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ext2fs: add new APIs needed for fast commits
[tools/e2fsprogs.git] / lib / ext2fs / extent.c
index c12bc93..bde6b0f 100644 (file)
@@ -60,6 +60,7 @@ struct ext2_extent_handle {
        int                     type;
        int                     level;
        int                     max_depth;
+       int                     max_paths;
        struct extent_path      *path;
 };
 
@@ -198,7 +199,7 @@ void ext2fs_extent_free(ext2_extent_handle_t handle)
                return;
 
        if (handle->path) {
-               for (i=1; i <= handle->max_depth; i++) {
+               for (i = 1; i < handle->max_paths; i++) {
                        if (handle->path[i].buf)
                                ext2fs_free_mem(&handle->path[i].buf);
                }
@@ -272,11 +273,10 @@ errcode_t ext2fs_extent_open2(ext2_filsys fs, ext2_ino_t ino,
        handle->max_depth = ext2fs_le16_to_cpu(eh->eh_depth);
        handle->type = ext2fs_le16_to_cpu(eh->eh_magic);
 
-       retval = ext2fs_get_mem(((handle->max_depth+1) *
-                                sizeof(struct extent_path)),
-                               &handle->path);
-       memset(handle->path, 0,
-              (handle->max_depth+1) * sizeof(struct extent_path));
+       handle->max_paths = handle->max_depth + 1;
+       retval = ext2fs_get_memzero(handle->max_paths *
+                                   sizeof(struct extent_path),
+                                   &handle->path);
        handle->path[0].buf = (char *) handle->inode->i_block;
 
        handle->path[0].left = handle->path[0].entries =
@@ -313,6 +313,7 @@ errcode_t ext2fs_extent_get(ext2_extent_handle_t handle,
        blk64_t                         blk;
        blk64_t                         end_blk;
        int                             orig_op, op;
+       int                             failed_csum = 0;
 
        EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 
@@ -485,6 +486,11 @@ retry:
                        return retval;
                }
 
+               if (!(handle->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+                   !ext2fs_extent_block_csum_verify(handle->fs, handle->ino,
+                                                    eh))
+                       failed_csum = 1;
+
                newpath->left = newpath->entries =
                        ext2fs_le16_to_cpu(eh->eh_entries);
                newpath->max_entries = ext2fs_le16_to_cpu(eh->eh_max);
@@ -563,6 +569,9 @@ retry:
             (path->left != 0)))
                goto retry;
 
+       if (failed_csum)
+               return EXT2_ET_EXTENT_CSUM_INVALID;
+
        return 0;
 }
 
@@ -571,6 +580,7 @@ static errcode_t update_path(ext2_extent_handle_t handle)
        blk64_t                         blk;
        errcode_t                       retval;
        struct ext3_extent_idx          *ix;
+       struct ext3_extent_header       *eh;
 
        if (handle->level == 0) {
                retval = ext2fs_write_inode(handle->fs, handle->ino,
@@ -580,6 +590,14 @@ static errcode_t update_path(ext2_extent_handle_t handle)
                blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
                        ((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
 
+               /* then update the checksum */
+               eh = (struct ext3_extent_header *)
+                               handle->path[handle->level].buf;
+               retval = ext2fs_extent_block_csum_set(handle->fs, handle->ino,
+                                                     eh);
+               if (retval)
+                       return retval;
+
                retval = io_channel_write_blk64(handle->fs->io,
                                      blk, 1, handle->path[handle->level].buf);
        }
@@ -734,7 +752,14 @@ errcode_t ext2fs_extent_goto(ext2_extent_handle_t handle,
  * and so on.
  *
  * Safe to call for any position in node; if not at the first entry,
- * will  simply return.
+ * it will simply return.
+ *
+ * Note a subtlety of this function -- if there happen to be two extents
+ * mapping the same lblk and someone calls fix_parents on the second of the two
+ * extents, the position of the extent handle after the call will be the second
+ * extent if nothing happened, or the first extent if something did.  A caller
+ * in this situation must use ext2fs_extent_goto() after calling this function.
+ * Or simply don't map the same lblk with two extents, ever.
  */
 errcode_t ext2fs_extent_fix_parents(ext2_extent_handle_t handle)
 {
@@ -909,6 +934,25 @@ static errcode_t extent_node_split(ext2_extent_handle_t handle,
        orig_height = info.max_depth - info.curr_level;
        orig_lblk = extent.e_lblk;
 
+       /* Try to put the index block before the first extent */
+       path = handle->path + handle->level;
+       eh = (struct ext3_extent_header *) path->buf;
+       if (handle->level == handle->max_depth) {
+               struct ext3_extent      *ex;
+
+               ex = EXT_FIRST_EXTENT(eh);
+               goal_blk = ext2fs_le32_to_cpu(ex->ee_start) +
+                       ((__u64) ext2fs_le16_to_cpu(ex->ee_start_hi) << 32);
+       } else {
+               struct ext3_extent_idx  *ix;
+
+               ix = EXT_FIRST_INDEX(eh);
+               goal_blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
+                       ((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
+       }
+       goal_blk -= EXT2FS_CLUSTER_RATIO(handle->fs);
+       goal_blk &= ~EXT2FS_CLUSTER_MASK(handle->fs);
+
        /* Is there room in the parent for a new entry? */
        if (handle->level &&
                        (handle->path[handle->level - 1].entries >=
@@ -922,7 +966,6 @@ static errcode_t extent_node_split(ext2_extent_handle_t handle,
                retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP, &extent);
                if (retval)
                        goto done;
-               goal_blk = extent.e_pblk;
 
                retval = extent_node_split(handle, expand_allowed);
                if (retval)
@@ -954,13 +997,11 @@ static errcode_t extent_node_split(ext2_extent_handle_t handle,
        if (handle->level == 0) {
                new_root = 1;
                tocopy = ext2fs_le16_to_cpu(eh->eh_entries);
-               retval = ext2fs_get_mem(((handle->max_depth+2) *
-                                        sizeof(struct extent_path)),
-                                       &newpath);
+               retval = ext2fs_get_memzero((handle->max_paths + 1) *
+                                           sizeof(struct extent_path),
+                                           &newpath);
                if (retval)
                        goto done;
-               memset(newpath, 0,
-                      ((handle->max_depth+2) * sizeof(struct extent_path)));
        } else {
                if (no_balance)
                        tocopy = 1;
@@ -989,14 +1030,9 @@ static errcode_t extent_node_split(ext2_extent_handle_t handle,
                goto done;
        }
 
-       if (!goal_blk) {
-               dgrp_t  group = ext2fs_group_of_ino(handle->fs, handle->ino);
-               __u8    log_flex = handle->fs->super->s_log_groups_per_flex;
-
-               if (log_flex)
-                       group = group & ~((1 << (log_flex)) - 1);
-               goal_blk = ext2fs_group_first_block2(handle->fs, group);
-       }
+       if (!goal_blk)
+               goal_blk = ext2fs_find_inode_goal(handle->fs, handle->ino,
+                                                 handle->inode, 0);
        retval = ext2fs_alloc_block2(handle->fs, goal_blk, block_buf,
                                    &new_node_pblk);
        if (retval)
@@ -1024,6 +1060,11 @@ static errcode_t extent_node_split(ext2_extent_handle_t handle,
 
        new_node_start = ext2fs_le32_to_cpu(EXT_FIRST_INDEX(neweh)->ei_block);
 
+       /* then update the checksum */
+       retval = ext2fs_extent_block_csum_set(handle->fs, handle->ino, neweh);
+       if (retval)
+               goto done;
+
        /* ...and write the new node block out to disk. */
        retval = io_channel_write_blk64(handle->fs->io, new_node_pblk, 1,
                                        block_buf);
@@ -1036,13 +1077,14 @@ static errcode_t extent_node_split(ext2_extent_handle_t handle,
        /* current path now has fewer active entries, we copied some out */
        if (handle->level == 0) {
                memcpy(newpath, path,
-                      sizeof(struct extent_path) * (handle->max_depth+1));
+                      sizeof(struct extent_path) * handle->max_paths);
                handle->path = newpath;
                newpath = path;
                path = handle->path;
                path->entries = 1;
                path->left = path->max_entries - 1;
                handle->max_depth++;
+               handle->max_paths++;
                eh->eh_depth = ext2fs_cpu_to_le16(handle->max_depth);
        } else {
                path->entries -= tocopy;
@@ -1424,17 +1466,25 @@ errcode_t ext2fs_extent_set_bmap(ext2_extent_handle_t handle,
                                                               &next_extent);
                                if (retval)
                                        goto done;
-                               retval = ext2fs_extent_fix_parents(handle);
-                               if (retval)
-                                       goto done;
                        } else
                                retval = ext2fs_extent_insert(handle,
                                      EXT2_EXTENT_INSERT_AFTER, &newextent);
                        if (retval)
                                goto done;
-                       /* Now pointing at inserted extent; move back to prev */
+                       retval = ext2fs_extent_fix_parents(handle);
+                       if (retval)
+                               goto done;
+                       /*
+                        * Now pointing at inserted extent; move back to prev.
+                        *
+                        * We cannot use EXT2_EXTENT_PREV to go back; note the
+                        * subtlety in the comment for fix_parents().
+                        */
+                       retval = ext2fs_extent_goto(handle, logical);
+                       if (retval)
+                               goto done;
                        retval = ext2fs_extent_get(handle,
-                                                  EXT2_EXTENT_PREV_LEAF,
+                                                  EXT2_EXTENT_CURRENT,
                                                   &extent);
                        if (retval)
                                goto done;
@@ -1467,6 +1517,9 @@ errcode_t ext2fs_extent_set_bmap(ext2_extent_handle_t handle,
                                                              0, &newextent);
                        if (retval)
                                goto done;
+                       retval = ext2fs_extent_fix_parents(handle);
+                       if (retval)
+                               goto done;
                        retval = ext2fs_extent_get(handle,
                                                   EXT2_EXTENT_NEXT_LEAF,
                                                   &extent);
@@ -1483,18 +1536,18 @@ errcode_t ext2fs_extent_set_bmap(ext2_extent_handle_t handle,
                if (retval)
                        goto done;
        } else {
-               __u32   orig_length;
-               blk64_t orig_lblk;
-               struct ext2fs_extent orig_extent;
+               __u32   save_length;
+               blk64_t save_lblk;
+               struct ext2fs_extent save_extent;
                errcode_t r2;
 
 #ifdef DEBUG
                printf("(re/un)mapping in middle of extent\n");
 #endif
                /* need to split this extent; later */
-               orig_lblk = extent.e_lblk;
-               orig_length = extent.e_len;
-               orig_extent = extent;
+               save_lblk = extent.e_lblk;
+               save_length = extent.e_len;
+               save_extent = extent;
 
                /* shorten pre-split extent */
                extent.e_len = (logical - extent.e_lblk);
@@ -1507,17 +1560,17 @@ errcode_t ext2fs_extent_set_bmap(ext2_extent_handle_t handle,
                        retval = ext2fs_extent_insert(handle,
                                        EXT2_EXTENT_INSERT_AFTER, &newextent);
                        if (retval) {
-                               r2 = ext2fs_extent_goto(handle, orig_lblk);
+                               r2 = ext2fs_extent_goto(handle, save_lblk);
                                if (r2 == 0)
-                                       ext2fs_extent_replace(handle, 0,
-                                                             &orig_extent);
+                                       (void)ext2fs_extent_replace(handle, 0,
+                                                             &save_extent);
                                goto done;
                        }
                }
                /* add post-split extent */
                extent.e_pblk += extent.e_len + 1;
                extent.e_lblk += extent.e_len + 1;
-               extent.e_len = orig_length - extent.e_len - 1;
+               extent.e_len = save_length - extent.e_len - 1;
                retval = ext2fs_extent_insert(handle,
                                EXT2_EXTENT_INSERT_AFTER, &extent);
                if (retval) {
@@ -1525,11 +1578,12 @@ errcode_t ext2fs_extent_set_bmap(ext2_extent_handle_t handle,
                                r2 = ext2fs_extent_goto(handle,
                                                        newextent.e_lblk);
                                if (r2 == 0)
-                                       ext2fs_extent_delete(handle, 0);
+                                       (void)ext2fs_extent_delete(handle, 0);
                        }
-                       r2 = ext2fs_extent_goto(handle, orig_lblk);
+                       r2 = ext2fs_extent_goto(handle, save_lblk);
                        if (r2 == 0)
-                               ext2fs_extent_replace(handle, 0, &orig_extent);
+                               (void)ext2fs_extent_replace(handle, 0,
+                                                           &save_extent);
                        goto done;
                }
        }
@@ -1610,8 +1664,10 @@ errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, int flags)
        } else {
                eh = (struct ext3_extent_header *) path->buf;
                eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
-               if ((path->entries == 0) && (handle->level == 0))
-                       eh->eh_depth = handle->max_depth = 0;
+               if ((path->entries == 0) && (handle->level == 0)) {
+                       eh->eh_depth = 0;
+                       handle->max_depth = 0;
+               }
                retval = update_path(handle);
        }
        return retval;
@@ -1641,10 +1697,154 @@ errcode_t ext2fs_extent_get_info(ext2_extent_handle_t handle,
 
        info->curr_level = handle->level;
        info->max_depth = handle->max_depth;
-       info->max_lblk = ((__u64) 1 << 32) - 1;
-       info->max_pblk = ((__u64) 1 << 48) - 1;
-       info->max_len = (1UL << 15);
-       info->max_uninit_len = (1UL << 15) - 1;
+       info->max_lblk = EXT_MAX_EXTENT_LBLK;
+       info->max_pblk = EXT_MAX_EXTENT_PBLK;
+       info->max_len = EXT_INIT_MAX_LEN;
+       info->max_uninit_len = EXT_UNINIT_MAX_LEN;
+
+       return 0;
+}
+
+static int ul_log2(unsigned long arg)
+{
+       int     l = 0;
+
+       arg >>= 1;
+       while (arg) {
+               l++;
+               arg >>= 1;
+       }
+       return l;
+}
+
+size_t ext2fs_max_extent_depth(ext2_extent_handle_t handle)
+{
+       size_t iblock_sz = sizeof(((struct ext2_inode *)NULL)->i_block);
+       size_t iblock_extents = (iblock_sz - sizeof(struct ext3_extent_header)) /
+                               sizeof(struct ext3_extent);
+       size_t extents_per_block = (handle->fs->blocksize -
+                                   sizeof(struct ext3_extent_header)) /
+                                  sizeof(struct ext3_extent);
+       static unsigned int last_blocksize = 0;
+       static size_t last_result = 0;
+
+       if (last_blocksize && last_blocksize == handle->fs->blocksize)
+               return last_result;
+
+       last_result = 1 + ((ul_log2(EXT_MAX_EXTENT_LBLK) - ul_log2(iblock_extents)) /
+                   ul_log2(extents_per_block));
+       last_blocksize = handle->fs->blocksize;
+       return last_result;
+}
+
+errcode_t ext2fs_fix_extents_checksums(ext2_filsys fs, ext2_ino_t ino,
+                                      struct ext2_inode *inode)
+{
+       ext2_extent_handle_t    handle;
+       struct ext2fs_extent    extent;
+       errcode_t               errcode;
+       int                     save_flags = fs->flags;
+
+       if (!ext2fs_has_feature_metadata_csum(fs->super) ||
+           (inode && !(inode->i_flags & EXT4_EXTENTS_FL)))
+               return 0;
+
+       errcode = ext2fs_extent_open2(fs, ino, inode, &handle);
+       if (errcode) {
+               if (errcode == EXT2_ET_INODE_NOT_EXTENT)
+                       errcode = 0;
+               return errcode;
+       }
+
+       fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
+       errcode = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
+       if (errcode)
+               goto out;
+
+       do {
+               /* Skip to the end of a block of leaf nodes */
+               if (extent.e_flags & EXT2_EXTENT_FLAGS_LEAF) {
+                       errcode = ext2fs_extent_get(handle,
+                                                   EXT2_EXTENT_LAST_SIB,
+                                                   &extent);
+                       if (errcode)
+                               break;
+               }
+
+               errcode = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT, &extent);
+               if (errcode == EXT2_ET_EXTENT_CSUM_INVALID)
+                       errcode = update_path(handle);
+       } while (errcode == 0);
+
+out:
+       /* Ok if we run off the end */
+       if (errcode == EXT2_ET_EXTENT_NO_NEXT)
+               errcode = 0;
+       ext2fs_extent_free(handle);
+       fs->flags = save_flags;
+       return errcode;
+}
+
+errcode_t ext2fs_decode_extent(struct ext2fs_extent *to, void *addr, int len)
+{
+       struct ext3_extent *from = (struct ext3_extent *)addr;
+
+       if (len != sizeof(struct ext3_extent))
+               return EXT2_ET_INVALID_ARGUMENT;
+
+       to->e_pblk = ext2fs_le32_to_cpu(from->ee_start) +
+               ((__u64) ext2fs_le16_to_cpu(from->ee_start_hi)
+                       << 32);
+       to->e_lblk = ext2fs_le32_to_cpu(from->ee_block);
+       to->e_len = ext2fs_le16_to_cpu(from->ee_len);
+       to->e_flags |= EXT2_EXTENT_FLAGS_LEAF;
+       if (to->e_len > EXT_INIT_MAX_LEN) {
+               to->e_len -= EXT_INIT_MAX_LEN;
+               to->e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
+       }
+
+       return 0;
+}
+
+errcode_t ext2fs_count_blocks(ext2_filsys fs, ext2_ino_t ino,
+                             struct ext2_inode *inode, blk64_t *ret_count)
+{
+       ext2_extent_handle_t    handle;
+       struct ext2fs_extent    extent;
+       errcode_t               errcode;
+       int                     i;
+       blk64_t                 blkcount = 0;
+       blk64_t                 *intermediate_nodes;
+
+       errcode = ext2fs_extent_open2(fs, ino, inode, &handle);
+       if (errcode)
+               goto out;
+
+       errcode = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
+       if (errcode)
+               goto out;
+
+       ext2fs_get_array(handle->max_depth, sizeof(blk64_t),
+                               &intermediate_nodes);
+       blkcount = handle->level;
+       while (!errcode) {
+               if (extent.e_flags & EXT2_EXTENT_FLAGS_LEAF) {
+                       blkcount += extent.e_len;
+                       for (i = 0; i < handle->level; i++) {
+                               if (intermediate_nodes[i] !=
+                                       handle->path[i].end_blk) {
+                                       blkcount++;
+                                       intermediate_nodes[i] =
+                                               handle->path[i].end_blk;
+                               }
+                       }
+               }
+               errcode = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT, &extent);
+       }
+       ext2fs_free_mem(&intermediate_nodes);
+out:
+       *ret_count = blkcount;
+       ext2fs_extent_free(handle);
 
        return 0;
 }