- 根目录:
- fs
- btrfs
- ordered-data.c
/*
* Copyright (C) 2007 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/slab.h>
#include <linux/blkdev.h>
#include <linux/writeback.h>
#include <linux/pagevec.h>
#include "ctree.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "extent_io.h"
#include "disk-io.h"
static struct kmem_cache *btrfs_ordered_extent_cache;
static u64 entry_end(struct btrfs_ordered_extent *entry)
{
if (entry->file_offset + entry->len < entry->file_offset)
return (u64)-1;
return entry->file_offset + entry->len;
}
/* returns NULL if the insertion worked, or it returns the node it did find
* in the tree
*/
static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
struct rb_node *node)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
struct btrfs_ordered_extent *entry;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
if (file_offset < entry->file_offset)
p = &(*p)->rb_left;
else if (file_offset >= entry_end(entry))
p = &(*p)->rb_right;
else
return parent;
}
rb_link_node(node, parent, p);
rb_insert_color(node, root);
return NULL;
}
static void ordered_data_tree_panic(struct inode *inode, int errno,
u64 offset)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
btrfs_panic(fs_info, errno, "Inconsistency in ordered tree at offset "
"%llu", offset);
}
/*
* look for a given offset in the tree, and if it can't be found return the
* first lesser offset
*/
static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
struct rb_node **prev_ret)
{
struct rb_node *n = root->rb_node;
struct rb_node *prev = NULL;
struct rb_node *test;
struct btrfs_ordered_extent *entry;
struct btrfs_ordered_extent *prev_entry = NULL;
while (n) {
entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
prev = n;
prev_entry = entry;
if (file_offset < entry->file_offset)
n = n->rb_left;
else if (file_offset >= entry_end(entry))
n = n->rb_right;
else
return n;
}
if (!prev_ret)
return NULL;
while (prev && file_offset >= entry_end(prev_entry)) {
test = rb_next(prev);
if (!test)
break;
prev_entry = rb_entry(test, struct btrfs_ordered_extent,
rb_node);
if (file_offset < entry_end(prev_entry))
break;
prev = test;
}
if (prev)
prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
rb_node);
while (prev && file_offset < entry_end(prev_entry)) {
test = rb_prev(prev);
if (!test)
break;
prev_entry = rb_entry(test, struct btrfs_ordered_extent,
rb_node);
prev = test;
}
*prev_ret = prev;
return NULL;
}
/*
* helper to check if a given offset is inside a given entry
*/
static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
{
if (file_offset < entry->file_offset ||
entry->file_offset + entry->len <= file_offset)
return 0;
return 1;
}
static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
u64 len)
{
if (file_offset + len <= entry->file_offset ||
entry->file_offset + entry->len <= file_offset)
return 0;
return 1;
}
/*
* look find the first ordered struct that has this offset, otherwise
* the first one less than this offset
*/
static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
u64 file_offset)
{
struct rb_root *root = &tree->tree;
struct rb_node *prev = NULL;
struct rb_node *ret;
struct btrfs_ordered_extent *entry;
if (tree->last) {
entry = rb_entry(tree->last, struct btrfs_ordered_extent,
rb_node);
if (offset_in_entry(entry, file_offset))
return tree->last;
}
ret = __tree_search(root, file_offset, &prev);
if (!ret)
ret = prev;
if (ret)
tree->last = ret;
return ret;
}
/* allocate and add a new ordered_extent into the per-inode tree.
* file_offset is the logical offset in the file
*
* start is the disk block number of an extent already reserved in the
* extent allocation tree
*
* len is the length of the extent
*
* The tree is given a single reference on the ordered extent that was
* inserted.
*/
static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
u64 start, u64 len, u64 disk_len,
int type, int dio, int compress_type)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_ordered_inode_tree *tree;
struct rb_node *node;
struct btrfs_ordered_extent *entry;
tree = &BTRFS_I(inode)->ordered_tree;
entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
if (!entry)
return -ENOMEM;
entry->file_offset = file_offset;
entry->start = start;
entry->len = len;
entry->disk_len = disk_len;
entry->bytes_left = len;
entry->inode = igrab(inode);
entry->compress_type = compress_type;
entry->truncated_len = (u64)-1;
if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
set_bit(type, &entry->flags);
if (dio)
set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
/* one ref for the tree */
atomic_set(&entry->refs, 1);
init_waitqueue_head(&entry->wait);
INIT_LIST_HEAD(&entry->list);
INIT_LIST_HEAD(&entry->root_extent_list);
INIT_LIST_HEAD(&entry->work_list);
init_completion(&entry->completion);
INIT_LIST_HEAD(&entry->log_list);
INIT_LIST_HEAD(&entry->trans_list);
trace_btrfs_ordered_extent_add(inode, entry);
spin_lock_irq(&tree->lock);
node = tree_insert(&tree->tree, file_offset,
&entry->rb_node);
if (node)
ordered_data_tree_panic(inode, -EEXIST, file_offset);
spin_unlock_irq(&tree->lock);
spin_lock(&root->ordered_extent_lock);
list_add_tail(&entry->root_extent_list,
&root->ordered_extents);
root->nr_ordered_extents++;
if (root->nr_ordered_extents == 1) {
spin_lock(&root->fs_info->ordered_root_lock);
BUG_ON(!list_empty(&root->ordered_root));
list_add_tail(&root->ordered_root,
&root->fs_info->ordered_roots);
spin_unlock(&root->fs_info->ordered_root_lock);
}
spin_unlock(&root->ordered_extent_lock);
return 0;
}
int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
u64 start, u64 len, u64 disk_len, int type)
{
return __btrfs_add_ordered_extent(inode, file_offset, start, len,
disk_len, type, 0,
BTRFS_COMPRESS_NONE);
}
int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
u64 start, u64 len, u64 disk_len, int type)
{
return __btrfs_add_ordered_extent(inode, file_offset, start, len,
disk_len, type, 1,
BTRFS_COMPRESS_NONE);
}
int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
u64 start, u64 len, u64 disk_len,
int type, int compress_type)
{
return __btrfs_add_ordered_extent(inode, file_offset, start, len,
disk_len, type, 0,
compress_type);
}
/*
* Add a struct btrfs_ordered_sum into the list of checksums to be inserted
* when an ordered extent is finished. If the list covers more than one
* ordered extent, it is split across multiples.
*/
void btrfs_add_ordered_sum(struct inode *inode,
struct btrfs_ordered_extent *entry,
struct btrfs_ordered_sum *sum)
{
struct btrfs_ordered_inode_tree *tree;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irq(&tree->lock);
list_add_tail(&sum->list, &entry->list);
spin_unlock_irq(&tree->lock);
}
/*
* this is used to account for finished IO across a given range
* of the file. The IO may span ordered extents. If
* a given ordered_extent is completely done, 1 is returned, otherwise
* 0.
*
* test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
* to make sure this function only returns 1 once for a given ordered extent.
*
* file_offset is updated to one byte past the range that is recorded as
* complete. This allows you to walk forward in the file.
*/
int btrfs_dec_test_first_ordered_pending(struct inode *inode,
struct btrfs_ordered_extent **cached,
u64 *file_offset, u64 io_size, int uptodate)
{
struct btrfs_ordered_inode_tree *tree;
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
int ret;
unsigned long flags;
u64 dec_end;
u64 dec_start;
u64 to_dec;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irqsave(&tree->lock, flags);
node = tree_search(tree, *file_offset);
if (!node) {
ret = 1;
goto out;
}
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
if (!offset_in_entry(entry, *file_offset)) {
ret = 1;
goto out;
}
dec_start = max(*file_offset, entry->file_offset);
dec_end = min(*file_offset + io_size, entry->file_offset +
entry->len);
*file_offset = dec_end;
if (dec_start > dec_end) {
btrfs_crit(BTRFS_I(inode)->root->fs_info,
"bad ordering dec_start %llu end %llu", dec_start, dec_end);
}
to_dec = dec_end - dec_start;
if (to_dec > entry->bytes_left) {
btrfs_crit(BTRFS_I(inode)->root->fs_info,
"bad ordered accounting left %llu size %llu",
entry->bytes_left, to_dec);
}
entry->bytes_left -= to_dec;
if (!uptodate)
set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
if (entry->bytes_left == 0) {
ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
/*
* Implicit memory barrier after test_and_set_bit
*/
if (waitqueue_active(&entry->wait))
wake_up(&entry->wait);
} else {
ret = 1;
}
out:
if (!ret && cached && entry) {
*cached = entry;
atomic_inc(&entry->refs);
}
spin_unlock_irqrestore(&tree->lock, flags);
return ret == 0;
}
/*
* this is used to account for finished IO across a given range
* of the file. The IO should not span ordered extents. If
* a given ordered_extent is completely done, 1 is returned, otherwise
* 0.
*
* test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
* to make sure this function only returns 1 once for a given ordered extent.
*/
int btrfs_dec_test_ordered_pending(struct inode *inode,
struct btrfs_ordered_extent **cached,
u64 file_offset, u64 io_size, int uptodate)
{
struct btrfs_ordered_inode_tree *tree;
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
unsigned long flags;
int ret;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irqsave(&tree->lock, flags);
if (cached && *cached) {
entry = *cached;
goto have_entry;
}
node = tree_search(tree, file_offset);
if (!node) {
ret = 1;
goto out;
}
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
have_entry:
if (!offset_in_entry(entry, file_offset)) {
ret = 1;
goto out;
}
if (io_size > entry->bytes_left) {
btrfs_crit(BTRFS_I(inode)->root->fs_info,
"bad ordered accounting left %llu size %llu",
entry->bytes_left, io_size);
}
entry->bytes_left -= io_size;
if (!uptodate)
set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
if (entry->bytes_left == 0) {
ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
/*
* Implicit memory barrier after test_and_set_bit
*/
if (waitqueue_active(&entry->wait))
wake_up(&entry->wait);
} else {
ret = 1;
}
out:
if (!ret && cached && entry) {
*cached = entry;
atomic_inc(&entry->refs);
}
spin_unlock_irqrestore(&tree->lock, flags);
return ret == 0;
}
/* Needs to either be called under a log transaction or the log_mutex */
void btrfs_get_logged_extents(struct inode *inode,
struct list_head *logged_list,
const loff_t start,
const loff_t end)
{
struct btrfs_ordered_inode_tree *tree;
struct btrfs_ordered_extent *ordered;
struct rb_node *n;
struct rb_node *prev;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irq(&tree->lock);
n = __tree_search(&tree->tree, end, &prev);
if (!n)
n = prev;
for (; n; n = rb_prev(n)) {
ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
if (ordered->file_offset > end)
continue;
if (entry_end(ordered) <= start)
break;
if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
continue;
list_add(&ordered->log_list, logged_list);
atomic_inc(&ordered->refs);
}
spin_unlock_irq(&tree->lock);
}
void btrfs_put_logged_extents(struct list_head *logged_list)
{
struct btrfs_ordered_extent *ordered;
while (!list_empty(logged_list)) {
ordered = list_first_entry(logged_list,
struct btrfs_ordered_extent,
log_list);
list_del_init(&ordered->log_list);
btrfs_put_ordered_extent(ordered);
}
}
void btrfs_submit_logged_extents(struct list_head *logged_list,
struct btrfs_root *log)
{
int index = log->log_transid % 2;
spin_lock_irq(&log->log_extents_lock[index]);
list_splice_tail(logged_list, &log->logged_list[index]);
spin_unlock_irq(&log->log_extents_lock[index]);
}
void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
struct btrfs_root *log, u64 transid)
{
struct btrfs_ordered_extent *ordered;
int index = transid % 2;
spin_lock_irq(&log->log_extents_lock[index]);
while (!list_empty(&log->logged_list[index])) {
struct inode *inode;
ordered = list_first_entry(&log->logged_list[index],
struct btrfs_ordered_extent,
log_list);
list_del_init(&ordered->log_list);
inode = ordered->inode;
spin_unlock_irq(&log->log_extents_lock[index]);
if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
!test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
u64 start = ordered->file_offset;
u64 end = ordered->file_offset + ordered->len - 1;
WARN_ON(!inode);
filemap_fdatawrite_range(inode->i_mapping, start, end);
}
wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE,
&ordered->flags));
/*
* In order to keep us from losing our ordered extent
* information when committing the transaction we have to make
* sure that any logged extents are completed when we go to
* commit the transaction. To do this we simply increase the
* current transactions pending_ordered counter and decrement it
* when the ordered extent completes.
*/
if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
struct btrfs_ordered_inode_tree *tree;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irq(&tree->lock);
if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
atomic_inc(&trans->transaction->pending_ordered);
}
spin_unlock_irq(&tree->lock);
}
btrfs_put_ordered_extent(ordered);
spin_lock_irq(&log->log_extents_lock[index]);
}
spin_unlock_irq(&log->log_extents_lock[index]);
}
void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid)
{
struct btrfs_ordered_extent *ordered;
int index = transid % 2;
spin_lock_irq(&log->log_extents_lock[index]);
while (!list_empty(&log->logged_list[index])) {
ordered = list_first_entry(&log->logged_list[index],
struct btrfs_ordered_extent,
log_list);
list_del_init(&ordered->log_list);
spin_unlock_irq(&log->log_extents_lock[index]);
btrfs_put_ordered_extent(ordered);
spin_lock_irq(&log->log_extents_lock[index]);
}
spin_unlock_irq(&log->log_extents_lock[index]);
}
/*
* used to drop a reference on an ordered extent. This will free
* the extent if the last reference is dropped
*/
void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
{
struct list_head *cur;
struct btrfs_ordered_sum *sum;
trace_btrfs_ordered_extent_put(entry->inode, entry);
if (atomic_dec_and_test(&entry->refs)) {
ASSERT(list_empty(&entry->log_list));
ASSERT(list_empty(&entry->trans_list));
ASSERT(list_empty(&entry->root_extent_list));
ASSERT(RB_EMPTY_NODE(&entry->rb_node));
if (entry->inode)
btrfs_add_delayed_iput(entry->inode);
while (!list_empty(&entry->list)) {
cur = entry->list.next;
sum = list_entry(cur, struct btrfs_ordered_sum, list);
list_del(&sum->list);
kfree(sum);
}
kmem_cache_free(btrfs_ordered_extent_cache, entry);
}
}
/*
* remove an ordered extent from the tree. No references are dropped
* and waiters are woken up.
*/
void btrfs_remove_ordered_extent(struct inode *inode,
struct btrfs_ordered_extent *entry)
{
struct btrfs_ordered_inode_tree *tree;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct rb_node *node;
bool dec_pending_ordered = false;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irq(&tree->lock);
node = &entry->rb_node;
rb_erase(node, &tree->tree);
RB_CLEAR_NODE(node);
if (tree->last == node)
tree->last = NULL;
set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
if (test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags))
dec_pending_ordered = true;
spin_unlock_irq(&tree->lock);
/*
* The current running transaction is waiting on us, we need to let it
* know that we're complete and wake it up.
*/
if (dec_pending_ordered) {
struct btrfs_transaction *trans;
/*
* The checks for trans are just a formality, it should be set,
* but if it isn't we don't want to deref/assert under the spin
* lock, so be nice and check if trans is set, but ASSERT() so
* if it isn't set a developer will notice.
*/
spin_lock(&root->fs_info->trans_lock);
trans = root->fs_info->running_transaction;
if (trans)
atomic_inc(&trans->use_count);
spin_unlock(&root->fs_info->trans_lock);
ASSERT(trans);
if (trans) {
if (atomic_dec_and_test(&trans->pending_ordered))
wake_up(&trans->pending_wait);
btrfs_put_transaction(trans);
}
}
spin_lock(&root->ordered_extent_lock);
list_del_init(&entry->root_extent_list);
root->nr_ordered_extents--;
trace_btrfs_ordered_extent_remove(inode, entry);
if (!root->nr_ordered_extents) {
spin_lock(&root->fs_info->ordered_root_lock);
BUG_ON(list_empty(&root->ordered_root));
list_del_init(&root->ordered_root);
spin_unlock(&root->fs_info->ordered_root_lock);
}
spin_unlock(&root->ordered_extent_lock);
wake_up(&entry->wait);
}
static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
{
struct btrfs_ordered_extent *ordered;
ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
btrfs_start_ordered_extent(ordered->inode, ordered, 1);
complete(&ordered->completion);
}
/*
* wait for all the ordered extents in a root. This is done when balancing
* space between drives.
*/
int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
{
struct list_head splice, works;
struct btrfs_ordered_extent *ordered, *next;
int count = 0;
INIT_LIST_HEAD(&splice);
INIT_LIST_HEAD(&works);
mutex_lock(&root->ordered_extent_mutex);
spin_lock(&root->ordered_extent_lock);
list_splice_init(&root->ordered_extents, &splice);
while (!list_empty(&splice) && nr) {
ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
root_extent_list);
list_move_tail(&ordered->root_extent_list,
&root->ordered_extents);
atomic_inc(&ordered->refs);
spin_unlock(&root->ordered_extent_lock);
btrfs_init_work(&ordered->flush_work,
btrfs_flush_delalloc_helper,
btrfs_run_ordered_extent_work, NULL, NULL);
list_add_tail(&ordered->work_list, &works);
btrfs_queue_work(root->fs_info->flush_workers,
&ordered->flush_work);
cond_resched();
spin_lock(&root->ordered_extent_lock);
if (nr != -1)
nr--;
count++;
}
list_splice_tail(&splice, &root->ordered_extents);
spin_unlock(&root->ordered_extent_lock);
list_for_each_entry_safe(ordered, next, &works, work_list) {
list_del_init(&ordered->work_list);
wait_for_completion(&ordered->completion);
btrfs_put_ordered_extent(ordered);
cond_resched();
}
mutex_unlock(&root->ordered_extent_mutex);
return count;
}
void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr)
{
struct btrfs_root *root;
struct list_head splice;
int done;
INIT_LIST_HEAD(&splice);
mutex_lock(&fs_info->ordered_operations_mutex);
spin_lock(&fs_info->ordered_root_lock);
list_splice_init(&fs_info->ordered_roots, &splice);
while (!list_empty(&splice) && nr) {
root = list_first_entry(&splice, struct btrfs_root,
ordered_root);
root = btrfs_grab_fs_root(root);
BUG_ON(!root);
list_move_tail(&root->ordered_root,
&fs_info->ordered_roots);
spin_unlock(&fs_info->ordered_root_lock);
done = btrfs_wait_ordered_extents(root, nr);
btrfs_put_fs_root(root);
spin_lock(&fs_info->ordered_root_lock);
if (nr != -1) {
nr -= done;
WARN_ON(nr < 0);
}
}
list_splice_tail(&splice, &fs_info->ordered_roots);
spin_unlock(&fs_info->ordered_root_lock);
mutex_unlock(&fs_info->ordered_operations_mutex);
}
/*
* Used to start IO or wait for a given ordered extent to finish.
*
* If wait is one, this effectively waits on page writeback for all the pages
* in the extent, and it waits on the io completion code to insert
* metadata into the btree corresponding to the extent
*/
void btrfs_start_ordered_extent(struct inode *inode,
struct btrfs_ordered_extent *entry,
int wait)
{
u64 start = entry->file_offset;
u64 end = start + entry->len - 1;
trace_btrfs_ordered_extent_start(inode, entry);
/*
* pages in the range can be dirty, clean or writeback. We
* start IO on any dirty ones so the wait doesn't stall waiting
* for the flusher thread to find them
*/
if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
filemap_fdatawrite_range(inode->i_mapping, start, end);
if (wait) {
wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
&entry->flags));
}
}
/*
* Used to wait on ordered extents across a large range of bytes.
*/
int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
{
int ret = 0;
int ret_wb = 0;
u64 end;
u64 orig_end;
struct btrfs_ordered_extent *ordered;
if (start + len < start) {
orig_end = INT_LIMIT(loff_t);
} else {
orig_end = start + len - 1;
if (orig_end > INT_LIMIT(loff_t))
orig_end = INT_LIMIT(loff_t);
}
/* start IO across the range first to instantiate any delalloc
* extents
*/
ret = btrfs_fdatawrite_range(inode, start, orig_end);
if (ret)
return ret;
/*
* If we have a writeback error don't return immediately. Wait first
* for any ordered extents that haven't completed yet. This is to make
* sure no one can dirty the same page ranges and call writepages()
* before the ordered extents complete - to avoid failures (-EEXIST)
* when adding the new ordered extents to the ordered tree.
*/
ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
end = orig_end;
while (1) {
ordered = btrfs_lookup_first_ordered_extent(inode, end);
if (!ordered)
break;
if (ordered->file_offset > orig_end) {
btrfs_put_ordered_extent(ordered);
break;
}
if (ordered->file_offset + ordered->len <= start) {
btrfs_put_ordered_extent(ordered);
break;
}
btrfs_start_ordered_extent(inode, ordered, 1);
end = ordered->file_offset;
if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
ret = -EIO;
btrfs_put_ordered_extent(ordered);
if (ret || end == 0 || end == start)
break;
end--;
}
return ret_wb ? ret_wb : ret;
}
/*
* find an ordered extent corresponding to file_offset. return NULL if
* nothing is found, otherwise take a reference on the extent and return it
*/
struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
u64 file_offset)
{
struct btrfs_ordered_inode_tree *tree;
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irq(&tree->lock);
node = tree_search(tree, file_offset);
if (!node)
goto out;
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
if (!offset_in_entry(entry, file_offset))
entry = NULL;
if (entry)
atomic_inc(&entry->refs);
out:
spin_unlock_irq(&tree->lock);
return entry;
}
/* Since the DIO code tries to lock a wide area we need to look for any ordered
* extents that exist in the range, rather than just the start of the range.
*/
struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
u64 file_offset,
u64 len)
{
struct btrfs_ordered_inode_tree *tree;
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irq(&tree->lock);
node = tree_search(tree, file_offset);
if (!node) {
node = tree_search(tree, file_offset + len);
if (!node)
goto out;
}
while (1) {
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
if (range_overlaps(entry, file_offset, len))
break;
if (entry->file_offset >= file_offset + len) {
entry = NULL;
break;
}
entry = NULL;
node = rb_next(node);
if (!node)
break;
}
out:
if (entry)
atomic_inc(&entry->refs);
spin_unlock_irq(&tree->lock);
return entry;
}
bool btrfs_have_ordered_extents_in_range(struct inode *inode,
u64 file_offset,
u64 len)
{
struct btrfs_ordered_extent *oe;
oe = btrfs_lookup_ordered_range(inode, file_offset, len);
if (oe) {
btrfs_put_ordered_extent(oe);
return true;
}
return false;
}
/*
* lookup and return any extent before 'file_offset'. NULL is returned
* if none is found
*/
struct btrfs_ordered_extent *
btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
{
struct btrfs_ordered_inode_tree *tree;
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irq(&tree->lock);
node = tree_search(tree, file_offset);
if (!node)
goto out;
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
atomic_inc(&entry->refs);
out:
spin_unlock_irq(&tree->lock);
return entry;
}
/*
* After an extent is done, call this to conditionally update the on disk
* i_size. i_size is updated to cover any fully written part of the file.
*/
int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
struct btrfs_ordered_extent *ordered)
{
struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
u64 disk_i_size;
u64 new_i_size;
u64 i_size = i_size_read(inode);
struct rb_node *node;
struct rb_node *prev = NULL;
struct btrfs_ordered_extent *test;
int ret = 1;
spin_lock_irq(&tree->lock);
if (ordered) {
offset = entry_end(ordered);
if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
offset = min(offset,
ordered->file_offset +
ordered->truncated_len);
} else {
offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
}
disk_i_size = BTRFS_I(inode)->disk_i_size;
/* truncate file */
if (disk_i_size > i_size) {
BTRFS_I(inode)->disk_i_size = i_size;
ret = 0;
goto out;
}
/*
* if the disk i_size is already at the inode->i_size, or
* this ordered extent is inside the disk i_size, we're done
*/
if (disk_i_size == i_size)
goto out;
/*
* We still need to update disk_i_size if outstanding_isize is greater
* than disk_i_size.
*/
if (offset <= disk_i_size &&
(!ordered || ordered->outstanding_isize <= disk_i_size))
goto out;
/*
* walk backward from this ordered extent to disk_i_size.
* if we find an ordered extent then we can't update disk i_size
* yet
*/
if (ordered) {
node = rb_prev(&ordered->rb_node);
} else {
prev = tree_search(tree, offset);
/*
* we insert file extents without involving ordered struct,
* so there should be no ordered struct cover this offset
*/
if (prev) {
test = rb_entry(prev, struct btrfs_ordered_extent,
rb_node);
BUG_ON(offset_in_entry(test, offset));
}
node = prev;
}
for (; node; node = rb_prev(node)) {
test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
/* We treat this entry as if it doesnt exist */
if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
continue;
if (test->file_offset + test->len <= disk_i_size)
break;
if (test->file_offset >= i_size)
break;
if (entry_end(test) > disk_i_size) {
/*
* we don't update disk_i_size now, so record this
* undealt i_size. Or we will not know the real
* i_size.
*/
if (test->outstanding_isize < offset)
test->outstanding_isize = offset;
if (ordered &&
ordered->outstanding_isize >
test->outstanding_isize)
test->outstanding_isize =
ordered->outstanding_isize;
goto out;
}
}
new_i_size = min_t(u64, offset, i_size);
/*
* Some ordered extents may completed before the current one, and
* we hold the real i_size in ->outstanding_isize.
*/
if (ordered && ordered->outstanding_isize > new_i_size)
new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
BTRFS_I(inode)->disk_i_size = new_i_size;
ret = 0;
out:
/*
* We need to do this because we can't remove ordered extents until
* after the i_disk_size has been updated and then the inode has been
* updated to reflect the change, so we need to tell anybody who finds
* this ordered extent that we've already done all the real work, we
* just haven't completed all the other work.
*/
if (ordered)
set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
spin_unlock_irq(&tree->lock);
return ret;
}
/*
* search the ordered extents for one corresponding to 'offset' and
* try to find a checksum. This is used because we allow pages to
* be reclaimed before their checksum is actually put into the btree
*/
int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
u32 *sum, int len)
{
struct btrfs_ordered_sum *ordered_sum;
struct btrfs_ordered_extent *ordered;
struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
unsigned long num_sectors;
unsigned long i;
u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
int index = 0;
ordered = btrfs_lookup_ordered_extent(inode, offset);
if (!ordered)
return 0;
spin_lock_irq(&tree->lock);
list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
if (disk_bytenr >= ordered_sum->bytenr &&
disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
i = (disk_bytenr - ordered_sum->bytenr) >>
inode->i_sb->s_blocksize_bits;
num_sectors = ordered_sum->len >>
inode->i_sb->s_blocksize_bits;
num_sectors = min_t(int, len - index, num_sectors - i);
memcpy(sum + index, ordered_sum->sums + i,
num_sectors);
index += (int)num_sectors;
if (index == len)
goto out;
disk_bytenr += num_sectors * sectorsize;
}
}
out:
spin_unlock_irq(&tree->lock);
btrfs_put_ordered_extent(ordered);
return index;
}
int __init ordered_data_init(void)
{
btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
sizeof(struct btrfs_ordered_extent), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
NULL);
if (!btrfs_ordered_extent_cache)
return -ENOMEM;
return 0;
}
void ordered_data_exit(void)
{
if (btrfs_ordered_extent_cache)
kmem_cache_destroy(btrfs_ordered_extent_cache);
}