/*
* 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/gfp.h>
#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"
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;
}
/*
* 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;
}
/*
* 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;
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.
*/
int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
u64 start, u64 len, u64 disk_len, int type)
{
struct btrfs_ordered_inode_tree *tree;
struct rb_node *node;
struct btrfs_ordered_extent *entry;
tree = &BTRFS_I(inode)->ordered_tree;
entry = kzalloc(sizeof(*entry), GFP_NOFS);
if (!entry)
return -ENOMEM;
mutex_lock(&tree->mutex);
entry->file_offset = file_offset;
entry->start = start;
entry->len = len;
entry->disk_len = disk_len;
entry->bytes_left = len;
entry->inode = inode;
if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
set_bit(type, &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);
node = tree_insert(&tree->tree, file_offset,
&entry->rb_node);
BUG_ON(node);
spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
list_add_tail(&entry->root_extent_list,
&BTRFS_I(inode)->root->fs_info->ordered_extents);
spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
mutex_unlock(&tree->mutex);
BUG_ON(node);
return 0;
}
/*
* 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.
*/
int 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;
mutex_lock(&tree->mutex);
list_add_tail(&sum->list, &entry->list);
mutex_unlock(&tree->mutex);
return 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,
u64 file_offset, u64 io_size)
{
struct btrfs_ordered_inode_tree *tree;
struct rb_node *node;
struct btrfs_ordered_extent *entry;
int ret;
tree = &BTRFS_I(inode)->ordered_tree;
mutex_lock(&tree->mutex);
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;
}
if (io_size > entry->bytes_left) {
printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
(unsigned long long)entry->bytes_left,
(unsigned long long)io_size);
}
entry->bytes_left -= io_size;
if (entry->bytes_left == 0)
ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
else
ret = 1;
out:
mutex_unlock(&tree->mutex);
return ret == 0;
}
/*
* used to drop a reference on an ordered extent. This will free
* the extent if the last reference is dropped
*/
int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
{
struct list_head *cur;
struct btrfs_ordered_sum *sum;
if (atomic_dec_and_test(&entry->refs)) {
while (!list_empty(&entry->list)) {
cur = entry->list.next;
sum = list_entry(cur, struct btrfs_ordered_sum, list);
list_del(&sum->list);
kfree(sum);
}
kfree(entry);
}
return 0;
}
/*
* remove an ordered extent from the tree. No references are dropped
* and you must wake_up entry->wait. You must hold the tree mutex
* while you call this function.
*/
static int __btrfs_remove_ordered_extent(struct inode *inode,
struct btrfs_ordered_extent *entry)
{
struct btrfs_ordered_inode_tree *tree;
struct rb_node *node;
tree = &BTRFS_I(inode)->ordered_tree;
node = &entry->rb_node;
rb_erase(node, &tree->tree);
tree->last = NULL;
set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
spin_lock(&BTRFS_I(inode)->accounting_lock);
BTRFS_I(inode)->outstanding_extents--;
spin_unlock(&BTRFS_I(inode)->accounting_lock);
btrfs_unreserve_metadata_for_delalloc(BTRFS_I(inode)->root,
inode, 1);
spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
list_del_init(&entry->root_extent_list);
/*
* we have no more ordered extents for this inode and
* no dirty pages. We can safely remove it from the
* list of ordered extents
*/
if (RB_EMPTY_ROOT(&tree->tree) &&
!mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) {
list_del_init(&BTRFS_I(inode)->ordered_operations);
}
spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
return 0;
}
/*
* remove an ordered extent from the tree. No references are dropped
* but any waiters are woken.
*/
int btrfs_remove_ordered_extent(struct inode *inode,
struct btrfs_ordered_extent *entry)
{
struct btrfs_ordered_inode_tree *tree;
int ret;
tree = &BTRFS_I(inode)->ordered_tree;
mutex_lock(&tree->mutex);
ret = __btrfs_remove_ordered_extent(inode, entry);
mutex_unlock(&tree->mutex);
wake_up(&entry->wait);
return ret;
}
/*
* 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 nocow_only, int delay_iput)
{
struct list_head splice;
struct list_head *cur;
struct btrfs_ordered_extent *ordered;
struct inode *inode;
INIT_LIST_HEAD(&splice);
spin_lock(&root->fs_info->ordered_extent_lock);
list_splice_init(&root->fs_info->ordered_extents, &splice);
while (!list_empty(&splice)) {
cur = splice.next;
ordered = list_entry(cur, struct btrfs_ordered_extent,
root_extent_list);
if (nocow_only &&
!test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
list_move(&ordered->root_extent_list,
&root->fs_info->ordered_extents);
cond_resched_lock(&root->fs_info->ordered_extent_lock);
continue;
}
list_del_init(&ordered->root_extent_list);
atomic_inc(&ordered->refs);
/*
* the inode may be getting freed (in sys_unlink path).
*/
inode = igrab(ordered->inode);
spin_unlock(&root->fs_info->ordered_extent_lock);
if (inode) {
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
if (delay_iput)
btrfs_add_delayed_iput(inode);
else
iput(inode);
} else {
btrfs_put_ordered_extent(ordered);
}
spin_lock(&root->fs_info->ordered_extent_lock);
}
spin_unlock(&root->fs_info->ordered_extent_lock);
return 0;
}
/*
* this is used during transaction commit to write all the inodes
* added to the ordered operation list. These files must be fully on
* disk before the transaction commits.
*
* we have two modes here, one is to just start the IO via filemap_flush
* and the other is to wait for all the io. When we wait, we have an
* extra check to make sure the ordered operation list really is empty
* before we return
*/
int btrfs_run_ordered_operations(struct btrfs_root *root, int wait)
{
struct btrfs_inode *btrfs_inode;
struct inode *inode;
struct list_head splice;
INIT_LIST_HEAD(&splice);
mutex_lock(&root->fs_info->ordered_operations_mutex);
spin_lock(&root->fs_info->ordered_extent_lock);
again:
list_splice_init(&root->fs_info->ordered_operations, &splice);
while (!list_empty(&splice)) {
btrfs_inode = list_entry(splice.next, struct btrfs_inode,
ordered_operations);
inode = &btrfs_inode->vfs_inode;
list_del_init(&btrfs_inode->ordered_operations);
/*
* the inode may be getting freed (in sys_unlink path).
*/
inode = igrab(inode);
if (!wait && inode) {
list_add_tail(&BTRFS_I(inode)->ordered_operations,
&root->fs_info->ordered_operations);
}
spin_unlock(&root->fs_info->ordered_extent_lock);
if (inode) {
if (wait)
btrfs_wait_ordered_range(inode, 0, (u64)-1);
else
filemap_flush(inode->i_mapping);
btrfs_add_delayed_iput(inode);
}
cond_resched();
spin_lock(&root->fs_info->ordered_extent_lock);
}
if (wait && !list_empty(&root->fs_info->ordered_operations))
goto again;
spin_unlock(&root->fs_info->ordered_extent_lock);
mutex_unlock(&root->fs_info->ordered_operations_mutex);
return 0;
}
/*
* 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;
/*
* 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 pdflush to find them
*/
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)
{
u64 end;
u64 orig_end;
u64 wait_end;
struct btrfs_ordered_extent *ordered;
int found;
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);
}
wait_end = orig_end;
again:
/* start IO across the range first to instantiate any delalloc
* extents
*/
filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
/* The compression code will leave pages locked but return from
* writepage without setting the page writeback. Starting again
* with WB_SYNC_ALL will end up waiting for the IO to actually start.
*/
filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
filemap_fdatawait_range(inode->i_mapping, start, orig_end);
end = orig_end;
found = 0;
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;
}
found++;
btrfs_start_ordered_extent(inode, ordered, 1);
end = ordered->file_offset;
btrfs_put_ordered_extent(ordered);
if (end == 0 || end == start)
break;
end--;
}
if (found || test_range_bit(&BTRFS_I(inode)->io_tree, start, orig_end,
EXTENT_DELALLOC, 0, NULL)) {
schedule_timeout(1);
goto again;
}
return 0;
}
/*
* 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;
mutex_lock(&tree->mutex);
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:
mutex_unlock(&tree->mutex);
return entry;
}
/*
* 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;
mutex_lock(&tree->mutex);
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:
mutex_unlock(&tree->mutex);
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;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
u64 disk_i_size;
u64 new_i_size;
u64 i_size_test;
u64 i_size = i_size_read(inode);
struct rb_node *node;
struct rb_node *prev = NULL;
struct btrfs_ordered_extent *test;
int ret = 1;
if (ordered)
offset = entry_end(ordered);
mutex_lock(&tree->mutex);
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 || offset <= disk_i_size) {
goto out;
}
/*
* we can't update the disk_isize if there are delalloc bytes
* between disk_i_size and this ordered extent
*/
if (test_range_bit(io_tree, disk_i_size, offset - 1,
EXTENT_DELALLOC, 0, NULL)) {
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;
}
while (node) {
test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
if (test->file_offset + test->len <= disk_i_size)
break;
if (test->file_offset >= i_size)
break;
if (test->file_offset >= disk_i_size)
goto out;
node = rb_prev(node);
}
new_i_size = min_t(u64, offset, i_size);
/*
* at this point, we know we can safely update i_size to at least
* the offset from this ordered extent. But, we need to
* walk forward and see if ios from higher up in the file have
* finished.
*/
if (ordered) {
node = rb_next(&ordered->rb_node);
} else {
if (prev)
node = rb_next(prev);
else
node = rb_first(&tree->tree);
}
i_size_test = 0;
if (node) {
/*
* do we have an area where IO might have finished
* between our ordered extent and the next one.
*/
test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
if (test->file_offset > offset)
i_size_test = test->file_offset;
} else {
i_size_test = i_size;
}
/*
* i_size_test is the end of a region after this ordered
* extent where there are no ordered extents. As long as there
* are no delalloc bytes in this area, it is safe to update
* disk_i_size to the end of the region.
*/
if (i_size_test > offset &&
!test_range_bit(io_tree, offset, i_size_test - 1,
EXTENT_DELALLOC, 0, NULL)) {
new_i_size = min_t(u64, i_size_test, i_size);
}
BTRFS_I(inode)->disk_i_size = new_i_size;
ret = 0;
out:
/*
* we need to remove the ordered extent with the tree lock held
* so that other people calling this function don't find our fully
* processed ordered entry and skip updating the i_size
*/
if (ordered)
__btrfs_remove_ordered_extent(inode, ordered);
mutex_unlock(&tree->mutex);
if (ordered)
wake_up(&ordered->wait);
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)
{
struct btrfs_ordered_sum *ordered_sum;
struct btrfs_sector_sum *sector_sums;
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 ret = 1;
ordered = btrfs_lookup_ordered_extent(inode, offset);
if (!ordered)
return 1;
mutex_lock(&tree->mutex);
list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
if (disk_bytenr >= ordered_sum->bytenr) {
num_sectors = ordered_sum->len / sectorsize;
sector_sums = ordered_sum->sums;
for (i = 0; i < num_sectors; i++) {
if (sector_sums[i].bytenr == disk_bytenr) {
*sum = sector_sums[i].sum;
ret = 0;
goto out;
}
}
}
}
out:
mutex_unlock(&tree->mutex);
btrfs_put_ordered_extent(ordered);
return ret;
}
/*
* add a given inode to the list of inodes that must be fully on
* disk before a transaction commit finishes.
*
* This basically gives us the ext3 style data=ordered mode, and it is mostly
* used to make sure renamed files are fully on disk.
*
* It is a noop if the inode is already fully on disk.
*
* If trans is not null, we'll do a friendly check for a transaction that
* is already flushing things and force the IO down ourselves.
*/
int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
u64 last_mod;
last_mod = max(BTRFS_I(inode)->generation, BTRFS_I(inode)->last_trans);
/*
* if this file hasn't been changed since the last transaction
* commit, we can safely return without doing anything
*/
if (last_mod < root->fs_info->last_trans_committed)
return 0;
/*
* the transaction is already committing. Just start the IO and
* don't bother with all of this list nonsense
*/
if (trans && root->fs_info->running_transaction->blocked) {
btrfs_wait_ordered_range(inode, 0, (u64)-1);
return 0;
}
spin_lock(&root->fs_info->ordered_extent_lock);
if (list_empty(&BTRFS_I(inode)->ordered_operations)) {
list_add_tail(&BTRFS_I(inode)->ordered_operations,
&root->fs_info->ordered_operations);
}
spin_unlock(&root->fs_info->ordered_extent_lock);
return 0;
}
