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cb8e70901d
linux/fs/btrfs/inode.c
Christoph Hellwig cb8e70901d Btrfs: Fix subvolume creation locking rules 
Creating a subvolume is in many ways like a normal VFS ->mkdir, and we
really need to play with the VFS topology locking rules.  So instead of
just creating the snapshot on disk and then later getting rid of
confliting aliases do it correctly from the start.  This will become
especially important once we allow for subvolumes anywhere in the tree,
and not just below a hidden root.

Note that snapshots will need the same treatment, but do to the delay
in creating them we can't do it currently.  Chris promised to fix that
issue, so I'll wait on that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-10-09 13:39:39 -04:00

3909 lines
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/*
* 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/kernel.h>
#include <linux/bio.h>
#include <linux/buffer_head.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/backing-dev.h>
#include <linux/mpage.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
#include <linux/bit_spinlock.h>
#include <linux/version.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"
#include "volumes.h"
#include "ordered-data.h"
#include "xattr.h"
#include "compat.h"
#include "tree-log.h"
#include "ref-cache.h"
struct btrfs_iget_args {
u64 ino;
struct btrfs_root *root;
};
static struct inode_operations btrfs_dir_inode_operations;
static struct inode_operations btrfs_symlink_inode_operations;
static struct inode_operations btrfs_dir_ro_inode_operations;
static struct inode_operations btrfs_special_inode_operations;
static struct inode_operations btrfs_file_inode_operations;
static struct address_space_operations btrfs_aops;
static struct address_space_operations btrfs_symlink_aops;
static struct file_operations btrfs_dir_file_operations;
static struct extent_io_ops btrfs_extent_io_ops;
static struct kmem_cache *btrfs_inode_cachep;
struct kmem_cache *btrfs_trans_handle_cachep;
struct kmem_cache *btrfs_transaction_cachep;
struct kmem_cache *btrfs_bit_radix_cachep;
struct kmem_cache *btrfs_path_cachep;
#define S_SHIFT 12
static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
[S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
[S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
[S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
[S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
[S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
[S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
[S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
};
static void btrfs_truncate(struct inode *inode);
/*
* a very lame attempt at stopping writes when the FS is 85% full. There
* are countless ways this is incorrect, but it is better than nothing.
*/
int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
int for_del)
{
u64 total;
u64 used;
u64 thresh;
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
total = btrfs_super_total_bytes(&root->fs_info->super_copy);
used = btrfs_super_bytes_used(&root->fs_info->super_copy);
if (for_del)
thresh = total * 90;
else
thresh = total * 85;
do_div(thresh, 100);
if (used + root->fs_info->delalloc_bytes + num_required > thresh)
ret = -ENOSPC;
spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
return ret;
}
/*
* when extent_io.c finds a delayed allocation range in the file,
* the call backs end up in this code. The basic idea is to
* allocate extents on disk for the range, and create ordered data structs
* in ram to track those extents.
*/
static int cow_file_range(struct inode *inode, u64 start, u64 end)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
u64 alloc_hint = 0;
u64 num_bytes;
u64 cur_alloc_size;
u64 blocksize = root->sectorsize;
u64 orig_num_bytes;
struct btrfs_key ins;
struct extent_map *em;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
int ret = 0;
trans = btrfs_join_transaction(root, 1);
BUG_ON(!trans);
btrfs_set_trans_block_group(trans, inode);
num_bytes = (end - start + blocksize) & ~(blocksize - 1);
num_bytes = max(blocksize, num_bytes);
orig_num_bytes = num_bytes;
if (alloc_hint == EXTENT_MAP_INLINE)
goto out;
BUG_ON(num_bytes > btrfs_super_total_bytes(&root->fs_info->super_copy));
mutex_lock(&BTRFS_I(inode)->extent_mutex);
btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
while(num_bytes > 0) {
cur_alloc_size = min(num_bytes, root->fs_info->max_extent);
ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
root->sectorsize, 0, alloc_hint,
(u64)-1, &ins, 1);
if (ret) {
WARN_ON(1);
goto out;
}
em = alloc_extent_map(GFP_NOFS);
em->start = start;
em->len = ins.offset;
em->block_start = ins.objectid;
em->bdev = root->fs_info->fs_devices->latest_bdev;
mutex_lock(&BTRFS_I(inode)->extent_mutex);
set_bit(EXTENT_FLAG_PINNED, &em->flags);
while(1) {
spin_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
spin_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
}
btrfs_drop_extent_cache(inode, start,
start + ins.offset - 1, 0);
}
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
cur_alloc_size = ins.offset;
ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
ins.offset, 0);
BUG_ON(ret);
if (num_bytes < cur_alloc_size) {
printk("num_bytes %Lu cur_alloc %Lu\n", num_bytes,
cur_alloc_size);
break;
}
num_bytes -= cur_alloc_size;
alloc_hint = ins.objectid + ins.offset;
start += cur_alloc_size;
}
out:
btrfs_end_transaction(trans, root);
return ret;
}
/*
* when nowcow writeback call back. This checks for snapshots or COW copies
* of the extents that exist in the file, and COWs the file as required.
*
* If no cow copies or snapshots exist, we write directly to the existing
* blocks on disk
*/
static int run_delalloc_nocow(struct inode *inode, u64 start, u64 end)
{
u64 extent_start;
u64 extent_end;
u64 bytenr;
u64 loops = 0;
u64 total_fs_bytes;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_group_cache *block_group;
struct btrfs_trans_handle *trans;
struct extent_buffer *leaf;
int found_type;
struct btrfs_path *path;
struct btrfs_file_extent_item *item;
int ret;
int err = 0;
struct btrfs_key found_key;
total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
path = btrfs_alloc_path();
BUG_ON(!path);
trans = btrfs_join_transaction(root, 1);
BUG_ON(!trans);
again:
ret = btrfs_lookup_file_extent(NULL, root, path,
inode->i_ino, start, 0);
if (ret < 0) {
err = ret;
goto out;
}
if (ret != 0) {
if (path->slots[0] == 0)
goto not_found;
path->slots[0]--;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
/* are we inside the extent that was found? */
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = btrfs_key_type(&found_key);
if (found_key.objectid != inode->i_ino ||
found_type != BTRFS_EXTENT_DATA_KEY)
goto not_found;
found_type = btrfs_file_extent_type(leaf, item);
extent_start = found_key.offset;
if (found_type == BTRFS_FILE_EXTENT_REG) {
u64 extent_num_bytes;
extent_num_bytes = btrfs_file_extent_num_bytes(leaf, item);
extent_end = extent_start + extent_num_bytes;
err = 0;
if (loops && start != extent_start)
goto not_found;
if (start < extent_start || start >= extent_end)
goto not_found;
bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
if (bytenr == 0)
goto not_found;
if (btrfs_cross_ref_exists(trans, root, &found_key, bytenr))
goto not_found;
/*
* we may be called by the resizer, make sure we're inside
* the limits of the FS
*/
block_group = btrfs_lookup_block_group(root->fs_info,
bytenr);
if (!block_group || block_group->ro)
goto not_found;
bytenr += btrfs_file_extent_offset(leaf, item);
extent_num_bytes = min(end + 1, extent_end) - start;
ret = btrfs_add_ordered_extent(inode, start, bytenr,
extent_num_bytes, 1);
if (ret) {
err = ret;
goto out;
}
btrfs_release_path(root, path);
start = extent_end;
if (start <= end) {
loops++;
goto again;
}
} else {
not_found:
btrfs_end_transaction(trans, root);
btrfs_free_path(path);
return cow_file_range(inode, start, end);
}
out:
WARN_ON(err);
btrfs_end_transaction(trans, root);
btrfs_free_path(path);
return err;
}
/*
* extent_io.c call back to do delayed allocation processing
*/
static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
if (btrfs_test_opt(root, NODATACOW) ||
btrfs_test_flag(inode, NODATACOW))
ret = run_delalloc_nocow(inode, start, end);
else
ret = cow_file_range(inode, start, end);
return ret;
}
/*
* extent_io.c set_bit_hook, used to track delayed allocation
* bytes in this file, and to maintain the list of inodes that
* have pending delalloc work to be done.
*/
int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
unsigned long old, unsigned long bits)
{
unsigned long flags;
if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
BTRFS_I(inode)->delalloc_bytes += end - start + 1;
root->fs_info->delalloc_bytes += end - start + 1;
if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
&root->fs_info->delalloc_inodes);
}
spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
}
return 0;
}
/*
* extent_io.c clear_bit_hook, see set_bit_hook for why
*/
int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end,
unsigned long old, unsigned long bits)
{
if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
unsigned long flags;
spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
if (end - start + 1 > root->fs_info->delalloc_bytes) {
printk("warning: delalloc account %Lu %Lu\n",
end - start + 1, root->fs_info->delalloc_bytes);
root->fs_info->delalloc_bytes = 0;
BTRFS_I(inode)->delalloc_bytes = 0;
} else {
root->fs_info->delalloc_bytes -= end - start + 1;
BTRFS_I(inode)->delalloc_bytes -= end - start + 1;
}
if (BTRFS_I(inode)->delalloc_bytes == 0 &&
!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_del_init(&BTRFS_I(inode)->delalloc_inodes);
}
spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
}
return 0;
}
/*
* extent_io.c merge_bio_hook, this must check the chunk tree to make sure
* we don't create bios that span stripes or chunks
*/
int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
size_t size, struct bio *bio)
{
struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
struct btrfs_mapping_tree *map_tree;
u64 logical = (u64)bio->bi_sector << 9;
u64 length = 0;
u64 map_length;
int ret;
length = bio->bi_size;
map_tree = &root->fs_info->mapping_tree;
map_length = length;
ret = btrfs_map_block(map_tree, READ, logical,
&map_length, NULL, 0);
if (map_length < length + size) {
return 1;
}
return 0;
}
/*
* in order to insert checksums into the metadata in large chunks,
* we wait until bio submission time. All the pages in the bio are
* checksummed and sums are attached onto the ordered extent record.
*
* At IO completion time the cums attached on the ordered extent record
* are inserted into the btree
*/
int __btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
int mirror_num)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret = 0;
ret = btrfs_csum_one_bio(root, inode, bio);
BUG_ON(ret);
return btrfs_map_bio(root, rw, bio, mirror_num, 1);
}
/*
* extent_io.c submission hook. This does the right thing for csum calculation on write,
* or reading the csums from the tree before a read
*/
int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
int mirror_num)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret = 0;
ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
BUG_ON(ret);
if (btrfs_test_opt(root, NODATASUM) ||
btrfs_test_flag(inode, NODATASUM)) {
goto mapit;
}
if (!(rw & (1 << BIO_RW))) {
btrfs_lookup_bio_sums(root, inode, bio);
goto mapit;
}
return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
inode, rw, bio, mirror_num,
__btrfs_submit_bio_hook);
mapit:
return btrfs_map_bio(root, rw, bio, mirror_num, 0);
}
/*
* given a list of ordered sums record them in the inode. This happens
* at IO completion time based on sums calculated at bio submission time.
*/
static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
struct inode *inode, u64 file_offset,
struct list_head *list)
{
struct list_head *cur;
struct btrfs_ordered_sum *sum;
btrfs_set_trans_block_group(trans, inode);
list_for_each(cur, list) {
sum = list_entry(cur, struct btrfs_ordered_sum, list);
btrfs_csum_file_blocks(trans, BTRFS_I(inode)->root,
inode, sum);
}
return 0;
}
int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end)
{
return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
GFP_NOFS);
}
/* see btrfs_writepage_start_hook for details on why this is required */
struct btrfs_writepage_fixup {
struct page *page;
struct btrfs_work work;
};
void btrfs_writepage_fixup_worker(struct btrfs_work *work)
{
struct btrfs_writepage_fixup *fixup;
struct btrfs_ordered_extent *ordered;
struct page *page;
struct inode *inode;
u64 page_start;
u64 page_end;
fixup = container_of(work, struct btrfs_writepage_fixup, work);
page = fixup->page;
again:
lock_page(page);
if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
ClearPageChecked(page);
goto out_page;
}
inode = page->mapping->host;
page_start = page_offset(page);
page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
/* already ordered? We're done */
if (test_range_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
EXTENT_ORDERED, 0)) {
goto out;
}
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
unlock_extent(&BTRFS_I(inode)->io_tree, page_start,
page_end, GFP_NOFS);
unlock_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
goto again;
}
btrfs_set_extent_delalloc(inode, page_start, page_end);
ClearPageChecked(page);
out:
unlock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
out_page:
unlock_page(page);
page_cache_release(page);
}
/*
* There are a few paths in the higher layers of the kernel that directly
* set the page dirty bit without asking the filesystem if it is a
* good idea. This causes problems because we want to make sure COW
* properly happens and the data=ordered rules are followed.
*
* In our case any range that doesn't have the EXTENT_ORDERED bit set
* hasn't been properly setup for IO. We kick off an async process
* to fix it up. The async helper will wait for ordered extents, set
* the delalloc bit and make it safe to write the page.
*/
int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
{
struct inode *inode = page->mapping->host;
struct btrfs_writepage_fixup *fixup;
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
ret = test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
EXTENT_ORDERED, 0);
if (ret)
return 0;
if (PageChecked(page))
return -EAGAIN;
fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
if (!fixup)
return -EAGAIN;
SetPageChecked(page);
page_cache_get(page);
fixup->work.func = btrfs_writepage_fixup_worker;
fixup->page = page;
btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
return -EAGAIN;
}
/* as ordered data IO finishes, this gets called so we can finish
* an ordered extent if the range of bytes in the file it covers are
* fully written.
*/
static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
struct btrfs_ordered_extent *ordered_extent;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_file_extent_item *extent_item;
struct btrfs_path *path = NULL;
struct extent_buffer *leaf;
u64 alloc_hint = 0;
struct list_head list;
struct btrfs_key ins;
int ret;
ret = btrfs_dec_test_ordered_pending(inode, start, end - start + 1);
if (!ret)
return 0;
trans = btrfs_join_transaction(root, 1);
ordered_extent = btrfs_lookup_ordered_extent(inode, start);
BUG_ON(!ordered_extent);
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags))
goto nocow;
path = btrfs_alloc_path();
BUG_ON(!path);
lock_extent(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
GFP_NOFS);
INIT_LIST_HEAD(&list);
mutex_lock(&BTRFS_I(inode)->extent_mutex);
ret = btrfs_drop_extents(trans, root, inode,
ordered_extent->file_offset,
ordered_extent->file_offset +
ordered_extent->len,
ordered_extent->file_offset, &alloc_hint);
BUG_ON(ret);
ins.objectid = inode->i_ino;
ins.offset = ordered_extent->file_offset;
ins.type = BTRFS_EXTENT_DATA_KEY;
ret = btrfs_insert_empty_item(trans, root, path, &ins,
sizeof(*extent_item));
BUG_ON(ret);
leaf = path->nodes[0];
extent_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, extent_item, trans->transid);
btrfs_set_file_extent_type(leaf, extent_item, BTRFS_FILE_EXTENT_REG);
btrfs_set_file_extent_disk_bytenr(leaf, extent_item,
ordered_extent->start);
btrfs_set_file_extent_disk_num_bytes(leaf, extent_item,
ordered_extent->len);
btrfs_set_file_extent_offset(leaf, extent_item, 0);
btrfs_set_file_extent_num_bytes(leaf, extent_item,
ordered_extent->len);
btrfs_mark_buffer_dirty(leaf);
btrfs_drop_extent_cache(inode, ordered_extent->file_offset,
ordered_extent->file_offset +
ordered_extent->len - 1, 0);
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
ins.objectid = ordered_extent->start;
ins.offset = ordered_extent->len;
ins.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_alloc_reserved_extent(trans, root, leaf->start,
root->root_key.objectid,
trans->transid, inode->i_ino, &ins);
BUG_ON(ret);
btrfs_release_path(root, path);
inode_add_bytes(inode, ordered_extent->len);
unlock_extent(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
GFP_NOFS);
nocow:
add_pending_csums(trans, inode, ordered_extent->file_offset,
&ordered_extent->list);
mutex_lock(&BTRFS_I(inode)->extent_mutex);
btrfs_ordered_update_i_size(inode, ordered_extent);
btrfs_update_inode(trans, root, inode);
btrfs_remove_ordered_extent(inode, ordered_extent);
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
/* once for us */
btrfs_put_ordered_extent(ordered_extent);
/* once for the tree */
btrfs_put_ordered_extent(ordered_extent);
btrfs_end_transaction(trans, root);
if (path)
btrfs_free_path(path);
return 0;
}
int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
struct extent_state *state, int uptodate)
{
return btrfs_finish_ordered_io(page->mapping->host, start, end);
}
/*
* When IO fails, either with EIO or csum verification fails, we
* try other mirrors that might have a good copy of the data. This
* io_failure_record is used to record state as we go through all the
* mirrors. If another mirror has good data, the page is set up to date
* and things continue. If a good mirror can't be found, the original
* bio end_io callback is called to indicate things have failed.
*/
struct io_failure_record {
struct page *page;
u64 start;
u64 len;
u64 logical;
int last_mirror;
};
int btrfs_io_failed_hook(struct bio *failed_bio,
struct page *page, u64 start, u64 end,
struct extent_state *state)
{
struct io_failure_record *failrec = NULL;
u64 private;
struct extent_map *em;
struct inode *inode = page->mapping->host;
struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct bio *bio;
int num_copies;
int ret;
int rw;
u64 logical;
ret = get_state_private(failure_tree, start, &private);
if (ret) {
failrec = kmalloc(sizeof(*failrec), GFP_NOFS);
if (!failrec)
return -ENOMEM;
failrec->start = start;
failrec->len = end - start + 1;
failrec->last_mirror = 0;
spin_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, failrec->len);
if (em->start > start || em->start + em->len < start) {
free_extent_map(em);
em = NULL;
}
spin_unlock(&em_tree->lock);
if (!em || IS_ERR(em)) {
kfree(failrec);
return -EIO;
}
logical = start - em->start;
logical = em->block_start + logical;
failrec->logical = logical;
free_extent_map(em);
set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
EXTENT_DIRTY, GFP_NOFS);
set_state_private(failure_tree, start,
(u64)(unsigned long)failrec);
} else {
failrec = (struct io_failure_record *)(unsigned long)private;
}
num_copies = btrfs_num_copies(
&BTRFS_I(inode)->root->fs_info->mapping_tree,
failrec->logical, failrec->len);
failrec->last_mirror++;
if (!state) {
spin_lock_irq(&BTRFS_I(inode)->io_tree.lock);
state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
failrec->start,
EXTENT_LOCKED);
if (state && state->start != failrec->start)
state = NULL;
spin_unlock_irq(&BTRFS_I(inode)->io_tree.lock);
}
if (!state || failrec->last_mirror > num_copies) {
set_state_private(failure_tree, failrec->start, 0);
clear_extent_bits(failure_tree, failrec->start,
failrec->start + failrec->len - 1,
EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
kfree(failrec);
return -EIO;
}
bio = bio_alloc(GFP_NOFS, 1);
bio->bi_private = state;
bio->bi_end_io = failed_bio->bi_end_io;
bio->bi_sector = failrec->logical >> 9;
bio->bi_bdev = failed_bio->bi_bdev;
bio->bi_size = 0;
bio_add_page(bio, page, failrec->len, start - page_offset(page));
if (failed_bio->bi_rw & (1 << BIO_RW))
rw = WRITE;
else
rw = READ;
BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio,
failrec->last_mirror);
return 0;
}
/*
* each time an IO finishes, we do a fast check in the IO failure tree
* to see if we need to process or clean up an io_failure_record
*/
int btrfs_clean_io_failures(struct inode *inode, u64 start)
{
u64 private;
u64 private_failure;
struct io_failure_record *failure;
int ret;
private = 0;
if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
(u64)-1, 1, EXTENT_DIRTY)) {
ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
start, &private_failure);
if (ret == 0) {
failure = (struct io_failure_record *)(unsigned long)
private_failure;
set_state_private(&BTRFS_I(inode)->io_failure_tree,
failure->start, 0);
clear_extent_bits(&BTRFS_I(inode)->io_failure_tree,
failure->start,
failure->start + failure->len - 1,
EXTENT_DIRTY | EXTENT_LOCKED,
GFP_NOFS);
kfree(failure);
}
}
return 0;
}
/*
* when reads are done, we need to check csums to verify the data is correct
* if there's a match, we allow the bio to finish. If not, we go through
* the io_failure_record routines to find good copies
*/
int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
struct extent_state *state)
{
size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
struct inode *inode = page->mapping->host;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
char *kaddr;
u64 private = ~(u32)0;
int ret;
struct btrfs_root *root = BTRFS_I(inode)->root;
u32 csum = ~(u32)0;
unsigned long flags;
if (btrfs_test_opt(root, NODATASUM) ||
btrfs_test_flag(inode, NODATASUM))
return 0;
if (state && state->start == start) {
private = state->private;
ret = 0;
} else {
ret = get_state_private(io_tree, start, &private);
}
local_irq_save(flags);
kaddr = kmap_atomic(page, KM_IRQ0);
if (ret) {
goto zeroit;
}
csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
btrfs_csum_final(csum, (char *)&csum);
if (csum != private) {
goto zeroit;
}
kunmap_atomic(kaddr, KM_IRQ0);
local_irq_restore(flags);
/* if the io failure tree for this inode is non-empty,
* check to see if we've recovered from a failed IO
*/
btrfs_clean_io_failures(inode, start);
return 0;
zeroit:
printk("btrfs csum failed ino %lu off %llu csum %u private %Lu\n",
page->mapping->host->i_ino, (unsigned long long)start, csum,
private);
memset(kaddr + offset, 1, end - start + 1);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_IRQ0);
local_irq_restore(flags);
if (private == 0)
return 0;
return -EIO;
}
/*
* This creates an orphan entry for the given inode in case something goes
* wrong in the middle of an unlink/truncate.
*/
int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret = 0;
spin_lock(&root->list_lock);
/* already on the orphan list, we're good */
if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
spin_unlock(&root->list_lock);
return 0;
}
list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
spin_unlock(&root->list_lock);
/*
* insert an orphan item to track this unlinked/truncated file
*/
ret = btrfs_insert_orphan_item(trans, root, inode->i_ino);
return ret;
}
/*
* We have done the truncate/delete so we can go ahead and remove the orphan
* item for this particular inode.
*/
int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret = 0;
spin_lock(&root->list_lock);
if (list_empty(&BTRFS_I(inode)->i_orphan)) {
spin_unlock(&root->list_lock);
return 0;
}
list_del_init(&BTRFS_I(inode)->i_orphan);
if (!trans) {
spin_unlock(&root->list_lock);
return 0;
}
spin_unlock(&root->list_lock);
ret = btrfs_del_orphan_item(trans, root, inode->i_ino);
return ret;
}
/*
* this cleans up any orphans that may be left on the list from the last use
* of this root.
*/
void btrfs_orphan_cleanup(struct btrfs_root *root)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_item *item;
struct btrfs_key key, found_key;
struct btrfs_trans_handle *trans;
struct inode *inode;
int ret = 0, nr_unlink = 0, nr_truncate = 0;
/* don't do orphan cleanup if the fs is readonly. */
if (root->fs_info->sb->s_flags & MS_RDONLY)
return;
path = btrfs_alloc_path();
if (!path)
return;
path->reada = -1;
key.objectid = BTRFS_ORPHAN_OBJECTID;
btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
printk(KERN_ERR "Error searching slot for orphan: %d"
"\n", ret);
break;
}
/*
* if ret == 0 means we found what we were searching for, which
* is weird, but possible, so only screw with path if we didnt
* find the key and see if we have stuff that matches
*/
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
/* pull out the item */
leaf = path->nodes[0];
item = btrfs_item_nr(leaf, path->slots[0]);
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
/* make sure the item matches what we want */
if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
break;
if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
break;
/* release the path since we're done with it */
btrfs_release_path(root, path);
/*
* this is where we are basically btrfs_lookup, without the
* crossing root thing. we store the inode number in the
* offset of the orphan item.
*/
inode = btrfs_iget_locked(root->fs_info->sb,
found_key.offset, root);
if (!inode)
break;
if (inode->i_state & I_NEW) {
BTRFS_I(inode)->root = root;
/* have to set the location manually */
BTRFS_I(inode)->location.objectid = inode->i_ino;
BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
BTRFS_I(inode)->location.offset = 0;
btrfs_read_locked_inode(inode);
unlock_new_inode(inode);
}
/*
* add this inode to the orphan list so btrfs_orphan_del does
* the proper thing when we hit it
*/
spin_lock(&root->list_lock);
list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
spin_unlock(&root->list_lock);
/*
* if this is a bad inode, means we actually succeeded in
* removing the inode, but not the orphan record, which means
* we need to manually delete the orphan since iput will just
* do a destroy_inode
*/
if (is_bad_inode(inode)) {
trans = btrfs_start_transaction(root, 1);
btrfs_orphan_del(trans, inode);
btrfs_end_transaction(trans, root);
iput(inode);
continue;
}
/* if we have links, this was a truncate, lets do that */
if (inode->i_nlink) {
nr_truncate++;
btrfs_truncate(inode);
} else {
nr_unlink++;
}
/* this will do delete_inode and everything for us */
iput(inode);
}
if (nr_unlink)
printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
if (nr_truncate)
printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
btrfs_free_path(path);
}
/*
* read an inode from the btree into the in-memory inode
*/
void btrfs_read_locked_inode(struct inode *inode)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_inode_item *inode_item;
struct btrfs_timespec *tspec;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key location;
u64 alloc_group_block;
u32 rdev;
int ret;
path = btrfs_alloc_path();
BUG_ON(!path);
memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
if (ret)
goto make_bad;
leaf = path->nodes[0];
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
inode->i_mode = btrfs_inode_mode(leaf, inode_item);
inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
inode->i_uid = btrfs_inode_uid(leaf, inode_item);
inode->i_gid = btrfs_inode_gid(leaf, inode_item);
btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
tspec = btrfs_inode_atime(inode_item);
inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
tspec = btrfs_inode_mtime(inode_item);
inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
tspec = btrfs_inode_ctime(inode_item);
inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
inode->i_generation = BTRFS_I(inode)->generation;
inode->i_rdev = 0;
rdev = btrfs_inode_rdev(leaf, inode_item);
BTRFS_I(inode)->index_cnt = (u64)-1;
alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
alloc_group_block);
BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
if (!BTRFS_I(inode)->block_group) {
BTRFS_I(inode)->block_group = btrfs_find_block_group(root,
NULL, 0,
BTRFS_BLOCK_GROUP_METADATA, 0);
}
btrfs_free_path(path);
inode_item = NULL;
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
inode->i_mapping->a_ops = &btrfs_aops;
inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
break;
case S_IFDIR:
inode->i_fop = &btrfs_dir_file_operations;
if (root == root->fs_info->tree_root)
inode->i_op = &btrfs_dir_ro_inode_operations;
else
inode->i_op = &btrfs_dir_inode_operations;
break;
case S_IFLNK:
inode->i_op = &btrfs_symlink_inode_operations;
inode->i_mapping->a_ops = &btrfs_symlink_aops;
inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
break;
default:
init_special_inode(inode, inode->i_mode, rdev);
break;
}
return;
make_bad:
btrfs_free_path(path);
make_bad_inode(inode);
}
/*
* given a leaf and an inode, copy the inode fields into the leaf
*/
static void fill_inode_item(struct btrfs_trans_handle *trans,
struct extent_buffer *leaf,
struct btrfs_inode_item *item,
struct inode *inode)
{
btrfs_set_inode_uid(leaf, item, inode->i_uid);
btrfs_set_inode_gid(leaf, item, inode->i_gid);
btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
btrfs_set_inode_mode(leaf, item, inode->i_mode);
btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
inode->i_atime.tv_sec);
btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
inode->i_atime.tv_nsec);
btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
inode->i_mtime.tv_sec);
btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
inode->i_mtime.tv_nsec);
btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
inode->i_ctime.tv_sec);
btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
inode->i_ctime.tv_nsec);
btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
btrfs_set_inode_transid(leaf, item, trans->transid);
btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
btrfs_set_inode_block_group(leaf, item,
BTRFS_I(inode)->block_group->key.objectid);
}
/*
* copy everything in the in-memory inode into the btree.
*/
int noinline btrfs_update_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_inode_item *inode_item;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_lookup_inode(trans, root, path,
&BTRFS_I(inode)->location, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto failed;
}
leaf = path->nodes[0];
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, leaf, inode_item, inode);
btrfs_mark_buffer_dirty(leaf);
btrfs_set_inode_last_trans(trans, inode);
ret = 0;
failed:
btrfs_free_path(path);
return ret;
}
/*
* unlink helper that gets used here in inode.c and in the tree logging
* recovery code. It remove a link in a directory with a given name, and
* also drops the back refs in the inode to the directory
*/
int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir, struct inode *inode,
const char *name, int name_len)
{
struct btrfs_path *path;
int ret = 0;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key key;
u64 index;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto err;
}
di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
name, name_len, -1);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto err;
}
if (!di) {
ret = -ENOENT;
goto err;
}
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &key);
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret)
goto err;
btrfs_release_path(root, path);
ret = btrfs_del_inode_ref(trans, root, name, name_len,
inode->i_ino,
dir->i_ino, &index);
if (ret) {
printk("failed to delete reference to %.*s, "
"inode %lu parent %lu\n", name_len, name,
inode->i_ino, dir->i_ino);
goto err;
}
di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
index, name, name_len, -1);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto err;
}
if (!di) {
ret = -ENOENT;
goto err;
}
ret = btrfs_delete_one_dir_name(trans, root, path, di);
btrfs_release_path(root, path);
ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
inode, dir->i_ino);
BUG_ON(ret != 0 && ret != -ENOENT);
if (ret != -ENOENT)
BTRFS_I(dir)->log_dirty_trans = trans->transid;
ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
dir, index);
BUG_ON(ret);
err:
btrfs_free_path(path);
if (ret)
goto out;
btrfs_i_size_write(dir, dir->i_size - name_len * 2);
inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
btrfs_update_inode(trans, root, dir);
btrfs_drop_nlink(inode);
ret = btrfs_update_inode(trans, root, inode);
dir->i_sb->s_dirt = 1;
out:
return ret;
}
static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
struct btrfs_root *root;
struct btrfs_trans_handle *trans;
struct inode *inode = dentry->d_inode;
int ret;
unsigned long nr = 0;
root = BTRFS_I(dir)->root;
ret = btrfs_check_free_space(root, 1, 1);
if (ret)
goto fail;
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
dentry->d_name.name, dentry->d_name.len);
if (inode->i_nlink == 0)
ret = btrfs_orphan_add(trans, inode);
nr = trans->blocks_used;
btrfs_end_transaction_throttle(trans, root);
fail:
btrfs_btree_balance_dirty(root, nr);
return ret;
}
static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
int err = 0;
int ret;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_trans_handle *trans;
unsigned long nr = 0;
if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
return -ENOTEMPTY;
}
ret = btrfs_check_free_space(root, 1, 1);
if (ret)
goto fail;
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
err = btrfs_orphan_add(trans, inode);
if (err)
goto fail_trans;
/* now the directory is empty */
err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
dentry->d_name.name, dentry->d_name.len);
if (!err) {
btrfs_i_size_write(inode, 0);
}
fail_trans:
nr = trans->blocks_used;
ret = btrfs_end_transaction_throttle(trans, root);
fail:
btrfs_btree_balance_dirty(root, nr);
if (ret && !err)
err = ret;
return err;
}
/*
* when truncating bytes in a file, it is possible to avoid reading
* the leaves that contain only checksum items. This can be the
* majority of the IO required to delete a large file, but it must
* be done carefully.
*
* The keys in the level just above the leaves are checked to make sure
* the lowest key in a given leaf is a csum key, and starts at an offset
* after the new size.
*
* Then the key for the next leaf is checked to make sure it also has
* a checksum item for the same file. If it does, we know our target leaf
* contains only checksum items, and it can be safely freed without reading
* it.
*
* This is just an optimization targeted at large files. It may do
* nothing. It will return 0 unless things went badly.
*/
static noinline int drop_csum_leaves(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct inode *inode, u64 new_size)
{
struct btrfs_key key;
int ret;
int nritems;
struct btrfs_key found_key;
struct btrfs_key other_key;
struct btrfs_leaf_ref *ref;
u64 leaf_gen;
u64 leaf_start;
path->lowest_level = 1;
key.objectid = inode->i_ino;
key.type = BTRFS_CSUM_ITEM_KEY;
key.offset = new_size;
again:
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (path->nodes[1] == NULL) {
ret = 0;
goto out;
}
ret = 0;
btrfs_node_key_to_cpu(path->nodes[1], &found_key, path->slots[1]);
nritems = btrfs_header_nritems(path->nodes[1]);
if (!nritems)
goto out;
if (path->slots[1] >= nritems)
goto next_node;
/* did we find a key greater than anything we want to delete? */
if (found_key.objectid > inode->i_ino ||
(found_key.objectid == inode->i_ino && found_key.type > key.type))
goto out;
/* we check the next key in the node to make sure the leave contains
* only checksum items. This comparison doesn't work if our
* leaf is the last one in the node
*/
if (path->slots[1] + 1 >= nritems) {
next_node:
/* search forward from the last key in the node, this
* will bring us into the next node in the tree
*/
btrfs_node_key_to_cpu(path->nodes[1], &found_key, nritems - 1);
/* unlikely, but we inc below, so check to be safe */
if (found_key.offset == (u64)-1)
goto out;
/* search_forward needs a path with locks held, do the
* search again for the original key. It is possible
* this will race with a balance and return a path that
* we could modify, but this drop is just an optimization
* and is allowed to miss some leaves.
*/
btrfs_release_path(root, path);
found_key.offset++;
/* setup a max key for search_forward */
other_key.offset = (u64)-1;
other_key.type = key.type;
other_key.objectid = key.objectid;
path->keep_locks = 1;
ret = btrfs_search_forward(root, &found_key, &other_key,
path, 0, 0);
path->keep_locks = 0;
if (ret || found_key.objectid != key.objectid ||
found_key.type != key.type) {
ret = 0;
goto out;
}
key.offset = found_key.offset;
btrfs_release_path(root, path);
cond_resched();
goto again;
}
/* we know there's one more slot after us in the tree,
* read that key so we can verify it is also a checksum item
*/
btrfs_node_key_to_cpu(path->nodes[1], &other_key, path->slots[1] + 1);
if (found_key.objectid < inode->i_ino)
goto next_key;
if (found_key.type != key.type || found_key.offset < new_size)
goto next_key;
/*
* if the key for the next leaf isn't a csum key from this objectid,
* we can't be sure there aren't good items inside this leaf.
* Bail out
*/
if (other_key.objectid != inode->i_ino || other_key.type != key.type)
goto out;
leaf_start = btrfs_node_blockptr(path->nodes[1], path->slots[1]);
leaf_gen = btrfs_node_ptr_generation(path->nodes[1], path->slots[1]);
/*
* it is safe to delete this leaf, it contains only
* csum items from this inode at an offset >= new_size
*/
ret = btrfs_del_leaf(trans, root, path, leaf_start);
BUG_ON(ret);
if (root->ref_cows && leaf_gen < trans->transid) {
ref = btrfs_alloc_leaf_ref(root, 0);
if (ref) {
ref->root_gen = root->root_key.offset;
ref->bytenr = leaf_start;
ref->owner = 0;
ref->generation = leaf_gen;
ref->nritems = 0;
ret = btrfs_add_leaf_ref(root, ref, 0);
WARN_ON(ret);
btrfs_free_leaf_ref(root, ref);
} else {
WARN_ON(1);
}
}
next_key:
btrfs_release_path(root, path);
if (other_key.objectid == inode->i_ino &&
other_key.type == key.type && other_key.offset > key.offset) {
key.offset = other_key.offset;
cond_resched();
goto again;
}
ret = 0;
out:
/* fixup any changes we've made to the path */
path->lowest_level = 0;
path->keep_locks = 0;
btrfs_release_path(root, path);
return ret;
}
/*
* this can truncate away extent items, csum items and directory items.
* It starts at a high offset and removes keys until it can't find
* any higher than new_size
*
* csum items that cross the new i_size are truncated to the new size
* as well.
*
* min_type is the minimum key type to truncate down to. If set to 0, this
* will kill all the items on this inode, including the INODE_ITEM_KEY.
*/
noinline int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode,
u64 new_size, u32 min_type)
{
int ret;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_key found_key;
u32 found_type;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
u64 extent_start = 0;
u64 extent_num_bytes = 0;
u64 item_end = 0;
u64 root_gen = 0;
u64 root_owner = 0;
int found_extent;
int del_item;
int pending_del_nr = 0;
int pending_del_slot = 0;
int extent_type = -1;
u64 mask = root->sectorsize - 1;
if (root->ref_cows)
btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
path = btrfs_alloc_path();
path->reada = -1;
BUG_ON(!path);
/* FIXME, add redo link to tree so we don't leak on crash */
key.objectid = inode->i_ino;
key.offset = (u64)-1;
key.type = (u8)-1;
btrfs_init_path(path);
ret = drop_csum_leaves(trans, root, path, inode, new_size);
BUG_ON(ret);
search_again:
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
goto error;
}
if (ret > 0) {
/* there are no items in the tree for us to truncate, we're
* done
*/
if (path->slots[0] == 0) {
ret = 0;
goto error;
}
path->slots[0]--;
}
while(1) {
fi = NULL;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = btrfs_key_type(&found_key);
if (found_key.objectid != inode->i_ino)
break;
if (found_type < min_type)
break;
item_end = found_key.offset;
if (found_type == BTRFS_EXTENT_DATA_KEY) {
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
item_end +=
btrfs_file_extent_num_bytes(leaf, fi);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
struct btrfs_item *item = btrfs_item_nr(leaf,
path->slots[0]);
item_end += btrfs_file_extent_inline_len(leaf,
item);
}
item_end--;
}
if (found_type == BTRFS_CSUM_ITEM_KEY) {
ret = btrfs_csum_truncate(trans, root, path,
new_size);
BUG_ON(ret);
}
if (item_end < new_size) {
if (found_type == BTRFS_DIR_ITEM_KEY) {
found_type = BTRFS_INODE_ITEM_KEY;
} else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
found_type = BTRFS_CSUM_ITEM_KEY;
} else if (found_type == BTRFS_EXTENT_DATA_KEY) {
found_type = BTRFS_XATTR_ITEM_KEY;
} else if (found_type == BTRFS_XATTR_ITEM_KEY) {
found_type = BTRFS_INODE_REF_KEY;
} else if (found_type) {
found_type--;
} else {
break;
}
btrfs_set_key_type(&key, found_type);
goto next;
}
if (found_key.offset >= new_size)
del_item = 1;
else
del_item = 0;
found_extent = 0;
/* FIXME, shrink the extent if the ref count is only 1 */
if (found_type != BTRFS_EXTENT_DATA_KEY)
goto delete;
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
u64 num_dec;
extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
if (!del_item) {
u64 orig_num_bytes =
btrfs_file_extent_num_bytes(leaf, fi);
extent_num_bytes = new_size -
found_key.offset + root->sectorsize - 1;
extent_num_bytes = extent_num_bytes &
~((u64)root->sectorsize - 1);
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_num_bytes);
num_dec = (orig_num_bytes -
extent_num_bytes);
if (root->ref_cows && extent_start != 0)
inode_sub_bytes(inode, num_dec);
btrfs_mark_buffer_dirty(leaf);
} else {
extent_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf,
fi);
/* FIXME blocksize != 4096 */
num_dec = btrfs_file_extent_num_bytes(leaf, fi);
if (extent_start != 0) {
found_extent = 1;
if (root->ref_cows)
inode_sub_bytes(inode, num_dec);
}
root_gen = btrfs_header_generation(leaf);
root_owner = btrfs_header_owner(leaf);
}
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
if (!del_item) {
u32 size = new_size - found_key.offset;
if (root->ref_cows) {
inode_sub_bytes(inode, item_end + 1 -
new_size);
}
size =
btrfs_file_extent_calc_inline_size(size);
ret = btrfs_truncate_item(trans, root, path,
size, 1);
BUG_ON(ret);
} else if (root->ref_cows) {
inode_sub_bytes(inode, item_end + 1 -
found_key.offset);
}
}
delete:
if (del_item) {
if (!pending_del_nr) {
/* no pending yet, add ourselves */
pending_del_slot = path->slots[0];
pending_del_nr = 1;
} else if (pending_del_nr &&
path->slots[0] + 1 == pending_del_slot) {
/* hop on the pending chunk */
pending_del_nr++;
pending_del_slot = path->slots[0];
} else {
printk("bad pending slot %d pending_del_nr %d pending_del_slot %d\n", path->slots[0], pending_del_nr, pending_del_slot);
}
} else {
break;
}
if (found_extent) {
ret = btrfs_free_extent(trans, root, extent_start,
extent_num_bytes,
leaf->start, root_owner,
root_gen, inode->i_ino, 0);
BUG_ON(ret);
}
next:
if (path->slots[0] == 0) {
if (pending_del_nr)
goto del_pending;
btrfs_release_path(root, path);
goto search_again;
}
path->slots[0]--;
if (pending_del_nr &&
path->slots[0] + 1 != pending_del_slot) {
struct btrfs_key debug;
del_pending:
btrfs_item_key_to_cpu(path->nodes[0], &debug,
pending_del_slot);
ret = btrfs_del_items(trans, root, path,
pending_del_slot,
pending_del_nr);
BUG_ON(ret);
pending_del_nr = 0;
btrfs_release_path(root, path);
goto search_again;
}
}
ret = 0;
error:
if (pending_del_nr) {
ret = btrfs_del_items(trans, root, path, pending_del_slot,
pending_del_nr);
}
btrfs_free_path(path);
inode->i_sb->s_dirt = 1;
return ret;
}
/*
* taken from block_truncate_page, but does cow as it zeros out
* any bytes left in the last page in the file.
*/
static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
{
struct inode *inode = mapping->host;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
char *kaddr;
u32 blocksize = root->sectorsize;
pgoff_t index = from >> PAGE_CACHE_SHIFT;
unsigned offset = from & (PAGE_CACHE_SIZE-1);
struct page *page;
int ret = 0;
u64 page_start;
u64 page_end;
if ((offset & (blocksize - 1)) == 0)
goto out;
ret = -ENOMEM;
again:
page = grab_cache_page(mapping, index);
if (!page)
goto out;
page_start = page_offset(page);
page_end = page_start + PAGE_CACHE_SIZE - 1;
if (!PageUptodate(page)) {
ret = btrfs_readpage(NULL, page);
lock_page(page);
if (page->mapping != mapping) {
unlock_page(page);
page_cache_release(page);
goto again;
}
if (!PageUptodate(page)) {
ret = -EIO;
goto out_unlock;
}
}
wait_on_page_writeback(page);
lock_extent(io_tree, page_start, page_end, GFP_NOFS);
set_page_extent_mapped(page);
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
unlock_page(page);
page_cache_release(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
btrfs_set_extent_delalloc(inode, page_start, page_end);
ret = 0;
if (offset != PAGE_CACHE_SIZE) {
kaddr = kmap(page);
memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
flush_dcache_page(page);
kunmap(page);
}
ClearPageChecked(page);
set_page_dirty(page);
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
out_unlock:
unlock_page(page);
page_cache_release(page);
out:
return ret;
}
static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
int err;
err = inode_change_ok(inode, attr);
if (err)
return err;
if (S_ISREG(inode->i_mode) &&
attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
u64 mask = root->sectorsize - 1;
u64 hole_start = (inode->i_size + mask) & ~mask;
u64 block_end = (attr->ia_size + mask) & ~mask;
u64 hole_size;
u64 alloc_hint = 0;
if (attr->ia_size <= hole_start)
goto out;
err = btrfs_check_free_space(root, 1, 0);
if (err)
goto fail;
btrfs_truncate_page(inode->i_mapping, inode->i_size);
hole_size = block_end - hole_start;
while(1) {
struct btrfs_ordered_extent *ordered;
btrfs_wait_ordered_range(inode, hole_start, hole_size);
lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
ordered = btrfs_lookup_ordered_extent(inode, hole_start);
if (ordered) {
unlock_extent(io_tree, hole_start,
block_end - 1, GFP_NOFS);
btrfs_put_ordered_extent(ordered);
} else {
break;
}
}
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
mutex_lock(&BTRFS_I(inode)->extent_mutex);
err = btrfs_drop_extents(trans, root, inode,
hole_start, block_end, hole_start,
&alloc_hint);
if (alloc_hint != EXTENT_MAP_INLINE) {
err = btrfs_insert_file_extent(trans, root,
inode->i_ino,
hole_start, 0, 0,
hole_size, 0);
btrfs_drop_extent_cache(inode, hole_start,
(u64)-1, 0);
btrfs_check_file(root, inode);
}
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
btrfs_end_transaction(trans, root);
unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
if (err)
return err;
}
out:
err = inode_setattr(inode, attr);
if (!err && ((attr->ia_valid & ATTR_MODE)))
err = btrfs_acl_chmod(inode);
fail:
return err;
}
void btrfs_delete_inode(struct inode *inode)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
unsigned long nr;
int ret;
truncate_inode_pages(&inode->i_data, 0);
if (is_bad_inode(inode)) {
btrfs_orphan_del(NULL, inode);
goto no_delete;
}
btrfs_wait_ordered_range(inode, 0, (u64)-1);
btrfs_i_size_write(inode, 0);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size, 0);
if (ret) {
btrfs_orphan_del(NULL, inode);
goto no_delete_lock;
}
btrfs_orphan_del(trans, inode);
nr = trans->blocks_used;
clear_inode(inode);
btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root, nr);
return;
no_delete_lock:
nr = trans->blocks_used;
btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root, nr);
no_delete:
clear_inode(inode);
}
/*
* this returns the key found in the dir entry in the location pointer.
* If no dir entries were found, location->objectid is 0.
*/
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
struct btrfs_key *location)
{
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
struct btrfs_dir_item *di;
struct btrfs_path *path;
struct btrfs_root *root = BTRFS_I(dir)->root;
int ret = 0;
path = btrfs_alloc_path();
BUG_ON(!path);
di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
namelen, 0);
if (IS_ERR(di))
ret = PTR_ERR(di);
if (!di || IS_ERR(di)) {
goto out_err;
}
btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
out:
btrfs_free_path(path);
return ret;
out_err:
location->objectid = 0;
goto out;
}
/*
* when we hit a tree root in a directory, the btrfs part of the inode
* needs to be changed to reflect the root directory of the tree root. This
* is kind of like crossing a mount point.
*/
static int fixup_tree_root_location(struct btrfs_root *root,
struct btrfs_key *location,
struct btrfs_root **sub_root,
struct dentry *dentry)
{
struct btrfs_root_item *ri;
if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
return 0;
if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
return 0;
*sub_root = btrfs_read_fs_root(root->fs_info, location,
dentry->d_name.name,
dentry->d_name.len);
if (IS_ERR(*sub_root))
return PTR_ERR(*sub_root);
ri = &(*sub_root)->root_item;
location->objectid = btrfs_root_dirid(ri);
btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
location->offset = 0;
return 0;
}
static noinline void init_btrfs_i(struct inode *inode)
{
struct btrfs_inode *bi = BTRFS_I(inode);
bi->i_acl = NULL;
bi->i_default_acl = NULL;
bi->generation = 0;
bi->last_trans = 0;
bi->logged_trans = 0;
bi->delalloc_bytes = 0;
bi->disk_i_size = 0;
bi->flags = 0;
bi->index_cnt = (u64)-1;
bi->log_dirty_trans = 0;
extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
extent_io_tree_init(&BTRFS_I(inode)->io_tree,
inode->i_mapping, GFP_NOFS);
extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
inode->i_mapping, GFP_NOFS);
INIT_LIST_HEAD(&BTRFS_I(inode)->delalloc_inodes);
btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree);
mutex_init(&BTRFS_I(inode)->csum_mutex);
mutex_init(&BTRFS_I(inode)->extent_mutex);
mutex_init(&BTRFS_I(inode)->log_mutex);
}
static int btrfs_init_locked_inode(struct inode *inode, void *p)
{
struct btrfs_iget_args *args = p;
inode->i_ino = args->ino;
init_btrfs_i(inode);
BTRFS_I(inode)->root = args->root;
return 0;
}
static int btrfs_find_actor(struct inode *inode, void *opaque)
{
struct btrfs_iget_args *args = opaque;
return (args->ino == inode->i_ino &&
args->root == BTRFS_I(inode)->root);
}
struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
struct btrfs_root *root, int wait)
{
struct inode *inode;
struct btrfs_iget_args args;
args.ino = objectid;
args.root = root;
if (wait) {
inode = ilookup5(s, objectid, btrfs_find_actor,
(void *)&args);
} else {
inode = ilookup5_nowait(s, objectid, btrfs_find_actor,
(void *)&args);
}
return inode;
}
struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
struct btrfs_root *root)
{
struct inode *inode;
struct btrfs_iget_args args;
args.ino = objectid;
args.root = root;
inode = iget5_locked(s, objectid, btrfs_find_actor,
btrfs_init_locked_inode,
(void *)&args);
return inode;
}
/* Get an inode object given its location and corresponding root.
* Returns in *is_new if the inode was read from disk
*/
struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
struct btrfs_root *root, int *is_new)
{
struct inode *inode;
inode = btrfs_iget_locked(s, location->objectid, root);
if (!inode)
return ERR_PTR(-EACCES);
if (inode->i_state & I_NEW) {
BTRFS_I(inode)->root = root;
memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
btrfs_read_locked_inode(inode);
unlock_new_inode(inode);
if (is_new)
*is_new = 1;
} else {
if (is_new)
*is_new = 0;
}
return inode;
}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct inode * inode;
struct btrfs_inode *bi = BTRFS_I(dir);
struct btrfs_root *root = bi->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
int ret, new, do_orphan = 0;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
ret = btrfs_inode_by_name(dir, dentry, &location);
if (ret < 0)
return ERR_PTR(ret);
inode = NULL;
if (location.objectid) {
ret = fixup_tree_root_location(root, &location, &sub_root,
dentry);
if (ret < 0)
return ERR_PTR(ret);
if (ret > 0)
return ERR_PTR(-ENOENT);
inode = btrfs_iget(dir->i_sb, &location, sub_root, &new);
if (IS_ERR(inode))
return ERR_CAST(inode);
/* the inode and parent dir are two different roots */
if (new && root != sub_root) {
igrab(inode);
sub_root->inode = inode;
do_orphan = 1;
}
}
if (unlikely(do_orphan))
btrfs_orphan_cleanup(sub_root);
return d_splice_alias(inode, dentry);
}
static unsigned char btrfs_filetype_table[] = {
DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
};
static int btrfs_real_readdir(struct file *filp, void *dirent,
filldir_t filldir)
{
struct inode *inode = filp->f_dentry->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_item *item;
struct btrfs_dir_item *di;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_path *path;
int ret;
u32 nritems;
struct extent_buffer *leaf;
int slot;
int advance;
unsigned char d_type;
int over = 0;
u32 di_cur;
u32 di_total;
u32 di_len;
int key_type = BTRFS_DIR_INDEX_KEY;
char tmp_name[32];
char *name_ptr;
int name_len;
/* FIXME, use a real flag for deciding about the key type */
if (root->fs_info->tree_root == root)
key_type = BTRFS_DIR_ITEM_KEY;
/* special case for "." */
if (filp->f_pos == 0) {
over = filldir(dirent, ".", 1,
1, inode->i_ino,
DT_DIR);
if (over)
return 0;
filp->f_pos = 1;
}
/* special case for .., just use the back ref */
if (filp->f_pos == 1) {
u64 pino = parent_ino(filp->f_path.dentry);
over = filldir(dirent, "..", 2,
2, pino, DT_DIR);
if (over)
return 0;
filp->f_pos = 2;
}
path = btrfs_alloc_path();
path->reada = 2;
btrfs_set_key_type(&key, key_type);
key.offset = filp->f_pos;
key.objectid = inode->i_ino;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
advance = 0;
while (1) {
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
slot = path->slots[0];
if (advance || slot >= nritems) {
if (slot >= nritems - 1) {
ret = btrfs_next_leaf(root, path);
if (ret)
break;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
slot = path->slots[0];
} else {
slot++;
path->slots[0]++;
}
}
advance = 1;
item = btrfs_item_nr(leaf, slot);
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != key.objectid)
break;
if (btrfs_key_type(&found_key) != key_type)
break;
if (found_key.offset < filp->f_pos)
continue;
filp->f_pos = found_key.offset;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
di_cur = 0;
di_total = btrfs_item_size(leaf, item);
while (di_cur < di_total) {
struct btrfs_key location;
name_len = btrfs_dir_name_len(leaf, di);
if (name_len <= sizeof(tmp_name)) {
name_ptr = tmp_name;
} else {
name_ptr = kmalloc(name_len, GFP_NOFS);
if (!name_ptr) {
ret = -ENOMEM;
goto err;
}
}
read_extent_buffer(leaf, name_ptr,
(unsigned long)(di + 1), name_len);
d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
btrfs_dir_item_key_to_cpu(leaf, di, &location);
over = filldir(dirent, name_ptr, name_len,
found_key.offset, location.objectid,
d_type);
if (name_ptr != tmp_name)
kfree(name_ptr);
if (over)
goto nopos;
di_len = btrfs_dir_name_len(leaf, di) +
btrfs_dir_data_len(leaf, di) + sizeof(*di);
di_cur += di_len;
di = (struct btrfs_dir_item *)((char *)di + di_len);
}
}
/* Reached end of directory/root. Bump pos past the last item. */
if (key_type == BTRFS_DIR_INDEX_KEY)
filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
else
filp->f_pos++;
nopos:
ret = 0;
err:
btrfs_free_path(path);
return ret;
}
int btrfs_write_inode(struct inode *inode, int wait)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret = 0;
if (root->fs_info->closing > 1)
return 0;
if (wait) {
trans = btrfs_join_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
ret = btrfs_commit_transaction(trans, root);
}
return ret;
}
/*
* This is somewhat expensive, updating the tree every time the
* inode changes. But, it is most likely to find the inode in cache.
* FIXME, needs more benchmarking...there are no reasons other than performance
* to keep or drop this code.
*/
void btrfs_dirty_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
trans = btrfs_join_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
btrfs_update_inode(trans, root, inode);
btrfs_end_transaction(trans, root);
}
/*
* find the highest existing sequence number in a directory
* and then set the in-memory index_cnt variable to reflect
* free sequence numbers
*/
static int btrfs_set_inode_index_count(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key key, found_key;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
key.objectid = inode->i_ino;
btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
key.offset = (u64)-1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/* FIXME: we should be able to handle this */
if (ret == 0)
goto out;
ret = 0;
/*
* MAGIC NUMBER EXPLANATION:
* since we search a directory based on f_pos we have to start at 2
* since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
* else has to start at 2
*/
if (path->slots[0] == 0) {
BTRFS_I(inode)->index_cnt = 2;
goto out;
}
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != inode->i_ino ||
btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
BTRFS_I(inode)->index_cnt = 2;
goto out;
}
BTRFS_I(inode)->index_cnt = found_key.offset + 1;
out:
btrfs_free_path(path);
return ret;
}
/*
* helper to find a free sequence number in a given directory. This current
* code is very simple, later versions will do smarter things in the btree
*/
static int btrfs_set_inode_index(struct inode *dir, struct inode *inode,
u64 *index)
{
int ret = 0;
if (BTRFS_I(dir)->index_cnt == (u64)-1) {
ret = btrfs_set_inode_index_count(dir);
if (ret) {
return ret;
}
}
*index = BTRFS_I(dir)->index_cnt;
BTRFS_I(dir)->index_cnt++;
return ret;
}
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir,
const char *name, int name_len,
u64 ref_objectid,
u64 objectid,
struct btrfs_block_group_cache *group,
int mode, u64 *index)
{
struct inode *inode;
struct btrfs_inode_item *inode_item;
struct btrfs_block_group_cache *new_inode_group;
struct btrfs_key *location;
struct btrfs_path *path;
struct btrfs_inode_ref *ref;
struct btrfs_key key[2];
u32 sizes[2];
unsigned long ptr;
int ret;
int owner;
path = btrfs_alloc_path();
BUG_ON(!path);
inode = new_inode(root->fs_info->sb);
if (!inode)
return ERR_PTR(-ENOMEM);
if (dir) {
ret = btrfs_set_inode_index(dir, inode, index);
if (ret)
return ERR_PTR(ret);
}
/*
* index_cnt is ignored for everything but a dir,
* btrfs_get_inode_index_count has an explanation for the magic
* number
*/
init_btrfs_i(inode);
BTRFS_I(inode)->index_cnt = 2;
BTRFS_I(inode)->root = root;
BTRFS_I(inode)->generation = trans->transid;
if (mode & S_IFDIR)
owner = 0;
else
owner = 1;
new_inode_group = btrfs_find_block_group(root, group, 0,
BTRFS_BLOCK_GROUP_METADATA, owner);
if (!new_inode_group) {
printk("find_block group failed\n");
new_inode_group = group;
}
BTRFS_I(inode)->block_group = new_inode_group;
key[0].objectid = objectid;
btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
key[0].offset = 0;
key[1].objectid = objectid;
btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
key[1].offset = ref_objectid;
sizes[0] = sizeof(struct btrfs_inode_item);
sizes[1] = name_len + sizeof(*ref);
ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
if (ret != 0)
goto fail;
if (objectid > root->highest_inode)
root->highest_inode = objectid;
inode->i_uid = current->fsuid;
inode->i_gid = current->fsgid;
inode->i_mode = mode;
inode->i_ino = objectid;
inode_set_bytes(inode, 0);
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, path->nodes[0], inode_item, inode);
ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
struct btrfs_inode_ref);
btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
ptr = (unsigned long)(ref + 1);
write_extent_buffer(path->nodes[0], name, ptr, name_len);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
location = &BTRFS_I(inode)->location;
location->objectid = objectid;
location->offset = 0;
btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
insert_inode_hash(inode);
return inode;
fail:
if (dir)
BTRFS_I(dir)->index_cnt--;
btrfs_free_path(path);
return ERR_PTR(ret);
}
static inline u8 btrfs_inode_type(struct inode *inode)
{
return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
}
/*
* utility function to add 'inode' into 'parent_inode' with
* a give name and a given sequence number.
* if 'add_backref' is true, also insert a backref from the
* inode to the parent directory.
*/
int btrfs_add_link(struct btrfs_trans_handle *trans,
struct inode *parent_inode, struct inode *inode,
const char *name, int name_len, int add_backref, u64 index)
{
int ret;
struct btrfs_key key;
struct btrfs_root *root = BTRFS_I(parent_inode)->root;
key.objectid = inode->i_ino;
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
key.offset = 0;
ret = btrfs_insert_dir_item(trans, root, name, name_len,
parent_inode->i_ino,
&key, btrfs_inode_type(inode),
index);
if (ret == 0) {
if (add_backref) {
ret = btrfs_insert_inode_ref(trans, root,
name, name_len,
inode->i_ino,
parent_inode->i_ino,
index);
}
btrfs_i_size_write(parent_inode, parent_inode->i_size +
name_len * 2);
parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
ret = btrfs_update_inode(trans, root, parent_inode);
}
return ret;
}
static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
struct dentry *dentry, struct inode *inode,
int backref, u64 index)
{
int err = btrfs_add_link(trans, dentry->d_parent->d_inode,
inode, dentry->d_name.name,
dentry->d_name.len, backref, index);
if (!err) {
d_instantiate(dentry, inode);
return 0;
}
if (err > 0)
err = -EEXIST;
return err;
}
static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
int mode, dev_t rdev)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
int err;
int drop_inode = 0;
u64 objectid;
unsigned long nr = 0;
u64 index = 0;
if (!new_valid_dev(rdev))
return -EINVAL;
err = btrfs_check_free_space(root, 1, 0);
if (err)
goto fail;
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
if (err) {
err = -ENOSPC;
goto out_unlock;
}
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len,
dentry->d_parent->d_inode->i_ino, objectid,
BTRFS_I(dir)->block_group, mode, &index);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_unlock;
err = btrfs_init_acl(inode, dir);
if (err) {
drop_inode = 1;
goto out_unlock;
}
btrfs_set_trans_block_group(trans, inode);
err = btrfs_add_nondir(trans, dentry, inode, 0, index);
if (err)
drop_inode = 1;
else {
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
btrfs_update_inode(trans, root, inode);
}
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
btrfs_update_inode_block_group(trans, dir);
out_unlock:
nr = trans->blocks_used;
btrfs_end_transaction_throttle(trans, root);
fail:
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root, nr);
return err;
}
static int btrfs_create(struct inode *dir, struct dentry *dentry,
int mode, struct nameidata *nd)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
int err;
int drop_inode = 0;
unsigned long nr = 0;
u64 objectid;
u64 index = 0;
err = btrfs_check_free_space(root, 1, 0);
if (err)
goto fail;
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
if (err) {
err = -ENOSPC;
goto out_unlock;
}
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len,
dentry->d_parent->d_inode->i_ino,
objectid, BTRFS_I(dir)->block_group, mode,
&index);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_unlock;
err = btrfs_init_acl(inode, dir);
if (err) {
drop_inode = 1;
goto out_unlock;
}
btrfs_set_trans_block_group(trans, inode);
err = btrfs_add_nondir(trans, dentry, inode, 0, index);
if (err)
drop_inode = 1;
else {
inode->i_mapping->a_ops = &btrfs_aops;
inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
}
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
btrfs_update_inode_block_group(trans, dir);
out_unlock:
nr = trans->blocks_used;
btrfs_end_transaction_throttle(trans, root);
fail:
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root, nr);
return err;
}
static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = old_dentry->d_inode;
u64 index;
unsigned long nr = 0;
int err;
int drop_inode = 0;
if (inode->i_nlink == 0)
return -ENOENT;
btrfs_inc_nlink(inode);
err = btrfs_check_free_space(root, 1, 0);
if (err)
goto fail;
err = btrfs_set_inode_index(dir, inode, &index);
if (err)
goto fail;
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
atomic_inc(&inode->i_count);
err = btrfs_add_nondir(trans, dentry, inode, 1, index);
if (err)
drop_inode = 1;
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, dir);
err = btrfs_update_inode(trans, root, inode);
if (err)
drop_inode = 1;
nr = trans->blocks_used;
btrfs_end_transaction_throttle(trans, root);
fail:
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root, nr);
return err;
}
static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct inode *inode = NULL;
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
int err = 0;
int drop_on_err = 0;
u64 objectid = 0;
u64 index = 0;
unsigned long nr = 1;
err = btrfs_check_free_space(root, 1, 0);
if (err)
goto out_unlock;
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_unlock;
}
err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
if (err) {
err = -ENOSPC;
goto out_unlock;
}
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len,
dentry->d_parent->d_inode->i_ino, objectid,
BTRFS_I(dir)->block_group, S_IFDIR | mode,
&index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_fail;
}
drop_on_err = 1;
err = btrfs_init_acl(inode, dir);
if (err)
goto out_fail;
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
btrfs_set_trans_block_group(trans, inode);
btrfs_i_size_write(inode, 0);
err = btrfs_update_inode(trans, root, inode);
if (err)
goto out_fail;
err = btrfs_add_link(trans, dentry->d_parent->d_inode,
inode, dentry->d_name.name,
dentry->d_name.len, 0, index);
if (err)
goto out_fail;
d_instantiate(dentry, inode);
drop_on_err = 0;
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
btrfs_update_inode_block_group(trans, dir);
out_fail:
nr = trans->blocks_used;
btrfs_end_transaction_throttle(trans, root);
out_unlock:
if (drop_on_err)
iput(inode);
btrfs_btree_balance_dirty(root, nr);
return err;
}
/* helper for btfs_get_extent. Given an existing extent in the tree,
* and an extent that you want to insert, deal with overlap and insert
* the new extent into the tree.
*/
static int merge_extent_mapping(struct extent_map_tree *em_tree,
struct extent_map *existing,
struct extent_map *em,
u64 map_start, u64 map_len)
{
u64 start_diff;
BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
start_diff = map_start - em->start;
em->start = map_start;
em->len = map_len;
if (em->block_start < EXTENT_MAP_LAST_BYTE)
em->block_start += start_diff;
return add_extent_mapping(em_tree, em);
}
/*
* a bit scary, this does extent mapping from logical file offset to the disk.
* the ugly parts come from merging extents from the disk with the
* in-ram representation. This gets more complex because of the data=ordered code,
* where the in-ram extents might be locked pending data=ordered completion.
*
* This also copies inline extents directly into the page.
*/
struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
size_t pg_offset, u64 start, u64 len,
int create)
{
int ret;
int err = 0;
u64 bytenr;
u64 extent_start = 0;
u64 extent_end = 0;
u64 objectid = inode->i_ino;
u32 found_type;
struct btrfs_path *path = NULL;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_extent_item *item;
struct extent_buffer *leaf;
struct btrfs_key found_key;
struct extent_map *em = NULL;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_trans_handle *trans = NULL;
again:
spin_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
if (em)
em->bdev = root->fs_info->fs_devices->latest_bdev;
spin_unlock(&em_tree->lock);
if (em) {
if (em->start > start || em->start + em->len <= start)
free_extent_map(em);
else if (em->block_start == EXTENT_MAP_INLINE && page)
free_extent_map(em);
else
goto out;
}
em = alloc_extent_map(GFP_NOFS);
if (!em) {
err = -ENOMEM;
goto out;
}
em->bdev = root->fs_info->fs_devices->latest_bdev;
em->start = EXTENT_MAP_HOLE;
em->len = (u64)-1;
if (!path) {
path = btrfs_alloc_path();
BUG_ON(!path);
}
ret = btrfs_lookup_file_extent(trans, root, path,
objectid, start, trans != NULL);
if (ret < 0) {
err = ret;
goto out;
}
if (ret != 0) {
if (path->slots[0] == 0)
goto not_found;
path->slots[0]--;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
/* are we inside the extent that was found? */
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = btrfs_key_type(&found_key);
if (found_key.objectid != objectid ||
found_type != BTRFS_EXTENT_DATA_KEY) {
goto not_found;
}
found_type = btrfs_file_extent_type(leaf, item);
extent_start = found_key.offset;
if (found_type == BTRFS_FILE_EXTENT_REG) {
extent_end = extent_start +
btrfs_file_extent_num_bytes(leaf, item);
err = 0;
if (start < extent_start || start >= extent_end) {
em->start = start;
if (start < extent_start) {
if (start + len <= extent_start)
goto not_found;
em->len = extent_end - extent_start;
} else {
em->len = len;
}
goto not_found_em;
}
bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
if (bytenr == 0) {
em->start = extent_start;
em->len = extent_end - extent_start;
em->block_start = EXTENT_MAP_HOLE;
goto insert;
}
bytenr += btrfs_file_extent_offset(leaf, item);
em->block_start = bytenr;
em->start = extent_start;
em->len = extent_end - extent_start;
goto insert;
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
u64 page_start;
unsigned long ptr;
char *map;
size_t size;
size_t extent_offset;
size_t copy_size;
size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
path->slots[0]));
extent_end = (extent_start + size + root->sectorsize - 1) &
~((u64)root->sectorsize - 1);
if (start < extent_start || start >= extent_end) {
em->start = start;
if (start < extent_start) {
if (start + len <= extent_start)
goto not_found;
em->len = extent_end - extent_start;
} else {
em->len = len;
}
goto not_found_em;
}
em->block_start = EXTENT_MAP_INLINE;
if (!page) {
em->start = extent_start;
em->len = size;
goto out;
}
page_start = page_offset(page) + pg_offset;
extent_offset = page_start - extent_start;
copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
size - extent_offset);
em->start = extent_start + extent_offset;
em->len = (copy_size + root->sectorsize - 1) &
~((u64)root->sectorsize - 1);
map = kmap(page);
ptr = btrfs_file_extent_inline_start(item) + extent_offset;
if (create == 0 && !PageUptodate(page)) {
read_extent_buffer(leaf, map + pg_offset, ptr,
copy_size);
flush_dcache_page(page);
} else if (create && PageUptodate(page)) {
if (!trans) {
kunmap(page);
free_extent_map(em);
em = NULL;
btrfs_release_path(root, path);
trans = btrfs_join_transaction(root, 1);
goto again;
}
write_extent_buffer(leaf, map + pg_offset, ptr,
copy_size);
btrfs_mark_buffer_dirty(leaf);
}
kunmap(page);
set_extent_uptodate(io_tree, em->start,
extent_map_end(em) - 1, GFP_NOFS);
goto insert;
} else {
printk("unkknown found_type %d\n", found_type);
WARN_ON(1);
}
not_found:
em->start = start;
em->len = len;
not_found_em:
em->block_start = EXTENT_MAP_HOLE;
insert:
btrfs_release_path(root, path);
if (em->start > start || extent_map_end(em) <= start) {
printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->len, start, len);
err = -EIO;
goto out;
}
err = 0;
spin_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
/* it is possible that someone inserted the extent into the tree
* while we had the lock dropped. It is also possible that
* an overlapping map exists in the tree
*/
if (ret == -EEXIST) {
struct extent_map *existing;
ret = 0;
existing = lookup_extent_mapping(em_tree, start, len);
if (existing && (existing->start > start ||
existing->start + existing->len <= start)) {
free_extent_map(existing);
existing = NULL;
}
if (!existing) {
existing = lookup_extent_mapping(em_tree, em->start,
em->len);
if (existing) {
err = merge_extent_mapping(em_tree, existing,
em, start,
root->sectorsize);
free_extent_map(existing);
if (err) {
free_extent_map(em);
em = NULL;
}
} else {
err = -EIO;
printk("failing to insert %Lu %Lu\n",
start, len);
free_extent_map(em);
em = NULL;
}
} else {
free_extent_map(em);
em = existing;
err = 0;
}
}
spin_unlock(&em_tree->lock);
out:
if (path)
btrfs_free_path(path);
if (trans) {
ret = btrfs_end_transaction(trans, root);
if (!err) {
err = ret;
}
}
if (err) {
free_extent_map(em);
WARN_ON(1);
return ERR_PTR(err);
}
return em;
}
static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
const struct iovec *iov, loff_t offset,
unsigned long nr_segs)
{
return -EINVAL;
}
static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
{
return extent_bmap(mapping, iblock, btrfs_get_extent);
}
int btrfs_readpage(struct file *file, struct page *page)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(page->mapping->host)->io_tree;
return extent_read_full_page(tree, page, btrfs_get_extent);
}
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
{
struct extent_io_tree *tree;
if (current->flags & PF_MEMALLOC) {
redirty_page_for_writepage(wbc, page);
unlock_page(page);
return 0;
}
tree = &BTRFS_I(page->mapping->host)->io_tree;
return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
}
int btrfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(mapping->host)->io_tree;
return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
}
static int
btrfs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(mapping->host)->io_tree;
return extent_readpages(tree, mapping, pages, nr_pages,
btrfs_get_extent);
}
static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
struct extent_io_tree *tree;
struct extent_map_tree *map;
int ret;
tree = &BTRFS_I(page->mapping->host)->io_tree;
map = &BTRFS_I(page->mapping->host)->extent_tree;
ret = try_release_extent_mapping(map, tree, page, gfp_flags);
if (ret == 1) {
ClearPagePrivate(page);
set_page_private(page, 0);
page_cache_release(page);
}
return ret;
}
static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
if (PageWriteback(page) || PageDirty(page))
return 0;
return __btrfs_releasepage(page, gfp_flags);
}
static void btrfs_invalidatepage(struct page *page, unsigned long offset)
{
struct extent_io_tree *tree;
struct btrfs_ordered_extent *ordered;
u64 page_start = page_offset(page);
u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
wait_on_page_writeback(page);
tree = &BTRFS_I(page->mapping->host)->io_tree;
if (offset) {
btrfs_releasepage(page, GFP_NOFS);
return;
}
lock_extent(tree, page_start, page_end, GFP_NOFS);
ordered = btrfs_lookup_ordered_extent(page->mapping->host,
page_offset(page));
if (ordered) {
/*
* IO on this page will never be started, so we need
* to account for any ordered extents now
*/
clear_extent_bit(tree, page_start, page_end,
EXTENT_DIRTY | EXTENT_DELALLOC |
EXTENT_LOCKED, 1, 0, GFP_NOFS);
btrfs_finish_ordered_io(page->mapping->host,
page_start, page_end);
btrfs_put_ordered_extent(ordered);
lock_extent(tree, page_start, page_end, GFP_NOFS);
}
clear_extent_bit(tree, page_start, page_end,
EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
EXTENT_ORDERED,
1, 1, GFP_NOFS);
__btrfs_releasepage(page, GFP_NOFS);
ClearPageChecked(page);
if (PagePrivate(page)) {
ClearPagePrivate(page);
set_page_private(page, 0);
page_cache_release(page);
}
}
/*
* btrfs_page_mkwrite() is not allowed to change the file size as it gets
* called from a page fault handler when a page is first dirtied. Hence we must
* be careful to check for EOF conditions here. We set the page up correctly
* for a written page which means we get ENOSPC checking when writing into
* holes and correct delalloc and unwritten extent mapping on filesystems that
* support these features.
*
* We are not allowed to take the i_mutex here so we have to play games to
* protect against truncate races as the page could now be beyond EOF. Because
* vmtruncate() writes the inode size before removing pages, once we have the
* page lock we can determine safely if the page is beyond EOF. If it is not
* beyond EOF, then the page is guaranteed safe against truncation until we
* unlock the page.
*/
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
{
struct inode *inode = fdentry(vma->vm_file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
char *kaddr;
unsigned long zero_start;
loff_t size;
int ret;
u64 page_start;
u64 page_end;
ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
if (ret)
goto out;
ret = -EINVAL;
again:
lock_page(page);
size = i_size_read(inode);
page_start = page_offset(page);
page_end = page_start + PAGE_CACHE_SIZE - 1;
if ((page->mapping != inode->i_mapping) ||
(page_start >= size)) {
/* page got truncated out from underneath us */
goto out_unlock;
}
wait_on_page_writeback(page);
lock_extent(io_tree, page_start, page_end, GFP_NOFS);
set_page_extent_mapped(page);
/*
* we can't set the delalloc bits if there are pending ordered
* extents. Drop our locks and wait for them to finish
*/
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
unlock_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
btrfs_set_extent_delalloc(inode, page_start, page_end);
ret = 0;
/* page is wholly or partially inside EOF */
if (page_start + PAGE_CACHE_SIZE > size)
zero_start = size & ~PAGE_CACHE_MASK;
else
zero_start = PAGE_CACHE_SIZE;
if (zero_start != PAGE_CACHE_SIZE) {
kaddr = kmap(page);
memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
flush_dcache_page(page);
kunmap(page);
}
ClearPageChecked(page);
set_page_dirty(page);
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
out_unlock:
unlock_page(page);
out:
return ret;
}
static void btrfs_truncate(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
struct btrfs_trans_handle *trans;
unsigned long nr;
u64 mask = root->sectorsize - 1;
if (!S_ISREG(inode->i_mode))
return;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return;
btrfs_truncate_page(inode->i_mapping, inode->i_size);
btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
btrfs_i_size_write(inode, inode->i_size);
ret = btrfs_orphan_add(trans, inode);
if (ret)
goto out;
/* FIXME, add redo link to tree so we don't leak on crash */
ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size,
BTRFS_EXTENT_DATA_KEY);
btrfs_update_inode(trans, root, inode);
ret = btrfs_orphan_del(trans, inode);
BUG_ON(ret);
out:
nr = trans->blocks_used;
ret = btrfs_end_transaction_throttle(trans, root);
BUG_ON(ret);
btrfs_btree_balance_dirty(root, nr);
}
/*
* Invalidate a single dcache entry at the root of the filesystem.
* Needed after creation of snapshot or subvolume.
*/
void btrfs_invalidate_dcache_root(struct btrfs_root *root, char *name,
int namelen)
{
struct dentry *alias, *entry;
struct qstr qstr;
alias = d_find_alias(root->fs_info->sb->s_root->d_inode);
if (alias) {
qstr.name = name;
qstr.len = namelen;
/* change me if btrfs ever gets a d_hash operation */
qstr.hash = full_name_hash(qstr.name, qstr.len);
entry = d_lookup(alias, &qstr);
dput(alias);
if (entry) {
d_invalidate(entry);
dput(entry);
}
}
}
/*
* create a new subvolume directory/inode (helper for the ioctl).
*/
int btrfs_create_subvol_root(struct btrfs_root *new_root, struct dentry *dentry,
struct btrfs_trans_handle *trans, u64 new_dirid,
struct btrfs_block_group_cache *block_group)
{
struct inode *inode;
int error;
u64 index = 0;
inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid,
new_dirid, block_group, S_IFDIR | 0700, &index);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
new_root->inode = inode;
inode->i_nlink = 1;
btrfs_i_size_write(inode, 0);
error = btrfs_update_inode(trans, new_root, inode);
if (error)
return error;
d_instantiate(dentry, inode);
return 0;
}
/* helper function for file defrag and space balancing. This
* forces readahead on a given range of bytes in an inode
*/
unsigned long btrfs_force_ra(struct address_space *mapping,
struct file_ra_state *ra, struct file *file,
pgoff_t offset, pgoff_t last_index)
{
pgoff_t req_size = last_index - offset + 1;
page_cache_sync_readahead(mapping, ra, file, offset, req_size);
return offset + req_size;
}
struct inode *btrfs_alloc_inode(struct super_block *sb)
{
struct btrfs_inode *ei;
ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
if (!ei)
return NULL;
ei->last_trans = 0;
ei->logged_trans = 0;
btrfs_ordered_inode_tree_init(&ei->ordered_tree);
ei->i_acl = BTRFS_ACL_NOT_CACHED;
ei->i_default_acl = BTRFS_ACL_NOT_CACHED;
INIT_LIST_HEAD(&ei->i_orphan);
return &ei->vfs_inode;
}
void btrfs_destroy_inode(struct inode *inode)
{
struct btrfs_ordered_extent *ordered;
WARN_ON(!list_empty(&inode->i_dentry));
WARN_ON(inode->i_data.nrpages);
if (BTRFS_I(inode)->i_acl &&
BTRFS_I(inode)->i_acl != BTRFS_ACL_NOT_CACHED)
posix_acl_release(BTRFS_I(inode)->i_acl);
if (BTRFS_I(inode)->i_default_acl &&
BTRFS_I(inode)->i_default_acl != BTRFS_ACL_NOT_CACHED)
posix_acl_release(BTRFS_I(inode)->i_default_acl);
spin_lock(&BTRFS_I(inode)->root->list_lock);
if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
printk(KERN_ERR "BTRFS: inode %lu: inode still on the orphan"
" list\n", inode->i_ino);
dump_stack();
}
spin_unlock(&BTRFS_I(inode)->root->list_lock);
while(1) {
ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
if (!ordered)
break;
else {
printk("found ordered extent %Lu %Lu\n",
ordered->file_offset, ordered->len);
btrfs_remove_ordered_extent(inode, ordered);
btrfs_put_ordered_extent(ordered);
btrfs_put_ordered_extent(ordered);
}
}
btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
static void init_once(void *foo)
{
struct btrfs_inode *ei = (struct btrfs_inode *) foo;
inode_init_once(&ei->vfs_inode);
}
void btrfs_destroy_cachep(void)
{
if (btrfs_inode_cachep)
kmem_cache_destroy(btrfs_inode_cachep);
if (btrfs_trans_handle_cachep)
kmem_cache_destroy(btrfs_trans_handle_cachep);
if (btrfs_transaction_cachep)
kmem_cache_destroy(btrfs_transaction_cachep);
if (btrfs_bit_radix_cachep)
kmem_cache_destroy(btrfs_bit_radix_cachep);
if (btrfs_path_cachep)
kmem_cache_destroy(btrfs_path_cachep);
}
struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
unsigned long extra_flags,
void (*ctor)(void *))
{
return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
SLAB_MEM_SPREAD | extra_flags), ctor);
}
int btrfs_init_cachep(void)
{
btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
sizeof(struct btrfs_inode),
0, init_once);
if (!btrfs_inode_cachep)
goto fail;
btrfs_trans_handle_cachep =
btrfs_cache_create("btrfs_trans_handle_cache",
sizeof(struct btrfs_trans_handle),
0, NULL);
if (!btrfs_trans_handle_cachep)
goto fail;
btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
sizeof(struct btrfs_transaction),
0, NULL);
if (!btrfs_transaction_cachep)
goto fail;
btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
sizeof(struct btrfs_path),
0, NULL);
if (!btrfs_path_cachep)
goto fail;
btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
SLAB_DESTROY_BY_RCU, NULL);
if (!btrfs_bit_radix_cachep)
goto fail;
return 0;
fail:
btrfs_destroy_cachep();
return -ENOMEM;
}
static int btrfs_getattr(struct vfsmount *mnt,
struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = dentry->d_inode;
generic_fillattr(inode, stat);
stat->blksize = PAGE_CACHE_SIZE;
stat->blocks = (inode_get_bytes(inode) +
BTRFS_I(inode)->delalloc_bytes) >> 9;
return 0;
}
static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
struct inode * new_dir,struct dentry *new_dentry)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(old_dir)->root;
struct inode *new_inode = new_dentry->d_inode;
struct inode *old_inode = old_dentry->d_inode;
struct timespec ctime = CURRENT_TIME;
u64 index = 0;
int ret;
if (S_ISDIR(old_inode->i_mode) && new_inode &&
new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
return -ENOTEMPTY;
}
ret = btrfs_check_free_space(root, 1, 0);
if (ret)
goto out_unlock;
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, new_dir);
btrfs_inc_nlink(old_dentry->d_inode);
old_dir->i_ctime = old_dir->i_mtime = ctime;
new_dir->i_ctime = new_dir->i_mtime = ctime;
old_inode->i_ctime = ctime;
ret = btrfs_unlink_inode(trans, root, old_dir, old_dentry->d_inode,
old_dentry->d_name.name,
old_dentry->d_name.len);
if (ret)
goto out_fail;
if (new_inode) {
new_inode->i_ctime = CURRENT_TIME;
ret = btrfs_unlink_inode(trans, root, new_dir,
new_dentry->d_inode,
new_dentry->d_name.name,
new_dentry->d_name.len);
if (ret)
goto out_fail;
if (new_inode->i_nlink == 0) {
ret = btrfs_orphan_add(trans, new_dentry->d_inode);
if (ret)
goto out_fail;
}
}
ret = btrfs_set_inode_index(new_dir, old_inode, &index);
if (ret)
goto out_fail;
ret = btrfs_add_link(trans, new_dentry->d_parent->d_inode,
old_inode, new_dentry->d_name.name,
new_dentry->d_name.len, 1, index);
if (ret)
goto out_fail;
out_fail:
btrfs_end_transaction_throttle(trans, root);
out_unlock:
return ret;
}
/*
* some fairly slow code that needs optimization. This walks the list
* of all the inodes with pending delalloc and forces them to disk.
*/
int btrfs_start_delalloc_inodes(struct btrfs_root *root)
{
struct list_head *head = &root->fs_info->delalloc_inodes;
struct btrfs_inode *binode;
struct inode *inode;
unsigned long flags;
spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
while(!list_empty(head)) {
binode = list_entry(head->next, struct btrfs_inode,
delalloc_inodes);
inode = igrab(&binode->vfs_inode);
if (!inode)
list_del_init(&binode->delalloc_inodes);
spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
if (inode) {
filemap_flush(inode->i_mapping);
iput(inode);
}
cond_resched();
spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
}
spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
/* the filemap_flush will queue IO into the worker threads, but
* we have to make sure the IO is actually started and that
* ordered extents get created before we return
*/
atomic_inc(&root->fs_info->async_submit_draining);
while(atomic_read(&root->fs_info->nr_async_submits)) {
wait_event(root->fs_info->async_submit_wait,
(atomic_read(&root->fs_info->nr_async_submits) == 0));
}
atomic_dec(&root->fs_info->async_submit_draining);
return 0;
}
static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_path *path;
struct btrfs_key key;
struct inode *inode = NULL;
int err;
int drop_inode = 0;
u64 objectid;
u64 index = 0 ;
int name_len;
int datasize;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
struct extent_buffer *leaf;
unsigned long nr = 0;
name_len = strlen(symname) + 1;
if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
return -ENAMETOOLONG;
err = btrfs_check_free_space(root, 1, 0);
if (err)
goto out_fail;
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
if (err) {
err = -ENOSPC;
goto out_unlock;
}
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len,
dentry->d_parent->d_inode->i_ino, objectid,
BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO,
&index);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_unlock;
err = btrfs_init_acl(inode, dir);
if (err) {
drop_inode = 1;
goto out_unlock;
}
btrfs_set_trans_block_group(trans, inode);
err = btrfs_add_nondir(trans, dentry, inode, 0, index);
if (err)
drop_inode = 1;
else {
inode->i_mapping->a_ops = &btrfs_aops;
inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
}
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
btrfs_update_inode_block_group(trans, dir);
if (drop_inode)
goto out_unlock;
path = btrfs_alloc_path();
BUG_ON(!path);
key.objectid = inode->i_ino;
key.offset = 0;
btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
datasize = btrfs_file_extent_calc_inline_size(name_len);
err = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (err) {
drop_inode = 1;
goto out_unlock;
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei,
BTRFS_FILE_EXTENT_INLINE);
ptr = btrfs_file_extent_inline_start(ei);
write_extent_buffer(leaf, symname, ptr, name_len);
btrfs_mark_buffer_dirty(leaf);
btrfs_free_path(path);
inode->i_op = &btrfs_symlink_inode_operations;
inode->i_mapping->a_ops = &btrfs_symlink_aops;
inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
btrfs_i_size_write(inode, name_len - 1);
err = btrfs_update_inode(trans, root, inode);
if (err)
drop_inode = 1;
out_unlock:
nr = trans->blocks_used;
btrfs_end_transaction_throttle(trans, root);
out_fail:
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root, nr);
return err;
}
static int btrfs_set_page_dirty(struct page *page)
{
return __set_page_dirty_nobuffers(page);
}
static int btrfs_permission(struct inode *inode, int mask)
{
if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
return -EACCES;
return generic_permission(inode, mask, btrfs_check_acl);
}
static struct inode_operations btrfs_dir_inode_operations = {
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,
.link = btrfs_link,
.mkdir = btrfs_mkdir,
.rmdir = btrfs_rmdir,
.rename = btrfs_rename,
.symlink = btrfs_symlink,
.setattr = btrfs_setattr,
.mknod = btrfs_mknod,
.setxattr = btrfs_setxattr,
.getxattr = btrfs_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.permission = btrfs_permission,
};
static struct inode_operations btrfs_dir_ro_inode_operations = {
.lookup = btrfs_lookup,
.permission = btrfs_permission,
};
static struct file_operations btrfs_dir_file_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.readdir = btrfs_real_readdir,
.unlocked_ioctl = btrfs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = btrfs_ioctl,
#endif
.release = btrfs_release_file,
.fsync = btrfs_sync_file,
};
static struct extent_io_ops btrfs_extent_io_ops = {
.fill_delalloc = run_delalloc_range,
.submit_bio_hook = btrfs_submit_bio_hook,
.merge_bio_hook = btrfs_merge_bio_hook,
.readpage_end_io_hook = btrfs_readpage_end_io_hook,
.writepage_end_io_hook = btrfs_writepage_end_io_hook,
.writepage_start_hook = btrfs_writepage_start_hook,
.readpage_io_failed_hook = btrfs_io_failed_hook,
.set_bit_hook = btrfs_set_bit_hook,
.clear_bit_hook = btrfs_clear_bit_hook,
};
static struct address_space_operations btrfs_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
.writepages = btrfs_writepages,
.readpages = btrfs_readpages,
.sync_page = block_sync_page,
.bmap = btrfs_bmap,
.direct_IO = btrfs_direct_IO,
.invalidatepage = btrfs_invalidatepage,
.releasepage = btrfs_releasepage,
.set_page_dirty = btrfs_set_page_dirty,
};
static struct address_space_operations btrfs_symlink_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
.invalidatepage = btrfs_invalidatepage,
.releasepage = btrfs_releasepage,
};
static struct inode_operations btrfs_file_inode_operations = {
.truncate = btrfs_truncate,
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.setxattr = btrfs_setxattr,
.getxattr = btrfs_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.permission = btrfs_permission,
};
static struct inode_operations btrfs_special_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.setxattr = btrfs_setxattr,
.getxattr = btrfs_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
};
static struct inode_operations btrfs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
.put_link = page_put_link,
.permission = btrfs_permission,
};
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