// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/writeback.h>
#include <linux/sched/mm.h>
#include "messages.h"
#include "misc.h"
#include "ctree.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "extent_io.h"
#include "disk-io.h"
#include "compression.h"
#include "delalloc-space.h"
#include "qgroup.h"
#include "subpage.h"
#include "file.h"
#include "block-group.h"
static struct kmem_cache *btrfs_ordered_extent_cache;
static u64 entry_end(struct btrfs_ordered_extent *entry)
{
if (entry->file_offset + entry->num_bytes < entry->file_offset)
return (u64)-1;
return entry->file_offset + entry->num_bytes;
}
/* 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;
}
/*
* 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;
}
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->num_bytes <= 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 *ordered_tree_search(struct btrfs_inode *inode,
u64 file_offset)
{
struct rb_node *prev = NULL;
struct rb_node *ret;
struct btrfs_ordered_extent *entry;
if (inode->ordered_tree_last) {
entry = rb_entry(inode->ordered_tree_last, struct btrfs_ordered_extent,
rb_node);
if (in_range(file_offset, entry->file_offset, entry->num_bytes))
return inode->ordered_tree_last;
}
ret = __tree_search(&inode->ordered_tree, file_offset, &prev);
if (!ret)
ret = prev;
if (ret)
inode->ordered_tree_last = ret;
return ret;
}
static struct btrfs_ordered_extent *alloc_ordered_extent(
struct btrfs_inode *inode, u64 file_offset, u64 num_bytes,
u64 ram_bytes, u64 disk_bytenr, u64 disk_num_bytes,
u64 offset, unsigned long flags, int compress_type)
{
struct btrfs_ordered_extent *entry;
int ret;
u64 qgroup_rsv = 0;
if (flags &
((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
/* For nocow write, we can release the qgroup rsv right now */
ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes, &qgroup_rsv);
if (ret < 0)
return ERR_PTR(ret);
} else {
/*
* The ordered extent has reserved qgroup space, release now
* and pass the reserved number for qgroup_record to free.
*/
ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes, &qgroup_rsv);
if (ret < 0)
return ERR_PTR(ret);
}
entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
if (!entry)
return ERR_PTR(-ENOMEM);
entry->file_offset = file_offset;
entry->num_bytes = num_bytes;
entry->ram_bytes = ram_bytes;
entry->disk_bytenr = disk_bytenr;
entry->disk_num_bytes = disk_num_bytes;
entry->offset = offset;
entry->bytes_left = num_bytes;
entry->inode = BTRFS_I(igrab(&inode->vfs_inode));
entry->compress_type = compress_type;
entry->truncated_len = (u64)-1;
entry->qgroup_rsv = qgroup_rsv;
entry->flags = flags;
refcount_set(&entry->refs, 1);
init_waitqueue_head(&entry->wait);
INIT_LIST_HEAD(&entry->list);
INIT_LIST_HEAD(&entry->log_list);
INIT_LIST_HEAD(&entry->root_extent_list);
INIT_LIST_HEAD(&entry->work_list);
INIT_LIST_HEAD(&entry->bioc_list);
init_completion(&entry->completion);
/*
* We don't need the count_max_extents here, we can assume that all of
* that work has been done at higher layers, so this is truly the
* smallest the extent is going to get.
*/
spin_lock(&inode->lock);
btrfs_mod_outstanding_extents(inode, 1);
spin_unlock(&inode->lock);
return entry;
}
static void insert_ordered_extent(struct btrfs_ordered_extent *entry)
{
struct btrfs_inode *inode = entry->inode;
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct rb_node *node;
trace_btrfs_ordered_extent_add(inode, entry);
percpu_counter_add_batch(&fs_info->ordered_bytes, entry->num_bytes,
fs_info->delalloc_batch);
/* One ref for the tree. */
refcount_inc(&entry->refs);
spin_lock_irq(&inode->ordered_tree_lock);
node = tree_insert(&inode->ordered_tree, entry->file_offset,
&entry->rb_node);
if (unlikely(node))
btrfs_panic(fs_info, -EEXIST,
"inconsistency in ordered tree at offset %llu",
entry->file_offset);
spin_unlock_irq(&inode->ordered_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(&fs_info->ordered_root_lock);
BUG_ON(!list_empty(&root->ordered_root));
list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
spin_unlock(&fs_info->ordered_root_lock);
}
spin_unlock(&root->ordered_extent_lock);
}
/*
* Add an ordered extent to the per-inode tree.
*
* @inode: Inode that this extent is for.
* @file_offset: Logical offset in file where the extent starts.
* @num_bytes: Logical length of extent in file.
* @ram_bytes: Full length of unencoded data.
* @disk_bytenr: Offset of extent on disk.
* @disk_num_bytes: Size of extent on disk.
* @offset: Offset into unencoded data where file data starts.
* @flags: Flags specifying type of extent (1 << BTRFS_ORDERED_*).
* @compress_type: Compression algorithm used for data.
*
* Most of these parameters correspond to &struct btrfs_file_extent_item. The
* tree is given a single reference on the ordered extent that was inserted, and
* the returned pointer is given a second reference.
*
* Return: the new ordered extent or error pointer.
*/
struct btrfs_ordered_extent *btrfs_alloc_ordered_extent(
struct btrfs_inode *inode, u64 file_offset,
const struct btrfs_file_extent *file_extent, unsigned long flags)
{
struct btrfs_ordered_extent *entry;
ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
/*
* For regular writes, we just use the members in @file_extent.
*
* For NOCOW, we don't really care about the numbers except @start and
* file_extent->num_bytes, as we won't insert a file extent item at all.
*
* For PREALLOC, we do not use ordered extent members, but
* btrfs_mark_extent_written() handles everything.
*
* So here we always pass 0 as offset for NOCOW/PREALLOC ordered extents,
* or btrfs_split_ordered_extent() cannot handle it correctly.
*/
if (flags & ((1U << BTRFS_ORDERED_NOCOW) | (1U << BTRFS_ORDERED_PREALLOC)))
entry = alloc_ordered_extent(inode, file_offset,
file_extent->num_bytes,
file_extent->num_bytes,
file_extent->disk_bytenr + file_extent->offset,
file_extent->num_bytes, 0, flags,
file_extent->compression);
else
entry = alloc_ordered_extent(inode, file_offset,
file_extent->num_bytes,
file_extent->ram_bytes,
file_extent->disk_bytenr,
file_extent->disk_num_bytes,
file_extent->offset, flags,
file_extent->compression);
if (!IS_ERR(entry))
insert_ordered_extent(entry);
return entry;
}
/*
* 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 btrfs_ordered_extent *entry,
struct btrfs_ordered_sum *sum)
{
struct btrfs_inode *inode = entry->inode;
spin_lock_irq(&inode->ordered_tree_lock);
list_add_tail(&sum->list, &entry->list);
spin_unlock_irq(&inode->ordered_tree_lock);
}
void btrfs_mark_ordered_extent_error(struct btrfs_ordered_extent *ordered)
{
if (!test_and_set_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
mapping_set_error(ordered->inode->vfs_inode.i_mapping, -EIO);
}
static void finish_ordered_fn(struct btrfs_work *work)
{
struct btrfs_ordered_extent *ordered_extent;
ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
btrfs_finish_ordered_io(ordered_extent);
}
static bool can_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
struct folio *folio, u64 file_offset,
u64 len, bool uptodate)
{
struct btrfs_inode *inode = ordered->inode;
struct btrfs_fs_info *fs_info = inode->root->fs_info;
lockdep_assert_held(&inode->ordered_tree_lock);
if (folio) {
ASSERT(folio->mapping);
ASSERT(folio_pos(folio) <= file_offset);
ASSERT(file_offset + len <= folio_pos(folio) + folio_size(folio));
/*
* Ordered (Private2) bit indicates whether we still have
* pending io unfinished for the ordered extent.
*
* If there's no such bit, we need to skip to next range.
*/
if (!btrfs_folio_test_ordered(fs_info, folio, file_offset, len))
return false;
btrfs_folio_clear_ordered(fs_info, folio, file_offset, len);
}
/* Now we're fine to update the accounting. */
if (WARN_ON_ONCE(len > ordered->bytes_left)) {
btrfs_crit(fs_info,
"bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%llu left=%llu",
btrfs_root_id(inode->root), btrfs_ino(inode),
ordered->file_offset, ordered->num_bytes,
len, ordered->bytes_left);
ordered->bytes_left = 0;
} else {
ordered->bytes_left -= len;
}
if (!uptodate)
set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
if (ordered->bytes_left)
return false;
/*
* All the IO of the ordered extent is finished, we need to queue
* the finish_func to be executed.
*/
set_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags);
cond_wake_up(&ordered->wait);
refcount_inc(&ordered->refs);
trace_btrfs_ordered_extent_mark_finished(inode, ordered);
return true;
}
static void btrfs_queue_ordered_fn(struct btrfs_ordered_extent *ordered)
{
struct btrfs_inode *inode = ordered->inode;
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct btrfs_workqueue *wq = btrfs_is_free_space_inode(inode) ?
fs_info->endio_freespace_worker : fs_info->endio_write_workers;
btrfs_init_work(&ordered->work, finish_ordered_fn, NULL);
btrfs_queue_work(wq, &ordered->work);
}
void btrfs_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
struct folio *folio, u64 file_offset, u64 len,
bool uptodate)
{
struct btrfs_inode *inode = ordered->inode;
unsigned long flags;
bool ret;
trace_btrfs_finish_ordered_extent(inode, file_offset, len, uptodate);
spin_lock_irqsave(&inode->ordered_tree_lock, flags);
ret = can_finish_ordered_extent(ordered, folio, file_offset, len,
uptodate);
spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
/*
* If this is a COW write it means we created new extent maps for the
* range and they point to unwritten locations if we got an error either
* before submitting a bio or during IO.
*
* We have marked the ordered extent with BTRFS_ORDERED_IOERR, and we
* are queuing its completion below. During completion, at
* btrfs_finish_one_ordered(), we will drop the extent maps for the
* unwritten extents.
*
* However because completion runs in a work queue we can end up having
* a fast fsync running before that. In the case of direct IO, once we
* unlock the inode the fsync might start, and we queue the completion
* before unlocking the inode. In the case of buffered IO when writeback
* finishes (end_bbio_data_write()) we queue the completion, so if the
* writeback was triggered by a fast fsync, the fsync might start
* logging before ordered extent completion runs in the work queue.
*
* The fast fsync will log file extent items based on the extent maps it
* finds, so if by the time it collects extent maps the ordered extent
* completion didn't happen yet, it will log file extent items that
* point to unwritten extents, resulting in a corruption if a crash
* happens and the log tree is replayed. Note that a fast fsync does not
* wait for completion of ordered extents in order to reduce latency.
*
* Set a flag in the inode so that the next fast fsync will wait for
* ordered extents to complete before starting to log.
*/
if (!uptodate && !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
set_bit(BTRFS_INODE_COW_WRITE_ERROR, &inode->runtime_flags);
if (ret)
btrfs_queue_ordered_fn(ordered);
}
/*
* Mark all ordered extents io inside the specified range finished.
*
* @folio: The involved folio for the operation.
* For uncompressed buffered IO, the folio status also needs to be
* updated to indicate whether the pending ordered io is finished.
* Can be NULL for direct IO and compressed write.
* For these cases, callers are ensured they won't execute the
* endio function twice.
*
* This function is called for endio, thus the range must have ordered
* extent(s) covering it.
*/
void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
struct folio *folio, u64 file_offset,
u64 num_bytes, bool uptodate)
{
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
unsigned long flags;
u64 cur = file_offset;
trace_btrfs_writepage_end_io_hook(inode, file_offset,
file_offset + num_bytes - 1,
uptodate);
spin_lock_irqsave(&inode->ordered_tree_lock, flags);
while (cur < file_offset + num_bytes) {
u64 entry_end;
u64 end;
u32 len;
node = ordered_tree_search(inode, cur);
/* No ordered extents at all */
if (!node)
break;
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
entry_end = entry->file_offset + entry->num_bytes;
/*
* |<-- OE --->| |
* cur
* Go to next OE.
*/
if (cur >= entry_end) {
node = rb_next(node);
/* No more ordered extents, exit */
if (!node)
break;
entry = rb_entry(node, struct btrfs_ordered_extent,
rb_node);
/* Go to next ordered extent and continue */
cur = entry->file_offset;
continue;
}
/*
* | |<--- OE --->|
* cur
* Go to the start of OE.
*/
if (cur < entry->file_offset) {
cur = entry->file_offset;
continue;
}
/*
* Now we are definitely inside one ordered extent.
*
* |<--- OE --->|
* |
* cur
*/
end = min(entry->file_offset + entry->num_bytes,
file_offset + num_bytes) - 1;
ASSERT(end + 1 - cur < U32_MAX);
len = end + 1 - cur;
if (can_finish_ordered_extent(entry, folio, cur, len, uptodate)) {
spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
btrfs_queue_ordered_fn(entry);
spin_lock_irqsave(&inode->ordered_tree_lock, flags);
}
cur += len;
}
spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
}
/*
* Finish IO for one ordered extent across a given range. The range can only
* contain one ordered extent.
*
* @cached: The cached ordered extent. If not NULL, we can skip the tree
* search and use the ordered extent directly.
* Will be also used to store the finished ordered extent.
* @file_offset: File offset for the finished IO
* @io_size: Length of the finish IO range
*
* Return true if the ordered extent is finished in the range, and update
* @cached.
* Return false otherwise.
*
* NOTE: The range can NOT cross multiple ordered extents.
* Thus caller should ensure the range doesn't cross ordered extents.
*/
bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
struct btrfs_ordered_extent **cached,
u64 file_offset, u64 io_size)
{
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
unsigned long flags;
bool finished = false;
spin_lock_irqsave(&inode->ordered_tree_lock, flags);
if (cached && *cached) {
entry = *cached;
goto have_entry;
}
node = ordered_tree_search(inode, file_offset);
if (!node)
goto out;
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
have_entry:
if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
goto out;
if (io_size > entry->bytes_left)
btrfs_crit(inode->root->fs_info,
"bad ordered accounting left %llu size %llu",
entry->bytes_left, io_size);
entry->bytes_left -= io_size;
if (entry->bytes_left == 0) {
/*
* Ensure only one caller can set the flag and finished_ret
* accordingly
*/
finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
/* test_and_set_bit implies a barrier */
cond_wake_up_nomb(&entry->wait);
}
out:
if (finished && cached && entry) {
*cached = entry;
refcount_inc(&entry->refs);
trace_btrfs_ordered_extent_dec_test_pending(inode, entry);
}
spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
return finished;
}
/*
* 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 (refcount_dec_and_test(&entry->refs)) {
ASSERT(list_empty(&entry->root_extent_list));
ASSERT(list_empty(&entry->log_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);
kvfree(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 btrfs_inode *btrfs_inode,
struct btrfs_ordered_extent *entry)
{
struct btrfs_root *root = btrfs_inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct rb_node *node;
bool pending;
bool freespace_inode;
/*
* If this is a free space inode the thread has not acquired the ordered
* extents lockdep map.
*/
freespace_inode = btrfs_is_free_space_inode(btrfs_inode);
btrfs_lockdep_acquire(fs_info, btrfs_trans_pending_ordered);
/* This is paired with alloc_ordered_extent(). */
spin_lock(&btrfs_inode->lock);
btrfs_mod_outstanding_extents(btrfs_inode, -1);
spin_unlock(&btrfs_inode->lock);
if (root != fs_info->tree_root) {
u64 release;
if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
release = entry->disk_num_bytes;
else
release = entry->num_bytes;
btrfs_delalloc_release_metadata(btrfs_inode, release,
test_bit(BTRFS_ORDERED_IOERR,
&entry->flags));
}
percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
fs_info->delalloc_batch);
spin_lock_irq(&btrfs_inode->ordered_tree_lock);
node = &entry->rb_node;
rb_erase(node, &btrfs_inode->ordered_tree);
RB_CLEAR_NODE(node);
if (btrfs_inode->ordered_tree_last == node)
btrfs_inode->ordered_tree_last = NULL;
set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
spin_unlock_irq(&btrfs_inode->ordered_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 (pending) {
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(&fs_info->trans_lock);
trans = fs_info->running_transaction;
if (trans)
refcount_inc(&trans->use_count);
spin_unlock(&fs_info->trans_lock);
ASSERT(trans || BTRFS_FS_ERROR(fs_info));
if (trans) {
if (atomic_dec_and_test(&trans->pending_ordered))
wake_up(&trans->pending_wait);
btrfs_put_transaction(trans);
}
}
btrfs_lockdep_release(fs_info, btrfs_trans_pending_ordered);
spin_lock(&root->ordered_extent_lock);
list_del_init(&entry->root_extent_list);
root->nr_ordered_extents--;
trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
if (!root->nr_ordered_extents) {
spin_lock(&fs_info->ordered_root_lock);
BUG_ON(list_empty(&root->ordered_root));
list_del_init(&root->ordered_root);
spin_unlock(&fs_info->ordered_root_lock);
}
spin_unlock(&root->ordered_extent_lock);
wake_up(&entry->wait);
if (!freespace_inode)
btrfs_lockdep_release(fs_info, btrfs_ordered_extent);
}
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);
complete(&ordered->completion);
}
/*
* Wait for all the ordered extents in a root. Use @bg as range or do whole
* range if it's NULL.
*/
u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
const struct btrfs_block_group *bg)
{
struct btrfs_fs_info *fs_info = root->fs_info;
LIST_HEAD(splice);
LIST_HEAD(skipped);
LIST_HEAD(works);
struct btrfs_ordered_extent *ordered, *next;
u64 count = 0;
u64 range_start, range_len;
u64 range_end;
if (bg) {
range_start = bg->start;
range_len = bg->length;
} else {
range_start = 0;
range_len = U64_MAX;
}
range_end = range_start + range_len;
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);
if (range_end <= ordered->disk_bytenr ||
ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
list_move_tail(&ordered->root_extent_list, &skipped);
cond_resched_lock(&root->ordered_extent_lock);
continue;
}
list_move_tail(&ordered->root_extent_list,
&root->ordered_extents);
refcount_inc(&ordered->refs);
spin_unlock(&root->ordered_extent_lock);
btrfs_init_work(&ordered->flush_work,
btrfs_run_ordered_extent_work, NULL);
list_add_tail(&ordered->work_list, &works);
btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
cond_resched();
if (nr != U64_MAX)
nr--;
count++;
spin_lock(&root->ordered_extent_lock);
}
list_splice_tail(&skipped, &root->ordered_extents);
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;
}
/*
* Wait for @nr ordered extents that intersect the @bg, or the whole range of
* the filesystem if @bg is NULL.
*/
void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
const struct btrfs_block_group *bg)
{
struct btrfs_root *root;
LIST_HEAD(splice);
u64 done;
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_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, bg);
btrfs_put_root(root);
if (nr != U64_MAX)
nr -= done;
spin_lock(&fs_info->ordered_root_lock);
}
list_splice_tail(&splice, &fs_info->ordered_roots);
spin_unlock(&fs_info->ordered_root_lock);
mutex_unlock(&fs_info->ordered_operations_mutex);
}
/*
* Start IO and wait for a given ordered extent to finish.
*
* Wait on page writeback for all the pages in the extent and the IO completion
* code to insert metadata into the btree corresponding to the extent.
*/
void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry)
{
u64 start = entry->file_offset;
u64 end = start + entry->num_bytes - 1;
struct btrfs_inode *inode = entry->inode;
bool freespace_inode;
trace_btrfs_ordered_extent_start(inode, entry);
/*
* If this is a free space inode do not take the ordered extents lockdep
* map.
*/
freespace_inode = btrfs_is_free_space_inode(inode);
/*
* 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->vfs_inode.i_mapping, start, end);
if (!freespace_inode)
btrfs_might_wait_for_event(inode->root->fs_info, btrfs_ordered_extent);
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 btrfs_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 = OFFSET_MAX;
} else {
orig_end = start + len - 1;
if (orig_end > OFFSET_MAX)
orig_end = OFFSET_MAX;
}
/* 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->vfs_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->num_bytes <= start) {
btrfs_put_ordered_extent(ordered);
break;
}
btrfs_start_ordered_extent(ordered);
end = ordered->file_offset;
/*
* If the ordered extent had an error save the error but don't
* exit without waiting first for all other ordered extents in
* the range to complete.
*/
if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
ret = -EIO;
btrfs_put_ordered_extent(ordered);
if (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 btrfs_inode *inode,
u64 file_offset)
{
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
unsigned long flags;
spin_lock_irqsave(&inode->ordered_tree_lock, flags);
node = ordered_tree_search(inode, file_offset);
if (!node)
goto out;
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
entry = NULL;
if (entry) {
refcount_inc(&entry->refs);
trace_btrfs_ordered_extent_lookup(inode, entry);
}
out:
spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
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 btrfs_inode *inode, u64 file_offset, u64 len)
{
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
spin_lock_irq(&inode->ordered_tree_lock);
node = ordered_tree_search(inode, file_offset);
if (!node) {
node = ordered_tree_search(inode, 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) {
refcount_inc(&entry->refs);
trace_btrfs_ordered_extent_lookup_range(inode, entry);
}
spin_unlock_irq(&inode->ordered_tree_lock);
return entry;
}
/*
* Adds all ordered extents to the given list. The list ends up sorted by the
* file_offset of the ordered extents.
*/
void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
struct list_head *list)
{
struct rb_node *n;
btrfs_assert_inode_locked(inode);
spin_lock_irq(&inode->ordered_tree_lock);
for (n = rb_first(&inode->ordered_tree); n; n = rb_next(n)) {
struct btrfs_ordered_extent *ordered;
ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
continue;
ASSERT(list_empty(&ordered->log_list));
list_add_tail(&ordered->log_list, list);
refcount_inc(&ordered->refs);
trace_btrfs_ordered_extent_lookup_for_logging(inode, ordered);
}
spin_unlock_irq(&inode->ordered_tree_lock);
}
/*
* 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 btrfs_inode *inode, u64 file_offset)
{
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
spin_lock_irq(&inode->ordered_tree_lock);
node = ordered_tree_search(inode, file_offset);
if (!node)
goto out;
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
refcount_inc(&entry->refs);
trace_btrfs_ordered_extent_lookup_first(inode, entry);
out:
spin_unlock_irq(&inode->ordered_tree_lock);
return entry;
}
/*
* Lookup the first ordered extent that overlaps the range
* [@file_offset, @file_offset + @len).
*
* The difference between this and btrfs_lookup_first_ordered_extent() is
* that this one won't return any ordered extent that does not overlap the range.
* And the difference against btrfs_lookup_ordered_extent() is, this function
* ensures the first ordered extent gets returned.
*/
struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
struct btrfs_inode *inode, u64 file_offset, u64 len)
{
struct rb_node *node;
struct rb_node *cur;
struct rb_node *prev;
struct rb_node *next;
struct btrfs_ordered_extent *entry = NULL;
spin_lock_irq(&inode->ordered_tree_lock);
node = inode->ordered_tree.rb_node;
/*
* Here we don't want to use tree_search() which will use tree->last
* and screw up the search order.
* And __tree_search() can't return the adjacent ordered extents
* either, thus here we do our own search.
*/
while (node) {
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
if (file_offset < entry->file_offset) {
node = node->rb_left;
} else if (file_offset >= entry_end(entry)) {
node = node->rb_right;
} else {
/*
* Direct hit, got an ordered extent that starts at
* @file_offset
*/
goto out;
}
}
if (!entry) {
/* Empty tree */
goto out;
}
cur = &entry->rb_node;
/* We got an entry around @file_offset, check adjacent entries */
if (entry->file_offset < file_offset) {
prev = cur;
next = rb_next(cur);
} else {
prev = rb_prev(cur);
next = cur;
}
if (prev) {
entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
if (range_overlaps(entry, file_offset, len))
goto out;
}
if (next) {
entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
if (range_overlaps(entry, file_offset, len))
goto out;
}
/* No ordered extent in the range */
entry = NULL;
out:
if (entry) {
refcount_inc(&entry->refs);
trace_btrfs_ordered_extent_lookup_first_range(inode, entry);
}
spin_unlock_irq(&inode->ordered_tree_lock);
return entry;
}
/*
* Lock the passed range and ensures all pending ordered extents in it are run
* to completion.
*
* @inode: Inode whose ordered tree is to be searched
* @start: Beginning of range to flush
* @end: Last byte of range to lock
* @cached_state: If passed, will return the extent state responsible for the
* locked range. It's the caller's responsibility to free the
* cached state.
*
* Always return with the given range locked, ensuring after it's called no
* order extent can be pending.
*/
void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
u64 end,
struct extent_state **cached_state)
{
struct btrfs_ordered_extent *ordered;
struct extent_state *cache = NULL;
struct extent_state **cachedp = &cache;
if (cached_state)
cachedp = cached_state;
while (1) {
lock_extent(&inode->io_tree, start, end, cachedp);
ordered = btrfs_lookup_ordered_range(inode, start,
end - start + 1);
if (!ordered) {
/*
* If no external cached_state has been passed then
* decrement the extra ref taken for cachedp since we
* aren't exposing it outside of this function
*/
if (!cached_state)
refcount_dec(&cache->refs);
break;
}
unlock_extent(&inode->io_tree, start, end, cachedp);
btrfs_start_ordered_extent(ordered);
btrfs_put_ordered_extent(ordered);
}
}
/*
* Lock the passed range and ensure all pending ordered extents in it are run
* to completion in nowait mode.
*
* Return true if btrfs_lock_ordered_range does not return any extents,
* otherwise false.
*/
bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
struct extent_state **cached_state)
{
struct btrfs_ordered_extent *ordered;
if (!try_lock_extent(&inode->io_tree, start, end, cached_state))
return false;
ordered = btrfs_lookup_ordered_range(inode, start, end - start + 1);
if (!ordered)
return true;
btrfs_put_ordered_extent(ordered);
unlock_extent(&inode->io_tree, start, end, cached_state);
return false;
}
/* Split out a new ordered extent for this first @len bytes of @ordered. */
struct btrfs_ordered_extent *btrfs_split_ordered_extent(
struct btrfs_ordered_extent *ordered, u64 len)
{
struct btrfs_inode *inode = ordered->inode;
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
u64 file_offset = ordered->file_offset;
u64 disk_bytenr = ordered->disk_bytenr;
unsigned long flags = ordered->flags;
struct btrfs_ordered_sum *sum, *tmpsum;
struct btrfs_ordered_extent *new;
struct rb_node *node;
u64 offset = 0;
trace_btrfs_ordered_extent_split(inode, ordered);
ASSERT(!(flags & (1U << BTRFS_ORDERED_COMPRESSED)));
/*
* The entire bio must be covered by the ordered extent, but we can't
* reduce the original extent to a zero length either.
*/
if (WARN_ON_ONCE(len >= ordered->num_bytes))
return ERR_PTR(-EINVAL);
/* We cannot split partially completed ordered extents. */
if (ordered->bytes_left) {
ASSERT(!(flags & ~BTRFS_ORDERED_TYPE_FLAGS));
if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes))
return ERR_PTR(-EINVAL);
}
/* We cannot split a compressed ordered extent. */
if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes))
return ERR_PTR(-EINVAL);
new = alloc_ordered_extent(inode, file_offset, len, len, disk_bytenr,
len, 0, flags, ordered->compress_type);
if (IS_ERR(new))
return new;
/* One ref for the tree. */
refcount_inc(&new->refs);
/*
* Take the root's ordered_extent_lock to avoid a race with
* btrfs_wait_ordered_extents() when updating the disk_bytenr and
* disk_num_bytes fields of the ordered extent below. And we disable
* IRQs because the inode's ordered_tree_lock is used in IRQ context
* elsewhere.
*
* There's no concern about a previous caller of
* btrfs_wait_ordered_extents() getting the trimmed ordered extent
* before we insert the new one, because even if it gets the ordered
* extent before it's trimmed and the new one inserted, right before it
* uses it or during its use, the ordered extent might have been
* trimmed in the meanwhile, and it missed the new ordered extent.
* There's no way around this and it's harmless for current use cases,
* so we take the root's ordered_extent_lock to fix that race during
* trimming and silence tools like KCSAN.
*/
spin_lock_irq(&root->ordered_extent_lock);
spin_lock(&inode->ordered_tree_lock);
/*
* We don't have overlapping ordered extents (that would imply double
* allocation of extents) and we checked above that the split length
* does not cross the ordered extent's num_bytes field, so there's
* no need to remove it and re-insert it in the tree.
*/
ordered->file_offset += len;
ordered->disk_bytenr += len;
ordered->num_bytes -= len;
ordered->disk_num_bytes -= len;
ordered->ram_bytes -= len;
if (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags)) {
ASSERT(ordered->bytes_left == 0);
new->bytes_left = 0;
} else {
ordered->bytes_left -= len;
}
if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags)) {
if (ordered->truncated_len > len) {
ordered->truncated_len -= len;
} else {
new->truncated_len = ordered->truncated_len;
ordered->truncated_len = 0;
}
}
list_for_each_entry_safe(sum, tmpsum, &ordered->list, list) {
if (offset == len)
break;
list_move_tail(&sum->list, &new->list);
offset += sum->len;
}
node = tree_insert(&inode->ordered_tree, new->file_offset, &new->rb_node);
if (unlikely(node))
btrfs_panic(fs_info, -EEXIST,
"inconsistency in ordered tree at offset %llu after split",
new->file_offset);
spin_unlock(&inode->ordered_tree_lock);
list_add_tail(&new->root_extent_list, &root->ordered_extents);
root->nr_ordered_extents++;
spin_unlock_irq(&root->ordered_extent_lock);
return new;
}
int __init ordered_data_init(void)
{
btrfs_ordered_extent_cache = KMEM_CACHE(btrfs_ordered_extent, 0);
if (!btrfs_ordered_extent_cache)
return -ENOMEM;
return 0;
}
void __cold ordered_data_exit(void)
{
kmem_cache_destroy(btrfs_ordered_extent_cache);
}
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