reada.c
fs/btrfs/scrub.c
fs/btrfs/volumes.c
fs/btrfs/volumes.h

index bdd6fb2..c0ddfd2 100644 (file)
@@ -8,6 +8,6 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
           extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \
           export.o tree-log.o free-space-cache.o zlib.o lzo.o \
           compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
-          reada.o
+          reada.o backref.o
 
 btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
new file mode 100644 (file)
index 0000000..2351df0
--- /dev/null
@@ -0,0 +1,776 @@
+/*
+ * Copyright (C) 2011 STRATO.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "ctree.h"
+#include "disk-io.h"
+#include "backref.h"
+
+struct __data_ref {
+       struct list_head list;
+       u64 inum;
+       u64 root;
+       u64 extent_data_item_offset;
+};
+
+struct __shared_ref {
+       struct list_head list;
+       u64 disk_byte;
+};
+
+static int __inode_info(u64 inum, u64 ioff, u8 key_type,
+                       struct btrfs_root *fs_root, struct btrfs_path *path,
+                       struct btrfs_key *found_key)
+{
+       int ret;
+       struct btrfs_key key;
+       struct extent_buffer *eb;
+
+       key.type = key_type;
+       key.objectid = inum;
+       key.offset = ioff;
+
+       ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
+       if (ret < 0)
+               return ret;
+
+       eb = path->nodes[0];
+       if (ret && path->slots[0] >= btrfs_header_nritems(eb)) {
+               ret = btrfs_next_leaf(fs_root, path);
+               if (ret)
+                       return ret;
+               eb = path->nodes[0];
+       }
+
+       btrfs_item_key_to_cpu(eb, found_key, path->slots[0]);
+       if (found_key->type != key.type || found_key->objectid != key.objectid)
+               return 1;
+
+       return 0;
+}
+
+/*
+ * this makes the path point to (inum INODE_ITEM ioff)
+ */
+int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root,
+                       struct btrfs_path *path)
+{
+       struct btrfs_key key;
+       return __inode_info(inum, ioff, BTRFS_INODE_ITEM_KEY, fs_root, path,
+                               &key);
+}
+
+static int inode_ref_info(u64 inum, u64 ioff, struct btrfs_root *fs_root,
+                               struct btrfs_path *path,
+                               struct btrfs_key *found_key)
+{
+       return __inode_info(inum, ioff, BTRFS_INODE_REF_KEY, fs_root, path,
+                               found_key);
+}
+
+/*
+ * this iterates to turn a btrfs_inode_ref into a full filesystem path. elements
+ * of the path are separated by '/' and the path is guaranteed to be
+ * 0-terminated. the path is only given within the current file system.
+ * Therefore, it never starts with a '/'. the caller is responsible to provide
+ * "size" bytes in "dest". the dest buffer will be filled backwards. finally,
+ * the start point of the resulting string is returned. this pointer is within
+ * dest, normally.
+ * in case the path buffer would overflow, the pointer is decremented further
+ * as if output was written to the buffer, though no more output is actually
+ * generated. that way, the caller can determine how much space would be
+ * required for the path to fit into the buffer. in that case, the returned
+ * value will be smaller than dest. callers must check this!
+ */
+static char *iref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
+                               struct btrfs_inode_ref *iref,
+                               struct extent_buffer *eb_in, u64 parent,
+                               char *dest, u32 size)
+{
+       u32 len;
+       int slot;
+       u64 next_inum;
+       int ret;
+       s64 bytes_left = size - 1;
+       struct extent_buffer *eb = eb_in;
+       struct btrfs_key found_key;
+
+       if (bytes_left >= 0)
+               dest[bytes_left] = '\0';
+
+       while (1) {
+               len = btrfs_inode_ref_name_len(eb, iref);
+               bytes_left -= len;
+               if (bytes_left >= 0)
+                       read_extent_buffer(eb, dest + bytes_left,
+                                               (unsigned long)(iref + 1), len);
+               if (eb != eb_in)
+                       free_extent_buffer(eb);
+               ret = inode_ref_info(parent, 0, fs_root, path, &found_key);
+               if (ret)
+                       break;
+               next_inum = found_key.offset;
+
+               /* regular exit ahead */
+               if (parent == next_inum)
+                       break;
+
+               slot = path->slots[0];
+               eb = path->nodes[0];
+               /* make sure we can use eb after releasing the path */
+               if (eb != eb_in)
+                       atomic_inc(&eb->refs);
+               btrfs_release_path(path);
+
+               iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
+               parent = next_inum;
+               --bytes_left;
+               if (bytes_left >= 0)
+                       dest[bytes_left] = '/';
+       }
+
+       btrfs_release_path(path);
+
+       if (ret)
+               return ERR_PTR(ret);
+
+       return dest + bytes_left;
+}
+
+/*
+ * this makes the path point to (logical EXTENT_ITEM *)
+ * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for
+ * tree blocks and <0 on error.
+ */
+int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
+                       struct btrfs_path *path, struct btrfs_key *found_key)
+{
+       int ret;
+       u64 flags;
+       u32 item_size;
+       struct extent_buffer *eb;
+       struct btrfs_extent_item *ei;
+       struct btrfs_key key;
+
+       key.type = BTRFS_EXTENT_ITEM_KEY;
+       key.objectid = logical;
+       key.offset = (u64)-1;
+
+       ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
+       if (ret < 0)
+               return ret;
+       ret = btrfs_previous_item(fs_info->extent_root, path,
+                                       0, BTRFS_EXTENT_ITEM_KEY);
+       if (ret < 0)
+               return ret;
+
+       btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]);
+       if (found_key->type != BTRFS_EXTENT_ITEM_KEY ||
+           found_key->objectid > logical ||
+           found_key->objectid + found_key->offset <= logical)
+               return -ENOENT;
+
+       eb = path->nodes[0];
+       item_size = btrfs_item_size_nr(eb, path->slots[0]);
+       BUG_ON(item_size < sizeof(*ei));
+
+       ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
+       flags = btrfs_extent_flags(eb, ei);
+
+       if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
+               return BTRFS_EXTENT_FLAG_TREE_BLOCK;
+       if (flags & BTRFS_EXTENT_FLAG_DATA)
+               return BTRFS_EXTENT_FLAG_DATA;
+
+       return -EIO;
+}
+
+/*
+ * helper function to iterate extent inline refs. ptr must point to a 0 value
+ * for the first call and may be modified. it is used to track state.
+ * if more refs exist, 0 is returned and the next call to
+ * __get_extent_inline_ref must pass the modified ptr parameter to get the
+ * next ref. after the last ref was processed, 1 is returned.
+ * returns <0 on error
+ */
+static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb,
+                               struct btrfs_extent_item *ei, u32 item_size,
+                               struct btrfs_extent_inline_ref **out_eiref,
+                               int *out_type)
+{
+       unsigned long end;
+       u64 flags;
+       struct btrfs_tree_block_info *info;
+
+       if (!*ptr) {
+               /* first call */
+               flags = btrfs_extent_flags(eb, ei);
+               if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
+                       info = (struct btrfs_tree_block_info *)(ei + 1);
+                       *out_eiref =
+                               (struct btrfs_extent_inline_ref *)(info + 1);
+               } else {
+                       *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1);
+               }
+               *ptr = (unsigned long)*out_eiref;
+               if ((void *)*ptr >= (void *)ei + item_size)
+                       return -ENOENT;
+       }
+
+       end = (unsigned long)ei + item_size;
+       *out_eiref = (struct btrfs_extent_inline_ref *)*ptr;
+       *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref);
+
+       *ptr += btrfs_extent_inline_ref_size(*out_type);
+       WARN_ON(*ptr > end);
+       if (*ptr == end)
+               return 1; /* last */
+
+       return 0;
+}
+
+/*
+ * reads the tree block backref for an extent. tree level and root are returned
+ * through out_level and out_root. ptr must point to a 0 value for the first
+ * call and may be modified (see __get_extent_inline_ref comment).
+ * returns 0 if data was provided, 1 if there was no more data to provide or
+ * <0 on error.
+ */
+int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
+                               struct btrfs_extent_item *ei, u32 item_size,
+                               u64 *out_root, u8 *out_level)
+{
+       int ret;
+       int type;
+       struct btrfs_tree_block_info *info;
+       struct btrfs_extent_inline_ref *eiref;
+
+       if (*ptr == (unsigned long)-1)
+               return 1;
+
+       while (1) {
+               ret = __get_extent_inline_ref(ptr, eb, ei, item_size,
+                                               &eiref, &type);
+               if (ret < 0)
+                       return ret;
+
+               if (type == BTRFS_TREE_BLOCK_REF_KEY ||
+                   type == BTRFS_SHARED_BLOCK_REF_KEY)
+                       break;
+
+               if (ret == 1)
+                       return 1;
+       }
+
+       /* we can treat both ref types equally here */
+       info = (struct btrfs_tree_block_info *)(ei + 1);
+       *out_root = btrfs_extent_inline_ref_offset(eb, eiref);
+       *out_level = btrfs_tree_block_level(eb, info);
+
+       if (ret == 1)
+               *ptr = (unsigned long)-1;
+
+       return 0;
+}
+
+static int __data_list_add(struct list_head *head, u64 inum,
+                               u64 extent_data_item_offset, u64 root)
+{
+       struct __data_ref *ref;
+
+       ref = kmalloc(sizeof(*ref), GFP_NOFS);
+       if (!ref)
+               return -ENOMEM;
+
+       ref->inum = inum;
+       ref->extent_data_item_offset = extent_data_item_offset;
+       ref->root = root;
+       list_add_tail(&ref->list, head);
+
+       return 0;
+}
+
+static int __data_list_add_eb(struct list_head *head, struct extent_buffer *eb,
+                               struct btrfs_extent_data_ref *dref)
+{
+       return __data_list_add(head, btrfs_extent_data_ref_objectid(eb, dref),
+                               btrfs_extent_data_ref_offset(eb, dref),
+                               btrfs_extent_data_ref_root(eb, dref));
+}
+
+static int __shared_list_add(struct list_head *head, u64 disk_byte)
+{
+       struct __shared_ref *ref;
+
+       ref = kmalloc(sizeof(*ref), GFP_NOFS);
+       if (!ref)
+               return -ENOMEM;
+
+       ref->disk_byte = disk_byte;
+       list_add_tail(&ref->list, head);
+
+       return 0;
+}
+
+static int __iter_shared_inline_ref_inodes(struct btrfs_fs_info *fs_info,
+                                          u64 logical, u64 inum,
+                                          u64 extent_data_item_offset,
+                                          u64 extent_offset,
+                                          struct btrfs_path *path,
+                                          struct list_head *data_refs,
+                                          iterate_extent_inodes_t *iterate,
+                                          void *ctx)
+{
+       u64 ref_root;
+       u32 item_size;
+       struct btrfs_key key;
+       struct extent_buffer *eb;
+       struct btrfs_extent_item *ei;
+       struct btrfs_extent_inline_ref *eiref;
+       struct __data_ref *ref;
+       int ret;
+       int type;
+       int last;
+       unsigned long ptr = 0;
+
+       WARN_ON(!list_empty(data_refs));
+       ret = extent_from_logical(fs_info, logical, path, &key);
+       if (ret & BTRFS_EXTENT_FLAG_DATA)
+               ret = -EIO;
+       if (ret < 0)
+               goto out;
+
+       eb = path->nodes[0];
+       ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
+       item_size = btrfs_item_size_nr(eb, path->slots[0]);
+
+       ret = 0;
+       ref_root = 0;
+       /*
+        * as done in iterate_extent_inodes, we first build a list of refs to
+        * iterate, then free the path and then iterate them to avoid deadlocks.
+        */
+       do {
+               last = __get_extent_inline_ref(&ptr, eb, ei, item_size,
+                                               &eiref, &type);
+               if (last < 0) {
+                       ret = last;
+                       goto out;
+               }
+               if (type == BTRFS_TREE_BLOCK_REF_KEY ||
+                   type == BTRFS_SHARED_BLOCK_REF_KEY) {
+                       ref_root = btrfs_extent_inline_ref_offset(eb, eiref);
+                       ret = __data_list_add(data_refs, inum,
+                                               extent_data_item_offset,
+                                               ref_root);
+               }
+       } while (!ret && !last);
+
+       btrfs_release_path(path);
+
+       if (ref_root == 0) {
+               printk(KERN_ERR "btrfs: failed to find tree block ref "
+                       "for shared data backref %llu\n", logical);
+               WARN_ON(1);
+               ret = -EIO;
+       }
+
+out:
+       while (!list_empty(data_refs)) {
+               ref = list_first_entry(data_refs, struct __data_ref, list);
+               list_del(&ref->list);
+               if (!ret)
+                       ret = iterate(ref->inum, extent_offset +
+                                       ref->extent_data_item_offset,
+                                       ref->root, ctx);
+               kfree(ref);
+       }
+
+       return ret;
+}
+
+static int __iter_shared_inline_ref(struct btrfs_fs_info *fs_info,
+                                   u64 logical, u64 orig_extent_item_objectid,
+                                   u64 extent_offset, struct btrfs_path *path,
+                                   struct list_head *data_refs,
+                                   iterate_extent_inodes_t *iterate,
+                                   void *ctx)
+{
+       u64 disk_byte;
+       struct btrfs_key key;
+       struct btrfs_file_extent_item *fi;
+       struct extent_buffer *eb;
+       int slot;
+       int nritems;
+       int ret;
+       int found = 0;
+
+       eb = read_tree_block(fs_info->tree_root, logical,
+                               fs_info->tree_root->leafsize, 0);
+       if (!eb)
+               return -EIO;
+
+       /*
+        * from the shared data ref, we only have the leaf but we need
+        * the key. thus, we must look into all items and see that we
+        * find one (some) with a reference to our extent item.
+        */
+       nritems = btrfs_header_nritems(eb);
+       for (slot = 0; slot < nritems; ++slot) {
+               btrfs_item_key_to_cpu(eb, &key, slot);
+               if (key.type != BTRFS_EXTENT_DATA_KEY)
+                       continue;
+               fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
+               if (!fi) {
+                       free_extent_buffer(eb);
+                       return -EIO;
+               }
+               disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
+               if (disk_byte != orig_extent_item_objectid) {
+                       if (found)
+                               break;
+                       else
+                               continue;
+               }
+               ++found;
+               ret = __iter_shared_inline_ref_inodes(fs_info, logical,
+                                                       key.objectid,
+                                                       key.offset,
+                                                       extent_offset, path,
+                                                       data_refs,
+                                                       iterate, ctx);
+               if (ret)
+                       break;
+       }
+
+       if (!found) {
+               printk(KERN_ERR "btrfs: failed to follow shared data backref "
+                       "to parent %llu\n", logical);
+               WARN_ON(1);
+               ret = -EIO;
+       }
+
+       free_extent_buffer(eb);
+       return ret;
+}
+
+/*
+ * calls iterate() for every inode that references the extent identified by
+ * the given parameters. will use the path given as a parameter and return it
+ * released.
+ * when the iterator function returns a non-zero value, iteration stops.
+ */
+int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
+                               struct btrfs_path *path,
+                               u64 extent_item_objectid,
+                               u64 extent_offset,
+                               iterate_extent_inodes_t *iterate, void *ctx)
+{
+       unsigned long ptr = 0;
+       int last;
+       int ret;
+       int type;
+       u64 logical;
+       u32 item_size;
+       struct btrfs_extent_inline_ref *eiref;
+       struct btrfs_extent_data_ref *dref;
+       struct extent_buffer *eb;
+       struct btrfs_extent_item *ei;
+       struct btrfs_key key;
+       struct list_head data_refs = LIST_HEAD_INIT(data_refs);
+       struct list_head shared_refs = LIST_HEAD_INIT(shared_refs);
+       struct __data_ref *ref_d;
+       struct __shared_ref *ref_s;
+
+       eb = path->nodes[0];
+       ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
+       item_size = btrfs_item_size_nr(eb, path->slots[0]);
+
+       /* first we iterate the inline refs, ... */
+       do {
+               last = __get_extent_inline_ref(&ptr, eb, ei, item_size,
+                                               &eiref, &type);
+               if (last == -ENOENT) {
+                       ret = 0;
+                       break;
+               }
+               if (last < 0) {
+                       ret = last;
+                       break;
+               }
+
+               if (type == BTRFS_EXTENT_DATA_REF_KEY) {
+                       dref = (struct btrfs_extent_data_ref *)(&eiref->offset);
+                       ret = __data_list_add_eb(&data_refs, eb, dref);
+               } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
+                       logical = btrfs_extent_inline_ref_offset(eb, eiref);
+                       ret = __shared_list_add(&shared_refs, logical);
+               }
+       } while (!ret && !last);
+
+       /* ... then we proceed to in-tree references and ... */
+       while (!ret) {
+               ++path->slots[0];
+               if (path->slots[0] > btrfs_header_nritems(eb)) {
+                       ret = btrfs_next_leaf(fs_info->extent_root, path);
+                       if (ret) {
+                               if (ret == 1)
+                                       ret = 0; /* we're done */
+                               break;
+                       }
+                       eb = path->nodes[0];
+               }
+               btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
+               if (key.objectid != extent_item_objectid)
+                       break;
+               if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
+                       dref = btrfs_item_ptr(eb, path->slots[0],
+                                               struct btrfs_extent_data_ref);
+                       ret = __data_list_add_eb(&data_refs, eb, dref);
+               } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
+                       ret = __shared_list_add(&shared_refs, key.offset);
+               }
+       }
+
+       btrfs_release_path(path);
+
+       /*
+        * ... only at the very end we can process the refs we found. this is
+        * because the iterator function we call is allowed to make tree lookups
+        * and we have to avoid deadlocks. additionally, we need more tree
+        * lookups ourselves for shared data refs.
+        */
+       while (!list_empty(&data_refs)) {
+               ref_d = list_first_entry(&data_refs, struct __data_ref, list);
+               list_del(&ref_d->list);
+               if (!ret)
+                       ret = iterate(ref_d->inum, extent_offset +
+                                       ref_d->extent_data_item_offset,
+                                       ref_d->root, ctx);
+               kfree(ref_d);
+       }
+
+       while (!list_empty(&shared_refs)) {
+               ref_s = list_first_entry(&shared_refs, struct __shared_ref,
+                                       list);
+               list_del(&ref_s->list);
+               if (!ret)
+                       ret = __iter_shared_inline_ref(fs_info,
+                                                       ref_s->disk_byte,
+                                                       extent_item_objectid,
+                                                       extent_offset, path,
+                                                       &data_refs,
+                                                       iterate, ctx);
+               kfree(ref_s);
+       }
+
+       return ret;
+}
+
+int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
+                               struct btrfs_path *path,
+                               iterate_extent_inodes_t *iterate, void *ctx)
+{
+       int ret;
+       u64 offset;
+       struct btrfs_key found_key;
+
+       ret = extent_from_logical(fs_info, logical, path,
+                                       &found_key);
+       if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
+               ret = -EINVAL;
+       if (ret < 0)
+               return ret;
+
+       offset = logical - found_key.objectid;
+       ret = iterate_extent_inodes(fs_info, path, found_key.objectid,
+                                       offset, iterate, ctx);
+
+       return ret;
+}
+
+static int iterate_irefs(u64 inum, struct btrfs_root *fs_root,
+                               struct btrfs_path *path,
+                               iterate_irefs_t *iterate, void *ctx)
+{
+       int ret;
+       int slot;
+       u32 cur;
+       u32 len;
+       u32 name_len;
+       u64 parent = 0;
+       int found = 0;
+       struct extent_buffer *eb;
+       struct btrfs_item *item;
+       struct btrfs_inode_ref *iref;
+       struct btrfs_key found_key;
+
+       while (1) {
+               ret = inode_ref_info(inum, parent ? parent+1 : 0, fs_root, path,
+                                       &found_key);
+               if (ret < 0)
+                       break;
+               if (ret) {
+                       ret = found ? 0 : -ENOENT;
+                       break;
+               }
+               ++found;
+
+               parent = found_key.offset;
+               slot = path->slots[0];
+               eb = path->nodes[0];
+               /* make sure we can use eb after releasing the path */
+               atomic_inc(&eb->refs);
+               btrfs_release_path(path);
+
+               item = btrfs_item_nr(eb, slot);
+               iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
+
+               for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) {
+                       name_len = btrfs_inode_ref_name_len(eb, iref);
+                       /* path must be released before calling iterate()! */
+                       ret = iterate(parent, iref, eb, ctx);
+                       if (ret) {
+                               free_extent_buffer(eb);
+                               break;
+                       }
+                       len = sizeof(*iref) + name_len;
+                       iref = (struct btrfs_inode_ref *)((char *)iref + len);
+               }
+               free_extent_buffer(eb);
+       }
+
+       btrfs_release_path(path);
+
+       return ret;
+}
+
+/*
+ * returns 0 if the path could be dumped (probably truncated)
+ * returns <0 in case of an error
+ */
+static int inode_to_path(u64 inum, struct btrfs_inode_ref *iref,
+                               struct extent_buffer *eb, void *ctx)
+{
+       struct inode_fs_paths *ipath = ctx;
+       char *fspath;
+       char *fspath_min;
+       int i = ipath->fspath->elem_cnt;
+       const int s_ptr = sizeof(char *);
+       u32 bytes_left;
+
+       bytes_left = ipath->fspath->bytes_left > s_ptr ?
+                                       ipath->fspath->bytes_left - s_ptr : 0;
+
+       fspath_min = (char *)ipath->fspath->str + (i + 1) * s_ptr;
+       fspath = iref_to_path(ipath->fs_root, ipath->btrfs_path, iref, eb,
+                               inum, fspath_min, bytes_left);
+       if (IS_ERR(fspath))
+               return PTR_ERR(fspath);
+
+       if (fspath > fspath_min) {
+               ipath->fspath->str[i] = fspath;
+               ++ipath->fspath->elem_cnt;
+               ipath->fspath->bytes_left = fspath - fspath_min;
+       } else {
+               ++ipath->fspath->elem_missed;
+               ipath->fspath->bytes_missing += fspath_min - fspath;
+               ipath->fspath->bytes_left = 0;
+       }
+
+       return 0;
+}
+
+/*
+ * this dumps all file system paths to the inode into the ipath struct, provided
+ * is has been created large enough. each path is zero-terminated and accessed
+ * from ipath->fspath->str[i].
+ * when it returns, there are ipath->fspath->elem_cnt number of paths available
+ * in ipath->fspath->str[]. when the allocated space wasn't sufficient, the
+ * number of missed paths in recored in ipath->fspath->elem_missed, otherwise,
+ * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would
+ * have been needed to return all paths.
+ */
+int paths_from_inode(u64 inum, struct inode_fs_paths *ipath)
+{
+       return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path,
+                               inode_to_path, ipath);
+}
+
+/*
+ * allocates space to return multiple file system paths for an inode.
+ * total_bytes to allocate are passed, note that space usable for actual path
+ * information will be total_bytes - sizeof(struct inode_fs_paths).
+ * the returned pointer must be freed with free_ipath() in the end.
+ */
+struct btrfs_data_container *init_data_container(u32 total_bytes)
+{
+       struct btrfs_data_container *data;
+       size_t alloc_bytes;
+
+       alloc_bytes = max_t(size_t, total_bytes, sizeof(*data));
+       data = kmalloc(alloc_bytes, GFP_NOFS);
+       if (!data)
+               return ERR_PTR(-ENOMEM);
+
+       if (total_bytes >= sizeof(*data)) {
+               data->bytes_left = total_bytes - sizeof(*data);
+               data->bytes_missing = 0;
+       } else {
+               data->bytes_missing = sizeof(*data) - total_bytes;
+               data->bytes_left = 0;
+       }
+
+       data->elem_cnt = 0;
+       data->elem_missed = 0;
+
+       return data;
+}
+
+/*
+ * allocates space to return multiple file system paths for an inode.
+ * total_bytes to allocate are passed, note that space usable for actual path
+ * information will be total_bytes - sizeof(struct inode_fs_paths).
+ * the returned pointer must be freed with free_ipath() in the end.
+ */
+struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
+                                       struct btrfs_path *path)
+{
+       struct inode_fs_paths *ifp;
+       struct btrfs_data_container *fspath;
+
+       fspath = init_data_container(total_bytes);
+       if (IS_ERR(fspath))
+               return (void *)fspath;
+
+       ifp = kmalloc(sizeof(*ifp), GFP_NOFS);
+       if (!ifp) {
+               kfree(fspath);
+               return ERR_PTR(-ENOMEM);
+       }
+
+       ifp->btrfs_path = path;
+       ifp->fspath = fspath;
+       ifp->fs_root = fs_root;
+
+       return ifp;
+}
+
+void free_ipath(struct inode_fs_paths *ipath)
+{
+       kfree(ipath);
+}
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
new file mode 100644 (file)
index 0000000..9261883
--- /dev/null
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2011 STRATO.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_BACKREF__
+#define __BTRFS_BACKREF__
+
+#include "ioctl.h"
+
+struct inode_fs_paths {
+       struct btrfs_path               *btrfs_path;
+       struct btrfs_root               *fs_root;
+       struct btrfs_data_container     *fspath;
+};
+
+typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root,
+               void *ctx);
+typedef int (iterate_irefs_t)(u64 parent, struct btrfs_inode_ref *iref,
+                               struct extent_buffer *eb, void *ctx);
+
+int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root,
+                       struct btrfs_path *path);
+
+int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
+                       struct btrfs_path *path, struct btrfs_key *found_key);
+
+int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
+                               struct btrfs_extent_item *ei, u32 item_size,
+                               u64 *out_root, u8 *out_level);
+
+int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
+                               struct btrfs_path *path,
+                               u64 extent_item_objectid,
+                               u64 extent_offset,
+                               iterate_extent_inodes_t *iterate, void *ctx);
+
+int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
+                               struct btrfs_path *path,
+                               iterate_extent_inodes_t *iterate, void *ctx);
+
+int paths_from_inode(u64 inum, struct inode_fs_paths *ipath);
+
+struct btrfs_data_container *init_data_container(u32 total_bytes);
+struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
+                                       struct btrfs_path *path);
+void free_ipath(struct inode_fs_paths *ipath);
+
+#endif
index cedfbfb..0eb1f09 100644 (file)
@@ -620,7 +620,7 @@ out:
 
 static int btree_io_failed_hook(struct bio *failed_bio,
                         struct page *page, u64 start, u64 end,
-                        struct extent_state *state)
+                        u64 mirror_num, struct extent_state *state)
 {
        struct extent_io_tree *tree;
        unsigned long len;
@@ -944,7 +944,7 @@ static int btree_readpage(struct file *file, struct page *page)
 {
        struct extent_io_tree *tree;
        tree = &BTRFS_I(page->mapping->host)->io_tree;
-       return extent_read_full_page(tree, page, btree_get_extent);
+       return extent_read_full_page(tree, page, btree_get_extent, 0);
 }
 
 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
index 23e936c..18ea90c 100644 (file)
@@ -1788,18 +1788,18 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
 {
        int ret;
        u64 discarded_bytes = 0;
-       struct btrfs_multi_bio *multi = NULL;
+       struct btrfs_bio *bbio = NULL;
 
 
        /* Tell the block device(s) that the sectors can be discarded */
        ret = btrfs_map_block(&root->fs_info->mapping_tree, REQ_DISCARD,
-                             bytenr, &num_bytes, &multi, 0);
+                             bytenr, &num_bytes, &bbio, 0);
        if (!ret) {
-               struct btrfs_bio_stripe *stripe = multi->stripes;
+               struct btrfs_bio_stripe *stripe = bbio->stripes;
                int i;
 
 
-               for (i = 0; i < multi->num_stripes; i++, stripe++) {
+               for (i = 0; i < bbio->num_stripes; i++, stripe++) {
                        if (!stripe->dev->can_discard)
                                continue;
 
@@ -1818,7 +1818,7 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
                         */
                        ret = 0;
                }
-               kfree(multi);
+               kfree(bbio);
        }
 
        if (actual_bytes)
index c127056..1f87c4d 100644 (file)
@@ -17,6 +17,7 @@
 #include "compat.h"
 #include "ctree.h"
 #include "btrfs_inode.h"
+#include "volumes.h"
 
 static struct kmem_cache *extent_state_cache;
 static struct kmem_cache *extent_buffer_cache;
@@ -1787,6 +1788,368 @@ static int check_page_writeback(struct extent_io_tree *tree,
        return 0;
 }
 
+/*
+ * When IO fails, either with EIO or csum verification fails, we
+ * try other mirrors that might have a good copy of the data.  This
+ * io_failure_record is used to record state as we go through all the
+ * mirrors.  If another mirror has good data, the page is set up to date
+ * and things continue.  If a good mirror can't be found, the original
+ * bio end_io callback is called to indicate things have failed.
+ */
+struct io_failure_record {
+       struct page *page;
+       u64 start;
+       u64 len;
+       u64 logical;
+       unsigned long bio_flags;
+       int this_mirror;
+       int failed_mirror;
+       int in_validation;
+};
+
+static int free_io_failure(struct inode *inode, struct io_failure_record *rec,
+                               int did_repair)
+{
+       int ret;
+       int err = 0;
+       struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
+
+       set_state_private(failure_tree, rec->start, 0);
+       ret = clear_extent_bits(failure_tree, rec->start,
+                               rec->start + rec->len - 1,
+                               EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
+       if (ret)
+               err = ret;
+
+       if (did_repair) {
+               ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
+                                       rec->start + rec->len - 1,
+                                       EXTENT_DAMAGED, GFP_NOFS);
+               if (ret && !err)
+                       err = ret;
+       }
+
+       kfree(rec);
+       return err;
+}
+
+static void repair_io_failure_callback(struct bio *bio, int err)
+{
+       complete(bio->bi_private);
+}
+
+/*
+ * this bypasses the standard btrfs submit functions deliberately, as
+ * the standard behavior is to write all copies in a raid setup. here we only
+ * want to write the one bad copy. so we do the mapping for ourselves and issue
+ * submit_bio directly.
+ * to avoid any synchonization issues, wait for the data after writing, which
+ * actually prevents the read that triggered the error from finishing.
+ * currently, there can be no more than two copies of every data bit. thus,
+ * exactly one rewrite is required.
+ */
+int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
+                       u64 length, u64 logical, struct page *page,
+                       int mirror_num)
+{
+       struct bio *bio;
+       struct btrfs_device *dev;
+       DECLARE_COMPLETION_ONSTACK(compl);
+       u64 map_length = 0;
+       u64 sector;
+       struct btrfs_bio *bbio = NULL;
+       int ret;
+
+       BUG_ON(!mirror_num);
+
+       bio = bio_alloc(GFP_NOFS, 1);
+       if (!bio)
+               return -EIO;
+       bio->bi_private = &compl;
+       bio->bi_end_io = repair_io_failure_callback;
+       bio->bi_size = 0;
+       map_length = length;
+
+       ret = btrfs_map_block(map_tree, WRITE, logical,
+                             &map_length, &bbio, mirror_num);
+       if (ret) {
+               bio_put(bio);
+               return -EIO;
+       }
+       BUG_ON(mirror_num != bbio->mirror_num);
+       sector = bbio->stripes[mirror_num-1].physical >> 9;
+       bio->bi_sector = sector;
+       dev = bbio->stripes[mirror_num-1].dev;
+       kfree(bbio);
+       if (!dev || !dev->bdev || !dev->writeable) {
+               bio_put(bio);
+               return -EIO;
+       }
+       bio->bi_bdev = dev->bdev;
+       bio_add_page(bio, page, length, start-page_offset(page));
+       submit_bio(WRITE_SYNC, bio);
+       wait_for_completion(&compl);
+
+       if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
+               /* try to remap that extent elsewhere? */
+               bio_put(bio);
+               return -EIO;
+       }
+
+       printk(KERN_INFO "btrfs read error corrected: ino %lu off %llu (dev %s "
+                       "sector %llu)\n", page->mapping->host->i_ino, start,
+                       dev->name, sector);
+
+       bio_put(bio);
+       return 0;
+}
+
+/*
+ * each time an IO finishes, we do a fast check in the IO failure tree
+ * to see if we need to process or clean up an io_failure_record
+ */
+static int clean_io_failure(u64 start, struct page *page)
+{
+       u64 private;
+       u64 private_failure;
+       struct io_failure_record *failrec;
+       struct btrfs_mapping_tree *map_tree;
+       struct extent_state *state;
+       int num_copies;
+       int did_repair = 0;
+       int ret;
+       struct inode *inode = page->mapping->host;
+
+       private = 0;
+       ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
+                               (u64)-1, 1, EXTENT_DIRTY, 0);
+       if (!ret)
+               return 0;
+
+       ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, start,
+                               &private_failure);
+       if (ret)
+               return 0;
+
+       failrec = (struct io_failure_record *)(unsigned long) private_failure;
+       BUG_ON(!failrec->this_mirror);
+
+       if (failrec->in_validation) {
+               /* there was no real error, just free the record */
+               pr_debug("clean_io_failure: freeing dummy error at %llu\n",
+                        failrec->start);
+               did_repair = 1;
+               goto out;
+       }
+
+       spin_lock(&BTRFS_I(inode)->io_tree.lock);
+       state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
+                                           failrec->start,
+                                           EXTENT_LOCKED);
+       spin_unlock(&BTRFS_I(inode)->io_tree.lock);
+
+       if (state && state->start == failrec->start) {
+               map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
+               num_copies = btrfs_num_copies(map_tree, failrec->logical,
+                                               failrec->len);
+               if (num_copies > 1)  {
+                       ret = repair_io_failure(map_tree, start, failrec->len,
+                                               failrec->logical, page,
+                                               failrec->failed_mirror);
+                       did_repair = !ret;
+               }
+       }
+
+out:
+       if (!ret)
+               ret = free_io_failure(inode, failrec, did_repair);
+
+       return ret;
+}
+
+/*
+ * this is a generic handler for readpage errors (default
+ * readpage_io_failed_hook). if other copies exist, read those and write back
+ * good data to the failed position. does not investigate in remapping the
+ * failed extent elsewhere, hoping the device will be smart enough to do this as
+ * needed
+ */
+
+static int bio_readpage_error(struct bio *failed_bio, struct page *page,
+                               u64 start, u64 end, int failed_mirror,
+                               struct extent_state *state)
+{
+       struct io_failure_record *failrec = NULL;
+       u64 private;
+       struct extent_map *em;
+       struct inode *inode = page->mapping->host;
+       struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
+       struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
+       struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+       struct bio *bio;
+       int num_copies;
+       int ret;
+       int read_mode;
+       u64 logical;
+
+       BUG_ON(failed_bio->bi_rw & REQ_WRITE);
+
+       ret = get_state_private(failure_tree, start, &private);
+       if (ret) {
+               failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
+               if (!failrec)
+                       return -ENOMEM;
+               failrec->start = start;
+               failrec->len = end - start + 1;
+               failrec->this_mirror = 0;
+               failrec->bio_flags = 0;
+               failrec->in_validation = 0;
+
+               read_lock(&em_tree->lock);
+               em = lookup_extent_mapping(em_tree, start, failrec->len);
+               if (!em) {
+                       read_unlock(&em_tree->lock);
+                       kfree(failrec);
+                       return -EIO;
+               }
+
+               if (em->start > start || em->start + em->len < start) {
+                       free_extent_map(em);
+                       em = NULL;
+               }
+               read_unlock(&em_tree->lock);
+
+               if (!em || IS_ERR(em)) {
+                       kfree(failrec);
+                       return -EIO;
+               }
+               logical = start - em->start;
+               logical = em->block_start + logical;
+               if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
+                       logical = em->block_start;
+                       failrec->bio_flags = EXTENT_BIO_COMPRESSED;
+                       extent_set_compress_type(&failrec->bio_flags,
+                                                em->compress_type);
+               }
+               pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
+                        "len=%llu\n", logical, start, failrec->len);
+               failrec->logical = logical;
+               free_extent_map(em);
+
+               /* set the bits in the private failure tree */
+               ret = set_extent_bits(failure_tree, start, end,
+                                       EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
+               if (ret >= 0)
+                       ret = set_state_private(failure_tree, start,
+                                               (u64)(unsigned long)failrec);
+               /* set the bits in the inode's tree */
+               if (ret >= 0)
+                       ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED,
+                                               GFP_NOFS);
+               if (ret < 0) {
+                       kfree(failrec);
+                       return ret;
+               }
+       } else {
+               failrec = (struct io_failure_record *)(unsigned long)private;
+               pr_debug("bio_readpage_error: (found) logical=%llu, "
+                        "start=%llu, len=%llu, validation=%d\n",
+                        failrec->logical, failrec->start, failrec->len,
+                        failrec->in_validation);
+               /*
+                * when data can be on disk more than twice, add to failrec here
+                * (e.g. with a list for failed_mirror) to make
+                * clean_io_failure() clean all those errors at once.
+                */
+       }
+       num_copies = btrfs_num_copies(
+                             &BTRFS_I(inode)->root->fs_info->mapping_tree,
+                             failrec->logical, failrec->len);
+       if (num_copies == 1) {
+               /*
+                * we only have a single copy of the data, so don't bother with
+                * all the retry and error correction code that follows. no
+                * matter what the error is, it is very likely to persist.
+                */
+               pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
+                        "state=%p, num_copies=%d, next_mirror %d, "
+                        "failed_mirror %d\n", state, num_copies,
+                        failrec->this_mirror, failed_mirror);
+               free_io_failure(inode, failrec, 0);
+               return -EIO;
+       }
+
+       if (!state) {
+               spin_lock(&tree->lock);
+               state = find_first_extent_bit_state(tree, failrec->start,
+                                                   EXTENT_LOCKED);
+               if (state && state->start != failrec->start)
+                       state = NULL;
+               spin_unlock(&tree->lock);
+       }
+
+       /*
+        * there are two premises:
+        *      a) deliver good data to the caller
+        *      b) correct the bad sectors on disk
+        */
+       if (failed_bio->bi_vcnt > 1) {
+               /*
+                * to fulfill b), we need to know the exact failing sectors, as
+                * we don't want to rewrite any more than the failed ones. thus,
+                * we need separate read requests for the failed bio
+                *
+                * if the following BUG_ON triggers, our validation request got
+                * merged. we need separate requests for our algorithm to work.
+                */
+               BUG_ON(failrec->in_validation);
+               failrec->in_validation = 1;
+               failrec->this_mirror = failed_mirror;
+               read_mode = READ_SYNC | REQ_FAILFAST_DEV;
+       } else {
+               /*
+                * we're ready to fulfill a) and b) alongside. get a good copy
+                * of the failed sector and if we succeed, we have setup
+                * everything for repair_io_failure to do the rest for us.
+                */
+               if (failrec->in_validation) {
+                       BUG_ON(failrec->this_mirror != failed_mirror);
+                       failrec->in_validation = 0;
+                       failrec->this_mirror = 0;
+               }
+               failrec->failed_mirror = failed_mirror;
+               failrec->this_mirror++;
+               if (failrec->this_mirror == failed_mirror)
+                       failrec->this_mirror++;
+               read_mode = READ_SYNC;
+       }
+
+       if (!state || failrec->this_mirror > num_copies) {
+               pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
+                        "next_mirror %d, failed_mirror %d\n", state,
+                        num_copies, failrec->this_mirror, failed_mirror);
+               free_io_failure(inode, failrec, 0);
+               return -EIO;
+       }
+
+       bio = bio_alloc(GFP_NOFS, 1);
+       bio->bi_private = state;
+       bio->bi_end_io = failed_bio->bi_end_io;
+       bio->bi_sector = failrec->logical >> 9;
+       bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
+       bio->bi_size = 0;
+
+       bio_add_page(bio, page, failrec->len, start - page_offset(page));
+
+       pr_debug("bio_readpage_error: submitting new read[%#x] to "
+                "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode,
+                failrec->this_mirror, num_copies, failrec->in_validation);
+
+       tree->ops->submit_bio_hook(inode, read_mode, bio, failrec->this_mirror,
+                                       failrec->bio_flags, 0);
+       return 0;
+}
+
 /* lots and lots of room for performance fixes in the end_bio funcs */
 
 /*
@@ -1885,6 +2248,9 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
                struct extent_state *cached = NULL;
                struct extent_state *state;
 
+               pr_debug("end_bio_extent_readpage: bi_vcnt=%d, idx=%d, err=%d, "
+                        "mirror=%ld\n", bio->bi_vcnt, bio->bi_idx, err,
+                        (long int)bio->bi_bdev);
                tree = &BTRFS_I(page->mapping->host)->io_tree;
 
                start = ((u64)page->index << PAGE_CACHE_SHIFT) +
@@ -1915,11 +2281,19 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
                                                              state);
                        if (ret)
                                uptodate = 0;
+                       else
+                               clean_io_failure(start, page);
                }
-               if (!uptodate && tree->ops &&
-                   tree->ops->readpage_io_failed_hook) {
-                       ret = tree->ops->readpage_io_failed_hook(bio, page,
-                                                        start, end, state);
+               if (!uptodate) {
+                       u64 failed_mirror;
+                       failed_mirror = (u64)bio->bi_bdev;
+                       if (tree->ops && tree->ops->readpage_io_failed_hook)
+                               ret = tree->ops->readpage_io_failed_hook(
+                                               bio, page, start, end,
+                                               failed_mirror, state);
+                       else
+                               ret = bio_readpage_error(bio, page, start, end,
+                                                        failed_mirror, NULL);
                        if (ret == 0) {
                                uptodate =
                                        test_bit(BIO_UPTODATE, &bio->bi_flags);
@@ -1999,6 +2373,7 @@ static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
                                           mirror_num, bio_flags, start);
        else
                submit_bio(rw, bio);
+
        if (bio_flagged(bio, BIO_EOPNOTSUPP))
                ret = -EOPNOTSUPP;
        bio_put(bio);
@@ -2264,16 +2639,16 @@ out:
 }
 
 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
-                           get_extent_t *get_extent)
+                           get_extent_t *get_extent, int mirror_num)
 {
        struct bio *bio = NULL;
        unsigned long bio_flags = 0;
        int ret;
 
-       ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
+       ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
                                      &bio_flags);
        if (bio)
-               ret = submit_one_bio(READ, bio, 0, bio_flags);
+               ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
        return ret;
 }
 
@@ -3127,7 +3502,7 @@ out:
        return ret;
 }
 
-static inline struct page *extent_buffer_page(struct extent_buffer *eb,
+inline struct page *extent_buffer_page(struct extent_buffer *eb,
                                              unsigned long i)
 {
        struct page *p;
@@ -3152,7 +3527,7 @@ static inline struct page *extent_buffer_page(struct extent_buffer *eb,
        return p;
 }
 
-static inline unsigned long num_extent_pages(u64 start, u64 len)
+inline unsigned long num_extent_pages(u64 start, u64 len)
 {
        return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
                (start >> PAGE_CACHE_SHIFT);
index 697570e..feb9be0 100644 (file)
@@ -18,6 +18,7 @@
 #define EXTENT_DO_ACCOUNTING (1 << 11)
 #define EXTENT_FIRST_DELALLOC (1 << 12)
 #define EXTENT_NEED_WAIT (1 << 13)
+#define EXTENT_DAMAGED (1 << 14)
 #define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
 #define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
 
@@ -69,7 +70,7 @@ struct extent_io_ops {
                              unsigned long bio_flags);
        int (*readpage_io_hook)(struct page *page, u64 start, u64 end);
        int (*readpage_io_failed_hook)(struct bio *bio, struct page *page,
-                                      u64 start, u64 end,
+                                      u64 start, u64 end, u64 failed_mirror,
                                       struct extent_state *state);
        int (*writepage_io_failed_hook)(struct bio *bio, struct page *page,
                                        u64 start, u64 end,
@@ -188,7 +189,7 @@ int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
                    gfp_t mask);
 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
-                         get_extent_t *get_extent);
+                         get_extent_t *get_extent, int mirror_num);
 int __init extent_io_init(void);
 void extent_io_exit(void);
 
@@ -259,6 +260,8 @@ void free_extent_buffer(struct extent_buffer *eb);
 int read_extent_buffer_pages(struct extent_io_tree *tree,
                             struct extent_buffer *eb, u64 start, int wait,
                             get_extent_t *get_extent, int mirror_num);
+unsigned long num_extent_pages(u64 start, u64 len);
+struct page *extent_buffer_page(struct extent_buffer *eb, unsigned long i);
 
 static inline void extent_buffer_get(struct extent_buffer *eb)
 {
@@ -308,4 +311,10 @@ int extent_clear_unlock_delalloc(struct inode *inode,
 struct bio *
 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
                gfp_t gfp_flags);
+
+struct btrfs_mapping_tree;
+
+int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
+                       u64 length, u64 logical, struct page *page,
+                       int mirror_num);
 #endif
index b6b612e..9d0eaa5 100644 (file)
 #include "btrfs_inode.h"
 #include "ioctl.h"
 #include "print-tree.h"
-#include "volumes.h"
 #include "ordered-data.h"
 #include "xattr.h"
 #include "tree-log.h"
+#include "volumes.h"
 #include "compression.h"
 #include "locking.h"
 #include "free-space-cache.h"
@@ -1822,154 +1822,10 @@ static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
        return btrfs_finish_ordered_io(page->mapping->host, start, end);
 }
 
-/*
- * When IO fails, either with EIO or csum verification fails, we
- * try other mirrors that might have a good copy of the data.  This
- * io_failure_record is used to record state as we go through all the
- * mirrors.  If another mirror has good data, the page is set up to date
- * and things continue.  If a good mirror can't be found, the original
- * bio end_io callback is called to indicate things have failed.
- */
-struct io_failure_record {
-       struct page *page;
-       u64 start;
-       u64 len;
-       u64 logical;
-       unsigned long bio_flags;
-       int last_mirror;
-};
-
-static int btrfs_io_failed_hook(struct bio *failed_bio,
-                        struct page *page, u64 start, u64 end,
-                        struct extent_state *state)
-{
-       struct io_failure_record *failrec = NULL;
-       u64 private;
-       struct extent_map *em;
-       struct inode *inode = page->mapping->host;
-       struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
-       struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
-       struct bio *bio;
-       int num_copies;
-       int ret;
-       int rw;
-       u64 logical;
-
-       ret = get_state_private(failure_tree, start, &private);
-       if (ret) {
-               failrec = kmalloc(sizeof(*failrec), GFP_NOFS);
-               if (!failrec)
-                       return -ENOMEM;
-               failrec->start = start;
-               failrec->len = end - start + 1;
-               failrec->last_mirror = 0;
-               failrec->bio_flags = 0;
-
-               read_lock(&em_tree->lock);
-               em = lookup_extent_mapping(em_tree, start, failrec->len);
-               if (em->start > start || em->start + em->len < start) {
-                       free_extent_map(em);
-                       em = NULL;
-               }
-               read_unlock(&em_tree->lock);
-
-               if (IS_ERR_OR_NULL(em)) {
-                       kfree(failrec);
-                       return -EIO;
-               }
-               logical = start - em->start;
-               logical = em->block_start + logical;
-               if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
-                       logical = em->block_start;
-                       failrec->bio_flags = EXTENT_BIO_COMPRESSED;
-                       extent_set_compress_type(&failrec->bio_flags,
-                                                em->compress_type);
-               }
-               failrec->logical = logical;
-               free_extent_map(em);
-               set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
-                               EXTENT_DIRTY, GFP_NOFS);
-               set_state_private(failure_tree, start,
-                                (u64)(unsigned long)failrec);
-       } else {
-               failrec = (struct io_failure_record *)(unsigned long)private;
-       }
-       num_copies = btrfs_num_copies(
-                             &BTRFS_I(inode)->root->fs_info->mapping_tree,
-                             failrec->logical, failrec->len);
-       failrec->last_mirror++;
-       if (!state) {
-               spin_lock(&BTRFS_I(inode)->io_tree.lock);
-               state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
-                                                   failrec->start,
-                                                   EXTENT_LOCKED);
-               if (state && state->start != failrec->start)
-                       state = NULL;
-               spin_unlock(&BTRFS_I(inode)->io_tree.lock);
-       }
-       if (!state || failrec->last_mirror > num_copies) {
-               set_state_private(failure_tree, failrec->start, 0);
-               clear_extent_bits(failure_tree, failrec->start,
-                                 failrec->start + failrec->len - 1,
-                                 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
-               kfree(failrec);
-               return -EIO;
-       }
-       bio = bio_alloc(GFP_NOFS, 1);
-       bio->bi_private = state;
-       bio->bi_end_io = failed_bio->bi_end_io;
-       bio->bi_sector = failrec->logical >> 9;
-       bio->bi_bdev = failed_bio->bi_bdev;
-       bio->bi_size = 0;
-
-       bio_add_page(bio, page, failrec->len, start - page_offset(page));
-       if (failed_bio->bi_rw & REQ_WRITE)
-               rw = WRITE;
-       else
-               rw = READ;
-
-       ret = BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio,
-                                                     failrec->last_mirror,
-                                                     failrec->bio_flags, 0);
-       return ret;
-}
-
-/*
- * each time an IO finishes, we do a fast check in the IO failure tree
- * to see if we need to process or clean up an io_failure_record
- */
-static int btrfs_clean_io_failures(struct inode *inode, u64 start)
-{
-       u64 private;
-       u64 private_failure;
-       struct io_failure_record *failure;
-       int ret;
-
-       private = 0;
-       if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
-                            (u64)-1, 1, EXTENT_DIRTY, 0)) {
-               ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
-                                       start, &private_failure);
-               if (ret == 0) {
-                       failure = (struct io_failure_record *)(unsigned long)
-                                  private_failure;
-                       set_state_private(&BTRFS_I(inode)->io_failure_tree,
-                                         failure->start, 0);
-                       clear_extent_bits(&BTRFS_I(inode)->io_failure_tree,
-                                         failure->start,
-                                         failure->start + failure->len - 1,
-                                         EXTENT_DIRTY | EXTENT_LOCKED,
-                                         GFP_NOFS);
-                       kfree(failure);
-               }
-       }
-       return 0;
-}
-
 /*
  * when reads are done, we need to check csums to verify the data is correct
- * if there's a match, we allow the bio to finish.  If not, we go through
- * the io_failure_record routines to find good copies
+ * if there's a match, we allow the bio to finish.  If not, the code in
+ * extent_io.c will try to find good copies for us.
  */
 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
                               struct extent_state *state)
@@ -2015,10 +1871,6 @@ static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 
        kunmap_atomic(kaddr, KM_USER0);
 good:
-       /* if the io failure tree for this inode is non-empty,
-        * check to see if we've recovered from a failed IO
-        */
-       btrfs_clean_io_failures(inode, start);
        return 0;
 
 zeroit:
@@ -6273,7 +6125,7 @@ int btrfs_readpage(struct file *file, struct page *page)
 {
        struct extent_io_tree *tree;
        tree = &BTRFS_I(page->mapping->host)->io_tree;
-       return extent_read_full_page(tree, page, btrfs_get_extent);
+       return extent_read_full_page(tree, page, btrfs_get_extent, 0);
 }
 
 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
@@ -7406,7 +7258,6 @@ static struct extent_io_ops btrfs_extent_io_ops = {
        .readpage_end_io_hook = btrfs_readpage_end_io_hook,
        .writepage_end_io_hook = btrfs_writepage_end_io_hook,
        .writepage_start_hook = btrfs_writepage_start_hook,
-       .readpage_io_failed_hook = btrfs_io_failed_hook,
        .set_bit_hook = btrfs_set_bit_hook,
        .clear_bit_hook = btrfs_clear_bit_hook,
        .merge_extent_hook = btrfs_merge_extent_hook,
index 8f6e142..cc98939 100644 (file)
@@ -51,6 +51,7 @@
 #include "volumes.h"
 #include "locking.h"
 #include "inode-map.h"
+#include "backref.h"
 
 /* Mask out flags that are inappropriate for the given type of inode. */
 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
@@ -2890,6 +2891,144 @@ static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
        return ret;
 }
 
+static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
+{
+       int ret = 0;
+       int i;
+       unsigned long rel_ptr;
+       int size;
+       struct btrfs_ioctl_ino_path_args *ipa = NULL;
+       struct inode_fs_paths *ipath = NULL;
+       struct btrfs_path *path;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       path = btrfs_alloc_path();
+       if (!path) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       ipa = memdup_user(arg, sizeof(*ipa));
+       if (IS_ERR(ipa)) {
+               ret = PTR_ERR(ipa);
+               ipa = NULL;
+               goto out;
+       }
+
+       size = min_t(u32, ipa->size, 4096);
+       ipath = init_ipath(size, root, path);
+       if (IS_ERR(ipath)) {
+               ret = PTR_ERR(ipath);
+               ipath = NULL;
+               goto out;
+       }
+
+       ret = paths_from_inode(ipa->inum, ipath);
+       if (ret < 0)
+               goto out;
+
+       for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
+               rel_ptr = ipath->fspath->str[i] - (char *)ipath->fspath->str;
+               ipath->fspath->str[i] = (void *)rel_ptr;
+       }
+
+       ret = copy_to_user(ipa->fspath, ipath->fspath, size);
+       if (ret) {
+               ret = -EFAULT;
+               goto out;
+       }
+
+out:
+       btrfs_free_path(path);
+       free_ipath(ipath);
+       kfree(ipa);
+
+       return ret;
+}
+
+static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
+{
+       struct btrfs_data_container *inodes = ctx;
+       const size_t c = 3 * sizeof(u64);
+
+       if (inodes->bytes_left >= c) {
+               inodes->bytes_left -= c;
+               inodes->val[inodes->elem_cnt] = inum;
+               inodes->val[inodes->elem_cnt + 1] = offset;
+               inodes->val[inodes->elem_cnt + 2] = root;
+               inodes->elem_cnt += 3;
+       } else {
+               inodes->bytes_missing += c - inodes->bytes_left;
+               inodes->bytes_left = 0;
+               inodes->elem_missed += 3;
+       }
+
+       return 0;
+}
+
+static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
+                                       void __user *arg)
+{
+       int ret = 0;
+       int size;
+       u64 extent_offset;
+       struct btrfs_ioctl_logical_ino_args *loi;
+       struct btrfs_data_container *inodes = NULL;
+       struct btrfs_path *path = NULL;
+       struct btrfs_key key;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       loi = memdup_user(arg, sizeof(*loi));
+       if (IS_ERR(loi)) {
+               ret = PTR_ERR(loi);
+               loi = NULL;
+               goto out;
+       }
+
+       path = btrfs_alloc_path();
+       if (!path) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       size = min_t(u32, loi->size, 4096);
+       inodes = init_data_container(size);
+       if (IS_ERR(inodes)) {
+               ret = PTR_ERR(inodes);
+               inodes = NULL;
+               goto out;
+       }
+
+       ret = extent_from_logical(root->fs_info, loi->logical, path, &key);
+
+       if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
+               ret = -ENOENT;
+       if (ret < 0)
+               goto out;
+
+       extent_offset = loi->logical - key.objectid;
+       ret = iterate_extent_inodes(root->fs_info, path, key.objectid,
+                                       extent_offset, build_ino_list, inodes);
+
+       if (ret < 0)
+               goto out;
+
+       ret = copy_to_user(loi->inodes, inodes, size);
+       if (ret)
+               ret = -EFAULT;
+
+out:
+       btrfs_free_path(path);
+       kfree(inodes);
+       kfree(loi);
+
+       return ret;
+}
+
 long btrfs_ioctl(struct file *file, unsigned int
                cmd, unsigned long arg)
 {
@@ -2947,6 +3086,10 @@ long btrfs_ioctl(struct file *file, unsigned int
                return btrfs_ioctl_tree_search(file, argp);
        case BTRFS_IOC_INO_LOOKUP:
                return btrfs_ioctl_ino_lookup(file, argp);
+       case BTRFS_IOC_INO_PATHS:
+               return btrfs_ioctl_ino_to_path(root, argp);
+       case BTRFS_IOC_LOGICAL_INO:
+               return btrfs_ioctl_logical_to_ino(root, argp);
        case BTRFS_IOC_SPACE_INFO:
                return btrfs_ioctl_space_info(root, argp);
        case BTRFS_IOC_SYNC:
index ad1ea78..2da30d4 100644 (file)
@@ -193,6 +193,31 @@ struct btrfs_ioctl_space_args {
        struct btrfs_ioctl_space_info spaces[0];
 };
 
+struct btrfs_data_container {
+       __u32   bytes_left;     /* out -- bytes not needed to deliver output */
+       __u32   bytes_missing;  /* out -- additional bytes needed for result */
+       __u32   elem_cnt;       /* out */
+       __u32   elem_missed;    /* out */
+       union {
+               char    *str[0];        /* out */
+               __u64   val[0];         /* out */
+       };
+};
+
+struct btrfs_ioctl_ino_path_args {
+       __u64                           inum;           /* in */
+       __u32                           size;           /* in */
+       __u64                           reserved[4];
+       struct btrfs_data_container     *fspath;        /* out */
+};
+
+struct btrfs_ioctl_logical_ino_args {
+       __u64                           logical;        /* in */
+       __u32                           size;           /* in */
+       __u64                           reserved[4];
+       struct btrfs_data_container     *inodes;        /* out */
+};
+
 #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
                                   struct btrfs_ioctl_vol_args)
 #define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -248,4 +273,9 @@ struct btrfs_ioctl_space_args {
                                 struct btrfs_ioctl_dev_info_args)
 #define BTRFS_IOC_FS_INFO _IOR(BTRFS_IOCTL_MAGIC, 31, \
                               struct btrfs_ioctl_fs_info_args)
+#define BTRFS_IOC_INO_PATHS _IOWR(BTRFS_IOCTL_MAGIC, 35, \
+                                       struct btrfs_ioctl_ino_path_args)
+#define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
+                                       struct btrfs_ioctl_ino_path_args)
+
 #endif
index 2b701d0..cd85711 100644 (file)
@@ -247,7 +247,7 @@ int btree_readahead_hook(struct btrfs_root *root, struct extent_buffer *eb,
 
 static struct reada_zone *reada_find_zone(struct btrfs_fs_info *fs_info,
                                          struct btrfs_device *dev, u64 logical,
-                                         struct btrfs_multi_bio *multi)
+                                         struct btrfs_bio *multi)
 {
        int ret;
        int looped = 0;
@@ -327,7 +327,7 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root,
        struct reada_extent *re = NULL;
        struct btrfs_fs_info *fs_info = root->fs_info;
        struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
-       struct btrfs_multi_bio *multi = NULL;
+       struct btrfs_bio *multi = NULL;
        struct btrfs_device *dev;
        u32 blocksize;
        u64 length;
index 5bc4ec8..94cd3a1 100644 (file)
  */
 
 #include <linux/blkdev.h>
+#include <linux/ratelimit.h>
 #include "ctree.h"
 #include "volumes.h"
 #include "disk-io.h"
 #include "ordered-data.h"
+#include "transaction.h"
+#include "backref.h"
+#include "extent_io.h"
 
 /*
  * This is only the first step towards a full-features scrub. It reads all
@@ -60,7 +64,7 @@ static void scrub_fixup(struct scrub_bio *sbio, int ix);
 struct scrub_page {
        u64                     flags;  /* extent flags */
        u64                     generation;
-       u64                     mirror_num;
+       int                     mirror_num;
        int                     have_csum;
        u8                      csum[BTRFS_CSUM_SIZE];
 };
@@ -84,6 +88,7 @@ struct scrub_dev {
        int                     first_free;
        int                     curr;
        atomic_t                in_flight;
+       atomic_t                fixup_cnt;
        spinlock_t              list_lock;
        wait_queue_head_t       list_wait;
        u16                     csum_size;
@@ -97,6 +102,27 @@ struct scrub_dev {
        spinlock_t              stat_lock;
 };
 
+struct scrub_fixup_nodatasum {
+       struct scrub_dev        *sdev;
+       u64                     logical;
+       struct btrfs_root       *root;
+       struct btrfs_work       work;
+       int                     mirror_num;
+};
+
+struct scrub_warning {
+       struct btrfs_path       *path;
+       u64                     extent_item_size;
+       char                    *scratch_buf;
+       char                    *msg_buf;
+       const char              *errstr;
+       sector_t                sector;
+       u64                     logical;
+       struct btrfs_device     *dev;
+       int                     msg_bufsize;
+       int                     scratch_bufsize;
+};
+
 static void scrub_free_csums(struct scrub_dev *sdev)
 {
        while (!list_empty(&sdev->csum_list)) {
@@ -172,12 +198,13 @@ struct scrub_dev *scrub_setup_dev(struct btrfs_device *dev)
 
                if (i != SCRUB_BIOS_PER_DEV-1)
                        sdev->bios[i]->next_free = i + 1;
-                else
+               else
                        sdev->bios[i]->next_free = -1;
        }
        sdev->first_free = 0;
        sdev->curr = -1;
        atomic_set(&sdev->in_flight, 0);
+       atomic_set(&sdev->fixup_cnt, 0);
        atomic_set(&sdev->cancel_req, 0);
        sdev->csum_size = btrfs_super_csum_size(fs_info->super_copy);
        INIT_LIST_HEAD(&sdev->csum_list);
@@ -192,24 +219,361 @@ nomem:
        return ERR_PTR(-ENOMEM);
 }
 
+static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, void *ctx)
+{
+       u64 isize;
+       u32 nlink;
+       int ret;
+       int i;
+       struct extent_buffer *eb;
+       struct btrfs_inode_item *inode_item;
+       struct scrub_warning *swarn = ctx;
+       struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
+       struct inode_fs_paths *ipath = NULL;
+       struct btrfs_root *local_root;
+       struct btrfs_key root_key;
+
+       root_key.objectid = root;
+       root_key.type = BTRFS_ROOT_ITEM_KEY;
+       root_key.offset = (u64)-1;
+       local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
+       if (IS_ERR(local_root)) {
+               ret = PTR_ERR(local_root);
+               goto err;
+       }
+
+       ret = inode_item_info(inum, 0, local_root, swarn->path);
+       if (ret) {
+               btrfs_release_path(swarn->path);
+               goto err;
+       }
+
+       eb = swarn->path->nodes[0];
+       inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
+                                       struct btrfs_inode_item);
+       isize = btrfs_inode_size(eb, inode_item);
+       nlink = btrfs_inode_nlink(eb, inode_item);
+       btrfs_release_path(swarn->path);
+
+       ipath = init_ipath(4096, local_root, swarn->path);
+       ret = paths_from_inode(inum, ipath);
+
+       if (ret < 0)
+               goto err;
+
+       /*
+        * we deliberately ignore the bit ipath might have been too small to
+        * hold all of the paths here
+        */
+       for (i = 0; i < ipath->fspath->elem_cnt; ++i)
+               printk(KERN_WARNING "btrfs: %s at logical %llu on dev "
+                       "%s, sector %llu, root %llu, inode %llu, offset %llu, "
+                       "length %llu, links %u (path: %s)\n", swarn->errstr,
+                       swarn->logical, swarn->dev->name,
+                       (unsigned long long)swarn->sector, root, inum, offset,
+                       min(isize - offset, (u64)PAGE_SIZE), nlink,
+                       ipath->fspath->str[i]);
+
+       free_ipath(ipath);
+       return 0;
+
+err:
+       printk(KERN_WARNING "btrfs: %s at logical %llu on dev "
+               "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
+               "resolving failed with ret=%d\n", swarn->errstr,
+               swarn->logical, swarn->dev->name,
+               (unsigned long long)swarn->sector, root, inum, offset, ret);
+
+       free_ipath(ipath);
+       return 0;
+}
+
+static void scrub_print_warning(const char *errstr, struct scrub_bio *sbio,
+                               int ix)
+{
+       struct btrfs_device *dev = sbio->sdev->dev;
+       struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
+       struct btrfs_path *path;
+       struct btrfs_key found_key;
+       struct extent_buffer *eb;
+       struct btrfs_extent_item *ei;
+       struct scrub_warning swarn;
+       u32 item_size;
+       int ret;
+       u64 ref_root;
+       u8 ref_level;
+       unsigned long ptr = 0;
+       const int bufsize = 4096;
+       u64 extent_offset;
+
+       path = btrfs_alloc_path();
+
+       swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
+       swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
+       swarn.sector = (sbio->physical + ix * PAGE_SIZE) >> 9;
+       swarn.logical = sbio->logical + ix * PAGE_SIZE;
+       swarn.errstr = errstr;
+       swarn.dev = dev;
+       swarn.msg_bufsize = bufsize;
+       swarn.scratch_bufsize = bufsize;
+
+       if (!path || !swarn.scratch_buf || !swarn.msg_buf)
+               goto out;
+
+       ret = extent_from_logical(fs_info, swarn.logical, path, &found_key);
+       if (ret < 0)
+               goto out;
+
+       extent_offset = swarn.logical - found_key.objectid;
+       swarn.extent_item_size = found_key.offset;
+
+       eb = path->nodes[0];
+       ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
+       item_size = btrfs_item_size_nr(eb, path->slots[0]);
+
+       if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
+               do {
+                       ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
+                                                       &ref_root, &ref_level);
+                       printk(KERN_WARNING "%s at logical %llu on dev %s, "
+                               "sector %llu: metadata %s (level %d) in tree "
+                               "%llu\n", errstr, swarn.logical, dev->name,
+                               (unsigned long long)swarn.sector,
+                               ref_level ? "node" : "leaf",
+                               ret < 0 ? -1 : ref_level,
+                               ret < 0 ? -1 : ref_root);
+               } while (ret != 1);
+       } else {
+               swarn.path = path;
+               iterate_extent_inodes(fs_info, path, found_key.objectid,
+                                       extent_offset,
+                                       scrub_print_warning_inode, &swarn);
+       }
+
+out:
+       btrfs_free_path(path);
+       kfree(swarn.scratch_buf);
+       kfree(swarn.msg_buf);
+}
+
+static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *ctx)
+{
+       struct page *page = NULL;
+       unsigned long index;
+       struct scrub_fixup_nodatasum *fixup = ctx;
+       int ret;
+       int corrected = 0;
+       struct btrfs_key key;
+       struct inode *inode = NULL;
+       u64 end = offset + PAGE_SIZE - 1;
+       struct btrfs_root *local_root;
+
+       key.objectid = root;
+       key.type = BTRFS_ROOT_ITEM_KEY;
+       key.offset = (u64)-1;
+       local_root = btrfs_read_fs_root_no_name(fixup->root->fs_info, &key);
+       if (IS_ERR(local_root))
+               return PTR_ERR(local_root);
+
+       key.type = BTRFS_INODE_ITEM_KEY;
+       key.objectid = inum;
+       key.offset = 0;
+       inode = btrfs_iget(fixup->root->fs_info->sb, &key, local_root, NULL);
+       if (IS_ERR(inode))
+               return PTR_ERR(inode);
+
+       index = offset >> PAGE_CACHE_SHIFT;
+
+       page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
+       if (!page) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       if (PageUptodate(page)) {
+               struct btrfs_mapping_tree *map_tree;
+               if (PageDirty(page)) {
+                       /*
+                        * we need to write the data to the defect sector. the
+                        * data that was in that sector is not in memory,
+                        * because the page was modified. we must not write the
+                        * modified page to that sector.
+                        *
+                        * TODO: what could be done here: wait for the delalloc
+                        *       runner to write out that page (might involve
+                        *       COW) and see whether the sector is still
+                        *       referenced afterwards.
+                        *
+                        * For the meantime, we'll treat this error
+                        * incorrectable, although there is a chance that a
+                        * later scrub will find the bad sector again and that
+                        * there's no dirty page in memory, then.
+                        */
+                       ret = -EIO;
+                       goto out;
+               }
+               map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
+               ret = repair_io_failure(map_tree, offset, PAGE_SIZE,
+                                       fixup->logical, page,
+                                       fixup->mirror_num);
+               unlock_page(page);
+               corrected = !ret;
+       } else {
+               /*
+                * we need to get good data first. the general readpage path
+                * will call repair_io_failure for us, we just have to make
+                * sure we read the bad mirror.
+                */
+               ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
+                                       EXTENT_DAMAGED, GFP_NOFS);
+               if (ret) {
+                       /* set_extent_bits should give proper error */
+                       WARN_ON(ret > 0);
+                       if (ret > 0)
+                               ret = -EFAULT;
+                       goto out;
+               }
+
+               ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
+                                               btrfs_get_extent,
+                                               fixup->mirror_num);
+               wait_on_page_locked(page);
+
+               corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
+                                               end, EXTENT_DAMAGED, 0, NULL);
+               if (!corrected)
+                       clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
+                                               EXTENT_DAMAGED, GFP_NOFS);
+       }
+
+out:
+       if (page)
+               put_page(page);
+       if (inode)
+               iput(inode);
+
+       if (ret < 0)
+               return ret;
+
+       if (ret == 0 && corrected) {
+               /*
+                * we only need to call readpage for one of the inodes belonging
+                * to this extent. so make iterate_extent_inodes stop
+                */
+               return 1;
+       }
+
+       return -EIO;
+}
+
+static void scrub_fixup_nodatasum(struct btrfs_work *work)
+{
+       int ret;
+       struct scrub_fixup_nodatasum *fixup;
+       struct scrub_dev *sdev;
+       struct btrfs_trans_handle *trans = NULL;
+       struct btrfs_fs_info *fs_info;
+       struct btrfs_path *path;
+       int uncorrectable = 0;
+
+       fixup = container_of(work, struct scrub_fixup_nodatasum, work);
+       sdev = fixup->sdev;
+       fs_info = fixup->root->fs_info;
+
+       path = btrfs_alloc_path();
+       if (!path) {
+               spin_lock(&sdev->stat_lock);
+               ++sdev->stat.malloc_errors;
+               spin_unlock(&sdev->stat_lock);
+               uncorrectable = 1;
+               goto out;
+       }
+
+       trans = btrfs_join_transaction(fixup->root);
+       if (IS_ERR(trans)) {
+               uncorrectable = 1;
+               goto out;
+       }
+
+       /*
+        * the idea is to trigger a regular read through the standard path. we
+        * read a page from the (failed) logical address by specifying the
+        * corresponding copynum of the failed sector. thus, that readpage is
+        * expected to fail.
+        * that is the point where on-the-fly error correction will kick in
+        * (once it's finished) and rewrite the failed sector if a good copy
+        * can be found.
+        */
+       ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
+                                               path, scrub_fixup_readpage,
+                                               fixup);
+       if (ret < 0) {
+               uncorrectable = 1;
+               goto out;
+       }
+       WARN_ON(ret != 1);
+
+       spin_lock(&sdev->stat_lock);
+       ++sdev->stat.corrected_errors;
+       spin_unlock(&sdev->stat_lock);
+
+out:
+       if (trans && !IS_ERR(trans))
+               btrfs_end_transaction(trans, fixup->root);
+       if (uncorrectable) {
+               spin_lock(&sdev->stat_lock);
+               ++sdev->stat.uncorrectable_errors;
+               spin_unlock(&sdev->stat_lock);
+               printk_ratelimited(KERN_ERR "btrfs: unable to fixup "
+                                       "(nodatasum) error at logical %llu\n",
+                                       fixup->logical);
+       }
+
+       btrfs_free_path(path);
+       kfree(fixup);
+
+       /* see caller why we're pretending to be paused in the scrub counters */
+       mutex_lock(&fs_info->scrub_lock);
+       atomic_dec(&fs_info->scrubs_running);
+       atomic_dec(&fs_info->scrubs_paused);
+       mutex_unlock(&fs_info->scrub_lock);
+       atomic_dec(&sdev->fixup_cnt);
+       wake_up(&fs_info->scrub_pause_wait);
+       wake_up(&sdev->list_wait);
+}
+
 /*
  * scrub_recheck_error gets called when either verification of the page
  * failed or the bio failed to read, e.g. with EIO. In the latter case,
  * recheck_error gets called for every page in the bio, even though only
  * one may be bad
  */
-static void scrub_recheck_error(struct scrub_bio *sbio, int ix)
+static int scrub_recheck_error(struct scrub_bio *sbio, int ix)
 {
+       struct scrub_dev *sdev = sbio->sdev;
+       u64 sector = (sbio->physical + ix * PAGE_SIZE) >> 9;
+       static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
+                                       DEFAULT_RATELIMIT_BURST);
+
        if (sbio->err) {
-               if (scrub_fixup_io(READ, sbio->sdev->dev->bdev,
-                                  (sbio->physical + ix * PAGE_SIZE) >> 9,
+               if (scrub_fixup_io(READ, sbio->sdev->dev->bdev, sector,
                                   sbio->bio->bi_io_vec[ix].bv_page) == 0) {
                        if (scrub_fixup_check(sbio, ix) == 0)
-                               return;
+                               return 0;
                }
+               if (__ratelimit(&_rs))
+                       scrub_print_warning("i/o error", sbio, ix);
+       } else {
+               if (__ratelimit(&_rs))
+                       scrub_print_warning("checksum error", sbio, ix);
        }
 
+       spin_lock(&sdev->stat_lock);
+       ++sdev->stat.read_errors;
+       spin_unlock(&sdev->stat_lock);
+
        scrub_fixup(sbio, ix);
+       return 1;
 }
 
 static int scrub_fixup_check(struct scrub_bio *sbio, int ix)
@@ -247,7 +611,8 @@ static void scrub_fixup(struct scrub_bio *sbio, int ix)
        struct scrub_dev *sdev = sbio->sdev;
        struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
        struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
-       struct btrfs_multi_bio *multi = NULL;
+       struct btrfs_bio *bbio = NULL;
+       struct scrub_fixup_nodatasum *fixup;
        u64 logical = sbio->logical + ix * PAGE_SIZE;
        u64 length;
        int i;
@@ -256,18 +621,36 @@ static void scrub_fixup(struct scrub_bio *sbio, int ix)
 
        if ((sbio->spag[ix].flags & BTRFS_EXTENT_FLAG_DATA) &&
            (sbio->spag[ix].have_csum == 0)) {
+               fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
+               if (!fixup)
+                       goto uncorrectable;
+               fixup->sdev = sdev;
+               fixup->logical = logical;
+               fixup->root = fs_info->extent_root;
+               fixup->mirror_num = sbio->spag[ix].mirror_num;
                /*
-                * nodatasum, don't try to fix anything
-                * FIXME: we can do better, open the inode and trigger a
-                * writeback
+                * increment scrubs_running to prevent cancel requests from
+                * completing as long as a fixup worker is running. we must also
+                * increment scrubs_paused to prevent deadlocking on pause
+                * requests used for transactions commits (as the worker uses a
+                * transaction context). it is safe to regard the fixup worker
+                * as paused for all matters practical. effectively, we only
+                * avoid cancellation requests from completing.
                 */
-               goto uncorrectable;
+               mutex_lock(&fs_info->scrub_lock);
+               atomic_inc(&fs_info->scrubs_running);
+               atomic_inc(&fs_info->scrubs_paused);
+               mutex_unlock(&fs_info->scrub_lock);
+               atomic_inc(&sdev->fixup_cnt);
+               fixup->work.func = scrub_fixup_nodatasum;
+               btrfs_queue_worker(&fs_info->scrub_workers, &fixup->work);
+               return;
        }
 
        length = PAGE_SIZE;
        ret = btrfs_map_block(map_tree, REQ_WRITE, logical, &length,
-                             &multi, 0);
-       if (ret || !multi || length < PAGE_SIZE) {
+                             &bbio, 0);
+       if (ret || !bbio || length < PAGE_SIZE) {
                printk(KERN_ERR
                       "scrub_fixup: btrfs_map_block failed us for %llu\n",
                       (unsigned long long)logical);
@@ -275,19 +658,19 @@ static void scrub_fixup(struct scrub_bio *sbio, int ix)
                return;
        }
 
-       if (multi->num_stripes == 1)
+       if (bbio->num_stripes == 1)
                /* there aren't any replicas */
                goto uncorrectable;
 
        /*
         * first find a good copy
         */
-       for (i = 0; i < multi->num_stripes; ++i) {
-               if (i == sbio->spag[ix].mirror_num)
+       for (i = 0; i < bbio->num_stripes; ++i) {
+               if (i + 1 == sbio->spag[ix].mirror_num)
                        continue;
 
-               if (scrub_fixup_io(READ, multi->stripes[i].dev->bdev,
-                                  multi->stripes[i].physical >> 9,
+               if (scrub_fixup_io(READ, bbio->stripes[i].dev->bdev,
+                                  bbio->stripes[i].physical >> 9,
                                   sbio->bio->bi_io_vec[ix].bv_page)) {
                        /* I/O-error, this is not a good copy */
                        continue;
@@ -296,7 +679,7 @@ static void scrub_fixup(struct scrub_bio *sbio, int ix)
                if (scrub_fixup_check(sbio, ix) == 0)
                        break;
        }
-       if (i == multi->num_stripes)
+       if (i == bbio->num_stripes)
                goto uncorrectable;
 
        if (!sdev->readonly) {
@@ -311,25 +694,23 @@ static void scrub_fixup(struct scrub_bio *sbio, int ix)
                }
        }
 
-       kfree(multi);
+       kfree(bbio);
        spin_lock(&sdev->stat_lock);
        ++sdev->stat.corrected_errors;
        spin_unlock(&sdev->stat_lock);
 
-       if (printk_ratelimit())
-               printk(KERN_ERR "btrfs: fixed up at %llu\n",
-                      (unsigned long long)logical);
+       printk_ratelimited(KERN_ERR "btrfs: fixed up error at logical %llu\n",
+                              (unsigned long long)logical);
        return;
 
 uncorrectable:
-       kfree(multi);
+       kfree(bbio);
        spin_lock(&sdev->stat_lock);
        ++sdev->stat.uncorrectable_errors;
        spin_unlock(&sdev->stat_lock);
 
-       if (printk_ratelimit())
-               printk(KERN_ERR "btrfs: unable to fixup at %llu\n",
-                        (unsigned long long)logical);
+       printk_ratelimited(KERN_ERR "btrfs: unable to fixup (regular) error at "
+                               "logical %llu\n", (unsigned long long)logical);
 }
 
 static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
@@ -379,8 +760,14 @@ static void scrub_checksum(struct btrfs_work *work)
        int ret;
 
        if (sbio->err) {
+               ret = 0;
                for (i = 0; i < sbio->count; ++i)
-                       scrub_recheck_error(sbio, i);
+                       ret |= scrub_recheck_error(sbio, i);
+               if (!ret) {
+                       spin_lock(&sdev->stat_lock);
+                       ++sdev->stat.unverified_errors;
+                       spin_unlock(&sdev->stat_lock);
+               }
 
                sbio->bio->bi_flags &= ~(BIO_POOL_MASK - 1);
                sbio->bio->bi_flags |= 1 << BIO_UPTODATE;
@@ -393,10 +780,6 @@ static void scrub_checksum(struct btrfs_work *work)
                        bi->bv_offset = 0;
                        bi->bv_len = PAGE_SIZE;
                }
-
-               spin_lock(&sdev->stat_lock);
-               ++sdev->stat.read_errors;
-               spin_unlock(&sdev->stat_lock);
                goto out;
        }
        for (i = 0; i < sbio->count; ++i) {
@@ -417,8 +800,14 @@ static void scrub_checksum(struct btrfs_work *work)
                        WARN_ON(1);
                }
                kunmap_atomic(buffer, KM_USER0);
-               if (ret)
-                       scrub_recheck_error(sbio, i);
+               if (ret) {
+                       ret = scrub_recheck_error(sbio, i);
+                       if (!ret) {
+                               spin_lock(&sdev->stat_lock);
+                               ++sdev->stat.unverified_errors;
+                               spin_unlock(&sdev->stat_lock);
+                       }
+               }
        }
 
 out:
@@ -601,7 +990,7 @@ nomem:
 }
 
 static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len,
-                     u64 physical, u64 flags, u64 gen, u64 mirror_num,
+                     u64 physical, u64 flags, u64 gen, int mirror_num,
                      u8 *csum, int force)
 {
        struct scrub_bio *sbio;
@@ -698,7 +1087,7 @@ static int scrub_find_csum(struct scrub_dev *sdev, u64 logical, u64 len,
 
 /* scrub extent tries to collect up to 64 kB for each bio */
 static int scrub_extent(struct scrub_dev *sdev, u64 logical, u64 len,
-                       u64 physical, u64 flags, u64 gen, u64 mirror_num)
+                       u64 physical, u64 flags, u64 gen, int mirror_num)
 {
        int ret;
        u8 csum[BTRFS_CSUM_SIZE];
@@ -743,7 +1132,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
        u64 physical;
        u64 logical;
        u64 generation;
-       u64 mirror_num;
+       int mirror_num;
        struct reada_control *reada1;
        struct reada_control *reada2;
        struct btrfs_key key_start;
@@ -758,21 +1147,21 @@ static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
        if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
                offset = map->stripe_len * num;
                increment = map->stripe_len * map->num_stripes;
-               mirror_num = 0;
+               mirror_num = 1;
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
                int factor = map->num_stripes / map->sub_stripes;
                offset = map->stripe_len * (num / map->sub_stripes);
                increment = map->stripe_len * factor;
-               mirror_num = num % map->sub_stripes;
+               mirror_num = num % map->sub_stripes + 1;
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
                increment = map->stripe_len;
-               mirror_num = num % map->num_stripes;
+               mirror_num = num % map->num_stripes + 1;
        } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
                increment = map->stripe_len;
-               mirror_num = num % map->num_stripes;
+               mirror_num = num % map->num_stripes + 1;
        } else {
                increment = map->stripe_len;
-               mirror_num = 0;
+               mirror_num = 1;
        }
 
        path = btrfs_alloc_path();
@@ -1241,10 +1630,11 @@ int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
                ret = scrub_enumerate_chunks(sdev, start, end);
 
        wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
-
        atomic_dec(&fs_info->scrubs_running);
        wake_up(&fs_info->scrub_pause_wait);
 
+       wait_event(sdev->list_wait, atomic_read(&sdev->fixup_cnt) == 0);
+
        if (progress)
                memcpy(progress, &sdev->stat, sizeof(*progress));
 
index f1685a2..f8e2943 100644 (file)
@@ -2880,7 +2880,7 @@ static int find_live_mirror(struct map_lookup *map, int first, int num,
 
 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
                             u64 logical, u64 *length,
-                            struct btrfs_multi_bio **multi_ret,
+                            struct btrfs_bio **bbio_ret,
                             int mirror_num)
 {
        struct extent_map *em;
@@ -2898,18 +2898,18 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
        int i;
        int num_stripes;
        int max_errors = 0;
-       struct btrfs_multi_bio *multi = NULL;
+       struct btrfs_bio *bbio = NULL;
 
-       if (multi_ret && !(rw & (REQ_WRITE | REQ_DISCARD)))
+       if (bbio_ret && !(rw & (REQ_WRITE | REQ_DISCARD)))
                stripes_allocated = 1;
 again:
-       if (multi_ret) {
-               multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
+       if (bbio_ret) {
+               bbio = kzalloc(btrfs_bio_size(stripes_allocated),
                                GFP_NOFS);
-               if (!multi)
+               if (!bbio)
                        return -ENOMEM;
 
-               atomic_set(&multi->error, 0);
+               atomic_set(&bbio->error, 0);
        }
 
        read_lock(&em_tree->lock);
@@ -2930,7 +2930,7 @@ again:
        if (mirror_num > map->num_stripes)
                mirror_num = 0;
 
-       /* if our multi bio struct is too small, back off and try again */
+       /* if our btrfs_bio struct is too small, back off and try again */
        if (rw & REQ_WRITE) {
                if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
                                 BTRFS_BLOCK_GROUP_DUP)) {
@@ -2949,11 +2949,11 @@ again:
                        stripes_required = map->num_stripes;
                }
        }
-       if (multi_ret && (rw & (REQ_WRITE | REQ_DISCARD)) &&
+       if (bbio_ret && (rw & (REQ_WRITE | REQ_DISCARD)) &&
            stripes_allocated < stripes_required) {
                stripes_allocated = map->num_stripes;
                free_extent_map(em);
-               kfree(multi);
+               kfree(bbio);
                goto again;
        }
        stripe_nr = offset;
@@ -2982,7 +2982,7 @@ again:
                *length = em->len - offset;
        }
 
-       if (!multi_ret)
+       if (!bbio_ret)
                goto out;
 
        num_stripes = 1;
@@ -3007,13 +3007,17 @@ again:
                        stripe_index = find_live_mirror(map, 0,
                                            map->num_stripes,
                                            current->pid % map->num_stripes);
+                       mirror_num = stripe_index + 1;
                }
 
        } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
-               if (rw & (REQ_WRITE | REQ_DISCARD))
+               if (rw & (REQ_WRITE | REQ_DISCARD)) {
                        num_stripes = map->num_stripes;
-               else if (mirror_num)
+               } else if (mirror_num) {
                        stripe_index = mirror_num - 1;
+               } else {
+                       mirror_num = 1;
+               }
 
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
                int factor = map->num_stripes / map->sub_stripes;
@@ -3033,6 +3037,7 @@ again:
                        stripe_index = find_live_mirror(map, stripe_index,
                                              map->sub_stripes, stripe_index +
                                              current->pid % map->sub_stripes);
+                       mirror_num = stripe_index + 1;
                }
        } else {
                /*
@@ -3041,15 +3046,16 @@ again:
                 * stripe_index is the number of our device in the stripe array
                 */
                stripe_index = do_div(stripe_nr, map->num_stripes);
+               mirror_num = stripe_index + 1;
        }
        BUG_ON(stripe_index >= map->num_stripes);
 
        if (rw & REQ_DISCARD) {
                for (i = 0; i < num_stripes; i++) {
-                       multi->stripes[i].physical =
+                       bbio->stripes[i].physical =
                                map->stripes[stripe_index].physical +
                                stripe_offset + stripe_nr * map->stripe_len;
-                       multi->stripes[i].dev = map->stripes[stripe_index].dev;
+                       bbio->stripes[i].dev = map->stripes[stripe_index].dev;
 
                        if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
                                u64 stripes;
@@ -3070,16 +3076,16 @@ again:
                                }
                                stripes = stripe_nr_end - 1 - j;
                                do_div(stripes, map->num_stripes);
-                               multi->stripes[i].length = map->stripe_len *
+                               bbio->stripes[i].length = map->stripe_len *
                                        (stripes - stripe_nr + 1);
 
                                if (i == 0) {
-                                       multi->stripes[i].length -=
+                                       bbio->stripes[i].length -=
                                                stripe_offset;
                                        stripe_offset = 0;
                                }
                                if (stripe_index == last_stripe)
-                                       multi->stripes[i].length -=
+                                       bbio->stripes[i].length -=
                                                stripe_end_offset;
                        } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
                                u64 stripes;
@@ -3104,11 +3110,11 @@ again:
                                }
                                stripes = stripe_nr_end - 1 - j;
                                do_div(stripes, factor);
-                               multi->stripes[i].length = map->stripe_len *
+                               bbio->stripes[i].length = map->stripe_len *
                                        (stripes - stripe_nr + 1);
 
                                if (i < map->sub_stripes) {
-                                       multi->stripes[i].length -=
+                                       bbio->stripes[i].length -=
                                                stripe_offset;
                                        if (i == map->sub_stripes - 1)
                                                stripe_offset = 0;
@@ -3116,11 +3122,11 @@ again:
                                if (stripe_index >= last_stripe &&
                                    stripe_index <= (last_stripe +
                                                     map->sub_stripes - 1)) {
-                                       multi->stripes[i].length -=
+                                       bbio->stripes[i].length -=
                                                stripe_end_offset;
                                }
                        } else
-                               multi->stripes[i].length = *length;
+                               bbio->stripes[i].length = *length;
 
                        stripe_index++;
                        if (stripe_index == map->num_stripes) {
@@ -3131,19 +3137,20 @@ again:
                }
        } else {
                for (i = 0; i < num_stripes; i++) {
-                       multi->stripes[i].physical =
+                       bbio->stripes[i].physical =
                                map->stripes[stripe_index].physical +
                                stripe_offset +
                                stripe_nr * map->stripe_len;
-                       multi->stripes[i].dev =
+                       bbio->stripes[i].dev =
                                map->stripes[stripe_index].dev;
                        stripe_index++;
                }
        }
-       if (multi_ret) {
-               *multi_ret = multi;
-               multi->num_stripes = num_stripes;
-               multi->max_errors = max_errors;
+       if (bbio_ret) {
+               *bbio_ret = bbio;
+               bbio->num_stripes = num_stripes;
+               bbio->max_errors = max_errors;
+               bbio->mirror_num = mirror_num;
        }
 out:
        free_extent_map(em);
@@ -3152,9 +3159,9 @@ out:
 
 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
                      u64 logical, u64 *length,
-                     struct btrfs_multi_bio **multi_ret, int mirror_num)
+                     struct btrfs_bio **bbio_ret, int mirror_num)
 {
-       return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
+       return __btrfs_map_block(map_tree, rw, logical, length, bbio_ret,
                                 mirror_num);
 }
 
@@ -3223,28 +3230,30 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
        return 0;
 }
 
-static void end_bio_multi_stripe(struct bio *bio, int err)
+static void btrfs_end_bio(struct bio *bio, int err)
 {
-       struct btrfs_multi_bio *multi = bio->bi_private;
+       struct btrfs_bio *bbio = bio->bi_private;
        int is_orig_bio = 0;
 
        if (err)
-               atomic_inc(&multi->error);
+               atomic_inc(&bbio->error);
 
-       if (bio == multi->orig_bio)
+       if (bio == bbio->orig_bio)
                is_orig_bio = 1;
 
-       if (atomic_dec_and_test(&multi->stripes_pending)) {
+       if (atomic_dec_and_test(&bbio->stripes_pending)) {
                if (!is_orig_bio) {
                        bio_put(bio);
-                       bio = multi->orig_bio;
+                       bio = bbio->orig_bio;
                }
-               bio->bi_private = multi->private;
-               bio->bi_end_io = multi->end_io;
+               bio->bi_private = bbio->private;
+               bio->bi_end_io = bbio->end_io;
+               bio->bi_bdev = (struct block_device *)
+                                       (unsigned long)bbio->mirror_num;
                /* only send an error to the higher layers if it is
                 * beyond the tolerance of the multi-bio
                 */
-               if (atomic_read(&multi->error) > multi->max_errors) {
+               if (atomic_read(&bbio->error) > bbio->max_errors) {
                        err = -EIO;
                } else if (err) {
                        /*
@@ -3254,7 +3263,7 @@ static void end_bio_multi_stripe(struct bio *bio, int err)
                        set_bit(BIO_UPTODATE, &bio->bi_flags);
                        err = 0;
                }
-               kfree(multi);
+               kfree(bbio);
 
                bio_endio(bio, err);
        } else if (!is_orig_bio) {
@@ -3334,20 +3343,20 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
        u64 logical = (u64)bio->bi_sector << 9;
        u64 length = 0;
        u64 map_length;
-       struct btrfs_multi_bio *multi = NULL;
        int ret;
        int dev_nr = 0;
        int total_devs = 1;
+       struct btrfs_bio *bbio = NULL;
 
        length = bio->bi_size;
        map_tree = &root->fs_info->mapping_tree;
        map_length = length;
 
-       ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
+       ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio,
                              mirror_num);
        BUG_ON(ret);
 
-       total_devs = multi->num_stripes;
+       total_devs = bbio->num_stripes;
        if (map_length < length) {
                printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
                       "len %llu\n", (unsigned long long)logical,
@@ -3355,25 +3364,28 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
                       (unsigned long long)map_length);
                BUG();
        }
-       multi->end_io = first_bio->bi_end_io;
-       multi->private = first_bio->bi_private;
-       multi->orig_bio = first_bio;
-       atomic_set(&multi->stripes_pending, multi->num_stripes);
+
+       bbio->orig_bio = first_bio;
+       bbio->private = first_bio->bi_private;
+       bbio->end_io = first_bio->bi_end_io;
+       atomic_set(&bbio->stripes_pending, bbio->num_stripes);
 
        while (dev_nr < total_devs) {
-               if (total_devs > 1) {
-                       if (dev_nr < total_devs - 1) {
-                               bio = bio_clone(first_bio, GFP_NOFS);
-                               BUG_ON(!bio);
-                       } else {
-                               bio = first_bio;
-                       }
-                       bio->bi_private = multi;
-                       bio->bi_end_io = end_bio_multi_stripe;
+               if (dev_nr < total_devs - 1) {
+                       bio = bio_clone(first_bio, GFP_NOFS);
+                       BUG_ON(!bio);
+               } else {
+                       bio = first_bio;
                }
-               bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
-               dev = multi->stripes[dev_nr].dev;
+               bio->bi_private = bbio;
+               bio->bi_end_io = btrfs_end_bio;
+               bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
+               dev = bbio->stripes[dev_nr].dev;
                if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
+                       pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
+                                "(%s id %llu), size=%u\n", rw,
+                                (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
+                                dev->name, dev->devid, bio->bi_size);
                        bio->bi_bdev = dev->bdev;
                        if (async_submit)
                                schedule_bio(root, dev, rw, bio);
@@ -3386,8 +3398,6 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
                }
                dev_nr++;
        }
-       if (total_devs == 1)
-               kfree(multi);
        return 0;
 }
 
index 2a75124..ab5b1c4 100644 (file)
@@ -144,7 +144,10 @@ struct btrfs_bio_stripe {
        u64 length; /* only used for discard mappings */
 };
 
-struct btrfs_multi_bio {
+struct btrfs_bio;
+typedef void (btrfs_bio_end_io_t) (struct btrfs_bio *bio, int err);
+
+struct btrfs_bio {
        atomic_t stripes_pending;
        bio_end_io_t *end_io;
        struct bio *orig_bio;
@@ -152,6 +155,7 @@ struct btrfs_multi_bio {
        atomic_t error;
        int max_errors;
        int num_stripes;
+       int mirror_num;
        struct btrfs_bio_stripe stripes[];
 };
 
@@ -179,7 +183,7 @@ struct map_lookup {
 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
                                   u64 end, u64 *length);
 
-#define btrfs_multi_bio_size(n) (sizeof(struct btrfs_multi_bio) + \
+#define btrfs_bio_size(n) (sizeof(struct btrfs_bio) + \
                            (sizeof(struct btrfs_bio_stripe) * (n)))
 
 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
@@ -188,7 +192,7 @@ int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
                           u64 chunk_offset, u64 start, u64 num_bytes);
 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
                    u64 logical, u64 *length,
-                   struct btrfs_multi_bio **multi_ret, int mirror_num);
+                   struct btrfs_bio **bbio_ret, int mirror_num);
 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
                     u64 chunk_start, u64 physical, u64 devid,
                     u64 **logical, int *naddrs, int *stripe_len);