blob: 27076ebadb36b56358b107eb169c4134565369e8 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#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/writeback.h>
#include <linux/compat.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <linux/falloc.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/btrfs.h>
#include <linux/blkdev.h>
#include <linux/posix_acl_xattr.h>
#include <linux/uio.h>
#include <linux/magic.h>
#include <linux/iversion.h>
#include <linux/swap.h>
#include <linux/sched/mm.h>
#include <asm/unaligned.h>
#include "misc.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.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"
#include "props.h"
#include "qgroup.h"
#include "delalloc-space.h"
#include "block-group.h"
struct btrfs_iget_args {
struct btrfs_key *location;
struct btrfs_root *root;
};
struct btrfs_dio_data {
u64 reserve;
u64 unsubmitted_oe_range_start;
u64 unsubmitted_oe_range_end;
int overwrite;
};
static const struct inode_operations btrfs_dir_inode_operations;
static const struct inode_operations btrfs_symlink_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 file_operations btrfs_dir_file_operations;
static const 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_path_cachep;
struct kmem_cache *btrfs_free_space_cachep;
struct kmem_cache *btrfs_free_space_bitmap_cachep;
static int btrfs_setsize(struct inode *inode, struct iattr *attr);
static int btrfs_truncate(struct inode *inode, bool skip_writeback);
static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
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 struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
u64 orig_start, u64 block_start,
u64 block_len, u64 orig_block_len,
u64 ram_bytes, int compress_type,
int type);
static void __endio_write_update_ordered(struct inode *inode,
const u64 offset, const u64 bytes,
const bool uptodate);
/*
* Cleanup all submitted ordered extents in specified range to handle errors
* from the btrfs_run_delalloc_range() callback.
*
* NOTE: caller must ensure that when an error happens, it can not call
* extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
* and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
* to be released, which we want to happen only when finishing the ordered
* extent (btrfs_finish_ordered_io()).
*/
static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
struct page *locked_page,
u64 offset, u64 bytes)
{
unsigned long index = offset >> PAGE_SHIFT;
unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
u64 page_start = page_offset(locked_page);
u64 page_end = page_start + PAGE_SIZE - 1;
struct page *page;
while (index <= end_index) {
page = find_get_page(inode->i_mapping, index);
index++;
if (!page)
continue;
ClearPagePrivate2(page);
put_page(page);
}
/*
* In case this page belongs to the delalloc range being instantiated
* then skip it, since the first page of a range is going to be
* properly cleaned up by the caller of run_delalloc_range
*/
if (page_start >= offset && page_end <= (offset + bytes - 1)) {
offset += PAGE_SIZE;
bytes -= PAGE_SIZE;
}
return __endio_write_update_ordered(inode, offset, bytes, false);
}
static int btrfs_dirty_inode(struct inode *inode);
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
void btrfs_test_inode_set_ops(struct inode *inode)
{
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
}
#endif
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 int insert_inline_extent(struct btrfs_trans_handle *trans,
struct btrfs_path *path, int extent_inserted,
struct btrfs_root *root, struct inode *inode,
u64 start, size_t size, size_t compressed_size,
int compress_type,
struct page **compressed_pages)
{
struct extent_buffer *leaf;
struct page *page = NULL;
char *kaddr;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
int ret;
size_t cur_size = size;
unsigned long offset;
ASSERT((compressed_size > 0 && compressed_pages) ||
(compressed_size == 0 && !compressed_pages));
if (compressed_size && compressed_pages)
cur_size = compressed_size;
inode_add_bytes(inode, size);
if (!extent_inserted) {
struct btrfs_key key;
size_t datasize;
key.objectid = btrfs_ino(BTRFS_I(inode));
key.offset = start;
key.type = BTRFS_EXTENT_DATA_KEY;
datasize = btrfs_file_extent_calc_inline_size(cur_size);
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (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_SIZE);
kaddr = kmap_atomic(cpage);
write_extent_buffer(leaf, kaddr, ptr, cur_size);
kunmap_atomic(kaddr);
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_SHIFT);
btrfs_set_file_extent_compression(leaf, ei, 0);
kaddr = kmap_atomic(page);
offset = offset_in_page(start);
write_extent_buffer(leaf, kaddr + offset, ptr, size);
kunmap_atomic(kaddr);
put_page(page);
}
btrfs_mark_buffer_dirty(leaf);
btrfs_release_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;
ret = btrfs_update_inode(trans, root, inode);
fail:
return ret;
}
/*
* 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 inode *inode, u64 start,
u64 end, size_t compressed_size,
int compress_type,
struct page **compressed_pages)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_trans_handle *trans;
u64 isize = i_size_read(inode);
u64 actual_end = min(end + 1, isize);
u64 inline_len = actual_end - start;
u64 aligned_end = ALIGN(end, fs_info->sectorsize);
u64 data_len = inline_len;
int ret;
struct btrfs_path *path;
int extent_inserted = 0;
u32 extent_item_size;
if (compressed_size)
data_len = compressed_size;
if (start > 0 ||
actual_end > fs_info->sectorsize ||
data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
(!compressed_size &&
(actual_end & (fs_info->sectorsize - 1)) == 0) ||
end + 1 < isize ||
data_len > fs_info->max_inline) {
return 1;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
trans->block_rsv = &BTRFS_I(inode)->block_rsv;
if (compressed_size && compressed_pages)
extent_item_size = btrfs_file_extent_calc_inline_size(
compressed_size);
else
extent_item_size = btrfs_file_extent_calc_inline_size(
inline_len);
ret = __btrfs_drop_extents(trans, root, inode, path,
start, aligned_end, NULL,
1, 1, extent_item_size, &extent_inserted);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
if (isize > actual_end)
inline_len = min_t(u64, isize, actual_end);
ret = insert_inline_extent(trans, path, extent_inserted,
root, inode, start,
inline_len, compressed_size,
compress_type, compressed_pages);
if (ret && ret != -ENOSPC) {
btrfs_abort_transaction(trans, ret);
goto out;
} else if (ret == -ENOSPC) {
ret = 1;
goto out;
}
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
out:
/*
* Don't forget to free the reserved space, as for inlined extent
* it won't count as data extent, free them directly here.
* And at reserve time, it's always aligned to page size, so
* just free one page here.
*/
btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
btrfs_free_path(path);
btrfs_end_transaction(trans);
return ret;
}
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_chunk {
struct inode *inode;
struct page *locked_page;
u64 start;
u64 end;
unsigned int write_flags;
struct list_head extents;
struct cgroup_subsys_state *blkcg_css;
struct btrfs_work work;
atomic_t *pending;
};
struct async_cow {
/* Number of chunks in flight; must be first in the structure */
atomic_t num_chunks;
struct async_chunk chunks[];
};
static noinline int add_async_extent(struct async_chunk *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); /* -ENOMEM */
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;
}
/*
* Check if the inode has flags compatible with compression
*/
static inline bool inode_can_compress(struct inode *inode)
{
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW ||
BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
return false;
return true;
}
/*
* Check if the inode needs to be submitted to compression, based on mount
* options, defragmentation, properties or heuristics.
*/
static inline int inode_need_compress(struct inode *inode, u64 start, u64 end)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
if (!inode_can_compress(inode)) {
WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
KERN_ERR "BTRFS: unexpected compression for ino %llu\n",
btrfs_ino(BTRFS_I(inode)));
return 0;
}
/* force compress */
if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
return 1;
/* defrag ioctl */
if (BTRFS_I(inode)->defrag_compress)
return 1;
/* bad compression ratios */
if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
return 0;
if (btrfs_test_opt(fs_info, COMPRESS) ||
BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
BTRFS_I(inode)->prop_compress)
return btrfs_compress_heuristic(inode, start, end);
return 0;
}
static inline void inode_should_defrag(struct btrfs_inode *inode,
u64 start, u64 end, u64 num_bytes, u64 small_write)
{
/* If this is a small write inside eof, kick off a defrag */
if (num_bytes < small_write &&
(start > 0 || end + 1 < inode->disk_i_size))
btrfs_add_inode_defrag(NULL, inode);
}
/*
* 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 the flusher thread sent them
* down.
*/
static noinline int compress_file_range(struct async_chunk *async_chunk)
{
struct inode *inode = async_chunk->inode;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
u64 blocksize = fs_info->sectorsize;
u64 start = async_chunk->start;
u64 end = async_chunk->end;
u64 actual_end;
u64 i_size;
int ret = 0;
struct page **pages = NULL;
unsigned long nr_pages;
unsigned long total_compressed = 0;
unsigned long total_in = 0;
int i;
int will_compress;
int compress_type = fs_info->compress_type;
int compressed_extents = 0;
int redirty = 0;
inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
SZ_16K);
/*
* We need to save i_size before now because it could change in between
* us evaluating the size and assigning it. This is because we lock and
* unlock the page in truncate and fallocate, and then modify the i_size
* later on.
*
* The barriers are to emulate READ_ONCE, remove that once i_size_read
* does that for us.
*/
barrier();
i_size = i_size_read(inode);
barrier();
actual_end = min_t(u64, i_size, end + 1);
again:
will_compress = 0;
nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
nr_pages = min_t(unsigned long, nr_pages,
BTRFS_MAX_COMPRESSED / PAGE_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;
/*
* skip compression for a small file range(<=blocksize) that
* isn't an inline extent, since it doesn't save disk space at all.
*/
if (total_compressed <= blocksize &&
(start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
goto cleanup_and_bail_uncompressed;
total_compressed = min_t(unsigned long, total_compressed,
BTRFS_MAX_UNCOMPRESSED);
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 (inode_need_compress(inode, start, end)) {
WARN_ON(pages);
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
if (!pages) {
/* just bail out to the uncompressed code */
nr_pages = 0;
goto cont;
}
if (BTRFS_I(inode)->defrag_compress)
compress_type = BTRFS_I(inode)->defrag_compress;
else if (BTRFS_I(inode)->prop_compress)
compress_type = BTRFS_I(inode)->prop_compress;
/*
* we need to call clear_page_dirty_for_io on each
* page in the range. Otherwise applications with the file
* mmap'd can wander in and change the page contents while
* we are compressing them.
*
* If the compression fails for any reason, we set the pages
* dirty again later on.
*
* Note that the remaining part is redirtied, the start pointer
* has moved, the end is the original one.
*/
if (!redirty) {
extent_range_clear_dirty_for_io(inode, start, end);
redirty = 1;
}
/* Compression level is applied here and only here */
ret = btrfs_compress_pages(
compress_type | (fs_info->compress_level << 4),
inode->i_mapping, start,
pages,
&nr_pages,
&total_in,
&total_compressed);
if (!ret) {
unsigned long offset = offset_in_page(total_compressed);
struct page *page = pages[nr_pages - 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);
memset(kaddr + offset, 0,
PAGE_SIZE - offset);
kunmap_atomic(kaddr);
}
will_compress = 1;
}
}
cont:
if (start == 0) {
/* lets try to make an inline extent */
if (ret || total_in < actual_end) {
/* we didn't compress the entire range, try
* to make an uncompressed inline extent.
*/
ret = cow_file_range_inline(inode, start, end, 0,
BTRFS_COMPRESS_NONE, NULL);
} else {
/* try making a compressed inline extent */
ret = cow_file_range_inline(inode, start, end,
total_compressed,
compress_type, pages);
}
if (ret <= 0) {
unsigned long clear_flags = EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING;
unsigned long page_error_op;
page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
/*
* inline extent creation worked or returned error,
* we don't need to create any more async work items.
* Unlock and free up our temp pages.
*
* We use DO_ACCOUNTING here because we need the
* delalloc_release_metadata to be done _after_ we drop
* our outstanding extent for clearing delalloc for this
* range.
*/
extent_clear_unlock_delalloc(inode, start, end, NULL,
clear_flags,
PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
page_error_op |
PAGE_END_WRITEBACK);
for (i = 0; i < nr_pages; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
kfree(pages);
return 0;
}
}
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 = ALIGN(total_compressed, blocksize);
/*
* one last check to make sure the compression is really a
* win, compare the page count read with the blocks on disk,
* compression must free at least one sector size
*/
total_in = ALIGN(total_in, PAGE_SIZE);
if (total_compressed + blocksize <= total_in) {
compressed_extents++;
/*
* 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_chunk, start, total_in,
total_compressed, pages, nr_pages,
compress_type);
if (start + total_in < end) {
start += total_in;
pages = NULL;
cond_resched();
goto again;
}
return compressed_extents;
}
}
if (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; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
kfree(pages);
pages = NULL;
total_compressed = 0;
nr_pages = 0;
/* flag the file so we don't compress in the future */
if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
!(BTRFS_I(inode)->prop_compress)) {
BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
}
}
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 (async_chunk->locked_page &&
(page_offset(async_chunk->locked_page) >= start &&
page_offset(async_chunk->locked_page)) <= end) {
__set_page_dirty_nobuffers(async_chunk->locked_page);
/* unlocked later on in the async handlers */
}
if (redirty)
extent_range_redirty_for_io(inode, start, end);
add_async_extent(async_chunk, start, end - start + 1, 0, NULL, 0,
BTRFS_COMPRESS_NONE);
compressed_extents++;
return compressed_extents;
}
static void free_async_extent_pages(struct async_extent *async_extent)
{
int i;
if (!async_extent->pages)
return;
for (i = 0; i < async_extent->nr_pages; i++) {
WARN_ON(async_extent->pages[i]->mapping);
put_page(async_extent->pages[i]);
}
kfree(async_extent->pages);
async_extent->nr_pages = 0;
async_extent->pages = NULL;
}
/*
* 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 void submit_compressed_extents(struct async_chunk *async_chunk)
{
struct inode *inode = async_chunk->inode;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct async_extent *async_extent;
u64 alloc_hint = 0;
struct btrfs_key ins;
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
int ret = 0;
again:
while (!list_empty(&async_chunk->extents)) {
async_extent = list_entry(async_chunk->extents.next,
struct async_extent, list);
list_del(&async_extent->list);
retry:
lock_extent(io_tree, async_extent->start,
async_extent->start + async_extent->ram_size - 1);
/* did the compression code fall back to uncompressed IO? */
if (!async_extent->pages) {
int page_started = 0;
unsigned long nr_written = 0;
/* allocate blocks */
ret = cow_file_range(inode, async_chunk->locked_page,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
&page_started, &nr_written, 0);
/* JDM XXX */
/*
* 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(inode,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
WB_SYNC_ALL);
else if (ret && async_chunk->locked_page)
unlock_page(async_chunk->locked_page);
kfree(async_extent);
cond_resched();
continue;
}
ret = btrfs_reserve_extent(root, async_extent->ram_size,
async_extent->compressed_size,
async_extent->compressed_size,
0, alloc_hint, &ins, 1, 1);
if (ret) {
free_async_extent_pages(async_extent);
if (ret == -ENOSPC) {
unlock_extent(io_tree, async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
/*
* we need to redirty the pages if we decide to
* fallback to uncompressed IO, otherwise we
* will not submit these pages down to lower
* layers.
*/
extent_range_redirty_for_io(inode,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
goto retry;
}
goto out_free;
}
/*
* here we're doing allocation and writeback of the
* compressed pages
*/
em = create_io_em(inode, async_extent->start,
async_extent->ram_size, /* len */
async_extent->start, /* orig_start */
ins.objectid, /* block_start */
ins.offset, /* block_len */
ins.offset, /* orig_block_len */
async_extent->ram_size, /* ram_bytes */
async_extent->compress_type,
BTRFS_ORDERED_COMPRESSED);
if (IS_ERR(em))
/* ret value is not necessary due to void function */
goto out_free_reserve;
free_extent_map(em);
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);
if (ret) {
btrfs_drop_extent_cache(BTRFS_I(inode),
async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);
goto out_free_reserve;
}
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
/*
* clear dirty, set writeback and unlock the pages.
*/
extent_clear_unlock_delalloc(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK);
if (btrfs_submit_compressed_write(inode,
async_extent->start,
async_extent->ram_size,
ins.objectid,
ins.offset, async_extent->pages,
async_extent->nr_pages,
async_chunk->write_flags,
async_chunk->blkcg_css)) {
struct page *p = async_extent->pages[0];
const u64 start = async_extent->start;
const u64 end = start + async_extent->ram_size - 1;
p->mapping = inode->i_mapping;
btrfs_writepage_endio_finish_ordered(p, start, end, 0);
p->mapping = NULL;
extent_clear_unlock_delalloc(inode, start, end,
NULL, 0,
PAGE_END_WRITEBACK |
PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
}
alloc_hint = ins.objectid + ins.offset;
kfree(async_extent);
cond_resched();
}
return;
out_free_reserve:
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
out_free:
extent_clear_unlock_delalloc(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW |
EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
kfree(async_extent);
goto again;
}
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_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 alloc_hint = 0;
u64 num_bytes;
unsigned long ram_size;
u64 cur_alloc_size = 0;
u64 blocksize = fs_info->sectorsize;
struct btrfs_key ins;
struct extent_map *em;
unsigned clear_bits;
unsigned long page_ops;
bool extent_reserved = false;
int ret = 0;
if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
WARN_ON_ONCE(1);
ret = -EINVAL;
goto out_unlock;
}
num_bytes = ALIGN(end - start + 1, blocksize);
num_bytes = max(blocksize, num_bytes);
ASSERT(num_bytes <= btrfs_super_total_bytes(fs_info->super_copy));
inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
if (start == 0) {
/* lets try to make an inline extent */
ret = cow_file_range_inline(inode, start, end, 0,
BTRFS_COMPRESS_NONE, NULL);
if (ret == 0) {
/*
* We use DO_ACCOUNTING here because we need the
* delalloc_release_metadata to be run _after_ we drop
* our outstanding extent for clearing delalloc for this
* range.
*/
extent_clear_unlock_delalloc(inode, start, end, NULL,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
*nr_written = *nr_written +
(end - start + PAGE_SIZE) / PAGE_SIZE;
*page_started = 1;
goto out;
} else if (ret < 0) {
goto out_unlock;
}
}
alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
btrfs_drop_extent_cache(BTRFS_I(inode), start,
start + num_bytes - 1, 0);
while (num_bytes > 0) {
cur_alloc_size = num_bytes;
ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
fs_info->sectorsize, 0, alloc_hint,
&ins, 1, 1);
if (ret < 0)
goto out_unlock;
cur_alloc_size = ins.offset;
extent_reserved = true;
ram_size = ins.offset;
em = create_io_em(inode, start, ins.offset, /* len */
start, /* orig_start */
ins.objectid, /* block_start */
ins.offset, /* block_len */
ins.offset, /* orig_block_len */
ram_size, /* ram_bytes */
BTRFS_COMPRESS_NONE, /* compress_type */
BTRFS_ORDERED_REGULAR /* type */);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out_reserve;
}
free_extent_map(em);
ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
ram_size, cur_alloc_size, 0);
if (ret)
goto out_drop_extent_cache;
if (root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID) {
ret = btrfs_reloc_clone_csums(inode, start,
cur_alloc_size);
/*
* Only drop cache here, and process as normal.
*
* We must not allow extent_clear_unlock_delalloc()
* at out_unlock label to free meta of this ordered
* extent, as its meta should be freed by
* btrfs_finish_ordered_io().
*
* So we must continue until @start is increased to
* skip current ordered extent.
*/
if (ret)
btrfs_drop_extent_cache(BTRFS_I(inode), start,
start + ram_size - 1, 0);
}
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
/* 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
*/
page_ops = unlock ? PAGE_UNLOCK : 0;
page_ops |= PAGE_SET_PRIVATE2;
extent_clear_unlock_delalloc(inode, start,
start + ram_size - 1,
locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC,
page_ops);
if (num_bytes < cur_alloc_size)
num_bytes = 0;
else
num_bytes -= cur_alloc_size;
alloc_hint = ins.objectid + ins.offset;
start += cur_alloc_size;
extent_reserved = false;
/*
* btrfs_reloc_clone_csums() error, since start is increased
* extent_clear_unlock_delalloc() at out_unlock label won't
* free metadata of current ordered extent, we're OK to exit.
*/
if (ret)
goto out_unlock;
}
out:
return ret;
out_drop_extent_cache:
btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
out_reserve:
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
out_unlock:
clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK;
/*
* If we reserved an extent for our delalloc range (or a subrange) and
* failed to create the respective ordered extent, then it means that
* when we reserved the extent we decremented the extent's size from
* the data space_info's bytes_may_use counter and incremented the
* space_info's bytes_reserved counter by the same amount. We must make
* sure extent_clear_unlock_delalloc() does not try to decrement again
* the data space_info's bytes_may_use counter, therefore we do not pass
* it the flag EXTENT_CLEAR_DATA_RESV.
*/
if (extent_reserved) {
extent_clear_unlock_delalloc(inode, start,
start + cur_alloc_size,
locked_page,
clear_bits,
page_ops);
start += cur_alloc_size;
if (start >= end)
goto out;
}
extent_clear_unlock_delalloc(inode, start, end, locked_page,
clear_bits | EXTENT_CLEAR_DATA_RESV,
page_ops);
goto out;
}
/*
* work queue call back to started compression on a file and pages
*/
static noinline void async_cow_start(struct btrfs_work *work)
{
struct async_chunk *async_chunk;
int compressed_extents;
async_chunk = container_of(work, struct async_chunk, work);
compressed_extents = compress_file_range(async_chunk);
if (compressed_extents == 0) {
btrfs_add_delayed_iput(async_chunk->inode);
async_chunk->inode = NULL;
}
}
/*
* work queue call back to submit previously compressed pages
*/
static noinline void async_cow_submit(struct btrfs_work *work)
{
struct async_chunk *async_chunk = container_of(work, struct async_chunk,
work);
struct btrfs_fs_info *fs_info = btrfs_work_owner(work);
unsigned long nr_pages;
nr_pages = (async_chunk->end - async_chunk->start + PAGE_SIZE) >>
PAGE_SHIFT;
/* atomic_sub_return implies a barrier */
if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
5 * SZ_1M)
cond_wake_up_nomb(&fs_info->async_submit_wait);
/*
* ->inode could be NULL if async_chunk_start has failed to compress,
* in which case we don't have anything to submit, yet we need to
* always adjust ->async_delalloc_pages as its paired with the init
* happening in cow_file_range_async
*/
if (async_chunk->inode)
submit_compressed_extents(async_chunk);
}
static noinline void async_cow_free(struct btrfs_work *work)
{
struct async_chunk *async_chunk;
async_chunk = container_of(work, struct async_chunk, work);
if (async_chunk->inode)
btrfs_add_delayed_iput(async_chunk->inode);
if (async_chunk->blkcg_css)
css_put(async_chunk->blkcg_css);
/*
* Since the pointer to 'pending' is at the beginning of the array of
* async_chunk's, freeing it ensures the whole array has been freed.
*/
if (atomic_dec_and_test(async_chunk->pending))
kvfree(async_chunk->pending);
}
static int cow_file_range_async(struct inode *inode,
struct writeback_control *wbc,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct cgroup_subsys_state *blkcg_css = wbc_blkcg_css(wbc);
struct async_cow *ctx;
struct async_chunk *async_chunk;
unsigned long nr_pages;
u64 cur_end;
u64 num_chunks = DIV_ROUND_UP(end - start, SZ_512K);
int i;
bool should_compress;
unsigned nofs_flag;
const unsigned int write_flags = wbc_to_write_flags(wbc);
unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
!btrfs_test_opt(fs_info, FORCE_COMPRESS)) {
num_chunks = 1;
should_compress = false;
} else {
should_compress = true;
}
nofs_flag = memalloc_nofs_save();
ctx = kvmalloc(struct_size(ctx, chunks, num_chunks), GFP_KERNEL);
memalloc_nofs_restore(nofs_flag);
if (!ctx) {
unsigned clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING;
unsigned long page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
PAGE_SET_ERROR;
extent_clear_unlock_delalloc(inode, start, end, locked_page,
clear_bits, page_ops);
return -ENOMEM;
}
async_chunk = ctx->chunks;
atomic_set(&ctx->num_chunks, num_chunks);
for (i = 0; i < num_chunks; i++) {
if (should_compress)
cur_end = min(end, start + SZ_512K - 1);
else
cur_end = end;
/*
* igrab is called higher up in the call chain, take only the
* lightweight reference for the callback lifetime
*/
ihold(inode);
async_chunk[i].pending = &ctx->num_chunks;
async_chunk[i].inode = inode;
async_chunk[i].start = start;
async_chunk[i].end = cur_end;
async_chunk[i].write_flags = write_flags;
INIT_LIST_HEAD(&async_chunk[i].extents);
/*
* The locked_page comes all the way from writepage and its
* the original page we were actually given. As we spread
* this large delalloc region across multiple async_chunk
* structs, only the first struct needs a pointer to locked_page
*
* This way we don't need racey decisions about who is supposed
* to unlock it.
*/
if (locked_page) {
/*
* Depending on the compressibility, the pages might or
* might not go through async. We want all of them to
* be accounted against wbc once. Let's do it here
* before the paths diverge. wbc accounting is used
* only for foreign writeback detection and doesn't
* need full accuracy. Just account the whole thing
* against the first page.
*/
wbc_account_cgroup_owner(wbc, locked_page,
cur_end - start);
async_chunk[i].locked_page = locked_page;
locked_page = NULL;
} else {
async_chunk[i].locked_page = NULL;
}
if (blkcg_css != blkcg_root_css) {
css_get(blkcg_css);
async_chunk[i].blkcg_css = blkcg_css;
} else {
async_chunk[i].blkcg_css = NULL;
}
btrfs_init_work(&async_chunk[i].work, async_cow_start,
async_cow_submit, async_cow_free);
nr_pages = DIV_ROUND_UP(cur_end - start, PAGE_SIZE);
atomic_add(nr_pages, &fs_info->async_delalloc_pages);
btrfs_queue_work(fs_info->delalloc_workers, &async_chunk[i].work);
*nr_written += nr_pages;
start = cur_end + 1;
}
*page_started = 1;
return 0;
}
static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
u64 bytenr, u64 num_bytes)
{
int ret;
struct btrfs_ordered_sum *sums;
LIST_HEAD(list);
ret = btrfs_lookup_csums_range(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);
}
if (ret < 0)
return ret;
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,
const u64 start, const u64 end,
int *page_started, int force,
unsigned long *nr_written)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_path *path;
u64 cow_start = (u64)-1;
u64 cur_offset = start;
int ret;
bool check_prev = true;
const bool freespace_inode = btrfs_is_free_space_inode(BTRFS_I(inode));
u64 ino = btrfs_ino(BTRFS_I(inode));
bool nocow = false;
u64 disk_bytenr = 0;
path = btrfs_alloc_path();
if (!path) {
extent_clear_unlock_delalloc(inode, start, end, locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
return -ENOMEM;
}
while (1) {
struct btrfs_key found_key;
struct btrfs_file_extent_item *fi;
struct extent_buffer *leaf;
u64 extent_end;
u64 extent_offset;
u64 num_bytes = 0;
u64 disk_num_bytes;
u64 ram_bytes;
int extent_type;
nocow = false;
ret = btrfs_lookup_file_extent(NULL, root, path, ino,
cur_offset, 0);
if (ret < 0)
goto error;
/*
* If there is no extent for our range when doing the initial
* search, then go back to the previous slot as it will be the
* one containing the search offset
*/
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 = false;
next_slot:
/* Go to next leaf if we have exhausted the current one */
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
if (cow_start != (u64)-1)
cur_offset = cow_start;
goto error;
}
if (ret > 0)
break;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
/* Didn't find anything for our INO */
if (found_key.objectid > ino)
break;
/*
* Keep searching until we find an EXTENT_ITEM or there are no
* more extents for this inode
*/
if (WARN_ON_ONCE(found_key.objectid < ino) ||
found_key.type < BTRFS_EXTENT_DATA_KEY) {
path->slots[0]++;
goto next_slot;
}
/* Found key is not EXTENT_DATA_KEY or starts after req range */
if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
found_key.offset > end)
break;
/*
* If the found extent starts after requested offset, then
* adjust extent_end to be right before this extent begins
*/
if (found_key.offset > cur_offset) {
extent_end = found_key.offset;
extent_type = 0;
goto out_check;
}
/*
* Found extent which begins before our range and potentially
* intersect it
*/
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
ram_bytes = btrfs_file_extent_ram_bytes(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);
disk_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf, fi);
/*
* If the extent we got ends before our current offset,
* skip to the next extent.
*/
if (extent_end <= cur_offset) {
path->slots[0]++;
goto next_slot;
}
/* Skip holes */
if (disk_bytenr == 0)
goto out_check;
/* Skip compressed/encrypted/encoded extents */
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 is created before the last volume's snapshot
* this implies the extent is shared, hence we can't do
* nocow. This is the same check as in
* btrfs_cross_ref_exist but without calling
* btrfs_search_slot.
*/
if (!freespace_inode &&
btrfs_file_extent_generation(leaf, fi) <=
btrfs_root_last_snapshot(&root->root_item))
goto out_check;
if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
goto out_check;
/* If extent is RO, we must COW it */
if (btrfs_extent_readonly(fs_info, disk_bytenr))
goto out_check;
ret = btrfs_cross_ref_exist(root, ino,
found_key.offset -
extent_offset, disk_bytenr);
if (ret) {
/*
* ret could be -EIO if the above fails to read
* metadata.
*/
if (ret < 0) {
if (cow_start != (u64)-1)
cur_offset = cow_start;
goto error;
}
WARN_ON_ONCE(freespace_inode);
goto out_check;
}
disk_bytenr += extent_offset;
disk_bytenr += cur_offset - found_key.offset;
num_bytes = min(end + 1, extent_end) - cur_offset;
/*
* If there are pending snapshots for this root, we
* fall into common COW way
*/
if (!freespace_inode && atomic_read(&root->snapshot_force_cow))
goto out_check;
/*
* force cow if csum exists in the range.
* this ensure that csum for a given extent are
* either valid or do not exist.
*/
ret = csum_exist_in_range(fs_info, disk_bytenr,
num_bytes);
if (ret) {
/*
* ret could be -EIO if the above fails to read
* metadata.
*/
if (ret < 0) {
if (cow_start != (u64)-1)
cur_offset = cow_start;
goto error;
}
WARN_ON_ONCE(freespace_inode);
goto out_check;
}
if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr))
goto out_check;
nocow = true;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
extent_end = found_key.offset + ram_bytes;
extent_end = ALIGN(extent_end, fs_info->sectorsize);
/* Skip extents outside of our requested range */
if (extent_end <= start) {
path->slots[0]++;
goto next_slot;
}
} else {
/* If this triggers then we have a memory corruption */
BUG();
}
out_check:
/*
* If nocow is false then record the beginning of the range
* that needs to be COWed
*/
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);
/*
* COW range from cow_start to found_key.offset - 1. As the key
* will contain the beginning of the first extent that can be
* NOCOW, following one which needs to be COW'ed
*/
if (cow_start != (u64)-1) {
ret = cow_file_range(inode, locked_page,
cow_start, found_key.offset - 1,
page_started, nr_written, 1);
if (ret) {
if (nocow)
btrfs_dec_nocow_writers(fs_info,
disk_bytenr);
goto error;
}
cow_start = (u64)-1;
}
if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 orig_start = found_key.offset - extent_offset;
struct extent_map *em;
em = create_io_em(inode, cur_offset, num_bytes,
orig_start,
disk_bytenr, /* block_start */
num_bytes, /* block_len */
disk_num_bytes, /* orig_block_len */
ram_bytes, BTRFS_COMPRESS_NONE,
BTRFS_ORDERED_PREALLOC);
if (IS_ERR(em)) {
if (nocow)
btrfs_dec_nocow_writers(fs_info,
disk_bytenr);
ret = PTR_ERR(em);
goto error;
}
free_extent_map(em);
ret = btrfs_add_ordered_extent(inode, cur_offset,
disk_bytenr, num_bytes,
num_bytes,
BTRFS_ORDERED_PREALLOC);
if (ret) {
btrfs_drop_extent_cache(BTRFS_I(inode),
cur_offset,
cur_offset + num_bytes - 1,
0);
goto error;
}
} else {
ret = btrfs_add_ordered_extent(inode, cur_offset,
disk_bytenr, num_bytes,
num_bytes,
BTRFS_ORDERED_NOCOW);
if (ret)
goto error;
}
if (nocow)
btrfs_dec_nocow_writers(fs_info, disk_bytenr);
nocow = false;
if (root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID)
/*
* Error handled later, as we must prevent
* extent_clear_unlock_delalloc() in error handler
* from freeing metadata of created ordered extent.
*/
ret = btrfs_reloc_clone_csums(inode, cur_offset,
num_bytes);
extent_clear_unlock_delalloc(inode, cur_offset,
cur_offset + num_bytes - 1,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC |
EXTENT_CLEAR_DATA_RESV,
PAGE_UNLOCK | PAGE_SET_PRIVATE2);
cur_offset = extent_end;
/*
* btrfs_reloc_clone_csums() error, now we're OK to call error
* handler, as metadata for created ordered extent will only
* be freed by btrfs_finish_ordered_io().
*/
if (ret)
goto error;
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) {
cur_offset = end;
ret = cow_file_range(inode, locked_page, cow_start, end,
page_started, nr_written, 1);
if (ret)
goto error;
}
error:
if (nocow)
btrfs_dec_nocow_writers(fs_info, disk_bytenr);
if (ret && cur_offset < end)
extent_clear_unlock_delalloc(inode, cur_offset, end,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
btrfs_free_path(path);
return ret;
}
static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
{
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
!(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
return 0;
/*
* @defrag_bytes is a hint value, no spinlock held here,
* if is not zero, it means the file is defragging.
* Force cow if given extent needs to be defragged.
*/
if (BTRFS_I(inode)->defrag_bytes &&
test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
EXTENT_DEFRAG, 0, NULL))
return 1;
return 0;
}
/*
* Function to process delayed allocation (create CoW) for ranges which are
* being touched for the first time.
*/
int btrfs_run_delalloc_range(struct inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started, unsigned long *nr_written,
struct writeback_control *wbc)
{
int ret;
int force_cow = need_force_cow(inode, start, end);
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 1, nr_written);
} else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 0, nr_written);
} else if (!inode_can_compress(inode) ||
!inode_need_compress(inode, start, end)) {
ret = cow_file_range(inode, locked_page, start, end,
page_started, nr_written, 1);
} else {
set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags);
ret = cow_file_range_async(inode, wbc, locked_page, start, end,
page_started, nr_written);
}
if (ret)
btrfs_cleanup_ordered_extents(inode, locked_page, start,
end - start + 1);
return ret;
}
void btrfs_split_delalloc_extent(struct inode *inode,
struct extent_state *orig, u64 split)
{
u64 size;
/* not delalloc, ignore it */
if (!(orig->state & EXTENT_DELALLOC))
return;
size = orig->end - orig->start + 1;
if (size > BTRFS_MAX_EXTENT_SIZE) {
u32 num_extents;
u64 new_size;
/*
* See the explanation in btrfs_merge_delalloc_extent, the same
* applies here, just in reverse.
*/
new_size = orig->end - split + 1;
num_extents = count_max_extents(new_size);
new_size = split - orig->start;
num_extents += count_max_extents(new_size);
if (count_max_extents(size) >= num_extents)
return;
}
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
spin_unlock(&BTRFS_I(inode)->lock);
}
/*
* Handle 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.
*/
void btrfs_merge_delalloc_extent(struct inode *inode, struct extent_state *new,
struct extent_state *other)
{
u64 new_size, old_size;
u32 num_extents;
/* not delalloc, ignore it */
if (!(other->state & EXTENT_DELALLOC))
return;
if (new->start > other->start)
new_size = new->end - other->start + 1;
else
new_size = other->end - new->start + 1;
/* we're not bigger than the max, unreserve the space and go */
if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
spin_unlock(&BTRFS_I(inode)->lock);
return;
}
/*
* We have to add up either side to figure out how many extents were
* accounted for before we merged into one big extent. If the number of
* extents we accounted for is <= the amount we need for the new range
* then we can return, otherwise drop. Think of it like this
*
* [ 4k][MAX_SIZE]
*
* So we've grown the extent by a MAX_SIZE extent, this would mean we
* need 2 outstanding extents, on one side we have 1 and the other side
* we have 1 so they are == and we can return. But in this case
*
* [MAX_SIZE+4k][MAX_SIZE+4k]
*
* Each range on their own accounts for 2 extents, but merged together
* they are only 3 extents worth of accounting, so we need to drop in
* this case.
*/
old_size = other->end - other->start + 1;
num_extents = count_max_extents(old_size);
old_size = new->end - new->start + 1;
num_extents += count_max_extents(old_size);
if (count_max_extents(new_size) >= num_extents)
return;
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
spin_unlock(&BTRFS_I(inode)->lock);
}
static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
spin_lock(&root->delalloc_lock);
if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
&root->delalloc_inodes);
set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags);
root->nr_delalloc_inodes++;
if (root->nr_delalloc_inodes == 1) {
spin_lock(&fs_info->delalloc_root_lock);
BUG_ON(!list_empty(&root->delalloc_root));
list_add_tail(&root->delalloc_root,
&fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
}
}
spin_unlock(&root->delalloc_lock);
}
void __btrfs_del_delalloc_inode(struct btrfs_root *root,
struct btrfs_inode *inode)
{
struct btrfs_fs_info *fs_info = root->fs_info;
if (!list_empty(&inode->delalloc_inodes)) {
list_del_init(&inode->delalloc_inodes);
clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&inode->runtime_flags);
root->nr_delalloc_inodes--;
if (!root->nr_delalloc_inodes) {
ASSERT(list_empty(&root->delalloc_inodes));
spin_lock(&fs_info->delalloc_root_lock);
BUG_ON(list_empty(&root->delalloc_root));
list_del_init(&root->delalloc_root);
spin_unlock(&fs_info->delalloc_root_lock);
}
}
}
static void btrfs_del_delalloc_inode(struct btrfs_root *root,
struct btrfs_inode *inode)
{
spin_lock(&root->delalloc_lock);
__btrfs_del_delalloc_inode(root, inode);
spin_unlock(&root->delalloc_lock);
}
/*
* Properly track delayed allocation bytes in the inode and to maintain the
* list of inodes that have pending delalloc work to be done.
*/
void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state,
unsigned *bits)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
WARN_ON(1);
/*
* 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;
u32 num_extents = count_max_extents(len);
bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents);
spin_unlock(&BTRFS_I(inode)->lock);
/* For sanity tests */
if (btrfs_is_testing(fs_info))
return;
percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
fs_info->delalloc_batch);
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->delalloc_bytes += len;
if (*bits & EXTENT_DEFRAG)
BTRFS_I(inode)->defrag_bytes += len;
if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags))
btrfs_add_delalloc_inodes(root, inode);
spin_unlock(&BTRFS_I(inode)->lock);
}
if (!(state->state & EXTENT_DELALLOC_NEW) &&
(*bits & EXTENT_DELALLOC_NEW)) {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
state->start;
spin_unlock(&BTRFS_I(inode)->lock);
}
}
/*
* Once a range is no longer delalloc this function ensures that proper
* accounting happens.
*/
void btrfs_clear_delalloc_extent(struct inode *vfs_inode,
struct extent_state *state, unsigned *bits)
{
struct btrfs_inode *inode = BTRFS_I(vfs_inode);
struct btrfs_fs_info *fs_info = btrfs_sb(vfs_inode->i_sb);
u64 len = state->end + 1 - state->start;
u32 num_extents = count_max_extents(len);
if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
spin_lock(&inode->lock);
inode->defrag_bytes -= len;
spin_unlock(&inode->lock);
}
/*
* 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 = inode->root;
bool do_list = !btrfs_is_free_space_inode(inode);
spin_lock(&inode->lock);
btrfs_mod_outstanding_extents(inode, -num_extents);
spin_unlock(&inode->lock);
/*
* We don't reserve metadata space for space cache inodes so we
* don't need to call delalloc_release_metadata if there is an
* error.
*/
if (*bits & EXTENT_CLEAR_META_RESV &&
root != fs_info->tree_root)
btrfs_delalloc_release_metadata(inode, len, false);
/* For sanity tests. */
if (btrfs_is_testing(fs_info))
return;
if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID &&
do_list && !(state->state & EXTENT_NORESERVE) &&
(*bits & EXTENT_CLEAR_DATA_RESV))
btrfs_free_reserved_data_space_noquota(
&inode->vfs_inode,
state->start, len);
percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
fs_info->delalloc_batch);
spin_lock(&inode->lock);
inode->delalloc_bytes -= len;
if (do_list && inode->delalloc_bytes == 0 &&
test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&inode->runtime_flags))
btrfs_del_delalloc_inode(root, inode);
spin_unlock(&inode->lock);
}
if ((state->state & EXTENT_DELALLOC_NEW) &&
(*bits & EXTENT_DELALLOC_NEW)) {
spin_lock(&inode->lock);
ASSERT(inode->new_delalloc_bytes >= len);
inode->new_delalloc_bytes -= len;
spin_unlock(&inode->lock);
}
}
/*
* btrfs_bio_fits_in_stripe - Checks whether the size of the given bio will fit
* in a chunk's stripe. This function ensures that bios do not span a
* stripe/chunk
*
* @page - The page we are about to add to the bio
* @size - size we want to add to the bio
* @bio - bio we want to ensure is smaller than a stripe
* @bio_flags - flags of the bio
*
* return 1 if page cannot be added to the bio
* return 0 if page can be added to the bio
* return error otherwise
*/
int btrfs_bio_fits_in_stripe(struct page *page, size_t size, struct bio *bio,
unsigned long bio_flags)
{
struct inode *inode = page->mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
u64 logical = (u64)bio->bi_iter.bi_sector << 9;
u64 length = 0;
u64 map_length;
int ret;
struct btrfs_io_geometry geom;
if (bio_flags & EXTENT_BIO_COMPRESSED)
return 0;
length = bio->bi_iter.bi_size;
map_length = length;
ret = btrfs_get_io_geometry(fs_info, btrfs_op(bio), logical, map_length,
&geom);
if (ret < 0)
return ret;
if (geom.len < 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
*/
static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
u64 bio_offset)
{
struct inode *inode = private_data;
blk_status_t ret = 0;
ret = btrfs_csum_one_bio(inode, bio, 0, 0);
BUG_ON(ret); /* -ENOMEM */
return 0;
}
/*
* 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.
*
* Rules about async/sync submit,
* a) read: sync submit
*
* b) write without checksum: sync submit
*
* c) write with checksum:
* c-1) if bio is issued by fsync: sync submit
* (sync_writers != 0)
*
* c-2) if root is reloc root: sync submit
* (only in case of buffered IO)
*
* c-3) otherwise: async submit
*/
static blk_status_t btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
int mirror_num,
unsigned long bio_flags)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
blk_status_t ret = 0;
int skip_sum;
int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
if (btrfs_is_free_space_inode(BTRFS_I(inode)))
metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
if (bio_op(bio) != REQ_OP_WRITE) {
ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
if (ret)
goto out;
if (bio_flags & EXTENT_BIO_COMPRESSED) {
ret = btrfs_submit_compressed_read(inode, bio,
mirror_num,
bio_flags);
goto out;
} else if (!skip_sum) {
ret = btrfs_lookup_bio_sums(inode, bio, (u64)-1, NULL);
if (ret)
goto out;
}
goto mapit;
} else if (async && !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 */
ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
0, inode, btrfs_submit_bio_start);
goto out;
} else if (!skip_sum) {
ret = btrfs_csum_one_bio(inode, bio, 0, 0);
if (ret)
goto out;
}
mapit:
ret = btrfs_map_bio(fs_info, bio, mirror_num);
out:
if (ret) {
bio->bi_status = ret;
bio_endio(bio);
}
return ret;
}
/*
* 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, struct list_head *list)
{
struct btrfs_ordered_sum *sum;
int ret;
list_for_each_entry(sum, list, list) {
trans->adding_csums = true;
ret = btrfs_csum_file_blocks(trans,
BTRFS_I(inode)->root->fs_info->csum_root, sum);
trans->adding_csums = false;
if (ret)
return ret;
}
return 0;
}
int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
unsigned int extra_bits,
struct extent_state **cached_state)
{
WARN_ON(PAGE_ALIGNED(end));
return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
extra_bits, cached_state);
}
/* see btrfs_writepage_start_hook for details on why this is required */
struct btrfs_writepage_fixup {
struct page *page;
struct inode *inode;
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 extent_changeset *data_reserved = NULL;
struct page *page;
struct inode *inode;
u64 page_start;
u64 page_end;
int ret = 0;
bool free_delalloc_space = true;
fixup = container_of(work, struct btrfs_writepage_fixup, work);
page = fixup->page;
inode = fixup->inode;
page_start = page_offset(page);
page_end = page_offset(page) + PAGE_SIZE - 1;
/*
* This is similar to page_mkwrite, we need to reserve the space before
* we take the page lock.
*/
ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
PAGE_SIZE);
again:
lock_page(page);
/*
* Before we queued this fixup, we took a reference on the page.
* page->mapping may go NULL, but it shouldn't be moved to a different
* address space.
*/
if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
/*
* Unfortunately this is a little tricky, either
*
* 1) We got here and our page had already been dealt with and
* we reserved our space, thus ret == 0, so we need to just
* drop our space reservation and bail. This can happen the
* first time we come into the fixup worker, or could happen
* while waiting for the ordered extent.
* 2) Our page was already dealt with, but we happened to get an
* ENOSPC above from the btrfs_delalloc_reserve_space. In
* this case we obviously don't have anything to release, but
* because the page was already dealt with we don't want to
* mark the page with an error, so make sure we're resetting
* ret to 0. This is why we have this check _before_ the ret
* check, because we do not want to have a surprise ENOSPC
* when the page was already properly dealt with.
*/
if (!ret) {
btrfs_delalloc_release_extents(BTRFS_I(inode),
PAGE_SIZE);
btrfs_delalloc_release_space(inode, data_reserved,
page_start, PAGE_SIZE,
true);
}
ret = 0;
goto out_page;
}
/*
* We can't mess with the page state unless it is locked, so now that
* it is locked bail if we failed to make our space reservation.
*/
if (ret)
goto out_page;
lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
&cached_state);
/* already ordered? We're done */
if (PagePrivate2(page))
goto out_reserved;
ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
PAGE_SIZE);
if (ordered) {
unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
page_end, &cached_state);
unlock_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
&cached_state);
if (ret)
goto out_reserved;
/*
* Everything went as planned, we're now the owner of a dirty page with
* delayed allocation bits set and space reserved for our COW
* destination.
*
* The page was dirty when we started, nothing should have cleaned it.
*/
BUG_ON(!PageDirty(page));
free_delalloc_space = false;
out_reserved:
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
if (free_delalloc_space)
btrfs_delalloc_release_space(inode, data_reserved, page_start,
PAGE_SIZE, true);
unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
&cached_state);
out_page:
if (ret) {
/*
* We hit ENOSPC or other errors. Update the mapping and page
* to reflect the errors and clean the page.
*/
mapping_set_error(page->mapping, ret);
end_extent_writepage(page, ret, page_start, page_end);
clear_page_dirty_for_io(page);
SetPageError(page);
}
ClearPageChecked(page);
unlock_page(page);
put_page(page);
kfree(fixup);
extent_changeset_free(data_reserved);
/*
* As a precaution, do a delayed iput in case it would be the last iput
* that could need flushing space. Recursing back to fixup worker would
* deadlock.
*/
btrfs_add_delayed_iput(inode);
}
/*
* 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.
*/
int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end)
{
struct inode *inode = page->mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_writepage_fixup *fixup;
/* this page is properly in the ordered list */
if (TestClearPagePrivate2(page))
return 0;
/*
* PageChecked is set below when we create a fixup worker for this page,
* don't try to create another one if we're already PageChecked()
*
* The extent_io writepage code will redirty the page if we send back
* EAGAIN.
*/
if (PageChecked(page))
return -EAGAIN;
fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
if (!fixup)
return -EAGAIN;
/*
* We are already holding a reference to this inode from
* write_cache_pages. We need to hold it because the space reservation
* takes place outside of the page lock, and we can't trust
* page->mapping outside of the page lock.
*/
ihold(inode);
SetPageChecked(page);
get_page(page);
btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL);
fixup->page = page;
fixup->inode = inode;
btrfs_queue_work(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 qg_released;
int extent_inserted = 0;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* 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, root, inode, path, file_pos,
file_pos + num_bytes, NULL, 0,
1, sizeof(*fi), &extent_inserted);
if (ret)
goto out;
if (!extent_inserted) {
ins.objectid = btrfs_ino(BTRFS_I(inode));
ins.offset = file_pos;
ins.type = BTRFS_EXTENT_DATA_KEY;
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, root, path, &ins,
sizeof(*fi));
if (ret)
goto out;
}
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_mark_buffer_dirty(leaf);
btrfs_release_path(path);
inode_add_bytes(inode, num_bytes);
ins.objectid = disk_bytenr;
ins.offset = disk_num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
/*
* Release the reserved range from inode dirty range map, as it is
* already moved into delayed_ref_head
*/
ret = btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
if (ret < 0)
goto out;
qg_released = ret;
ret = btrfs_alloc_reserved_file_extent(trans, root,
btrfs_ino(BTRFS_I(inode)),
file_pos, qg_released, &ins);
out:
btrfs_free_path(path);
return ret;
}
static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
u64 start, u64 len)
{
struct btrfs_block_group *cache;
cache = btrfs_lookup_block_group(fs_info, start);
ASSERT(cache);
spin_lock(&cache->lock);
cache->delalloc_bytes -= len;
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
}
/* 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 btrfs_ordered_extent *ordered_extent)
{
struct inode *inode = ordered_extent->inode;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans = NULL;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_state *cached_state = NULL;
u64 start, end;
int compress_type = 0;
int ret = 0;
u64 logical_len = ordered_extent->num_bytes;
bool freespace_inode;
bool truncated = false;
bool range_locked = false;
bool clear_new_delalloc_bytes = false;
bool clear_reserved_extent = true;
unsigned int clear_bits;
start = ordered_extent->file_offset;
end = start + ordered_extent->num_bytes - 1;
if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
clear_new_delalloc_bytes = true;
freespace_inode = btrfs_is_free_space_inode(BTRFS_I(inode));
if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
ret = -EIO;
goto out;
}
btrfs_free_io_failure_record(BTRFS_I(inode), start, end);
if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
truncated = true;
logical_len = ordered_extent->truncated_len;
/* Truncated the entire extent, don't bother adding */
if (!logical_len)
goto out;
}
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
/*
* For mwrite(mmap + memset to write) case, we still reserve
* space for NOCOW range.
* As NOCOW won't cause a new delayed ref, just free the space
*/
btrfs_qgroup_free_data(inode, NULL, start,
ordered_extent->num_bytes);
btrfs_ordered_update_i_size(inode, 0, ordered_extent);
if (freespace_inode)
trans = btrfs_join_transaction_spacecache(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
trans->block_rsv = &BTRFS_I(inode)->block_rsv;
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, ret);
goto out;
}
range_locked = true;
lock_extent_bits(io_tree, start, end, &cached_state);
if (freespace_inode)
trans = btrfs_join_transaction_spacecache(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
trans->block_rsv = &BTRFS_I(inode)->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);
btrfs_qgroup_free_data(inode, NULL, start,
ordered_extent->num_bytes);
ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
ordered_extent->file_offset,
ordered_extent->file_offset +
logical_len);
} else {
BUG_ON(root == fs_info->tree_root);
ret = insert_reserved_file_extent(trans, inode, start,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes,
logical_len, logical_len,
compress_type, 0, 0,
BTRFS_FILE_EXTENT_REG);
if (!ret) {
clear_reserved_extent = false;
btrfs_release_delalloc_bytes(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes);
}
}
unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
ordered_extent->file_offset,
ordered_extent->num_bytes, trans->transid);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = add_pending_csums(trans, inode, &ordered_extent->list);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
btrfs_ordered_update_i_size(inode, 0, ordered_extent);
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) { /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = 0;
out:
clear_bits = EXTENT_DEFRAG;
if (range_locked)
clear_bits |= EXTENT_LOCKED;
if (clear_new_delalloc_bytes)
clear_bits |= EXTENT_DELALLOC_NEW;
clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits,
(clear_bits & EXTENT_LOCKED) ? 1 : 0, 0,
&cached_state);
if (trans)
btrfs_end_transaction(trans);
if (ret || truncated) {
u64 unwritten_start = start;
if (truncated)
unwritten_start += logical_len;
clear_extent_uptodate(io_tree, unwritten_start, end, NULL);
/* Drop the cache for the part of the extent we didn't write. */
btrfs_drop_extent_cache(BTRFS_I(inode), unwritten_start, end, 0);
/*
* If the ordered extent had an IOERR or something else went
* wrong we need to return the space for this ordered extent
* back to the allocator. We only free the extent in the
* truncated case if we didn't write out the extent at all.
*
* If we made it past insert_reserved_file_extent before we
* errored out then we don't need to do this as the accounting
* has already been done.
*/
if ((ret || !logical_len) &&
clear_reserved_extent &&
!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
/*
* Discard the range before returning it back to the
* free space pool
*/
if (ret && btrfs_test_opt(fs_info, DISCARD_SYNC))
btrfs_discard_extent(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes,
NULL);
btrfs_free_reserved_extent(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes, 1);
}
}
/*
* This needs to be done to make sure anybody waiting knows we are done
* updating everything for this ordered extent.
*/
btrfs_remove_ordered_extent(inode, ordered_extent);
/* once for us */
btrfs_put_ordered_extent(ordered_extent);
/* once for the tree */
btrfs_put_ordered_extent(ordered_extent);
return ret;
}
static void finish_ordered_fn(struct btrfs_work *work)
{
struct btrfs_ordered_extent *ordered_extent;
ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
btrfs_finish_ordered_io(ordered_extent);
}
void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
u64 end, int uptodate)
{
struct inode *inode = page->mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_ordered_extent *ordered_extent = NULL;
struct btrfs_workqueue *wq;
trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
ClearPagePrivate2(page);
if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
end - start + 1, uptodate))
return;
if (btrfs_is_free_space_inode(BTRFS_I(inode)))
wq = fs_info->endio_freespace_worker;
else
wq = fs_info->endio_write_workers;
btrfs_init_work(&ordered_extent->work, finish_ordered_fn, NULL, NULL);
btrfs_queue_work(wq, &ordered_extent->work);
}
static int __readpage_endio_check(struct inode *inode,
struct btrfs_io_bio *io_bio,
int icsum, struct page *page,
int pgoff, u64 start, size_t len)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
char *kaddr;
u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
u8 *csum_expected;
u8 csum[BTRFS_CSUM_SIZE];
csum_expected = ((u8 *)io_bio->csum) + icsum * csum_size;
kaddr = kmap_atomic(page);
shash->tfm = fs_info->csum_shash;
crypto_shash_init(shash);
crypto_shash_update(shash, kaddr + pgoff, len);
crypto_shash_final(shash, csum);
if (memcmp(csum, csum_expected, csum_size))
goto zeroit;
kunmap_atomic(kaddr);
return 0;
zeroit:
btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
io_bio->mirror_num);
memset(kaddr + pgoff, 1, len);
flush_dcache_page(page);
kunmap_atomic(kaddr);
return -EIO;
}
/*
* 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 btrfs_io_bio *io_bio,
u64 phy_offset, struct page *page,
u64 start, u64 end, int mirror)
{
size_t offset = start - page_offset(page);
struct inode *inode = page->mapping->host;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_root *root = BTRFS_I(inode)->root;
if (PageChecked(page)) {
ClearPageChecked(page);
return 0;
}
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
return 0;
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);
return 0;
}
phy_offset >>= inode->i_sb->s_blocksize_bits;
return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
start, (size_t)(end - start + 1));
}
/*
* btrfs_add_delayed_iput - perform a delayed iput on @inode
*
* @inode: The inode we want to perform iput on
*
* This function uses the generic vfs_inode::i_count to track whether we should
* just decrement it (in case it's > 1) or if this is the last iput then link
* the inode to the delayed iput machinery. Delayed iputs are processed at
* transaction commit time/superblock commit/cleaner kthread.
*/
void btrfs_add_delayed_iput(struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_inode *binode = BTRFS_I(inode);
if (atomic_add_unless(&inode->i_count, -1, 1))
return;
atomic_inc(&fs_info->nr_delayed_iputs);
spin_lock(&fs_info->delayed_iput_lock);
ASSERT(list_empty(&binode->delayed_iput));
list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
spin_unlock(&fs_info->delayed_iput_lock);
if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags))
wake_up_process(fs_info->cleaner_kthread);
}
static void run_delayed_iput_locked(struct btrfs_fs_info *fs_info,
struct btrfs_inode *inode)
{
lis