linux/fs/btrfs/tree-log.c

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/*
* Copyright (C) 2008 Oracle. 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 <linux/sched.h>
#include "ctree.h"
#include "transaction.h"
#include "disk-io.h"
#include "locking.h"
#include "print-tree.h"
#include "compat.h"
/* magic values for the inode_only field in btrfs_log_inode:
*
* LOG_INODE_ALL means to log everything
* LOG_INODE_EXISTS means to log just enough to recreate the inode
* during log replay
*/
#define LOG_INODE_ALL 0
#define LOG_INODE_EXISTS 1
/*
* stages for the tree walking. The first
* stage (0) is to only pin down the blocks we find
* the second stage (1) is to make sure that all the inodes
* we find in the log are created in the subvolume.
*
* The last stage is to deal with directories and links and extents
* and all the other fun semantics
*/
#define LOG_WALK_PIN_ONLY 0
#define LOG_WALK_REPLAY_INODES 1
#define LOG_WALK_REPLAY_ALL 2
static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode,
int inode_only);
/*
* tree logging is a special write ahead log used to make sure that
* fsyncs and O_SYNCs can happen without doing full tree commits.
*
* Full tree commits are expensive because they require commonly
* modified blocks to be recowed, creating many dirty pages in the
* extent tree an 4x-6x higher write load than ext3.
*
* Instead of doing a tree commit on every fsync, we use the
* key ranges and transaction ids to find items for a given file or directory
* that have changed in this transaction. Those items are copied into
* a special tree (one per subvolume root), that tree is written to disk
* and then the fsync is considered complete.
*
* After a crash, items are copied out of the log-tree back into the
* subvolume tree. Any file data extents found are recorded in the extent
* allocation tree, and the log-tree freed.
*
* The log tree is read three times, once to pin down all the extents it is
* using in ram and once, once to create all the inodes logged in the tree
* and once to do all the other items.
*/
/*
* btrfs_add_log_tree adds a new per-subvolume log tree into the
* tree of log tree roots. This must be called with a tree log transaction
* running (see start_log_trans).
*/
int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_key key;
struct btrfs_root_item root_item;
struct btrfs_inode_item *inode_item;
struct extent_buffer *leaf;
struct btrfs_root *new_root = root;
int ret;
u64 objectid = root->root_key.objectid;
leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
BTRFS_TREE_LOG_OBJECTID,
trans->transid, 0, 0, 0);
if (IS_ERR(leaf)) {
ret = PTR_ERR(leaf);
return ret;
}
btrfs_set_header_nritems(leaf, 0);
btrfs_set_header_level(leaf, 0);
btrfs_set_header_bytenr(leaf, leaf->start);
btrfs_set_header_generation(leaf, trans->transid);
btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
write_extent_buffer(leaf, root->fs_info->fsid,
(unsigned long)btrfs_header_fsid(leaf),
BTRFS_FSID_SIZE);
btrfs_mark_buffer_dirty(leaf);
inode_item = &root_item.inode;
memset(inode_item, 0, sizeof(*inode_item));
inode_item->generation = cpu_to_le64(1);
inode_item->size = cpu_to_le64(3);
inode_item->nlink = cpu_to_le32(1);
inode_item->nbytes = cpu_to_le64(root->leafsize);
inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
btrfs_set_root_bytenr(&root_item, leaf->start);
btrfs_set_root_generation(&root_item, trans->transid);
btrfs_set_root_level(&root_item, 0);
btrfs_set_root_refs(&root_item, 0);
btrfs_set_root_used(&root_item, 0);
memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
root_item.drop_level = 0;
btrfs_tree_unlock(leaf);
free_extent_buffer(leaf);
leaf = NULL;
btrfs_set_root_dirid(&root_item, 0);
key.objectid = BTRFS_TREE_LOG_OBJECTID;
key.offset = objectid;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
ret = btrfs_insert_root(trans, root->fs_info->log_root_tree, &key,
&root_item);
if (ret)
goto fail;
new_root = btrfs_read_fs_root_no_radix(root->fs_info->log_root_tree,
&key);
BUG_ON(!new_root);
WARN_ON(root->log_root);
root->log_root = new_root;
/*
* log trees do not get reference counted because they go away
* before a real commit is actually done. They do store pointers
* to file data extents, and those reference counts still get
* updated (along with back refs to the log tree).
*/
new_root->ref_cows = 0;
new_root->last_trans = trans->transid;
fail:
return ret;
}
/*
* start a sub transaction and setup the log tree
* this increments the log tree writer count to make the people
* syncing the tree wait for us to finish
*/
static int start_log_trans(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret;
mutex_lock(&root->fs_info->tree_log_mutex);
if (!root->fs_info->log_root_tree) {
ret = btrfs_init_log_root_tree(trans, root->fs_info);
BUG_ON(ret);
}
if (!root->log_root) {
ret = btrfs_add_log_tree(trans, root);
BUG_ON(ret);
}
atomic_inc(&root->fs_info->tree_log_writers);
root->fs_info->tree_log_batch++;
mutex_unlock(&root->fs_info->tree_log_mutex);
return 0;
}
/*
* returns 0 if there was a log transaction running and we were able
* to join, or returns -ENOENT if there were not transactions
* in progress
*/
static int join_running_log_trans(struct btrfs_root *root)
{
int ret = -ENOENT;
smp_mb();
if (!root->log_root)
return -ENOENT;
mutex_lock(&root->fs_info->tree_log_mutex);
if (root->log_root) {
ret = 0;
atomic_inc(&root->fs_info->tree_log_writers);
root->fs_info->tree_log_batch++;
}
mutex_unlock(&root->fs_info->tree_log_mutex);
return ret;
}
/*
* indicate we're done making changes to the log tree
* and wake up anyone waiting to do a sync
*/
static int end_log_trans(struct btrfs_root *root)
{
atomic_dec(&root->fs_info->tree_log_writers);
smp_mb();
if (waitqueue_active(&root->fs_info->tree_log_wait))
wake_up(&root->fs_info->tree_log_wait);
return 0;
}
/*
* the walk control struct is used to pass state down the chain when
* processing the log tree. The stage field tells us which part
* of the log tree processing we are currently doing. The others
* are state fields used for that specific part
*/
struct walk_control {
/* should we free the extent on disk when done? This is used
* at transaction commit time while freeing a log tree
*/
int free;
/* should we write out the extent buffer? This is used
* while flushing the log tree to disk during a sync
*/
int write;
/* should we wait for the extent buffer io to finish? Also used
* while flushing the log tree to disk for a sync
*/
int wait;
/* pin only walk, we record which extents on disk belong to the
* log trees
*/
int pin;
/* what stage of the replay code we're currently in */
int stage;
/* the root we are currently replaying */
struct btrfs_root *replay_dest;
/* the trans handle for the current replay */
struct btrfs_trans_handle *trans;
/* the function that gets used to process blocks we find in the
* tree. Note the extent_buffer might not be up to date when it is
* passed in, and it must be checked or read if you need the data
* inside it
*/
int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
struct walk_control *wc, u64 gen);
};
/*
* process_func used to pin down extents, write them or wait on them
*/
static int process_one_buffer(struct btrfs_root *log,
struct extent_buffer *eb,
struct walk_control *wc, u64 gen)
{
if (wc->pin) {
mutex_lock(&log->fs_info->pinned_mutex);
btrfs_update_pinned_extents(log->fs_info->extent_root,
eb->start, eb->len, 1);
mutex_unlock(&log->fs_info->pinned_mutex);
}
if (btrfs_buffer_uptodate(eb, gen)) {
if (wc->write)
btrfs_write_tree_block(eb);
if (wc->wait)
btrfs_wait_tree_block_writeback(eb);
}
return 0;
}
/*
* Item overwrite used by replay and tree logging. eb, slot and key all refer
* to the src data we are copying out.
*
* root is the tree we are copying into, and path is a scratch
* path for use in this function (it should be released on entry and
* will be released on exit).
*
* If the key is already in the destination tree the existing item is
* overwritten. If the existing item isn't big enough, it is extended.
* If it is too large, it is truncated.
*
* If the key isn't in the destination yet, a new item is inserted.
*/
static noinline int overwrite_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
int ret;
u32 item_size;
u64 saved_i_size = 0;
int save_old_i_size = 0;
unsigned long src_ptr;
unsigned long dst_ptr;
int overwrite_root = 0;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
overwrite_root = 1;
item_size = btrfs_item_size_nr(eb, slot);
src_ptr = btrfs_item_ptr_offset(eb, slot);
/* look for the key in the destination tree */
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret == 0) {
char *src_copy;
char *dst_copy;
u32 dst_size = btrfs_item_size_nr(path->nodes[0],
path->slots[0]);
if (dst_size != item_size)
goto insert;
if (item_size == 0) {
btrfs_release_path(root, path);
return 0;
}
dst_copy = kmalloc(item_size, GFP_NOFS);
src_copy = kmalloc(item_size, GFP_NOFS);
read_extent_buffer(eb, src_copy, src_ptr, item_size);
dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
item_size);
ret = memcmp(dst_copy, src_copy, item_size);
kfree(dst_copy);
kfree(src_copy);
/*
* they have the same contents, just return, this saves
* us from cowing blocks in the destination tree and doing
* extra writes that may not have been done by a previous
* sync
*/
if (ret == 0) {
btrfs_release_path(root, path);
return 0;
}
}
insert:
btrfs_release_path(root, path);
/* try to insert the key into the destination tree */
ret = btrfs_insert_empty_item(trans, root, path,
key, item_size);
/* make sure any existing item is the correct size */
if (ret == -EEXIST) {
u32 found_size;
found_size = btrfs_item_size_nr(path->nodes[0],
path->slots[0]);
if (found_size > item_size) {
btrfs_truncate_item(trans, root, path, item_size, 1);
} else if (found_size < item_size) {
ret = btrfs_del_item(trans, root,
path);
BUG_ON(ret);
btrfs_release_path(root, path);
ret = btrfs_insert_empty_item(trans,
root, path, key, item_size);
BUG_ON(ret);
}
} else if (ret) {
BUG();
}
dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
path->slots[0]);
/* don't overwrite an existing inode if the generation number
* was logged as zero. This is done when the tree logging code
* is just logging an inode to make sure it exists after recovery.
*
* Also, don't overwrite i_size on directories during replay.
* log replay inserts and removes directory items based on the
* state of the tree found in the subvolume, and i_size is modified
* as it goes
*/
if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
struct btrfs_inode_item *src_item;
struct btrfs_inode_item *dst_item;
src_item = (struct btrfs_inode_item *)src_ptr;
dst_item = (struct btrfs_inode_item *)dst_ptr;
if (btrfs_inode_generation(eb, src_item) == 0)
goto no_copy;
if (overwrite_root &&
S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
save_old_i_size = 1;
saved_i_size = btrfs_inode_size(path->nodes[0],
dst_item);
}
}
copy_extent_buffer(path->nodes[0], eb, dst_ptr,
src_ptr, item_size);
if (save_old_i_size) {
struct btrfs_inode_item *dst_item;
dst_item = (struct btrfs_inode_item *)dst_ptr;
btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
}
/* make sure the generation is filled in */
if (key->type == BTRFS_INODE_ITEM_KEY) {
struct btrfs_inode_item *dst_item;
dst_item = (struct btrfs_inode_item *)dst_ptr;
if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
btrfs_set_inode_generation(path->nodes[0], dst_item,
trans->transid);
}
}
if (overwrite_root &&
key->type == BTRFS_EXTENT_DATA_KEY) {
int extent_type;
struct btrfs_file_extent_item *fi;
fi = (struct btrfs_file_extent_item *)dst_ptr;
extent_type = btrfs_file_extent_type(path->nodes[0], fi);
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
struct btrfs_key ins;
ins.objectid = btrfs_file_extent_disk_bytenr(
path->nodes[0], fi);
ins.offset = btrfs_file_extent_disk_num_bytes(
path->nodes[0], fi);
ins.type = BTRFS_EXTENT_ITEM_KEY;
/*
* is this extent already allocated in the extent
* allocation tree? If so, just add a reference
*/
ret = btrfs_lookup_extent(root, ins.objectid,
ins.offset);
if (ret == 0) {
ret = btrfs_inc_extent_ref(trans, root,
ins.objectid, ins.offset,
path->nodes[0]->start,
root->root_key.objectid,
trans->transid, key->objectid);
} else {
/*
* insert the extent pointer in the extent
* allocation tree
*/
ret = btrfs_alloc_logged_extent(trans, root,
path->nodes[0]->start,
root->root_key.objectid,
trans->transid, key->objectid,
&ins);
BUG_ON(ret);
}
}
}
no_copy:
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(root, path);
return 0;
}
/*
* simple helper to read an inode off the disk from a given root
* This can only be called for subvolume roots and not for the log
*/
static noinline struct inode *read_one_inode(struct btrfs_root *root,
u64 objectid)
{
struct inode *inode;
inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
if (inode->i_state & I_NEW) {
BTRFS_I(inode)->root = root;
BTRFS_I(inode)->location.objectid = objectid;
BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
BTRFS_I(inode)->location.offset = 0;
btrfs_read_locked_inode(inode);
unlock_new_inode(inode);
}
if (is_bad_inode(inode)) {
iput(inode);
inode = NULL;
}
return inode;
}
/* replays a single extent in 'eb' at 'slot' with 'key' into the
* subvolume 'root'. path is released on entry and should be released
* on exit.
*
* extents in the log tree have not been allocated out of the extent
* tree yet. So, this completes the allocation, taking a reference
* as required if the extent already exists or creating a new extent
* if it isn't in the extent allocation tree yet.
*
* The extent is inserted into the file, dropping any existing extents
* from the file that overlap the new one.
*/
static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
int found_type;
u64 mask = root->sectorsize - 1;
u64 extent_end;
u64 alloc_hint;
u64 start = key->offset;
struct btrfs_file_extent_item *item;
struct inode *inode = NULL;
unsigned long size;
int ret = 0;
item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(eb, item);
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC)
extent_end = start + btrfs_file_extent_num_bytes(eb, item);
else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
Btrfs: Add zlib compression support This is a large change for adding compression on reading and writing, both for inline and regular extents. It does some fairly large surgery to the writeback paths. Compression is off by default and enabled by mount -o compress. Even when the -o compress mount option is not used, it is possible to read compressed extents off the disk. If compression for a given set of pages fails to make them smaller, the file is flagged to avoid future compression attempts later. * While finding delalloc extents, the pages are locked before being sent down to the delalloc handler. This allows the delalloc handler to do complex things such as cleaning the pages, marking them writeback and starting IO on their behalf. * Inline extents are inserted at delalloc time now. This allows us to compress the data before inserting the inline extent, and it allows us to insert an inline extent that spans multiple pages. * All of the in-memory extent representations (extent_map.c, ordered-data.c etc) are changed to record both an in-memory size and an on disk size, as well as a flag for compression. From a disk format point of view, the extent pointers in the file are changed to record the on disk size of a given extent and some encoding flags. Space in the disk format is allocated for compression encoding, as well as encryption and a generic 'other' field. Neither the encryption or the 'other' field are currently used. In order to limit the amount of data read for a single random read in the file, the size of a compressed extent is limited to 128k. This is a software only limit, the disk format supports u64 sized compressed extents. In order to limit the ram consumed while processing extents, the uncompressed size of a compressed extent is limited to 256k. This is a software only limit and will be subject to tuning later. Checksumming is still done on compressed extents, and it is done on the uncompressed version of the data. This way additional encodings can be layered on without having to figure out which encoding to checksum. Compression happens at delalloc time, which is basically singled threaded because it is usually done by a single pdflush thread. This makes it tricky to spread the compression load across all the cpus on the box. We'll have to look at parallel pdflush walks of dirty inodes at a later time. Decompression is hooked into readpages and it does spread across CPUs nicely. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-29 18:49:59 +00:00
size = btrfs_file_extent_inline_len(eb, item);
extent_end = (start + size + mask) & ~mask;
} else {
ret = 0;
goto out;
}
inode = read_one_inode(root, key->objectid);
if (!inode) {
ret = -EIO;
goto out;
}
/*
* first check to see if we already have this extent in the
* file. This must be done before the btrfs_drop_extents run
* so we don't try to drop this extent.
*/
ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
start, 0);
if (ret == 0 &&
(found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
struct btrfs_file_extent_item cmp1;
struct btrfs_file_extent_item cmp2;
struct btrfs_file_extent_item *existing;
struct extent_buffer *leaf;
leaf = path->nodes[0];
existing = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
read_extent_buffer(eb, &cmp1, (unsigned long)item,
sizeof(cmp1));
read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
sizeof(cmp2));
/*
* we already have a pointer to this exact extent,
* we don't have to do anything
*/
if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
btrfs_release_path(root, path);
goto out;
}
}
btrfs_release_path(root, path);
/* drop any overlapping extents */
ret = btrfs_drop_extents(trans, root, inode,
start, extent_end, start, &alloc_hint);
BUG_ON(ret);
/* insert the extent */
ret = overwrite_item(trans, root, path, eb, slot, key);
BUG_ON(ret);
/* btrfs_drop_extents changes i_bytes & i_blocks, update it here */
inode_add_bytes(inode, extent_end - start);
btrfs_update_inode(trans, root, inode);
out:
if (inode)
iput(inode);
return ret;
}
/*
* when cleaning up conflicts between the directory names in the
* subvolume, directory names in the log and directory names in the
* inode back references, we may have to unlink inodes from directories.
*
* This is a helper function to do the unlink of a specific directory
* item
*/
static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct inode *dir,
struct btrfs_dir_item *di)
{
struct inode *inode;
char *name;
int name_len;
struct extent_buffer *leaf;
struct btrfs_key location;
int ret;
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &location);
name_len = btrfs_dir_name_len(leaf, di);
name = kmalloc(name_len, GFP_NOFS);
read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
btrfs_release_path(root, path);
inode = read_one_inode(root, location.objectid);
BUG_ON(!inode);
btrfs_inc_nlink(inode);
ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
kfree(name);
iput(inode);
return ret;
}
/*
* helper function to see if a given name and sequence number found
* in an inode back reference are already in a directory and correctly
* point to this inode
*/
static noinline int inode_in_dir(struct btrfs_root *root,
struct btrfs_path *path,
u64 dirid, u64 objectid, u64 index,
const char *name, int name_len)
{
struct btrfs_dir_item *di;
struct btrfs_key location;
int match = 0;
di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
index, name, name_len, 0);
if (di && !IS_ERR(di)) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
if (location.objectid != objectid)
goto out;
} else
goto out;
btrfs_release_path(root, path);
di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
if (di && !IS_ERR(di)) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
if (location.objectid != objectid)
goto out;
} else
goto out;
match = 1;
out:
btrfs_release_path(root, path);
return match;
}
/*
* helper function to check a log tree for a named back reference in
* an inode. This is used to decide if a back reference that is
* found in the subvolume conflicts with what we find in the log.
*
* inode backreferences may have multiple refs in a single item,
* during replay we process one reference at a time, and we don't
* want to delete valid links to a file from the subvolume if that
* link is also in the log.
*/
static noinline int backref_in_log(struct btrfs_root *log,
struct btrfs_key *key,
char *name, int namelen)
{
struct btrfs_path *path;
struct btrfs_inode_ref *ref;
unsigned long ptr;
unsigned long ptr_end;
unsigned long name_ptr;
int found_name_len;
int item_size;
int ret;
int match = 0;
path = btrfs_alloc_path();
ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
if (ret != 0)
goto out;
item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
ptr_end = ptr + item_size;
while (ptr < ptr_end) {
ref = (struct btrfs_inode_ref *)ptr;
found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
if (found_name_len == namelen) {
name_ptr = (unsigned long)(ref + 1);
ret = memcmp_extent_buffer(path->nodes[0], name,
name_ptr, namelen);
if (ret == 0) {
match = 1;
goto out;
}
}
ptr = (unsigned long)(ref + 1) + found_name_len;
}
out:
btrfs_free_path(path);
return match;
}
/*
* replay one inode back reference item found in the log tree.
* eb, slot and key refer to the buffer and key found in the log tree.
* root is the destination we are replaying into, and path is for temp
* use by this function. (it should be released on return).
*/
static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
struct inode *dir;
int ret;
struct btrfs_key location;
struct btrfs_inode_ref *ref;
struct btrfs_dir_item *di;
struct inode *inode;
char *name;
int namelen;
unsigned long ref_ptr;
unsigned long ref_end;
location.objectid = key->objectid;
location.type = BTRFS_INODE_ITEM_KEY;
location.offset = 0;
/*
* it is possible that we didn't log all the parent directories
* for a given inode. If we don't find the dir, just don't
* copy the back ref in. The link count fixup code will take
* care of the rest
*/
dir = read_one_inode(root, key->offset);
if (!dir)
return -ENOENT;
inode = read_one_inode(root, key->objectid);
BUG_ON(!dir);
ref_ptr = btrfs_item_ptr_offset(eb, slot);
ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
again:
ref = (struct btrfs_inode_ref *)ref_ptr;
namelen = btrfs_inode_ref_name_len(eb, ref);
name = kmalloc(namelen, GFP_NOFS);
BUG_ON(!name);
read_extent_buffer(eb, name, (unsigned long)(ref + 1), namelen);
/* if we already have a perfect match, we're done */
if (inode_in_dir(root, path, dir->i_ino, inode->i_ino,
btrfs_inode_ref_index(eb, ref),
name, namelen)) {
goto out;
}
/*
* look for a conflicting back reference in the metadata.
* if we find one we have to unlink that name of the file
* before we add our new link. Later on, we overwrite any
* existing back reference, and we don't want to create
* dangling pointers in the directory.
*/
conflict_again:
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret == 0) {
char *victim_name;
int victim_name_len;
struct btrfs_inode_ref *victim_ref;
unsigned long ptr;
unsigned long ptr_end;
struct extent_buffer *leaf = path->nodes[0];
/* are we trying to overwrite a back ref for the root directory
* if so, just jump out, we're done
*/
if (key->objectid == key->offset)
goto out_nowrite;
/* check all the names in this back reference to see
* if they are in the log. if so, we allow them to stay
* otherwise they must be unlinked as a conflict
*/
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
while(ptr < ptr_end) {
victim_ref = (struct btrfs_inode_ref *)ptr;
victim_name_len = btrfs_inode_ref_name_len(leaf,
victim_ref);
victim_name = kmalloc(victim_name_len, GFP_NOFS);
BUG_ON(!victim_name);
read_extent_buffer(leaf, victim_name,
(unsigned long)(victim_ref + 1),
victim_name_len);
if (!backref_in_log(log, key, victim_name,
victim_name_len)) {
btrfs_inc_nlink(inode);
btrfs_release_path(root, path);
ret = btrfs_unlink_inode(trans, root, dir,
inode, victim_name,
victim_name_len);
kfree(victim_name);
btrfs_release_path(root, path);
goto conflict_again;
}
kfree(victim_name);
ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
}
BUG_ON(ret);
}
btrfs_release_path(root, path);
/* look for a conflicting sequence number */
di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
btrfs_inode_ref_index(eb, ref),
name, namelen, 0);
if (di && !IS_ERR(di)) {
ret = drop_one_dir_item(trans, root, path, dir, di);
BUG_ON(ret);
}
btrfs_release_path(root, path);
/* look for a conflicting name */
di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
name, namelen, 0);
if (di && !IS_ERR(di)) {
ret = drop_one_dir_item(trans, root, path, dir, di);
BUG_ON(ret);
}
btrfs_release_path(root, path);
/* insert our name */
ret = btrfs_add_link(trans, dir, inode, name, namelen, 0,
btrfs_inode_ref_index(eb, ref));
BUG_ON(ret);
btrfs_update_inode(trans, root, inode);
out:
ref_ptr = (unsigned long)(ref + 1) + namelen;
kfree(name);
if (ref_ptr < ref_end)
goto again;
/* finally write the back reference in the inode */
ret = overwrite_item(trans, root, path, eb, slot, key);
BUG_ON(ret);
out_nowrite:
btrfs_release_path(root, path);
iput(dir);
iput(inode);
return 0;
}
/*
* replay one csum item from the log tree into the subvolume 'root'
* eb, slot and key all refer to the log tree
* path is for temp use by this function and should be released on return
*
* This copies the checksums out of the log tree and inserts them into
* the subvolume. Any existing checksums for this range in the file
* are overwritten, and new items are added where required.
*
* We keep this simple by reusing the btrfs_ordered_sum code from
* the data=ordered mode. This basically means making a copy
* of all the checksums in ram, which we have to do anyway for kmap
* rules.
*
* The copy is then sent down to btrfs_csum_file_blocks, which
* does all the hard work of finding existing items in the file
* or adding new ones.
*/
static noinline int replay_one_csum(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
int ret;
u32 item_size = btrfs_item_size_nr(eb, slot);
u64 cur_offset;
unsigned long file_bytes;
struct btrfs_ordered_sum *sums;
struct btrfs_sector_sum *sector_sum;
struct inode *inode;
unsigned long ptr;
file_bytes = (item_size / BTRFS_CRC32_SIZE) * root->sectorsize;
inode = read_one_inode(root, key->objectid);
if (!inode) {
return -EIO;
}
sums = kzalloc(btrfs_ordered_sum_size(root, file_bytes), GFP_NOFS);
if (!sums) {
iput(inode);
return -ENOMEM;
}
INIT_LIST_HEAD(&sums->list);
sums->len = file_bytes;
sums->file_offset = key->offset;
/*
* copy all the sums into the ordered sum struct
*/
sector_sum = sums->sums;
cur_offset = key->offset;
ptr = btrfs_item_ptr_offset(eb, slot);
while(item_size > 0) {
sector_sum->offset = cur_offset;
read_extent_buffer(eb, &sector_sum->sum, ptr, BTRFS_CRC32_SIZE);
sector_sum++;
item_size -= BTRFS_CRC32_SIZE;
ptr += BTRFS_CRC32_SIZE;
cur_offset += root->sectorsize;
}
/* let btrfs_csum_file_blocks add them into the file */
ret = btrfs_csum_file_blocks(trans, root, inode, sums);
BUG_ON(ret);
kfree(sums);
iput(inode);
return 0;
}
/*
* There are a few corners where the link count of the file can't
* be properly maintained during replay. So, instead of adding
* lots of complexity to the log code, we just scan the backrefs
* for any file that has been through replay.
*
* The scan will update the link count on the inode to reflect the
* number of back refs found. If it goes down to zero, the iput
* will free the inode.
*/
static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_path *path;
int ret;
struct btrfs_key key;
u64 nlink = 0;
unsigned long ptr;
unsigned long ptr_end;
int name_len;
key.objectid = inode->i_ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = (u64)-1;
path = btrfs_alloc_path();
while(1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
break;
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid != inode->i_ino ||
key.type != BTRFS_INODE_REF_KEY)
break;
ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
path->slots[0]);
while(ptr < ptr_end) {
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ptr;
name_len = btrfs_inode_ref_name_len(path->nodes[0],
ref);
ptr = (unsigned long)(ref + 1) + name_len;
nlink++;
}
if (key.offset == 0)
break;
key.offset--;
btrfs_release_path(root, path);
}
btrfs_free_path(path);
if (nlink != inode->i_nlink) {
inode->i_nlink = nlink;
btrfs_update_inode(trans, root, inode);
}
BTRFS_I(inode)->index_cnt = (u64)-1;
return 0;
}
static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path)
{
int ret;
struct btrfs_key key;
struct inode *inode;
key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = (u64)-1;
while(1) {
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
break;
if (ret == 1) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
ret = btrfs_del_item(trans, root, path);
BUG_ON(ret);
btrfs_release_path(root, path);
inode = read_one_inode(root, key.offset);
BUG_ON(!inode);
ret = fixup_inode_link_count(trans, root, inode);
BUG_ON(ret);
iput(inode);
if (key.offset == 0)
break;
key.offset--;
}
btrfs_release_path(root, path);
return 0;
}
/*
* record a given inode in the fixup dir so we can check its link
* count when replay is done. The link count is incremented here
* so the inode won't go away until we check it
*/
static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid)
{
struct btrfs_key key;
int ret = 0;
struct inode *inode;
inode = read_one_inode(root, objectid);
BUG_ON(!inode);
key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
key.offset = objectid;
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
btrfs_release_path(root, path);
if (ret == 0) {
btrfs_inc_nlink(inode);
btrfs_update_inode(trans, root, inode);
} else if (ret == -EEXIST) {
ret = 0;
} else {
BUG();
}
iput(inode);
return ret;
}
/*
* when replaying the log for a directory, we only insert names
* for inodes that actually exist. This means an fsync on a directory
* does not implicitly fsync all the new files in it
*/
static noinline int insert_one_name(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 dirid, u64 index,
char *name, int name_len, u8 type,
struct btrfs_key *location)
{
struct inode *inode;
struct inode *dir;
int ret;
inode = read_one_inode(root, location->objectid);
if (!inode)
return -ENOENT;
dir = read_one_inode(root, dirid);
if (!dir) {
iput(inode);
return -EIO;
}
ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);
/* FIXME, put inode into FIXUP list */
iput(inode);
iput(dir);
return ret;
}
/*
* take a single entry in a log directory item and replay it into
* the subvolume.
*
* if a conflicting item exists in the subdirectory already,
* the inode it points to is unlinked and put into the link count
* fix up tree.
*
* If a name from the log points to a file or directory that does
* not exist in the FS, it is skipped. fsyncs on directories
* do not force down inodes inside that directory, just changes to the
* names or unlinks in a directory.
*/
static noinline int replay_one_name(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb,
struct btrfs_dir_item *di,
struct btrfs_key *key)
{
char *name;
int name_len;
struct btrfs_dir_item *dst_di;
struct btrfs_key found_key;
struct btrfs_key log_key;
struct inode *dir;
u8 log_type;
int exists;
int ret;
dir = read_one_inode(root, key->objectid);
BUG_ON(!dir);
name_len = btrfs_dir_name_len(eb, di);
name = kmalloc(name_len, GFP_NOFS);
log_type = btrfs_dir_type(eb, di);
read_extent_buffer(eb, name, (unsigned long)(di + 1),
name_len);
btrfs_dir_item_key_to_cpu(eb, di, &log_key);
exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
if (exists == 0)
exists = 1;
else
exists = 0;
btrfs_release_path(root, path);
if (key->type == BTRFS_DIR_ITEM_KEY) {
dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
name, name_len, 1);
}
else if (key->type == BTRFS_DIR_INDEX_KEY) {
dst_di = btrfs_lookup_dir_index_item(trans, root, path,
key->objectid,
key->offset, name,
name_len, 1);
} else {
BUG();
}
if (!dst_di || IS_ERR(dst_di)) {
/* we need a sequence number to insert, so we only
* do inserts for the BTRFS_DIR_INDEX_KEY types
*/
if (key->type != BTRFS_DIR_INDEX_KEY)
goto out;
goto insert;
}
btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
/* the existing item matches the logged item */
if (found_key.objectid == log_key.objectid &&
found_key.type == log_key.type &&
found_key.offset == log_key.offset &&
btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
goto out;
}
/*
* don't drop the conflicting directory entry if the inode
* for the new entry doesn't exist
*/
if (!exists)
goto out;
ret = drop_one_dir_item(trans, root, path, dir, dst_di);
BUG_ON(ret);
if (key->type == BTRFS_DIR_INDEX_KEY)
goto insert;
out:
btrfs_release_path(root, path);
kfree(name);
iput(dir);
return 0;
insert:
btrfs_release_path(root, path);
ret = insert_one_name(trans, root, path, key->objectid, key->offset,
name, name_len, log_type, &log_key);
if (ret && ret != -ENOENT)
BUG();
goto out;
}
/*
* find all the names in a directory item and reconcile them into
* the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
* one name in a directory item, but the same code gets used for
* both directory index types
*/
static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
int ret;
u32 item_size = btrfs_item_size_nr(eb, slot);
struct btrfs_dir_item *di;
int name_len;
unsigned long ptr;
unsigned long ptr_end;
ptr = btrfs_item_ptr_offset(eb, slot);
ptr_end = ptr + item_size;
while(ptr < ptr_end) {
di = (struct btrfs_dir_item *)ptr;
name_len = btrfs_dir_name_len(eb, di);
ret = replay_one_name(trans, root, path, eb, di, key);
BUG_ON(ret);
ptr = (unsigned long)(di + 1);
ptr += name_len;
}
return 0;
}
/*
* directory replay has two parts. There are the standard directory
* items in the log copied from the subvolume, and range items
* created in the log while the subvolume was logged.
*
* The range items tell us which parts of the key space the log
* is authoritative for. During replay, if a key in the subvolume
* directory is in a logged range item, but not actually in the log
* that means it was deleted from the directory before the fsync
* and should be removed.
*/
static noinline int find_dir_range(struct btrfs_root *root,
struct btrfs_path *path,
u64 dirid, int key_type,
u64 *start_ret, u64 *end_ret)
{
struct btrfs_key key;
u64 found_end;
struct btrfs_dir_log_item *item;
int ret;
int nritems;
if (*start_ret == (u64)-1)
return 1;
key.objectid = dirid;
key.type = key_type;
key.offset = *start_ret;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
}
if (ret != 0)
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.type != key_type || key.objectid != dirid) {
ret = 1;
goto next;
}
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
found_end = btrfs_dir_log_end(path->nodes[0], item);
if (*start_ret >= key.offset && *start_ret <= found_end) {
ret = 0;
*start_ret = key.offset;
*end_ret = found_end;
goto out;
}
ret = 1;
next:
/* check the next slot in the tree to see if it is a valid item */
nritems = btrfs_header_nritems(path->nodes[0]);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret)
goto out;
} else {
path->slots[0]++;
}
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.type != key_type || key.objectid != dirid) {
ret = 1;
goto out;
}
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
found_end = btrfs_dir_log_end(path->nodes[0], item);
*start_ret = key.offset;
*end_ret = found_end;
ret = 0;
out:
btrfs_release_path(root, path);
return ret;
}
/*
* this looks for a given directory item in the log. If the directory
* item is not in the log, the item is removed and the inode it points
* to is unlinked
*/
static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
struct btrfs_path *log_path,
struct inode *dir,
struct btrfs_key *dir_key)
{
int ret;
struct extent_buffer *eb;
int slot;
u32 item_size;
struct btrfs_dir_item *di;
struct btrfs_dir_item *log_di;
int name_len;
unsigned long ptr;
unsigned long ptr_end;
char *name;
struct inode *inode;
struct btrfs_key location;
again:
eb = path->nodes[0];
slot = path->slots[0];
item_size = btrfs_item_size_nr(eb, slot);
ptr = btrfs_item_ptr_offset(eb, slot);
ptr_end = ptr + item_size;
while(ptr < ptr_end) {
di = (struct btrfs_dir_item *)ptr;
name_len = btrfs_dir_name_len(eb, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
read_extent_buffer(eb, name, (unsigned long)(di + 1),
name_len);
log_di = NULL;
if (dir_key->type == BTRFS_DIR_ITEM_KEY) {
log_di = btrfs_lookup_dir_item(trans, log, log_path,
dir_key->objectid,
name, name_len, 0);
} else if (dir_key->type == BTRFS_DIR_INDEX_KEY) {
log_di = btrfs_lookup_dir_index_item(trans, log,
log_path,
dir_key->objectid,
dir_key->offset,
name, name_len, 0);
}
if (!log_di || IS_ERR(log_di)) {
btrfs_dir_item_key_to_cpu(eb, di, &location);
btrfs_release_path(root, path);
btrfs_release_path(log, log_path);
inode = read_one_inode(root, location.objectid);
BUG_ON(!inode);
ret = link_to_fixup_dir(trans, root,
path, location.objectid);
BUG_ON(ret);
btrfs_inc_nlink(inode);
ret = btrfs_unlink_inode(trans, root, dir, inode,
name, name_len);
BUG_ON(ret);
kfree(name);
iput(inode);
/* there might still be more names under this key
* check and repeat if required
*/
ret = btrfs_search_slot(NULL, root, dir_key, path,
0, 0);
if (ret == 0)
goto again;
ret = 0;
goto out;
}
btrfs_release_path(log, log_path);
kfree(name);
ptr = (unsigned long)(di + 1);
ptr += name_len;
}
ret = 0;
out:
btrfs_release_path(root, path);
btrfs_release_path(log, log_path);
return ret;
}
/*
* deletion replay happens before we copy any new directory items
* out of the log or out of backreferences from inodes. It
* scans the log to find ranges of keys that log is authoritative for,
* and then scans the directory to find items in those ranges that are
* not present in the log.
*
* Anything we don't find in the log is unlinked and removed from the
* directory.
*/
static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dirid)
{
u64 range_start;
u64 range_end;
int key_type = BTRFS_DIR_LOG_ITEM_KEY;
int ret = 0;
struct btrfs_key dir_key;
struct btrfs_key found_key;
struct btrfs_path *log_path;
struct inode *dir;
dir_key.objectid = dirid;
dir_key.type = BTRFS_DIR_ITEM_KEY;
log_path = btrfs_alloc_path();
if (!log_path)
return -ENOMEM;
dir = read_one_inode(root, dirid);
/* it isn't an error if the inode isn't there, that can happen
* because we replay the deletes before we copy in the inode item
* from the log
*/
if (!dir) {
btrfs_free_path(log_path);
return 0;
}
again:
range_start = 0;
range_end = 0;
while(1) {
ret = find_dir_range(log, path, dirid, key_type,
&range_start, &range_end);
if (ret != 0)
break;
dir_key.offset = range_start;
while(1) {
int nritems;
ret = btrfs_search_slot(NULL, root, &dir_key, path,
0, 0);
if (ret < 0)
goto out;
nritems = btrfs_header_nritems(path->nodes[0]);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret)
break;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != dirid ||
found_key.type != dir_key.type)
goto next_type;
if (found_key.offset > range_end)
break;
ret = check_item_in_log(trans, root, log, path,
log_path, dir, &found_key);
BUG_ON(ret);
if (found_key.offset == (u64)-1)
break;
dir_key.offset = found_key.offset + 1;
}
btrfs_release_path(root, path);
if (range_end == (u64)-1)
break;
range_start = range_end + 1;
}
next_type:
ret = 0;
if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
key_type = BTRFS_DIR_LOG_INDEX_KEY;
dir_key.type = BTRFS_DIR_INDEX_KEY;
btrfs_release_path(root, path);
goto again;
}
out:
btrfs_release_path(root, path);
btrfs_free_path(log_path);
iput(dir);
return ret;
}
/*
* the process_func used to replay items from the log tree. This
* gets called in two different stages. The first stage just looks
* for inodes and makes sure they are all copied into the subvolume.
*
* The second stage copies all the other item types from the log into
* the subvolume. The two stage approach is slower, but gets rid of
* lots of complexity around inodes referencing other inodes that exist
* only in the log (references come from either directory items or inode
* back refs).
*/
static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
struct walk_control *wc, u64 gen)
{
int nritems;
struct btrfs_path *path;
struct btrfs_root *root = wc->replay_dest;
struct btrfs_key key;
u32 item_size;
int level;
int i;
int ret;
btrfs_read_buffer(eb, gen);
level = btrfs_header_level(eb);
if (level != 0)
return 0;
path = btrfs_alloc_path();
BUG_ON(!path);
nritems = btrfs_header_nritems(eb);
for (i = 0; i < nritems; i++) {
btrfs_item_key_to_cpu(eb, &key, i);
item_size = btrfs_item_size_nr(eb, i);
/* inode keys are done during the first stage */
if (key.type == BTRFS_INODE_ITEM_KEY &&
wc->stage == LOG_WALK_REPLAY_INODES) {
struct inode *inode;
struct btrfs_inode_item *inode_item;
u32 mode;
inode_item = btrfs_item_ptr(eb, i,
struct btrfs_inode_item);
mode = btrfs_inode_mode(eb, inode_item);
if (S_ISDIR(mode)) {
ret = replay_dir_deletes(wc->trans,
root, log, path, key.objectid);
BUG_ON(ret);
}
ret = overwrite_item(wc->trans, root, path,
eb, i, &key);
BUG_ON(ret);
/* for regular files, truncate away
* extents past the new EOF
*/
if (S_ISREG(mode)) {
inode = read_one_inode(root,
key.objectid);
BUG_ON(!inode);
ret = btrfs_truncate_inode_items(wc->trans,
root, inode, inode->i_size,
BTRFS_EXTENT_DATA_KEY);
BUG_ON(ret);
iput(inode);
}
ret = link_to_fixup_dir(wc->trans, root,
path, key.objectid);
BUG_ON(ret);
}
if (wc->stage < LOG_WALK_REPLAY_ALL)
continue;
/* these keys are simply copied */
if (key.type == BTRFS_XATTR_ITEM_KEY) {
ret = overwrite_item(wc->trans, root, path,
eb, i, &key);
BUG_ON(ret);
} else if (key.type == BTRFS_INODE_REF_KEY) {
ret = add_inode_ref(wc->trans, root, log, path,
eb, i, &key);
BUG_ON(ret && ret != -ENOENT);
} else if (key.type == BTRFS_EXTENT_DATA_KEY) {
ret = replay_one_extent(wc->trans, root, path,
eb, i, &key);
BUG_ON(ret);
} else if (key.type == BTRFS_CSUM_ITEM_KEY) {
ret = replay_one_csum(wc->trans, root, path,
eb, i, &key);
BUG_ON(ret);
} else if (key.type == BTRFS_DIR_ITEM_KEY ||
key.type == BTRFS_DIR_INDEX_KEY) {
ret = replay_one_dir_item(wc->trans, root, path,
eb, i, &key);
BUG_ON(ret);
}
}
btrfs_free_path(path);
return 0;
}
static int noinline walk_down_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level,
struct walk_control *wc)
{
u64 root_owner;
u64 root_gen;
u64 bytenr;
u64 ptr_gen;
struct extent_buffer *next;
struct extent_buffer *cur;
struct extent_buffer *parent;
u32 blocksize;
int ret = 0;
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
while(*level > 0) {
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
cur = path->nodes[*level];
if (btrfs_header_level(cur) != *level)
WARN_ON(1);
if (path->slots[*level] >=
btrfs_header_nritems(cur))
break;
bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
blocksize = btrfs_level_size(root, *level - 1);
parent = path->nodes[*level];
root_owner = btrfs_header_owner(parent);
root_gen = btrfs_header_generation(parent);
next = btrfs_find_create_tree_block(root, bytenr, blocksize);
wc->process_func(root, next, wc, ptr_gen);
if (*level == 1) {
path->slots[*level]++;
if (wc->free) {
btrfs_read_buffer(next, ptr_gen);
btrfs_tree_lock(next);
clean_tree_block(trans, root, next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
ret = btrfs_drop_leaf_ref(trans, root, next);
BUG_ON(ret);
WARN_ON(root_owner !=
BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_free_reserved_extent(root,
bytenr, blocksize);
BUG_ON(ret);
}
free_extent_buffer(next);
continue;
}
btrfs_read_buffer(next, ptr_gen);
WARN_ON(*level <= 0);
if (path->nodes[*level-1])
free_extent_buffer(path->nodes[*level-1]);
path->nodes[*level-1] = next;
*level = btrfs_header_level(next);
path->slots[*level] = 0;
cond_resched();
}
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
if (path->nodes[*level] == root->node) {
parent = path->nodes[*level];
} else {
parent = path->nodes[*level + 1];
}
bytenr = path->nodes[*level]->start;
blocksize = btrfs_level_size(root, *level);
root_owner = btrfs_header_owner(parent);
root_gen = btrfs_header_generation(parent);
wc->process_func(root, path->nodes[*level], wc,
btrfs_header_generation(path->nodes[*level]));
if (wc->free) {
next = path->nodes[*level];
btrfs_tree_lock(next);
clean_tree_block(trans, root, next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
if (*level == 0) {
ret = btrfs_drop_leaf_ref(trans, root, next);
BUG_ON(ret);
}
WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_free_reserved_extent(root, bytenr, blocksize);
BUG_ON(ret);
}
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level += 1;
cond_resched();
return 0;
}
static int noinline walk_up_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level,
struct walk_control *wc)
{
u64 root_owner;
u64 root_gen;
int i;
int slot;
int ret;
for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
slot = path->slots[i];
if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
struct extent_buffer *node;
node = path->nodes[i];
path->slots[i]++;
*level = i;
WARN_ON(*level == 0);
return 0;
} else {
struct extent_buffer *parent;
if (path->nodes[*level] == root->node)
parent = path->nodes[*level];
else
parent = path->nodes[*level + 1];
root_owner = btrfs_header_owner(parent);
root_gen = btrfs_header_generation(parent);
wc->process_func(root, path->nodes[*level], wc,
btrfs_header_generation(path->nodes[*level]));
if (wc->free) {
struct extent_buffer *next;
next = path->nodes[*level];
btrfs_tree_lock(next);
clean_tree_block(trans, root, next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
if (*level == 0) {
ret = btrfs_drop_leaf_ref(trans, root,
next);
BUG_ON(ret);
}
WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_free_reserved_extent(root,
path->nodes[*level]->start,
path->nodes[*level]->len);
BUG_ON(ret);
}
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level = i + 1;
}
}
return 1;
}
/*
* drop the reference count on the tree rooted at 'snap'. This traverses
* the tree freeing any blocks that have a ref count of zero after being
* decremented.
*/
static int walk_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *log, struct walk_control *wc)
{
int ret = 0;
int wret;
int level;
struct btrfs_path *path;
int i;
int orig_level;
path = btrfs_alloc_path();
BUG_ON(!path);
level = btrfs_header_level(log->node);
orig_level = level;
path->nodes[level] = log->node;
extent_buffer_get(log->node);
path->slots[level] = 0;
while(1) {
wret = walk_down_log_tree(trans, log, path, &level, wc);
if (wret > 0)
break;
if (wret < 0)
ret = wret;
wret = walk_up_log_tree(trans, log, path, &level, wc);
if (wret > 0)
break;
if (wret < 0)
ret = wret;
}
/* was the root node processed? if not, catch it here */
if (path->nodes[orig_level]) {
wc->process_func(log, path->nodes[orig_level], wc,
btrfs_header_generation(path->nodes[orig_level]));
if (wc->free) {
struct extent_buffer *next;
next = path->nodes[orig_level];
btrfs_tree_lock(next);
clean_tree_block(trans, log, next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
if (orig_level == 0) {
ret = btrfs_drop_leaf_ref(trans, log,
next);
BUG_ON(ret);
}
WARN_ON(log->root_key.objectid !=
BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_free_reserved_extent(log, next->start,
next->len);
BUG_ON(ret);
}
}
for (i = 0; i <= orig_level; i++) {
if (path->nodes[i]) {
free_extent_buffer(path->nodes[i]);
path->nodes[i] = NULL;
}
}
btrfs_free_path(path);
if (wc->free)
free_extent_buffer(log->node);
return ret;
}
int wait_log_commit(struct btrfs_root *log)
{
DEFINE_WAIT(wait);
u64 transid = log->fs_info->tree_log_transid;
do {
prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
TASK_UNINTERRUPTIBLE);
mutex_unlock(&log->fs_info->tree_log_mutex);
if (atomic_read(&log->fs_info->tree_log_commit))
schedule();
finish_wait(&log->fs_info->tree_log_wait, &wait);
mutex_lock(&log->fs_info->tree_log_mutex);
} while(transid == log->fs_info->tree_log_transid &&
atomic_read(&log->fs_info->tree_log_commit));
return 0;
}
/*
* btrfs_sync_log does sends a given tree log down to the disk and
* updates the super blocks to record it. When this call is done,
* you know that any inodes previously logged are safely on disk
*/
int btrfs_sync_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret;
unsigned long batch;
struct btrfs_root *log = root->log_root;
mutex_lock(&log->fs_info->tree_log_mutex);
if (atomic_read(&log->fs_info->tree_log_commit)) {
wait_log_commit(log);
goto out;
}
atomic_set(&log->fs_info->tree_log_commit, 1);
while(1) {
batch = log->fs_info->tree_log_batch;
mutex_unlock(&log->fs_info->tree_log_mutex);
schedule_timeout_uninterruptible(1);
mutex_lock(&log->fs_info->tree_log_mutex);
while(atomic_read(&log->fs_info->tree_log_writers)) {
DEFINE_WAIT(wait);
prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
TASK_UNINTERRUPTIBLE);
mutex_unlock(&log->fs_info->tree_log_mutex);
if (atomic_read(&log->fs_info->tree_log_writers))
schedule();
mutex_lock(&log->fs_info->tree_log_mutex);
finish_wait(&log->fs_info->tree_log_wait, &wait);
}
if (batch == log->fs_info->tree_log_batch)
break;
}
ret = btrfs_write_and_wait_marked_extents(log, &log->dirty_log_pages);
BUG_ON(ret);
ret = btrfs_write_and_wait_marked_extents(root->fs_info->log_root_tree,
&root->fs_info->log_root_tree->dirty_log_pages);
BUG_ON(ret);
btrfs_set_super_log_root(&root->fs_info->super_for_commit,
log->fs_info->log_root_tree->node->start);
btrfs_set_super_log_root_level(&root->fs_info->super_for_commit,
btrfs_header_level(log->fs_info->log_root_tree->node));
write_ctree_super(trans, log->fs_info->tree_root);
log->fs_info->tree_log_transid++;
log->fs_info->tree_log_batch = 0;
atomic_set(&log->fs_info->tree_log_commit, 0);
smp_mb();
if (waitqueue_active(&log->fs_info->tree_log_wait))
wake_up(&log->fs_info->tree_log_wait);
out:
mutex_unlock(&log->fs_info->tree_log_mutex);
return 0;
}
/* * free all the extents used by the tree log. This should be called
* at commit time of the full transaction
*/
int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
{
int ret;
struct btrfs_root *log;
struct key;
u64 start;
u64 end;
struct walk_control wc = {
.free = 1,
.process_func = process_one_buffer
};
if (!root->log_root)
return 0;
log = root->log_root;
ret = walk_log_tree(trans, log, &wc);
BUG_ON(ret);
while(1) {
ret = find_first_extent_bit(&log->dirty_log_pages,
0, &start, &end, EXTENT_DIRTY);
if (ret)
break;
clear_extent_dirty(&log->dirty_log_pages,
start, end, GFP_NOFS);
}
log = root->log_root;
ret = btrfs_del_root(trans, root->fs_info->log_root_tree,
&log->root_key);
BUG_ON(ret);
root->log_root = NULL;
kfree(root->log_root);
return 0;
}
/*
* helper function to update the item for a given subvolumes log root
* in the tree of log roots
*/
static int update_log_root(struct btrfs_trans_handle *trans,
struct btrfs_root *log)
{
u64 bytenr = btrfs_root_bytenr(&log->root_item);
int ret;
if (log->node->start == bytenr)
return 0;
btrfs_set_root_bytenr(&log->root_item, log->node->start);
btrfs_set_root_generation(&log->root_item, trans->transid);
btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node));
ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
&log->root_key, &log->root_item);
BUG_ON(ret);
return ret;
}
/*
* If both a file and directory are logged, and unlinks or renames are
* mixed in, we have a few interesting corners:
*
* create file X in dir Y
* link file X to X.link in dir Y
* fsync file X
* unlink file X but leave X.link
* fsync dir Y
*
* After a crash we would expect only X.link to exist. But file X
* didn't get fsync'd again so the log has back refs for X and X.link.
*
* We solve this by removing directory entries and inode backrefs from the
* log when a file that was logged in the current transaction is
* unlinked. Any later fsync will include the updated log entries, and
* we'll be able to reconstruct the proper directory items from backrefs.
*
* This optimizations allows us to avoid relogging the entire inode
* or the entire directory.
*/
int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
struct inode *dir, u64 index)
{
struct btrfs_root *log;
struct btrfs_dir_item *di;
struct btrfs_path *path;
int ret;
int bytes_del = 0;
if (BTRFS_I(dir)->logged_trans < trans->transid)
return 0;
ret = join_running_log_trans(root);
if (ret)
return 0;
mutex_lock(&BTRFS_I(dir)->log_mutex);
log = root->log_root;
path = btrfs_alloc_path();
di = btrfs_lookup_dir_item(trans, log, path, dir->i_ino,
name, name_len, -1);
if (di && !IS_ERR(di)) {
ret = btrfs_delete_one_dir_name(trans, log, path, di);
bytes_del += name_len;
BUG_ON(ret);
}
btrfs_release_path(log, path);
di = btrfs_lookup_dir_index_item(trans, log, path, dir->i_ino,
index, name, name_len, -1);
if (di && !IS_ERR(di)) {
ret = btrfs_delete_one_dir_name(trans, log, path, di);
bytes_del += name_len;
BUG_ON(ret);
}
/* update the directory size in the log to reflect the names
* we have removed
*/
if (bytes_del) {
struct btrfs_key key;
key.objectid = dir->i_ino;
key.offset = 0;
key.type = BTRFS_INODE_ITEM_KEY;
btrfs_release_path(log, path);
ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
if (ret == 0) {
struct btrfs_inode_item *item;
u64 i_size;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
i_size = btrfs_inode_size(path->nodes[0], item);
if (i_size > bytes_del)
i_size -= bytes_del;
else
i_size = 0;
btrfs_set_inode_size(path->nodes[0], item, i_size);
btrfs_mark_buffer_dirty(path->nodes[0]);
} else
ret = 0;
btrfs_release_path(log, path);
}
btrfs_free_path(path);
mutex_unlock(&BTRFS_I(dir)->log_mutex);
end_log_trans(root);
return 0;
}
/* see comments for btrfs_del_dir_entries_in_log */
int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
struct inode *inode, u64 dirid)
{
struct btrfs_root *log;
u64 index;
int ret;
if (BTRFS_I(inode)->logged_trans < trans->transid)
return 0;
ret = join_running_log_trans(root);
if (ret)
return 0;
log = root->log_root;
mutex_lock(&BTRFS_I(inode)->log_mutex);
ret = btrfs_del_inode_ref(trans, log, name, name_len, inode->i_ino,
dirid, &index);
mutex_unlock(&BTRFS_I(inode)->log_mutex);
end_log_trans(root);
return ret;
}
/*
* creates a range item in the log for 'dirid'. first_offset and
* last_offset tell us which parts of the key space the log should
* be considered authoritative for.
*/
static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
int key_type, u64 dirid,
u64 first_offset, u64 last_offset)
{
int ret;
struct btrfs_key key;
struct btrfs_dir_log_item *item;
key.objectid = dirid;
key.offset = first_offset;
if (key_type == BTRFS_DIR_ITEM_KEY)
key.type = BTRFS_DIR_LOG_ITEM_KEY;
else
key.type = BTRFS_DIR_LOG_INDEX_KEY;
ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
BUG_ON(ret);
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(log, path);
return 0;
}
/*
* log all the items included in the current transaction for a given
* directory. This also creates the range items in the log tree required
* to replay anything deleted before the fsync
*/
static noinline int log_dir_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path, int key_type,
u64 min_offset, u64 *last_offset_ret)
{
struct btrfs_key min_key;
struct btrfs_key max_key;
struct btrfs_root *log = root->log_root;
struct extent_buffer *src;
int ret;
int i;
int nritems;
u64 first_offset = min_offset;
u64 last_offset = (u64)-1;
log = root->log_root;
max_key.objectid = inode->i_ino;
max_key.offset = (u64)-1;
max_key.type = key_type;
min_key.objectid = inode->i_ino;
min_key.type = key_type;
min_key.offset = min_offset;
path->keep_locks = 1;
ret = btrfs_search_forward(root, &min_key, &max_key,
path, 0, trans->transid);
/*
* we didn't find anything from this transaction, see if there
* is anything at all
*/
if (ret != 0 || min_key.objectid != inode->i_ino ||
min_key.type != key_type) {
min_key.objectid = inode->i_ino;
min_key.type = key_type;
min_key.offset = (u64)-1;
btrfs_release_path(root, path);
ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
if (ret < 0) {
btrfs_release_path(root, path);
return ret;
}
ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
/* if ret == 0 there are items for this type,
* create a range to tell us the last key of this type.
* otherwise, there are no items in this directory after
* *min_offset, and we create a range to indicate that.
*/
if (ret == 0) {
struct btrfs_key tmp;
btrfs_item_key_to_cpu(path->nodes[0], &tmp,
path->slots[0]);
if (key_type == tmp.type) {
first_offset = max(min_offset, tmp.offset) + 1;
}
}
goto done;
}
/* go backward to find any previous key */
ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
if (ret == 0) {
struct btrfs_key tmp;
btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
if (key_type == tmp.type) {
first_offset = tmp.offset;
ret = overwrite_item(trans, log, dst_path,
path->nodes[0], path->slots[0],
&tmp);
}
}
btrfs_release_path(root, path);
/* find the first key from this transaction again */
ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
if (ret != 0) {
WARN_ON(1);
goto done;
}
/*
* we have a block from this transaction, log every item in it
* from our directory
*/
while(1) {
struct btrfs_key tmp;
src = path->nodes[0];
nritems = btrfs_header_nritems(src);
for (i = path->slots[0]; i < nritems; i++) {
btrfs_item_key_to_cpu(src, &min_key, i);
if (min_key.objectid != inode->i_ino ||
min_key.type != key_type)
goto done;
ret = overwrite_item(trans, log, dst_path, src, i,
&min_key);
BUG_ON(ret);
}
path->slots[0] = nritems;
/*
* look ahead to the next item and see if it is also
* from this directory and from this transaction
*/
ret = btrfs_next_leaf(root, path);
if (ret == 1) {
last_offset = (u64)-1;
goto done;
}
btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
if (tmp.objectid != inode->i_ino || tmp.type != key_type) {
last_offset = (u64)-1;
goto done;
}
if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
ret = overwrite_item(trans, log, dst_path,
path->nodes[0], path->slots[0],
&tmp);
BUG_ON(ret);
last_offset = tmp.offset;
goto done;
}
}
done:
*last_offset_ret = last_offset;
btrfs_release_path(root, path);
btrfs_release_path(log, dst_path);
/* insert the log range keys to indicate where the log is valid */
ret = insert_dir_log_key(trans, log, path, key_type, inode->i_ino,
first_offset, last_offset);
BUG_ON(ret);
return 0;
}
/*
* logging directories is very similar to logging inodes, We find all the items
* from the current transaction and write them to the log.
*
* The recovery code scans the directory in the subvolume, and if it finds a
* key in the range logged that is not present in the log tree, then it means
* that dir entry was unlinked during the transaction.
*
* In order for that scan to work, we must include one key smaller than
* the smallest logged by this transaction and one key larger than the largest
* key logged by this transaction.
*/
static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path)
{
u64 min_key;
u64 max_key;
int ret;
int key_type = BTRFS_DIR_ITEM_KEY;
again:
min_key = 0;
max_key = 0;
while(1) {
ret = log_dir_items(trans, root, inode, path,
dst_path, key_type, min_key,
&max_key);
BUG_ON(ret);
if (max_key == (u64)-1)
break;
min_key = max_key + 1;
}
if (key_type == BTRFS_DIR_ITEM_KEY) {
key_type = BTRFS_DIR_INDEX_KEY;
goto again;
}
return 0;
}
/*
* a helper function to drop items from the log before we relog an
* inode. max_key_type indicates the highest item type to remove.
* This cannot be run for file data extents because it does not
* free the extents they point to.
*/
static int drop_objectid_items(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
u64 objectid, int max_key_type)
{
int ret;
struct btrfs_key key;
struct btrfs_key found_key;
key.objectid = objectid;
key.type = max_key_type;
key.offset = (u64)-1;
while(1) {
ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
if (ret != 1)
break;
if (path->slots[0] == 0)
break;
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != objectid)
break;
ret = btrfs_del_item(trans, log, path);
BUG_ON(ret);
btrfs_release_path(log, path);
}
btrfs_release_path(log, path);
return 0;
}
static noinline int copy_items(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *dst_path,
struct extent_buffer *src,
int start_slot, int nr, int inode_only)
{
unsigned long src_offset;
unsigned long dst_offset;
struct btrfs_file_extent_item *extent;
struct btrfs_inode_item *inode_item;
int ret;
struct btrfs_key *ins_keys;
u32 *ins_sizes;
char *ins_data;
int i;
ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
nr * sizeof(u32), GFP_NOFS);
ins_sizes = (u32 *)ins_data;
ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
for (i = 0; i < nr; i++) {
ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
}
ret = btrfs_insert_empty_items(trans, log, dst_path,
ins_keys, ins_sizes, nr);
BUG_ON(ret);
for (i = 0; i < nr; i++) {
dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
dst_path->slots[0]);
src_offset = btrfs_item_ptr_offset(src, start_slot + i);
copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
src_offset, ins_sizes[i]);
if (inode_only == LOG_INODE_EXISTS &&
ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
inode_item = btrfs_item_ptr(dst_path->nodes[0],
dst_path->slots[0],
struct btrfs_inode_item);
btrfs_set_inode_size(dst_path->nodes[0], inode_item, 0);
/* set the generation to zero so the recover code
* can tell the difference between an logging
* just to say 'this inode exists' and a logging
* to say 'update this inode with these values'
*/
btrfs_set_inode_generation(dst_path->nodes[0],
inode_item, 0);
}
/* take a reference on file data extents so that truncates
* or deletes of this inode don't have to relog the inode
* again
*/
if (btrfs_key_type(ins_keys + i) == BTRFS_EXTENT_DATA_KEY) {
int found_type;
extent = btrfs_item_ptr(src, start_slot + i,
struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(src, extent);
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 ds = btrfs_file_extent_disk_bytenr(src,
extent);
u64 dl = btrfs_file_extent_disk_num_bytes(src,
extent);
/* ds == 0 is a hole */
if (ds != 0) {
ret = btrfs_inc_extent_ref(trans, log,
ds, dl,
dst_path->nodes[0]->start,
BTRFS_TREE_LOG_OBJECTID,
trans->transid,
ins_keys[i].objectid);
BUG_ON(ret);
}
}
}
dst_path->slots[0]++;
}
btrfs_mark_buffer_dirty(dst_path->nodes[0]);
btrfs_release_path(log, dst_path);
kfree(ins_data);
return 0;
}
/* log a single inode in the tree log.
* At least one parent directory for this inode must exist in the tree
* or be logged already.
*
* Any items from this inode changed by the current transaction are copied
* to the log tree. An extra reference is taken on any extents in this
* file, allowing us to avoid a whole pile of corner cases around logging
* blocks that have been removed from the tree.
*
* See LOG_INODE_ALL and related defines for a description of what inode_only
* does.
*
* This handles both files and directories.
*/
static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode,
int inode_only)
{
struct btrfs_path *path;
struct btrfs_path *dst_path;
struct btrfs_key min_key;
struct btrfs_key max_key;
struct btrfs_root *log = root->log_root;
struct extent_buffer *src = NULL;
u32 size;
int ret;
int nritems;
int ins_start_slot = 0;
int ins_nr;
log = root->log_root;
path = btrfs_alloc_path();
dst_path = btrfs_alloc_path();
min_key.objectid = inode->i_ino;
min_key.type = BTRFS_INODE_ITEM_KEY;
min_key.offset = 0;
max_key.objectid = inode->i_ino;
if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode))
max_key.type = BTRFS_XATTR_ITEM_KEY;
else
max_key.type = (u8)-1;
max_key.offset = (u64)-1;
/*
* if this inode has already been logged and we're in inode_only
* mode, we don't want to delete the things that have already
* been written to the log.
*
* But, if the inode has been through an inode_only log,
* the logged_trans field is not set. This allows us to catch
* any new names for this inode in the backrefs by logging it
* again
*/
if (inode_only == LOG_INODE_EXISTS &&
BTRFS_I(inode)->logged_trans == trans->transid) {
btrfs_free_path(path);
btrfs_free_path(dst_path);
goto out;
}
mutex_lock(&BTRFS_I(inode)->log_mutex);
/*
* a brute force approach to making sure we get the most uptodate
* copies of everything.
*/
if (S_ISDIR(inode->i_mode)) {
int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
if (inode_only == LOG_INODE_EXISTS)
max_key_type = BTRFS_XATTR_ITEM_KEY;
ret = drop_objectid_items(trans, log, path,
inode->i_ino, max_key_type);
} else {
ret = btrfs_truncate_inode_items(trans, log, inode, 0, 0);
}
BUG_ON(ret);
path->keep_locks = 1;
while(1) {
ins_nr = 0;
ret = btrfs_search_forward(root, &min_key, &max_key,
path, 0, trans->transid);
if (ret != 0)
break;
again:
/* note, ins_nr might be > 0 here, cleanup outside the loop */
if (min_key.objectid != inode->i_ino)
break;
if (min_key.type > max_key.type)
break;
src = path->nodes[0];
size = btrfs_item_size_nr(src, path->slots[0]);
if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
ins_nr++;
goto next_slot;
} else if (!ins_nr) {
ins_start_slot = path->slots[0];
ins_nr = 1;
goto next_slot;
}
ret = copy_items(trans, log, dst_path, src, ins_start_slot,
ins_nr, inode_only);
BUG_ON(ret);
ins_nr = 1;
ins_start_slot = path->slots[0];
next_slot:
nritems = btrfs_header_nritems(path->nodes[0]);
path->slots[0]++;
if (path->slots[0] < nritems) {
btrfs_item_key_to_cpu(path->nodes[0], &min_key,
path->slots[0]);
goto again;
}
if (ins_nr) {
ret = copy_items(trans, log, dst_path, src,
ins_start_slot,
ins_nr, inode_only);
BUG_ON(ret);
ins_nr = 0;
}
btrfs_release_path(root, path);
if (min_key.offset < (u64)-1)
min_key.offset++;
else if (min_key.type < (u8)-1)
min_key.type++;
else if (min_key.objectid < (u64)-1)
min_key.objectid++;
else
break;
}
if (ins_nr) {
ret = copy_items(trans, log, dst_path, src,
ins_start_slot,
ins_nr, inode_only);
BUG_ON(ret);
ins_nr = 0;
}
WARN_ON(ins_nr);
if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
btrfs_release_path(root, path);
btrfs_release_path(log, dst_path);
BTRFS_I(inode)->log_dirty_trans = 0;
ret = log_directory_changes(trans, root, inode, path, dst_path);
BUG_ON(ret);
}
BTRFS_I(inode)->logged_trans = trans->transid;
mutex_unlock(&BTRFS_I(inode)->log_mutex);
btrfs_free_path(path);
btrfs_free_path(dst_path);
mutex_lock(&root->fs_info->tree_log_mutex);
ret = update_log_root(trans, log);
BUG_ON(ret);
mutex_unlock(&root->fs_info->tree_log_mutex);
out:
return 0;
}
int btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode,
int inode_only)
{
int ret;
start_log_trans(trans, root);
ret = __btrfs_log_inode(trans, root, inode, inode_only);
end_log_trans(root);
return ret;
}
/*
* helper function around btrfs_log_inode to make sure newly created
* parent directories also end up in the log. A minimal inode and backref
* only logging is done of any parent directories that are older than
* the last committed transaction
*/
int btrfs_log_dentry(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct dentry *dentry)
{
int inode_only = LOG_INODE_ALL;
struct super_block *sb;
int ret;
start_log_trans(trans, root);
sb = dentry->d_inode->i_sb;
while(1) {
ret = __btrfs_log_inode(trans, root, dentry->d_inode,
inode_only);
BUG_ON(ret);
inode_only = LOG_INODE_EXISTS;
dentry = dentry->d_parent;
if (!dentry || !dentry->d_inode || sb != dentry->d_inode->i_sb)
break;
if (BTRFS_I(dentry->d_inode)->generation <=
root->fs_info->last_trans_committed)
break;
}
end_log_trans(root);
return 0;
}
/*
* it is not safe to log dentry if the chunk root has added new
* chunks. This returns 0 if the dentry was logged, and 1 otherwise.
* If this returns 1, you must commit the transaction to safely get your
* data on disk.
*/
int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct dentry *dentry)
{
u64 gen;
gen = root->fs_info->last_trans_new_blockgroup;
if (gen > root->fs_info->last_trans_committed)
return 1;
else
return btrfs_log_dentry(trans, root, dentry);
}
/*
* should be called during mount to recover any replay any log trees
* from the FS
*/
int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
{
int ret;
struct btrfs_path *path;
struct btrfs_trans_handle *trans;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_key tmp_key;
struct btrfs_root *log;
struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
u64 highest_inode;
struct walk_control wc = {
.process_func = process_one_buffer,
.stage = 0,
};
fs_info->log_root_recovering = 1;
path = btrfs_alloc_path();
BUG_ON(!path);
trans = btrfs_start_transaction(fs_info->tree_root, 1);
wc.trans = trans;
wc.pin = 1;
walk_log_tree(trans, log_root_tree, &wc);
again:
key.objectid = BTRFS_TREE_LOG_OBJECTID;
key.offset = (u64)-1;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
while(1) {
ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
if (ret < 0)
break;
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
btrfs_release_path(log_root_tree, path);
if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
break;
log = btrfs_read_fs_root_no_radix(log_root_tree,
&found_key);
BUG_ON(!log);
tmp_key.objectid = found_key.offset;
tmp_key.type = BTRFS_ROOT_ITEM_KEY;
tmp_key.offset = (u64)-1;
wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
BUG_ON(!wc.replay_dest);
btrfs_record_root_in_trans(wc.replay_dest);
ret = walk_log_tree(trans, log, &wc);
BUG_ON(ret);
if (wc.stage == LOG_WALK_REPLAY_ALL) {
ret = fixup_inode_link_counts(trans, wc.replay_dest,
path);
BUG_ON(ret);
}
ret = btrfs_find_highest_inode(wc.replay_dest, &highest_inode);
if (ret == 0) {
wc.replay_dest->highest_inode = highest_inode;
wc.replay_dest->last_inode_alloc = highest_inode;
}
key.offset = found_key.offset - 1;
free_extent_buffer(log->node);
kfree(log);
if (found_key.offset == 0)
break;
}
btrfs_release_path(log_root_tree, path);
/* step one is to pin it all, step two is to replay just inodes */
if (wc.pin) {
wc.pin = 0;
wc.process_func = replay_one_buffer;
wc.stage = LOG_WALK_REPLAY_INODES;
goto again;
}
/* step three is to replay everything */
if (wc.stage < LOG_WALK_REPLAY_ALL) {
wc.stage++;
goto again;
}
btrfs_free_path(path);
free_extent_buffer(log_root_tree->node);
log_root_tree->log_root = NULL;
fs_info->log_root_recovering = 0;
/* step 4: commit the transaction, which also unpins the blocks */
btrfs_commit_transaction(trans, fs_info->tree_root);
kfree(log_root_tree);
return 0;
}