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gfiber / kernel / mindspeed / 46ff3b4b582e009a9a9253a8ba608d771b73604c / . / fs / btrfs / inode.c
blob: fd1a06df5bc637c5dad0b0b7e5ce1ce88d5c1616 [file] [log] [blame]
/*
* 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/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/xattr.h>
#include <linux/posix_acl.h>
#include <linux/falloc.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/mount.h>
#include "compat.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"
#include "ordered-data.h"
#include "xattr.h"
#include "tree-log.h"
#include "volumes.h"
#include "compression.h"
#include "locking.h"
#include "free-space-cache.h"
#include "inode-map.h"
struct btrfs_iget_args {
u64 ino;
struct btrfs_root *root;
};
static const struct inode_operations btrfs_dir_inode_operations;
static const struct inode_operations btrfs_symlink_inode_operations;
static const struct inode_operations btrfs_dir_ro_inode_operations;
static const struct inode_operations btrfs_special_inode_operations;
static const struct inode_operations btrfs_file_inode_operations;
static const struct address_space_operations btrfs_aops;
static const struct address_space_operations btrfs_symlink_aops;
static const 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_path_cachep;
struct kmem_cache *btrfs_free_space_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 int btrfs_setsize(struct inode *inode, loff_t newsize);
static int btrfs_truncate(struct inode *inode);
static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end);
static noinline int cow_file_range(struct inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written, int unlock);
static noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode);
static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
struct inode *inode, struct inode *dir,
const struct qstr *qstr)
{
int err;
err = btrfs_init_acl(trans, inode, dir);
if (!err)
err = btrfs_xattr_security_init(trans, inode, dir, qstr);
return err;
}
/*
* this does all the hard work for inserting an inline extent into
* the btree. The caller should have done a btrfs_drop_extents so that
* no overlapping inline items exist in the btree
*/
static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode,
u64 start, size_t size, size_t compressed_size,
int compress_type,
struct page **compressed_pages)
{
struct btrfs_key key;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct page *page = NULL;
char *kaddr;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
int err = 0;
int ret;
size_t cur_size = size;
size_t datasize;
unsigned long offset;
if (compressed_size && compressed_pages)
cur_size = compressed_size;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
key.objectid = btrfs_ino(inode);
key.offset = start;
btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
datasize = btrfs_file_extent_calc_inline_size(cur_size);
inode_add_bytes(inode, size);
ret = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
BUG_ON(ret);
if (ret) {
err = ret;
goto fail;
}
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);
btrfs_set_file_extent_encryption(leaf, ei, 0);
btrfs_set_file_extent_other_encoding(leaf, ei, 0);
btrfs_set_file_extent_ram_bytes(leaf, ei, size);
ptr = btrfs_file_extent_inline_start(ei);
if (compress_type != BTRFS_COMPRESS_NONE) {
struct page *cpage;
int i = 0;
while (compressed_size > 0) {
cpage = compressed_pages[i];
cur_size = min_t(unsigned long, compressed_size,
PAGE_CACHE_SIZE);
kaddr = kmap_atomic(cpage, KM_USER0);
write_extent_buffer(leaf, kaddr, ptr, cur_size);
kunmap_atomic(kaddr, KM_USER0);
i++;
ptr += cur_size;
compressed_size -= cur_size;
}
btrfs_set_file_extent_compression(leaf, ei,
compress_type);
} else {
page = find_get_page(inode->i_mapping,
start >> PAGE_CACHE_SHIFT);
btrfs_set_file_extent_compression(leaf, ei, 0);
kaddr = kmap_atomic(page, KM_USER0);
offset = start & (PAGE_CACHE_SIZE - 1);
write_extent_buffer(leaf, kaddr + offset, ptr, size);
kunmap_atomic(kaddr, KM_USER0);
page_cache_release(page);
}
btrfs_mark_buffer_dirty(leaf);
btrfs_free_path(path);
/*
* we're an inline extent, so nobody can
* extend the file past i_size without locking
* a page we already have locked.
*
* We must do any isize and inode updates
* before we unlock the pages. Otherwise we
* could end up racing with unlink.
*/
BTRFS_I(inode)->disk_i_size = inode->i_size;
btrfs_update_inode(trans, root, inode);
return 0;
fail:
btrfs_free_path(path);
return err;
}
/*
* conditionally insert an inline extent into the file. This
* does the checks required to make sure the data is small enough
* to fit as an inline extent.
*/
static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode, u64 start, u64 end,
size_t compressed_size, int compress_type,
struct page **compressed_pages)
{
u64 isize = i_size_read(inode);
u64 actual_end = min(end + 1, isize);
u64 inline_len = actual_end - start;
u64 aligned_end = (end + root->sectorsize - 1) &
~((u64)root->sectorsize - 1);
u64 hint_byte;
u64 data_len = inline_len;
int ret;
if (compressed_size)
data_len = compressed_size;
if (start > 0 ||
actual_end >= PAGE_CACHE_SIZE ||
data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
(!compressed_size &&
(actual_end & (root->sectorsize - 1)) == 0) ||
end + 1 < isize ||
data_len > root->fs_info->max_inline) {
return 1;
}
ret = btrfs_drop_extents(trans, inode, start, aligned_end,
&hint_byte, 1);
BUG_ON(ret);
if (isize > actual_end)
inline_len = min_t(u64, isize, actual_end);
ret = insert_inline_extent(trans, root, inode, start,
inline_len, compressed_size,
compress_type, compressed_pages);
BUG_ON(ret);
btrfs_delalloc_release_metadata(inode, end + 1 - start);
btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
return 0;
}
struct async_extent {
u64 start;
u64 ram_size;
u64 compressed_size;
struct page **pages;
unsigned long nr_pages;
int compress_type;
struct list_head list;
};
struct async_cow {
struct inode *inode;
struct btrfs_root *root;
struct page *locked_page;
u64 start;
u64 end;
struct list_head extents;
struct btrfs_work work;
};
static noinline int add_async_extent(struct async_cow *cow,
u64 start, u64 ram_size,
u64 compressed_size,
struct page **pages,
unsigned long nr_pages,
int compress_type)
{
struct async_extent *async_extent;
async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
BUG_ON(!async_extent);
async_extent->start = start;
async_extent->ram_size = ram_size;
async_extent->compressed_size = compressed_size;
async_extent->pages = pages;
async_extent->nr_pages = nr_pages;
async_extent->compress_type = compress_type;
list_add_tail(&async_extent->list, &cow->extents);
return 0;
}
/*
* we create compressed extents in two phases. The first
* phase compresses a range of pages that have already been
* locked (both pages and state bits are locked).
*
* This is done inside an ordered work queue, and the compression
* is spread across many cpus. The actual IO submission is step
* two, and the ordered work queue takes care of making sure that
* happens in the same order things were put onto the queue by
* writepages and friends.
*
* If this code finds it can't get good compression, it puts an
* entry onto the work queue to write the uncompressed bytes. This
* makes sure that both compressed inodes and uncompressed inodes
* are written in the same order that pdflush sent them down.
*/
static noinline int compress_file_range(struct inode *inode,
struct page *locked_page,
u64 start, u64 end,
struct async_cow *async_cow,
int *num_added)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
u64 num_bytes;
u64 blocksize = root->sectorsize;
u64 actual_end;
u64 isize = i_size_read(inode);
int ret = 0;
struct page **pages = NULL;
unsigned long nr_pages;
unsigned long nr_pages_ret = 0;
unsigned long total_compressed = 0;
unsigned long total_in = 0;
unsigned long max_compressed = 128 * 1024;
unsigned long max_uncompressed = 128 * 1024;
int i;
int will_compress;
int compress_type = root->fs_info->compress_type;
/* if this is a small write inside eof, kick off a defragbot */
if (end <= BTRFS_I(inode)->disk_i_size && (end - start + 1) < 16 * 1024)
btrfs_add_inode_defrag(NULL, inode);
actual_end = min_t(u64, isize, end + 1);
again:
will_compress = 0;
nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
/*
* we don't want to send crud past the end of i_size through
* compression, that's just a waste of CPU time. So, if the
* end of the file is before the start of our current
* requested range of bytes, we bail out to the uncompressed
* cleanup code that can deal with all of this.
*
* It isn't really the fastest way to fix things, but this is a
* very uncommon corner.
*/
if (actual_end <= start)
goto cleanup_and_bail_uncompressed;
total_compressed = actual_end - start;
/* we want to make sure that amount of ram required to uncompress
* an extent is reasonable, so we limit the total size in ram
* of a compressed extent to 128k. This is a crucial number
* because it also controls how easily we can spread reads across
* cpus for decompression.
*
* We also want to make sure the amount of IO required to do
* a random read is reasonably small, so we limit the size of
* a compressed extent to 128k.
*/
total_compressed = min(total_compressed, max_uncompressed);
num_bytes = (end - start + blocksize) & ~(blocksize - 1);
num_bytes = max(blocksize, num_bytes);
total_in = 0;
ret = 0;
/*
* we do compression for mount -o compress and when the
* inode has not been flagged as nocompress. This flag can
* change at any time if we discover bad compression ratios.
*/
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
(btrfs_test_opt(root, COMPRESS) ||
(BTRFS_I(inode)->force_compress) ||
(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
WARN_ON(pages);
pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
if (!pages) {
/* just bail out to the uncompressed code */
goto cont;
}
if (BTRFS_I(inode)->force_compress)
compress_type = BTRFS_I(inode)->force_compress;
ret = btrfs_compress_pages(compress_type,
inode->i_mapping, start,
total_compressed, pages,
nr_pages, &nr_pages_ret,
&total_in,
&total_compressed,
max_compressed);
if (!ret) {
unsigned long offset = total_compressed &
(PAGE_CACHE_SIZE - 1);
struct page *page = pages[nr_pages_ret - 1];
char *kaddr;
/* zero the tail end of the last page, we might be
* sending it down to disk
*/
if (offset) {
kaddr = kmap_atomic(page, KM_USER0);
memset(kaddr + offset, 0,
PAGE_CACHE_SIZE - offset);
kunmap_atomic(kaddr, KM_USER0);
}
will_compress = 1;
}
}
cont:
if (start == 0) {
trans = btrfs_join_transaction(root);
BUG_ON(IS_ERR(trans));
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
/* lets try to make an inline extent */
if (ret || total_in < (actual_end - start)) {
/* we didn't compress the entire range, try
* to make an uncompressed inline extent.
*/
ret = cow_file_range_inline(trans, root, inode,
start, end, 0, 0, NULL);
} else {
/* try making a compressed inline extent */
ret = cow_file_range_inline(trans, root, inode,
start, end,
total_compressed,
compress_type, pages);
}
if (ret == 0) {
/*
* inline extent creation worked, we don't need
* to create any more async work items. Unlock
* and free up our temp pages.
*/
extent_clear_unlock_delalloc(inode,
&BTRFS_I(inode)->io_tree,
start, end, NULL,
EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
EXTENT_CLEAR_DELALLOC |
EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
btrfs_end_transaction(trans, root);
goto free_pages_out;
}
btrfs_end_transaction(trans, root);
}
if (will_compress) {
/*
* we aren't doing an inline extent round the compressed size
* up to a block size boundary so the allocator does sane
* things
*/
total_compressed = (total_compressed + blocksize - 1) &
~(blocksize - 1);
/*
* one last check to make sure the compression is really a
* win, compare the page count read with the blocks on disk
*/
total_in = (total_in + PAGE_CACHE_SIZE - 1) &
~(PAGE_CACHE_SIZE - 1);
if (total_compressed >= total_in) {
will_compress = 0;
} else {
num_bytes = total_in;
}
}
if (!will_compress && pages) {
/*
* the compression code ran but failed to make things smaller,
* free any pages it allocated and our page pointer array
*/
for (i = 0; i < nr_pages_ret; i++) {
WARN_ON(pages[i]->mapping);
page_cache_release(pages[i]);
}
kfree(pages);
pages = NULL;
total_compressed = 0;
nr_pages_ret = 0;
/* flag the file so we don't compress in the future */
if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
!(BTRFS_I(inode)->force_compress)) {
BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
}
}
if (will_compress) {
*num_added += 1;
/* the async work queues will take care of doing actual
* allocation on disk for these compressed pages,
* and will submit them to the elevator.
*/
add_async_extent(async_cow, start, num_bytes,
total_compressed, pages, nr_pages_ret,
compress_type);
if (start + num_bytes < end) {
start += num_bytes;
pages = NULL;
cond_resched();
goto again;
}
} else {
cleanup_and_bail_uncompressed:
/*
* No compression, but we still need to write the pages in
* the file we've been given so far. redirty the locked
* page if it corresponds to our extent and set things up
* for the async work queue to run cow_file_range to do
* the normal delalloc dance
*/
if (page_offset(locked_page) >= start &&
page_offset(locked_page) <= end) {
__set_page_dirty_nobuffers(locked_page);
/* unlocked later on in the async handlers */
}
add_async_extent(async_cow, start, end - start + 1,
0, NULL, 0, BTRFS_COMPRESS_NONE);
*num_added += 1;
}
out:
return 0;
free_pages_out:
for (i = 0; i < nr_pages_ret; i++) {
WARN_ON(pages[i]->mapping);
page_cache_release(pages[i]);
}
kfree(pages);
goto out;
}
/*
* phase two of compressed writeback. This is the ordered portion
* of the code, which only gets called in the order the work was
* queued. We walk all the async extents created by compress_file_range
* and send them down to the disk.
*/
static noinline int submit_compressed_extents(struct inode *inode,
struct async_cow *async_cow)
{
struct async_extent *async_extent;
u64 alloc_hint = 0;
struct btrfs_trans_handle *trans;
struct btrfs_key ins;
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_io_tree *io_tree;
int ret = 0;
if (list_empty(&async_cow->extents))
return 0;
while (!list_empty(&async_cow->extents)) {
async_extent = list_entry(async_cow->extents.next,
struct async_extent, list);
list_del(&async_extent->list);
io_tree = &BTRFS_I(inode)->io_tree;
retry:
/* did the compression code fall back to uncompressed IO? */
if (!async_extent->pages) {
int page_started = 0;
unsigned long nr_written = 0;
lock_extent(io_tree, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, GFP_NOFS);
/* allocate blocks */
ret = cow_file_range(inode, async_cow->locked_page,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
&page_started, &nr_written, 0);
/*
* if page_started, cow_file_range inserted an
* inline extent and took care of all the unlocking
* and IO for us. Otherwise, we need to submit
* all those pages down to the drive.
*/
if (!page_started && !ret)
extent_write_locked_range(io_tree,
inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
btrfs_get_extent,
WB_SYNC_ALL);
kfree(async_extent);
cond_resched();
continue;
}
lock_extent(io_tree, async_extent->start,
async_extent->start + async_extent->ram_size - 1,
GFP_NOFS);
trans = btrfs_join_transaction(root);
BUG_ON(IS_ERR(trans));
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
ret = btrfs_reserve_extent(trans, root,
async_extent->compressed_size,
async_extent->compressed_size,
0, alloc_hint,
(u64)-1, &ins, 1);
btrfs_end_transaction(trans, root);
if (ret) {
int i;
for (i = 0; i < async_extent->nr_pages; i++) {
WARN_ON(async_extent->pages[i]->mapping);
page_cache_release(async_extent->pages[i]);
}
kfree(async_extent->pages);
async_extent->nr_pages = 0;
async_extent->pages = NULL;
unlock_extent(io_tree, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, GFP_NOFS);
goto retry;
}
/*
* here we're doing allocation and writeback of the
* compressed pages
*/
btrfs_drop_extent_cache(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);
em = alloc_extent_map();
BUG_ON(!em);
em->start = async_extent->start;
em->len = async_extent->ram_size;
em->orig_start = em->start;
em->block_start = ins.objectid;
em->block_len = ins.offset;
em->bdev = root->fs_info->fs_devices->latest_bdev;
em->compress_type = async_extent->compress_type;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
}
btrfs_drop_extent_cache(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);
}
ret = btrfs_add_ordered_extent_compress(inode,
async_extent->start,
ins.objectid,
async_extent->ram_size,
ins.offset,
BTRFS_ORDERED_COMPRESSED,
async_extent->compress_type);
BUG_ON(ret);
/*
* clear dirty, set writeback and unlock the pages.
*/
extent_clear_unlock_delalloc(inode,
&BTRFS_I(inode)->io_tree,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
NULL, EXTENT_CLEAR_UNLOCK_PAGE |
EXTENT_CLEAR_UNLOCK |
EXTENT_CLEAR_DELALLOC |
EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
ret = btrfs_submit_compressed_write(inode,
async_extent->start,
async_extent->ram_size,
ins.objectid,
ins.offset, async_extent->pages,
async_extent->nr_pages);
BUG_ON(ret);
alloc_hint = ins.objectid + ins.offset;
kfree(async_extent);
cond_resched();
}
return 0;
}
static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
u64 num_bytes)
{
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_map *em;
u64 alloc_hint = 0;
read_lock(&em_tree->lock);
em = search_extent_mapping(em_tree, start, num_bytes);
if (em) {
/*
* if block start isn't an actual block number then find the
* first block in this inode and use that as a hint. If that
* block is also bogus then just don't worry about it.
*/
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
free_extent_map(em);
em = search_extent_mapping(em_tree, 0, 0);
if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
alloc_hint = em->block_start;
if (em)
free_extent_map(em);
} else {
alloc_hint = em->block_start;
free_extent_map(em);
}
}
read_unlock(&em_tree->lock);
return alloc_hint;
}
/*
* 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.
*
* locked_page is the page that writepage had locked already. We use
* it to make sure we don't do extra locks or unlocks.
*
* *page_started is set to one if we unlock locked_page and do everything
* required to start IO on it. It may be clean and already done with
* IO when we return.
*/
static noinline int cow_file_range(struct inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written,
int unlock)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
u64 alloc_hint = 0;
u64 num_bytes;
unsigned long ram_size;
u64 disk_num_bytes;
u64 cur_alloc_size;
u64 blocksize = root->sectorsize;
struct btrfs_key ins;
struct extent_map *em;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
int ret = 0;
BUG_ON(btrfs_is_free_space_inode(root, inode));
trans = btrfs_join_transaction(root);
BUG_ON(IS_ERR(trans));
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
num_bytes = (end - start + blocksize) & ~(blocksize - 1);
num_bytes = max(blocksize, num_bytes);
disk_num_bytes = num_bytes;
ret = 0;
/* if this is a small write inside eof, kick off defrag */
if (end <= BTRFS_I(inode)->disk_i_size && num_bytes < 64 * 1024)
btrfs_add_inode_defrag(trans, inode);
if (start == 0) {
/* lets try to make an inline extent */
ret = cow_file_range_inline(trans, root, inode,
start, end, 0, 0, NULL);
if (ret == 0) {
extent_clear_unlock_delalloc(inode,
&BTRFS_I(inode)->io_tree,
start, end, NULL,
EXTENT_CLEAR_UNLOCK_PAGE |
EXTENT_CLEAR_UNLOCK |
EXTENT_CLEAR_DELALLOC |
EXTENT_CLEAR_DIRTY |
EXTENT_SET_WRITEBACK |
EXTENT_END_WRITEBACK);
*nr_written = *nr_written +
(end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
*page_started = 1;
ret = 0;
goto out;
}
}
BUG_ON(disk_num_bytes >
btrfs_super_total_bytes(root->fs_info->super_copy));
alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
while (disk_num_bytes > 0) {
unsigned long op;
cur_alloc_size = disk_num_bytes;
ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
root->sectorsize, 0, alloc_hint,
(u64)-1, &ins, 1);
BUG_ON(ret);
em = alloc_extent_map();
BUG_ON(!em);
em->start = start;
em->orig_start = em->start;
ram_size = ins.offset;
em->len = ins.offset;
em->block_start = ins.objectid;
em->block_len = ins.offset;
em->bdev = root->fs_info->fs_devices->latest_bdev;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
}
btrfs_drop_extent_cache(inode, start,
start + ram_size - 1, 0);
}
cur_alloc_size = ins.offset;
ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
ram_size, cur_alloc_size, 0);
BUG_ON(ret);
if (root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID) {
ret = btrfs_reloc_clone_csums(inode, start,
cur_alloc_size);
BUG_ON(ret);
}
if (disk_num_bytes < cur_alloc_size)
break;
/* we're not doing compressed IO, don't unlock the first
* page (which the caller expects to stay locked), don't
* clear any dirty bits and don't set any writeback bits
*
* Do set the Private2 bit so we know this page was properly
* setup for writepage
*/
op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
EXTENT_SET_PRIVATE2;
extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
start, start + ram_size - 1,
locked_page, op);
disk_num_bytes -= cur_alloc_size;
num_bytes -= cur_alloc_size;
alloc_hint = ins.objectid + ins.offset;
start += cur_alloc_size;
}
out:
ret = 0;
btrfs_end_transaction(trans, root);
return ret;
}
/*
* work queue call back to started compression on a file and pages
*/
static noinline void async_cow_start(struct btrfs_work *work)
{
struct async_cow *async_cow;
int num_added = 0;
async_cow = container_of(work, struct async_cow, work);
compress_file_range(async_cow->inode, async_cow->locked_page,
async_cow->start, async_cow->end, async_cow,
&num_added);
if (num_added == 0)
async_cow->inode = NULL;
}
/*
* work queue call back to submit previously compressed pages
*/
static noinline void async_cow_submit(struct btrfs_work *work)
{
struct async_cow *async_cow;
struct btrfs_root *root;
unsigned long nr_pages;
async_cow = container_of(work, struct async_cow, work);
root = async_cow->root;
nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
PAGE_CACHE_SHIFT;
atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages);
if (atomic_read(&root->fs_info->async_delalloc_pages) <
5 * 1042 * 1024 &&
waitqueue_active(&root->fs_info->async_submit_wait))
wake_up(&root->fs_info->async_submit_wait);
if (async_cow->inode)
submit_compressed_extents(async_cow->inode, async_cow);
}
static noinline void async_cow_free(struct btrfs_work *work)
{
struct async_cow *async_cow;
async_cow = container_of(work, struct async_cow, work);
kfree(async_cow);
}
static int cow_file_range_async(struct inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written)
{
struct async_cow *async_cow;
struct btrfs_root *root = BTRFS_I(inode)->root;
unsigned long nr_pages;
u64 cur_end;
int limit = 10 * 1024 * 1042;
clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1, 0, NULL, GFP_NOFS);
while (start < end) {
async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
BUG_ON(!async_cow);
async_cow->inode = inode;
async_cow->root = root;
async_cow->locked_page = locked_page;
async_cow->start = start;
if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
cur_end = end;
else
cur_end = min(end, start + 512 * 1024 - 1);
async_cow->end = cur_end;
INIT_LIST_HEAD(&async_cow->extents);
async_cow->work.func = async_cow_start;
async_cow->work.ordered_func = async_cow_submit;
async_cow->work.ordered_free = async_cow_free;
async_cow->work.flags = 0;
nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
PAGE_CACHE_SHIFT;
atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
btrfs_queue_worker(&root->fs_info->delalloc_workers,
&async_cow->work);
if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
wait_event(root->fs_info->async_submit_wait,
(atomic_read(&root->fs_info->async_delalloc_pages) <
limit));
}
while (atomic_read(&root->fs_info->async_submit_draining) &&
atomic_read(&root->fs_info->async_delalloc_pages)) {
wait_event(root->fs_info->async_submit_wait,
(atomic_read(&root->fs_info->async_delalloc_pages) ==
0));
}
*nr_written += nr_pages;
start = cur_end + 1;
}
*page_started = 1;
return 0;
}
static noinline int csum_exist_in_range(struct btrfs_root *root,
u64 bytenr, u64 num_bytes)
{
int ret;
struct btrfs_ordered_sum *sums;
LIST_HEAD(list);
ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
bytenr + num_bytes - 1, &list, 0);
if (ret == 0 && list_empty(&list))
return 0;
while (!list_empty(&list)) {
sums = list_entry(list.next, struct btrfs_ordered_sum, list);
list_del(&sums->list);
kfree(sums);
}
return 1;
}
/*
* 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 noinline int run_delalloc_nocow(struct inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started, int force,
unsigned long *nr_written)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
struct extent_buffer *leaf;
struct btrfs_path *path;
struct btrfs_file_extent_item *fi;
struct btrfs_key found_key;
u64 cow_start;
u64 cur_offset;
u64 extent_end;
u64 extent_offset;
u64 disk_bytenr;
u64 num_bytes;
int extent_type;
int ret;
int type;
int nocow;
int check_prev = 1;
bool nolock;
u64 ino = btrfs_ino(inode);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
nolock = btrfs_is_free_space_inode(root, inode);
if (nolock)
trans = btrfs_join_transaction_nolock(root);
else
trans = btrfs_join_transaction(root);
BUG_ON(IS_ERR(trans));
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
cow_start = (u64)-1;
cur_offset = start;
while (1) {
ret = btrfs_lookup_file_extent(trans, root, path, ino,
cur_offset, 0);
BUG_ON(ret < 0);
if (ret > 0 && path->slots[0] > 0 && check_prev) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key,
path->slots[0] - 1);
if (found_key.objectid == ino &&
found_key.type == BTRFS_EXTENT_DATA_KEY)
path->slots[0]--;
}
check_prev = 0;
next_slot:
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
BUG_ON(1);
if (ret > 0)
break;
leaf = path->nodes[0];
}
nocow = 0;
disk_bytenr = 0;
num_bytes = 0;
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid > ino ||
found_key.type > BTRFS_EXTENT_DATA_KEY ||
found_key.offset > end)
break;
if (found_key.offset > cur_offset) {
extent_end = found_key.offset;
extent_type = 0;
goto out_check;
}
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_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
extent_offset = btrfs_file_extent_offset(leaf, fi);
extent_end = found_key.offset +
btrfs_file_extent_num_bytes(leaf, fi);
if (extent_end <= start) {
path->slots[0]++;
goto next_slot;
}
if (disk_bytenr == 0)
goto out_check;
if (btrfs_file_extent_compression(leaf, fi) ||
btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
goto out_check;
if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
goto out_check;
if (btrfs_extent_readonly(root, disk_bytenr))
goto out_check;
if (btrfs_cross_ref_exist(trans, root, ino,
found_key.offset -
extent_offset, disk_bytenr))
goto out_check;
disk_bytenr += extent_offset;
disk_bytenr += cur_offset - found_key.offset;
num_bytes = min(end + 1, extent_end) - cur_offset;
/*
* force cow if csum exists in the range.
* this ensure that csum for a given extent are
* either valid or do not exist.
*/
if (csum_exist_in_range(root, disk_bytenr, num_bytes))
goto out_check;
nocow = 1;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
extent_end = found_key.offset +
btrfs_file_extent_inline_len(leaf, fi);
extent_end = ALIGN(extent_end, root->sectorsize);
} else {
BUG_ON(1);
}
out_check:
if (extent_end <= start) {
path->slots[0]++;
goto next_slot;
}
if (!nocow) {
if (cow_start == (u64)-1)
cow_start = cur_offset;
cur_offset = extent_end;
if (cur_offset > end)
break;
path->slots[0]++;
goto next_slot;
}
btrfs_release_path(path);
if (cow_start != (u64)-1) {
ret = cow_file_range(inode, locked_page, cow_start,
found_key.offset - 1, page_started,
nr_written, 1);
BUG_ON(ret);
cow_start = (u64)-1;
}
if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
struct extent_map *em;
struct extent_map_tree *em_tree;
em_tree = &BTRFS_I(inode)->extent_tree;
em = alloc_extent_map();
BUG_ON(!em);
em->start = cur_offset;
em->orig_start = em->start;
em->len = num_bytes;
em->block_len = num_bytes;
em->block_start = disk_bytenr;
em->bdev = root->fs_info->fs_devices->latest_bdev;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
}
btrfs_drop_extent_cache(inode, em->start,
em->start + em->len - 1, 0);
}
type = BTRFS_ORDERED_PREALLOC;
} else {
type = BTRFS_ORDERED_NOCOW;
}
ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
num_bytes, num_bytes, type);
BUG_ON(ret);
if (root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID) {
ret = btrfs_reloc_clone_csums(inode, cur_offset,
num_bytes);
BUG_ON(ret);
}
extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
cur_offset, cur_offset + num_bytes - 1,
locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
EXTENT_SET_PRIVATE2);
cur_offset = extent_end;
if (cur_offset > end)
break;
}
btrfs_release_path(path);
if (cur_offset <= end && cow_start == (u64)-1)
cow_start = cur_offset;
if (cow_start != (u64)-1) {
ret = cow_file_range(inode, locked_page, cow_start, end,
page_started, nr_written, 1);
BUG_ON(ret);
}
if (nolock) {
ret = btrfs_end_transaction_nolock(trans, root);
BUG_ON(ret);
} else {
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
}
btrfs_free_path(path);
return 0;
}
/*
* extent_io.c call back to do delayed allocation processing
*/
static int run_delalloc_range(struct inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written)
{
int ret;
struct btrfs_root *root = BTRFS_I(inode)->root;
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 1, nr_written);
else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 0, nr_written);
else if (!btrfs_test_opt(root, COMPRESS) &&
!(BTRFS_I(inode)->force_compress) &&
!(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))
ret = cow_file_range(inode, locked_page, start, end,
page_started, nr_written, 1);
else
ret = cow_file_range_async(inode, locked_page, start, end,
page_started, nr_written);
return ret;
}
static void btrfs_split_extent_hook(struct inode *inode,
struct extent_state *orig, u64 split)
{
/* not delalloc, ignore it */
if (!(orig->state & EXTENT_DELALLOC))
return;
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents++;
spin_unlock(&BTRFS_I(inode)->lock);
}
/*
* extent_io.c merge_extent_hook, used to track merged delayed allocation
* extents so we can keep track of new extents that are just merged onto old
* extents, such as when we are doing sequential writes, so we can properly
* account for the metadata space we'll need.
*/
static void btrfs_merge_extent_hook(struct inode *inode,
struct extent_state *new,
struct extent_state *other)
{
/* not delalloc, ignore it */
if (!(other->state & EXTENT_DELALLOC))
return;
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents--;
spin_unlock(&BTRFS_I(inode)->lock);
}
/*
* 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.
*/
static void btrfs_set_bit_hook(struct inode *inode,
struct extent_state *state, int *bits)
{
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 len = state->end + 1 - state->start;
bool do_list = !btrfs_is_free_space_inode(root, inode);
if (*bits & EXTENT_FIRST_DELALLOC) {
*bits &= ~EXTENT_FIRST_DELALLOC;
} else {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents++;
spin_unlock(&BTRFS_I(inode)->lock);
}
spin_lock(&root->fs_info->delalloc_lock);
BTRFS_I(inode)->delalloc_bytes += len;
root->fs_info->delalloc_bytes += len;
if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
&root->fs_info->delalloc_inodes);
}
spin_unlock(&root->fs_info->delalloc_lock);
}
}
/*
* extent_io.c clear_bit_hook, see set_bit_hook for why
*/
static void btrfs_clear_bit_hook(struct inode *inode,
struct extent_state *state, int *bits)
{
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 len = state->end + 1 - state->start;
bool do_list = !btrfs_is_free_space_inode(root, inode);
if (*bits & EXTENT_FIRST_DELALLOC) {
*bits &= ~EXTENT_FIRST_DELALLOC;
} else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents--;
spin_unlock(&BTRFS_I(inode)->lock);
}
if (*bits & EXTENT_DO_ACCOUNTING)
btrfs_delalloc_release_metadata(inode, len);
if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
&& do_list)
btrfs_free_reserved_data_space(inode, len);
spin_lock(&root->fs_info->delalloc_lock);
root->fs_info->delalloc_bytes -= len;
BTRFS_I(inode)->delalloc_bytes -= len;
if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_del_init(&BTRFS_I(inode)->delalloc_inodes);
}
spin_unlock(&root->fs_info->delalloc_lock);
}
}
/*
* 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,
unsigned long bio_flags)
{
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;
if (bio_flags & EXTENT_BIO_COMPRESSED)
return 0;
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 ret;
}
/*
* 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
*/
static int __btrfs_submit_bio_start(struct inode *inode, int rw,
struct bio *bio, int mirror_num,
unsigned long bio_flags,
u64 bio_offset)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret = 0;
ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
BUG_ON(ret);
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
*/
static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
int mirror_num, unsigned long bio_flags,
u64 bio_offset)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
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
*/
static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
int mirror_num, unsigned long bio_flags,
u64 bio_offset)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret = 0;
int skip_sum;
skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
if (btrfs_is_free_space_inode(root, inode))
ret = btrfs_bio_wq_end_io(root->fs_info, bio, 2);
else
ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
BUG_ON(ret);
if (!(rw & REQ_WRITE)) {
if (bio_flags & EXTENT_BIO_COMPRESSED) {
return btrfs_submit_compressed_read(inode, bio,
mirror_num, bio_flags);
} else if (!skip_sum) {
ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
if (ret)
return ret;
}
goto mapit;
} else if (!skip_sum) {
/* csum items have already been cloned */
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
goto mapit;
/* we're doing a write, do the async checksumming */
return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
inode, rw, bio, mirror_num,
bio_flags, bio_offset,
__btrfs_submit_bio_start,
__btrfs_submit_bio_done);
}
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 btrfs_ordered_sum *sum;
list_for_each_entry(sum, list, list) {
btrfs_csum_file_blocks(trans,
BTRFS_I(inode)->root->fs_info->csum_root, sum);
}
return 0;
}
int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
struct extent_state **cached_state)
{
if ((end & (PAGE_CACHE_SIZE - 1)) == 0)
WARN_ON(1);
return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
cached_state, 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;
};
static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
{
struct btrfs_writepage_fixup *fixup;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
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_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
&cached_state, GFP_NOFS);
/* already ordered? We're done */
if (PagePrivate2(page))
goto out;
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
page_end, &cached_state, GFP_NOFS);
unlock_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
goto again;
}
BUG();
btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
ClearPageChecked(page);
out:
unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
&cached_state, GFP_NOFS);
out_page:
unlock_page(page);
page_cache_release(page);
kfree(fixup);
}
/*
* 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 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.
*/
static 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;
/* this page is properly in the ordered list */
if (TestClearPagePrivate2(page))
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;
}
static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
struct inode *inode, u64 file_pos,
u64 disk_bytenr, u64 disk_num_bytes,
u64 num_bytes, u64 ram_bytes,
u8 compression, u8 encryption,
u16 other_encoding, int extent_type)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_extent_item *fi;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key ins;
u64 hint;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
/*
* we may be replacing one extent in the tree with another.
* The new extent is pinned in the extent map, and we don't want
* to drop it from the cache until it is completely in the btree.
*
* So, tell btrfs_drop_extents to leave this extent in the cache.
* the caller is expected to unpin it and allow it to be merged
* with the others.
*/
ret = btrfs_drop_extents(trans, inode, file_pos, file_pos + num_bytes,
&hint, 0);
BUG_ON(ret);
ins.objectid = btrfs_ino(inode);
ins.offset = file_pos;
ins.type = BTRFS_EXTENT_DATA_KEY;
ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
BUG_ON(ret);
leaf = path->nodes[0];
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, fi, trans->transid);
btrfs_set_file_extent_type(leaf, fi, extent_type);
btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
btrfs_set_file_extent_offset(leaf, fi, 0);
btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
btrfs_set_file_extent_compression(leaf, fi, compression);
btrfs_set_file_extent_encryption(leaf, fi, encryption);
btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
btrfs_unlock_up_safe(path, 1);
btrfs_set_lock_blocking(leaf);
btrfs_mark_buffer_dirty(leaf);
inode_add_bytes(inode, num_bytes);
ins.objectid = disk_bytenr;
ins.offset = disk_num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_alloc_reserved_file_extent(trans, root,
root->root_key.objectid,
btrfs_ino(inode), file_pos, &ins);
BUG_ON(ret);
btrfs_free_path(path);
return 0;
}
/*
* helper function for btrfs_finish_ordered_io, this
* just reads in some of the csum leaves to prime them into ram
* before we start the transaction. It limits the amount of btree
* reads required while inside the transaction.
*/
/* 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 = NULL;
struct btrfs_ordered_extent *ordered_extent = NULL;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_state *cached_state = NULL;
int compress_type = 0;
int ret;
bool nolock;
ret = btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
end - start + 1);
if (!ret)
return 0;
BUG_ON(!ordered_extent);
nolock = btrfs_is_free_space_inode(root, inode);
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
BUG_ON(!list_empty(&ordered_extent->list));
ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
if (!ret) {
if (nolock)
trans = btrfs_join_transaction_nolock(root);
else
trans = btrfs_join_transaction(root);
BUG_ON(IS_ERR(trans));
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
ret = btrfs_update_inode_fallback(trans, root, inode);
BUG_ON(ret);
}
goto out;
}
lock_extent_bits(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
0, &cached_state, GFP_NOFS);
if (nolock)
trans = btrfs_join_transaction_nolock(root);
else
trans = btrfs_join_transaction(root);
BUG_ON(IS_ERR(trans));
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
compress_type = ordered_extent->compress_type;
if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
BUG_ON(compress_type);
ret = btrfs_mark_extent_written(trans, inode,
ordered_extent->file_offset,
ordered_extent->file_offset +
ordered_extent->len);
BUG_ON(ret);
} else {
BUG_ON(root == root->fs_info->tree_root);
ret = insert_reserved_file_extent(trans, inode,
ordered_extent->file_offset,
ordered_extent->start,
ordered_extent->disk_len,
ordered_extent->len,
ordered_extent->len,
compress_type, 0, 0,
BTRFS_FILE_EXTENT_REG);
unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
ordered_extent->file_offset,
ordered_extent->len);
BUG_ON(ret);
}
unlock_extent_cached(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset +
ordered_extent->len - 1, &cached_state, GFP_NOFS);
add_pending_csums(trans, inode, ordered_extent->file_offset,
&ordered_extent->list);
ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
if (!ret || !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
ret = btrfs_update_inode_fallback(trans, root, inode);
BUG_ON(ret);
}
ret = 0;
out:
if (root != root->fs_info->tree_root)
btrfs_delalloc_release_metadata(inode, ordered_extent->len);
if (trans) {
if (nolock)
btrfs_end_transaction_nolock(trans, root);
else
btrfs_end_transaction(trans, root);
}
/* once for us */
btrfs_put_ordered_extent(ordered_extent);
/* once for the tree */
btrfs_put_ordered_extent(ordered_extent);
return 0;
}
static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
struct extent_state *state, int uptodate)
{
trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
ClearPagePrivate2(page);
return btrfs_finish_ordered_io(page->mapping->host, start, end);
}
/*
* 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, the code in
* extent_io.c will try to find good copies for us.
*/
static 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;
if (PageChecked(page)) {
ClearPageChecked(page);
goto good;
}
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
goto good;
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
GFP_NOFS);
return 0;
}
if (state && state->start == start) {
private = state->private;
ret = 0;
} else {
ret = get_state_private(io_tree, start, &private);
}
kaddr = kmap_atomic(page, KM_USER0);
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_USER0);
good:
return 0;
zeroit:
printk_ratelimited(KERN_INFO "btrfs csum failed ino %llu off %llu csum %u "
"private %llu\n",
(unsigned long long)btrfs_ino(page->mapping->host),
(unsigned long long)start, csum,
(unsigned long long)private);
memset(kaddr + offset, 1, end - start + 1);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
if (private == 0)
return 0;
return -EIO;
}
struct delayed_iput {
struct list_head list;
struct inode *inode;
};
void btrfs_add_delayed_iput(struct inode *inode)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct delayed_iput *delayed;
if (atomic_add_unless(&inode->i_count, -1, 1))
return;
delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
delayed->inode = inode;
spin_lock(&fs_info->delayed_iput_lock);
list_add_tail(&delayed->list, &fs_info->delayed_iputs);
spin_unlock(&fs_info->delayed_iput_lock);
}
void btrfs_run_delayed_iputs(struct btrfs_root *root)
{
LIST_HEAD(list);
struct btrfs_fs_info *fs_info = root->fs_info;
struct delayed_iput *delayed;
int empty;
spin_lock(&fs_info->delayed_iput_lock);
empty = list_empty(&fs_info->delayed_iputs);
spin_unlock(&fs_info->delayed_iput_lock);
if (empty)
return;
down_read(&root->fs_info->cleanup_work_sem);
spin_lock(&fs_info->delayed_iput_lock);
list_splice_init(&fs_info->delayed_iputs, &list);
spin_unlock(&fs_info->delayed_iput_lock);
while (!list_empty(&list)) {
delayed = list_entry(list.next, struct delayed_iput, list);
list_del(&delayed->list);
iput(delayed->inode);
kfree(delayed);
}
up_read(&root->fs_info->cleanup_work_sem);
}
enum btrfs_orphan_cleanup_state {
ORPHAN_CLEANUP_STARTED = 1,
ORPHAN_CLEANUP_DONE = 2,
};
/*
* This is called in transaction commmit time. If there are no orphan
* files in the subvolume, it removes orphan item and frees block_rsv
* structure.
*/
void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret;
if (!list_empty(&root->orphan_list) ||
root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
return;
if (root->orphan_item_inserted &&
btrfs_root_refs(&root->root_item) > 0) {
ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
root->root_key.objectid);
BUG_ON(ret);
root->orphan_item_inserted = 0;
}
if (root->orphan_block_rsv) {
WARN_ON(root->orphan_block_rsv->size > 0);
btrfs_free_block_rsv(root, root->orphan_block_rsv);
root->orphan_block_rsv = NULL;
}
}
/*
* This creates an orphan entry for the given inode in case something goes
* wrong in the middle of an unlink/truncate.
*
* NOTE: caller of this function should reserve 5 units of metadata for
* this function.
*/
int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *block_rsv = NULL;
int reserve = 0;
int insert = 0;
int ret;
if (!root->orphan_block_rsv) {
block_rsv = btrfs_alloc_block_rsv(root);
if (!block_rsv)
return -ENOMEM;
}
spin_lock(&root->orphan_lock);
if (!root->orphan_block_rsv) {
root->orphan_block_rsv = block_rsv;
} else if (block_rsv) {
btrfs_free_block_rsv(root, block_rsv);
block_rsv = NULL;
}
if (list_empty(&BTRFS_I(inode)->i_orphan)) {
list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
#if 0
/*
* For proper ENOSPC handling, we should do orphan
* cleanup when mounting. But this introduces backward
* compatibility issue.
*/
if (!xchg(&root->orphan_item_inserted, 1))
insert = 2;
else
insert = 1;
#endif
insert = 1;
}
if (!BTRFS_I(inode)->orphan_meta_reserved) {
BTRFS_I(inode)->orphan_meta_reserved = 1;
reserve = 1;
}
spin_unlock(&root->orphan_lock);
/* grab metadata reservation from transaction handle */
if (reserve) {
ret = btrfs_orphan_reserve_metadata(trans, inode);
BUG_ON(ret);
}
/* insert an orphan item to track this unlinked/truncated file */
if (insert >= 1) {
ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
BUG_ON(ret && ret != -EEXIST);
}
/* insert an orphan item to track subvolume contains orphan files */
if (insert >= 2) {
ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
root->root_key.objectid);
BUG_ON(ret);
}
return 0;
}
/*
* 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 delete_item = 0;
int release_rsv = 0;
int ret = 0;
spin_lock(&root->orphan_lock);
if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
list_del_init(&BTRFS_I(inode)->i_orphan);
delete_item = 1;
}
if (BTRFS_I(inode)->orphan_meta_reserved) {
BTRFS_I(inode)->orphan_meta_reserved = 0;
release_rsv = 1;
}
spin_unlock(&root->orphan_lock);
if (trans && delete_item) {
ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
BUG_ON(ret);
}
if (release_rsv)
btrfs_orphan_release_metadata(inode);
return 0;
}
/*
* this cleans up any orphans that may be left on the list from the last use
* of this root.
*/
int btrfs_orphan_cleanup(struct btrfs_root *root)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key, found_key;
struct btrfs_trans_handle *trans;
struct inode *inode;
u64 last_objectid = 0;
int ret = 0, nr_unlink = 0, nr_truncate = 0;
if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
return 0;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
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)
goto out;
/*
* if ret == 0 means we found what we were searching for, which
* is weird, but possible, so only screw with path if we didn't
* find the key and see if we have stuff that matches
*/
if (ret > 0) {
ret = 0;
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
/* pull out the item */
leaf = path->nodes[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(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.
*/
if (found_key.offset == last_objectid) {
printk(KERN_ERR "btrfs: Error removing orphan entry, "
"stopping orphan cleanup\n");
ret = -EINVAL;
goto out;
}
last_objectid = found_key.offset;
found_key.objectid = found_key.offset;
found_key.type = BTRFS_INODE_ITEM_KEY;
found_key.offset = 0;
inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
ret = PTR_RET(inode);
if (ret && ret != -ESTALE)
goto out;
if (ret == -ESTALE && root == root->fs_info->tree_root) {
struct btrfs_root *dead_root;
struct btrfs_fs_info *fs_info = root->fs_info;
int is_dead_root = 0;
/*
* this is an orphan in the tree root. Currently these
* could come from 2 sources:
* a) a snapshot deletion in progress
* b) a free space cache inode
* We need to distinguish those two, as the snapshot
* orphan must not get deleted.
* find_dead_roots already ran before us, so if this
* is a snapshot deletion, we should find the root
* in the dead_roots list
*/
spin_lock(&fs_info->trans_lock);
list_for_each_entry(dead_root, &fs_info->dead_roots,
root_list) {
if (dead_root->root_key.objectid ==
found_key.objectid) {
is_dead_root = 1;
break;
}
}
spin_unlock(&fs_info->trans_lock);
if (is_dead_root) {
/* prevent this orphan from being found again */
key.offset = found_key.objectid - 1;
continue;
}
}
/*
* Inode is already gone but the orphan item is still there,
* kill the orphan item.
*/
if (ret == -ESTALE) {
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
ret = btrfs_del_orphan_item(trans, root,
found_key.objectid);
BUG_ON(ret);
btrfs_end_transaction(trans, root);
continue;
}
/*
* add this inode to the orphan list so btrfs_orphan_del does
* the proper thing when we hit it
*/
spin_lock(&root->orphan_lock);
list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
spin_unlock(&root->orphan_lock);
/* if we have links, this was a truncate, lets do that */
if (inode->i_nlink) {
if (!S_ISREG(inode->i_mode)) {
WARN_ON(1);
iput(inode);
continue;
}
nr_truncate++;
/*
* Need to hold the imutex for reservation purposes, not
* a huge deal here but I have a WARN_ON in
* btrfs_delalloc_reserve_space to catch offenders.
*/
mutex_lock(&inode->i_mutex);
ret = btrfs_truncate(inode);
mutex_unlock(&inode->i_mutex);
} else {
nr_unlink++;
}
/* this will do delete_inode and everything for us */
iput(inode);
if (ret)
goto out;
}
/* release the path since we're done with it */
btrfs_release_path(path);
root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
if (root->orphan_block_rsv)
btrfs_block_rsv_release(root, root->orphan_block_rsv,
(u64)-1);
if (root->orphan_block_rsv || root->orphan_item_inserted) {
trans = btrfs_join_transaction(root);
if (!IS_ERR(trans))
btrfs_end_transaction(trans, root);
}
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);
out:
if (ret)
printk(KERN_CRIT "btrfs: could not do orphan cleanup %d\n", ret);
btrfs_free_path(path);
return ret;
}
/*
* very simple check to peek ahead in the leaf looking for xattrs. If we
* don't find any xattrs, we know there can't be any acls.
*
* slot is the slot the inode is in, objectid is the objectid of the inode
*/
static noinline int acls_after_inode_item(struct extent_buffer *leaf,
int slot, u64 objectid)
{
u32 nritems = btrfs_header_nritems(leaf);
struct btrfs_key found_key;
int scanned = 0;
slot++;
while (slot < nritems) {
btrfs_item_key_to_cpu(leaf, &found_key, slot);
/* we found a different objectid, there must not be acls */
if (found_key.objectid != objectid)
return 0;
/* we found an xattr, assume we've got an acl */
if (found_key.type == BTRFS_XATTR_ITEM_KEY)
return 1;
/*
* we found a key greater than an xattr key, there can't
* be any acls later on
*/
if (found_key.type > BTRFS_XATTR_ITEM_KEY)
return 0;
slot++;
scanned++;
/*
* it goes inode, inode backrefs, xattrs, extents,
* so if there are a ton of hard links to an inode there can
* be a lot of backrefs. Don't waste time searching too hard,
* this is just an optimization
*/
if (scanned >= 8)
break;
}
/* we hit the end of the leaf before we found an xattr or
* something larger than an xattr. We have to assume the inode
* has acls
*/
return 1;
}
/*
* read an inode from the btree into the in-memory inode
*/
static 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;
int maybe_acls;
u32 rdev;
int ret;
bool filled = false;
ret = btrfs_fill_inode(inode, &rdev);
if (!ret)
filled = true;
path = btrfs_alloc_path();
if (!path)
goto make_bad;
path->leave_spinning = 1;
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];
if (filled)
goto cache_acl;
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
inode->i_mode = btrfs_inode_mode(leaf, inode_item);
set_nlink(inode, 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);
BTRFS_I(inode)->sequence = btrfs_inode_sequence(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;
BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
cache_acl:
/*
* try to precache a NULL acl entry for files that don't have
* any xattrs or acls
*/
maybe_acls = acls_after_inode_item(leaf, path->slots[0],
btrfs_ino(inode));
if (!maybe_acls)
cache_no_acl(inode);
btrfs_free_path(path);
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:
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
break;
}
btrfs_update_iflags(inode);
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_sequence(leaf, item, BTRFS_I(inode)->sequence);
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, 0);
}
/*
* copy everything in the in-memory inode into the btree.
*/
static noinline int btrfs_update_inode_item(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();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto failed;
}
btrfs_unlock_up_safe(path, 1);
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;
}
/*
* copy everything in the in-memory inode into the btree.
*/
noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode)
{
int ret;
/*
* If the inode is a free space inode, we can deadlock during commit
* if we put it into the delayed code.
*
* The data relocation inode should also be directly updated
* without delay
*/
if (!btrfs_is_free_space_inode(root, inode)
&& root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
ret = btrfs_delayed_update_inode(trans, root, inode);
if (!ret)
btrfs_set_inode_last_trans(trans, inode);
return ret;
}
return btrfs_update_inode_item(trans, root, inode);
}
static noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode)
{
int ret;
ret = btrfs_update_inode(trans, root, inode);
if (ret == -ENOSPC)
return btrfs_update_inode_item(trans, root, inode);
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
*/
static 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;
u64 ino = btrfs_ino(inode);
u64 dir_ino = btrfs_ino(dir);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
path->leave_spinning = 1;
di = btrfs_lookup_dir_item(trans, root, path, dir_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(path);
ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
dir_ino, &index);
if (ret) {
printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
"inode %llu parent %llu\n", name_len, name,
(unsigned long long)ino, (unsigned long long)dir_ino);
goto err;
}
ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
if (ret)
goto err;
ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
inode, dir_ino);
BUG_ON(ret != 0 && ret != -ENOENT);
ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
dir, index);
if (ret == -ENOENT)
ret = 0;
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);
out:
return ret;
}
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)
{
int ret;
ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
if (!ret) {
btrfs_drop_nlink(inode);
ret = btrfs_update_inode(trans, root, inode);
}
return ret;
}
/* helper to check if there is any shared block in the path */
static int check_path_shared(struct btrfs_root *root,
struct btrfs_path *path)
{
struct extent_buffer *eb;
int level;
u64 refs = 1;
for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
int ret;
if (!path->nodes[level])
break;
eb = path->nodes[level];
if (!btrfs_block_can_be_shared(root, eb))
continue;
ret = btrfs_lookup_extent_info(NULL, root, eb->start, eb->len,
&refs, NULL);
if (refs > 1)
return 1;
}
return 0;
}
/*
* helper to start transaction for unlink and rmdir.
*
* unlink and rmdir are special in btrfs, they do not always free space.
* so in enospc case, we should make sure they will free space before
* allowing them to use the global metadata reservation.
*/
static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
struct dentry *dentry)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_path *path;
struct btrfs_inode_ref *ref;
struct btrfs_dir_item *di;
struct inode *inode = dentry->d_inode;
u64 index;
int check_link = 1;
int err = -ENOSPC;
int ret;
u64 ino = btrfs_ino(inode);
u64 dir_ino = btrfs_ino(dir);
/*
* 1 for the possible orphan item
* 1 for the dir item
* 1 for the dir index
* 1 for the inode ref
* 1 for the inode ref in the tree log
* 2 for the dir entries in the log
* 1 for the inode
*/
trans = btrfs_start_transaction(root, 8);
if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
return trans;
if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
return ERR_PTR(-ENOSPC);
/* check if there is someone else holds reference */
if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
return ERR_PTR(-ENOSPC);
if (atomic_read(&inode->i_count) > 2)
return ERR_PTR(-ENOSPC);
if (xchg(&root->fs_info->enospc_unlink, 1))
return ERR_PTR(-ENOSPC);
path = btrfs_alloc_path();
if (!path) {
root->fs_info->enospc_unlink = 0;
return ERR_PTR(-ENOMEM);
}
/* 1 for the orphan item */
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
btrfs_free_path(path);
root->fs_info->enospc_unlink = 0;
return trans;
}
path->skip_locking = 1;
path->search_commit_root = 1;
ret = btrfs_lookup_inode(trans, root, path,
&BTRFS_I(dir)->location, 0);
if (ret < 0) {
err = ret;
goto out;
}
if (ret == 0) {
if (check_path_shared(root, path))
goto out;
} else {
check_link = 0;
}
btrfs_release_path(path);
ret = btrfs_lookup_inode(trans, root, path,
&BTRFS_I(inode)->location, 0);
if (ret < 0) {
err = ret;
goto out;
}
if (ret == 0) {
if (check_path_shared(root, path))
goto out;
} else {
check_link = 0;
}
btrfs_release_path(path);
if (ret == 0 && S_ISREG(inode->i_mode)) {
ret = btrfs_lookup_file_extent(trans, root, path,
ino, (u64)-1, 0);
if (ret < 0) {
err = ret;
goto out;
}
BUG_ON(ret == 0);
if (check_path_shared(root, path))
goto out;
btrfs_release_path(path);
}
if (!check_link) {
err = 0;
goto out;
}
di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
dentry->d_name.name, dentry->d_name.len, 0);
if (IS_ERR(di)) {
err = PTR_ERR(di);
goto out;
}
if (di) {
if (check_path_shared(root, path))
goto out;
} else {
err = 0;
goto out;
}
btrfs_release_path(path);
ref = btrfs_lookup_inode_ref(trans, root, path,
dentry->d_name.name, dentry->d_name.len,
ino, dir_ino, 0);
if (IS_ERR(ref)) {
err = PTR_ERR(ref);
goto out;
}
BUG_ON(!ref);
if (check_path_shared(root, path))
goto out;
index = btrfs_inode_ref_index(path->nodes[0], ref);
btrfs_release_path(path);
/*
* This is a commit root search, if we can lookup inode item and other
* relative items in the commit root, it means the transaction of
* dir/file creation has been committed, and the dir index item that we
* delay to insert has also been inserted into the commit root. So
* we needn't worry about the delayed insertion of the dir index item
* here.
*/
di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index,
dentry->d_name.name, dentry->d_name.len, 0);
if (IS_ERR(di)) {
err = PTR_ERR(di);
goto out;
}
BUG_ON(ret == -ENOENT);
if (check_path_shared(root, path))
goto out;
err = 0;
out:
btrfs_free_path(path);
/* Migrate the orphan reservation over */
if (!err)
err = btrfs_block_rsv_migrate(trans->block_rsv,
&root->fs_info->global_block_rsv,
trans->bytes_reserved);
if (err) {
btrfs_end_transaction(trans, root);
root->fs_info->enospc_unlink = 0;
return ERR_PTR(err);
}
trans->block_rsv = &root->fs_info->global_block_rsv;
return trans;
}
static void __unlink_end_trans(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
if (trans->block_rsv == &root->fs_info->global_block_rsv) {
btrfs_block_rsv_release(root, trans->block_rsv,
trans->bytes_reserved);
trans->block_rsv = &root->fs_info->trans_block_rsv;
BUG_ON(!root->fs_info->enospc_unlink);
root->fs_info->enospc_unlink = 0;
}
btrfs_end_transaction_throttle(trans, root);
}
static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_trans_handle *trans;
struct inode *inode = dentry->d_inode;
int ret;
unsigned long nr = 0;
trans = __unlink_start_trans(dir, dentry);
if (IS_ERR(trans))
return PTR_ERR(trans);
btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
dentry->d_name.name, dentry->d_name.len);
if (ret)
goto out;
if (inode->i_nlink == 0) {
ret = btrfs_orphan_add(trans, inode);
if (ret)
goto out;
}
out:
nr = trans->blocks_used;
__unlink_end_trans(trans, root);
btrfs_btree_balance_dirty(root, nr);
return ret;
}
int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir, u64 objectid,
const char *name, int name_len)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key key;
u64 index;
int ret;
u64 dir_ino = btrfs_ino(dir);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
name, name_len, -1);
BUG_ON(IS_ERR_OR_NULL(di));
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &key);
WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
ret = btrfs_delete_one_dir_name(trans, root, path, di);
BUG_ON(ret);
btrfs_release_path(path);
ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
objectid, root->root_key.objectid,
dir_ino, &index, name, name_len);
if (ret < 0) {
BUG_ON(ret != -ENOENT);
di = btrfs_search_dir_index_item(root, path, dir_ino,
name, name_len);
BUG_ON(IS_ERR_OR_NULL(di));
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
btrfs_release_path(path);
index = key.offset;
}
btrfs_release_path(path);
ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
BUG_ON(ret);
btrfs_i_size_write(dir, dir->i_size - name_len * 2);
dir->i_mtime = dir->i_ctime = CURRENT_TIME;
ret = btrfs_update_inode(trans, root, dir);
BUG_ON(ret);
btrfs_free_path(path);
return 0;
}
static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
int err = 0;
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 ||
btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
return -ENOTEMPTY;
trans = __unlink_start_trans(dir, dentry);
if (IS_ERR(trans))
return PTR_ERR(trans);
if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
err = btrfs_unlink_subvol(trans, root, dir,
BTRFS_I(inode)->location.objectid,
dentry->d_name.name,
dentry->d_name.len);
goto out;
}
err = btrfs_orphan_add(trans, inode);
if (err)
goto out;
/* 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);
out:
nr = trans->blocks_used;
__unlink_end_trans(trans, root);
btrfs_btree_balance_dirty(root, nr);
return err;
}
/*
* 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.
*/
int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode,
u64 new_size, u32 min_type)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
struct btrfs_key found_key;
u64 extent_start = 0;
u64 extent_num_bytes = 0;
u64 extent_offset = 0;
u64 item_end = 0;
u64 mask = root->sectorsize - 1;
u32 found_type = (u8)-1;
int found_extent;
int del_item;
int pending_del_nr = 0;
int pending_del_slot = 0;
int extent_type = -1;
int encoding;
int ret;
int err = 0;
u64 ino = btrfs_ino(inode);
BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = -1;
if (root->ref_cows || root == root->fs_info->tree_root)
btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
/*
* This function is also used to drop the items in the log tree before
* we relog the inode, so if root != BTRFS_I(inode)->root, it means
* it is used to drop the loged items. So we shouldn't kill the delayed
* items.
*/
if (min_type == 0 && root == BTRFS_I(inode)->root)
btrfs_kill_delayed_inode_items(inode);
key.objectid = ino;
key.offset = (u64)-1;
key.type = (u8)-1;