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author | Paul Mundt <lethal@linux-sh.org> | 2012-08-01 13:49:13 +0900 |
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committer | Paul Mundt <lethal@linux-sh.org> | 2012-08-01 13:49:13 +0900 |
commit | 91ba548cfd5cc8ee93b9435527efb8fa4caf5c5e (patch) | |
tree | c96ed92413044a28d17783e84a8824bfd2437af1 /fs/btrfs/root-tree.c | |
parent | b9ccfda293ee6fca9a89a1584f0900e0627b975e (diff) | |
parent | 4dc4c51675c137c30838425ecc8d471ff5eb138b (diff) | |
download | op-kernel-dev-91ba548cfd5cc8ee93b9435527efb8fa4caf5c5e.zip op-kernel-dev-91ba548cfd5cc8ee93b9435527efb8fa4caf5c5e.tar.gz |
Merge branch 'sh/dmaengine' into sh-latest
Diffstat (limited to 'fs/btrfs/root-tree.c')
-rw-r--r-- | fs/btrfs/root-tree.c | 107 |
1 files changed, 101 insertions, 6 deletions
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index 24fb8ce..6bb465c 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -16,12 +16,55 @@ * Boston, MA 021110-1307, USA. */ +#include <linux/uuid.h> #include "ctree.h" #include "transaction.h" #include "disk-io.h" #include "print-tree.h" /* + * Read a root item from the tree. In case we detect a root item smaller then + * sizeof(root_item), we know it's an old version of the root structure and + * initialize all new fields to zero. The same happens if we detect mismatching + * generation numbers as then we know the root was once mounted with an older + * kernel that was not aware of the root item structure change. + */ +void btrfs_read_root_item(struct btrfs_root *root, + struct extent_buffer *eb, int slot, + struct btrfs_root_item *item) +{ + uuid_le uuid; + int len; + int need_reset = 0; + + len = btrfs_item_size_nr(eb, slot); + read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot), + min_t(int, len, (int)sizeof(*item))); + if (len < sizeof(*item)) + need_reset = 1; + if (!need_reset && btrfs_root_generation(item) + != btrfs_root_generation_v2(item)) { + if (btrfs_root_generation_v2(item) != 0) { + printk(KERN_WARNING "btrfs: mismatching " + "generation and generation_v2 " + "found in root item. This root " + "was probably mounted with an " + "older kernel. Resetting all " + "new fields.\n"); + } + need_reset = 1; + } + if (need_reset) { + memset(&item->generation_v2, 0, + sizeof(*item) - offsetof(struct btrfs_root_item, + generation_v2)); + + uuid_le_gen(&uuid); + memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE); + } +} + +/* * lookup the root with the highest offset for a given objectid. The key we do * find is copied into 'key'. If we find something return 0, otherwise 1, < 0 * on error. @@ -61,10 +104,10 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, goto out; } if (item) - read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot), - sizeof(*item)); + btrfs_read_root_item(root, l, slot, item); if (key) memcpy(key, &found_key, sizeof(found_key)); + ret = 0; out: btrfs_free_path(path); @@ -91,16 +134,15 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root int ret; int slot; unsigned long ptr; + int old_len; path = btrfs_alloc_path(); if (!path) return -ENOMEM; ret = btrfs_search_slot(trans, root, key, path, 0, 1); - if (ret < 0) { - btrfs_abort_transaction(trans, root, ret); - goto out; - } + if (ret < 0) + goto out_abort; if (ret != 0) { btrfs_print_leaf(root, path->nodes[0]); @@ -113,16 +155,56 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root l = path->nodes[0]; slot = path->slots[0]; ptr = btrfs_item_ptr_offset(l, slot); + old_len = btrfs_item_size_nr(l, slot); + + /* + * If this is the first time we update the root item which originated + * from an older kernel, we need to enlarge the item size to make room + * for the added fields. + */ + if (old_len < sizeof(*item)) { + btrfs_release_path(path); + ret = btrfs_search_slot(trans, root, key, path, + -1, 1); + if (ret < 0) + goto out_abort; + ret = btrfs_del_item(trans, root, path); + if (ret < 0) + goto out_abort; + btrfs_release_path(path); + ret = btrfs_insert_empty_item(trans, root, path, + key, sizeof(*item)); + if (ret < 0) + goto out_abort; + l = path->nodes[0]; + slot = path->slots[0]; + ptr = btrfs_item_ptr_offset(l, slot); + } + + /* + * Update generation_v2 so at the next mount we know the new root + * fields are valid. + */ + btrfs_set_root_generation_v2(item, btrfs_root_generation(item)); + write_extent_buffer(l, item, ptr, sizeof(*item)); btrfs_mark_buffer_dirty(path->nodes[0]); out: btrfs_free_path(path); return ret; + +out_abort: + btrfs_abort_transaction(trans, root, ret); + goto out; } int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key, struct btrfs_root_item *item) { + /* + * Make sure generation v1 and v2 match. See update_root for details. + */ + btrfs_set_root_generation_v2(item, btrfs_root_generation(item)); return btrfs_insert_item(trans, root, key, item, sizeof(*item)); } @@ -454,3 +536,16 @@ void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item) root_item->byte_limit = 0; } } + +void btrfs_update_root_times(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_root_item *item = &root->root_item; + struct timespec ct = CURRENT_TIME; + + spin_lock(&root->root_times_lock); + item->ctransid = trans->transid; + item->ctime.sec = cpu_to_le64(ct.tv_sec); + item->ctime.nsec = cpu_to_le64(ct.tv_nsec); + spin_unlock(&root->root_times_lock); +} |