![Liu Bo](/assets/img/avatar_default.png)
This has been reported and discussed for a long time, and this hang occurs in both 3.15 and 3.16. Btrfs now migrates to use kernel workqueue, but it introduces this hang problem. Btrfs has a kind of work queued as an ordered way, which means that its ordered_func() must be processed in the way of FIFO, so it usually looks like -- normal_work_helper(arg) work = container_of(arg, struct btrfs_work, normal_work); work->func() <---- (we name it work X) for ordered_work in wq->ordered_list ordered_work->ordered_func() ordered_work->ordered_free() The hang is a rare case, first when we find free space, we get an uncached block group, then we go to read its free space cache inode for free space information, so it will file a readahead request btrfs_readpages() for page that is not in page cache __do_readpage() submit_extent_page() btrfs_submit_bio_hook() btrfs_bio_wq_end_io() submit_bio() end_workqueue_bio() <--(ret by the 1st endio) queue a work(named work Y) for the 2nd also the real endio() So the hang occurs when work Y's work_struct and work X's work_struct happens to share the same address. A bit more explanation, A,B,C -- struct btrfs_work arg -- struct work_struct kthread: worker_thread() pick up a work_struct from @worklist process_one_work(arg) worker->current_work = arg; <-- arg is A->normal_work worker->current_func(arg) normal_work_helper(arg) A = container_of(arg, struct btrfs_work, normal_work); A->func() A->ordered_func() A->ordered_free() <-- A gets freed B->ordered_func() submit_compressed_extents() find_free_extent() load_free_space_inode() ... <-- (the above readhead stack) end_workqueue_bio() btrfs_queue_work(work C) B->ordered_free() As if work A has a high priority in wq->ordered_list and there are more ordered works queued after it, such as B->ordered_func(), its memory could have been freed before normal_work_helper() returns, which means that kernel workqueue code worker_thread() still has worker->current_work pointer to be work A->normal_work's, ie. arg's address. Meanwhile, work C is allocated after work A is freed, work C->normal_work and work A->normal_work are likely to share the same address(I confirmed this with ftrace output, so I'm not just guessing, it's rare though). When another kthread picks up work C->normal_work to process, and finds our kthread is processing it(see find_worker_executing_work()), it'll think work C as a collision and skip then, which ends up nobody processing work C. So the situation is that our kthread is waiting forever on work C. Besides, there're other cases that can lead to deadlock, but the real problem is that all btrfs workqueue shares one work->func, -- normal_work_helper, so this makes each workqueue to have its own helper function, but only a wraper pf normal_work_helper. With this patch, I no long hit the above hang. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
1054 lines
29 KiB
C
1054 lines
29 KiB
C
/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#include <linux/slab.h>
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#include <linux/blkdev.h>
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#include <linux/writeback.h>
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#include <linux/pagevec.h>
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#include "ctree.h"
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#include "transaction.h"
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#include "btrfs_inode.h"
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#include "extent_io.h"
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#include "disk-io.h"
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static struct kmem_cache *btrfs_ordered_extent_cache;
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static u64 entry_end(struct btrfs_ordered_extent *entry)
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{
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if (entry->file_offset + entry->len < entry->file_offset)
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return (u64)-1;
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return entry->file_offset + entry->len;
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}
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/* returns NULL if the insertion worked, or it returns the node it did find
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* in the tree
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*/
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static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
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struct rb_node *node)
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{
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struct rb_node **p = &root->rb_node;
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struct rb_node *parent = NULL;
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struct btrfs_ordered_extent *entry;
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while (*p) {
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parent = *p;
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entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
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if (file_offset < entry->file_offset)
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p = &(*p)->rb_left;
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else if (file_offset >= entry_end(entry))
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p = &(*p)->rb_right;
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else
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return parent;
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}
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rb_link_node(node, parent, p);
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rb_insert_color(node, root);
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return NULL;
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}
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static void ordered_data_tree_panic(struct inode *inode, int errno,
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u64 offset)
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{
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struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
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btrfs_panic(fs_info, errno, "Inconsistency in ordered tree at offset "
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"%llu", offset);
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}
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/*
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* look for a given offset in the tree, and if it can't be found return the
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* first lesser offset
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*/
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static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
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struct rb_node **prev_ret)
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{
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struct rb_node *n = root->rb_node;
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struct rb_node *prev = NULL;
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struct rb_node *test;
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struct btrfs_ordered_extent *entry;
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struct btrfs_ordered_extent *prev_entry = NULL;
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while (n) {
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entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
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prev = n;
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prev_entry = entry;
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if (file_offset < entry->file_offset)
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n = n->rb_left;
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else if (file_offset >= entry_end(entry))
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n = n->rb_right;
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else
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return n;
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}
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if (!prev_ret)
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return NULL;
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while (prev && file_offset >= entry_end(prev_entry)) {
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test = rb_next(prev);
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if (!test)
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break;
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prev_entry = rb_entry(test, struct btrfs_ordered_extent,
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rb_node);
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if (file_offset < entry_end(prev_entry))
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break;
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prev = test;
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}
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if (prev)
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prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
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rb_node);
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while (prev && file_offset < entry_end(prev_entry)) {
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test = rb_prev(prev);
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if (!test)
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break;
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prev_entry = rb_entry(test, struct btrfs_ordered_extent,
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rb_node);
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prev = test;
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}
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*prev_ret = prev;
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return NULL;
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}
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/*
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* helper to check if a given offset is inside a given entry
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*/
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static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
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{
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if (file_offset < entry->file_offset ||
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entry->file_offset + entry->len <= file_offset)
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return 0;
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return 1;
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}
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static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
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u64 len)
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{
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if (file_offset + len <= entry->file_offset ||
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entry->file_offset + entry->len <= file_offset)
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return 0;
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return 1;
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}
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/*
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* look find the first ordered struct that has this offset, otherwise
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* the first one less than this offset
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*/
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static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
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u64 file_offset)
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{
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struct rb_root *root = &tree->tree;
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struct rb_node *prev = NULL;
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struct rb_node *ret;
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struct btrfs_ordered_extent *entry;
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if (tree->last) {
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entry = rb_entry(tree->last, struct btrfs_ordered_extent,
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rb_node);
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if (offset_in_entry(entry, file_offset))
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return tree->last;
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}
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ret = __tree_search(root, file_offset, &prev);
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if (!ret)
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ret = prev;
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if (ret)
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tree->last = ret;
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return ret;
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}
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/* allocate and add a new ordered_extent into the per-inode tree.
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* file_offset is the logical offset in the file
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*
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* start is the disk block number of an extent already reserved in the
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* extent allocation tree
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*
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* len is the length of the extent
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*
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* The tree is given a single reference on the ordered extent that was
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* inserted.
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*/
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static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
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u64 start, u64 len, u64 disk_len,
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int type, int dio, int compress_type)
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{
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struct btrfs_root *root = BTRFS_I(inode)->root;
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struct btrfs_ordered_inode_tree *tree;
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struct rb_node *node;
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struct btrfs_ordered_extent *entry;
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tree = &BTRFS_I(inode)->ordered_tree;
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entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
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if (!entry)
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return -ENOMEM;
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entry->file_offset = file_offset;
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entry->start = start;
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entry->len = len;
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if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) &&
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!(type == BTRFS_ORDERED_NOCOW))
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entry->csum_bytes_left = disk_len;
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entry->disk_len = disk_len;
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entry->bytes_left = len;
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entry->inode = igrab(inode);
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entry->compress_type = compress_type;
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entry->truncated_len = (u64)-1;
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if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
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set_bit(type, &entry->flags);
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if (dio)
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set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
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/* one ref for the tree */
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atomic_set(&entry->refs, 1);
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init_waitqueue_head(&entry->wait);
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INIT_LIST_HEAD(&entry->list);
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INIT_LIST_HEAD(&entry->root_extent_list);
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INIT_LIST_HEAD(&entry->work_list);
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init_completion(&entry->completion);
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INIT_LIST_HEAD(&entry->log_list);
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trace_btrfs_ordered_extent_add(inode, entry);
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spin_lock_irq(&tree->lock);
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node = tree_insert(&tree->tree, file_offset,
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&entry->rb_node);
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if (node)
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ordered_data_tree_panic(inode, -EEXIST, file_offset);
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spin_unlock_irq(&tree->lock);
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spin_lock(&root->ordered_extent_lock);
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list_add_tail(&entry->root_extent_list,
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&root->ordered_extents);
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root->nr_ordered_extents++;
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if (root->nr_ordered_extents == 1) {
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spin_lock(&root->fs_info->ordered_root_lock);
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BUG_ON(!list_empty(&root->ordered_root));
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list_add_tail(&root->ordered_root,
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&root->fs_info->ordered_roots);
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spin_unlock(&root->fs_info->ordered_root_lock);
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}
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spin_unlock(&root->ordered_extent_lock);
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return 0;
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}
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int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
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u64 start, u64 len, u64 disk_len, int type)
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{
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return __btrfs_add_ordered_extent(inode, file_offset, start, len,
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disk_len, type, 0,
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BTRFS_COMPRESS_NONE);
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}
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int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
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u64 start, u64 len, u64 disk_len, int type)
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{
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return __btrfs_add_ordered_extent(inode, file_offset, start, len,
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disk_len, type, 1,
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BTRFS_COMPRESS_NONE);
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}
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int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
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u64 start, u64 len, u64 disk_len,
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int type, int compress_type)
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{
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return __btrfs_add_ordered_extent(inode, file_offset, start, len,
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disk_len, type, 0,
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compress_type);
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}
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/*
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* Add a struct btrfs_ordered_sum into the list of checksums to be inserted
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* when an ordered extent is finished. If the list covers more than one
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* ordered extent, it is split across multiples.
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*/
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void btrfs_add_ordered_sum(struct inode *inode,
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struct btrfs_ordered_extent *entry,
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struct btrfs_ordered_sum *sum)
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{
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struct btrfs_ordered_inode_tree *tree;
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tree = &BTRFS_I(inode)->ordered_tree;
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spin_lock_irq(&tree->lock);
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list_add_tail(&sum->list, &entry->list);
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WARN_ON(entry->csum_bytes_left < sum->len);
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entry->csum_bytes_left -= sum->len;
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if (entry->csum_bytes_left == 0)
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wake_up(&entry->wait);
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spin_unlock_irq(&tree->lock);
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}
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/*
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* this is used to account for finished IO across a given range
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* of the file. The IO may span ordered extents. If
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* a given ordered_extent is completely done, 1 is returned, otherwise
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* 0.
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*
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* test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
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* to make sure this function only returns 1 once for a given ordered extent.
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*
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* file_offset is updated to one byte past the range that is recorded as
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* complete. This allows you to walk forward in the file.
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*/
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int btrfs_dec_test_first_ordered_pending(struct inode *inode,
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struct btrfs_ordered_extent **cached,
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u64 *file_offset, u64 io_size, int uptodate)
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{
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struct btrfs_ordered_inode_tree *tree;
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struct rb_node *node;
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struct btrfs_ordered_extent *entry = NULL;
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int ret;
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unsigned long flags;
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u64 dec_end;
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u64 dec_start;
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u64 to_dec;
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tree = &BTRFS_I(inode)->ordered_tree;
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spin_lock_irqsave(&tree->lock, flags);
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node = tree_search(tree, *file_offset);
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if (!node) {
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ret = 1;
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goto out;
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}
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entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
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if (!offset_in_entry(entry, *file_offset)) {
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ret = 1;
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goto out;
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}
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dec_start = max(*file_offset, entry->file_offset);
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dec_end = min(*file_offset + io_size, entry->file_offset +
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entry->len);
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*file_offset = dec_end;
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if (dec_start > dec_end) {
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btrfs_crit(BTRFS_I(inode)->root->fs_info,
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"bad ordering dec_start %llu end %llu", dec_start, dec_end);
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}
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to_dec = dec_end - dec_start;
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if (to_dec > entry->bytes_left) {
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btrfs_crit(BTRFS_I(inode)->root->fs_info,
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"bad ordered accounting left %llu size %llu",
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entry->bytes_left, to_dec);
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}
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entry->bytes_left -= to_dec;
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if (!uptodate)
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set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
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if (entry->bytes_left == 0) {
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ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
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if (waitqueue_active(&entry->wait))
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wake_up(&entry->wait);
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} else {
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ret = 1;
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}
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out:
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if (!ret && cached && entry) {
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*cached = entry;
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atomic_inc(&entry->refs);
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}
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spin_unlock_irqrestore(&tree->lock, flags);
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return ret == 0;
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}
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/*
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* this is used to account for finished IO across a given range
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* of the file. The IO should not span ordered extents. If
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* a given ordered_extent is completely done, 1 is returned, otherwise
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* 0.
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*
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* test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
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* to make sure this function only returns 1 once for a given ordered extent.
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*/
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int btrfs_dec_test_ordered_pending(struct inode *inode,
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struct btrfs_ordered_extent **cached,
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u64 file_offset, u64 io_size, int uptodate)
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{
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struct btrfs_ordered_inode_tree *tree;
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struct rb_node *node;
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struct btrfs_ordered_extent *entry = NULL;
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unsigned long flags;
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int ret;
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tree = &BTRFS_I(inode)->ordered_tree;
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spin_lock_irqsave(&tree->lock, flags);
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if (cached && *cached) {
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entry = *cached;
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goto have_entry;
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}
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node = tree_search(tree, file_offset);
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if (!node) {
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ret = 1;
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goto out;
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}
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entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
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have_entry:
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if (!offset_in_entry(entry, file_offset)) {
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ret = 1;
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goto out;
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}
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if (io_size > entry->bytes_left) {
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btrfs_crit(BTRFS_I(inode)->root->fs_info,
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"bad ordered accounting left %llu size %llu",
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entry->bytes_left, io_size);
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}
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entry->bytes_left -= io_size;
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if (!uptodate)
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set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
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|
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if (entry->bytes_left == 0) {
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ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
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if (waitqueue_active(&entry->wait))
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wake_up(&entry->wait);
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} else {
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ret = 1;
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}
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out:
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if (!ret && cached && entry) {
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*cached = entry;
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atomic_inc(&entry->refs);
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}
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spin_unlock_irqrestore(&tree->lock, flags);
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return ret == 0;
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}
|
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|
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/* Needs to either be called under a log transaction or the log_mutex */
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void btrfs_get_logged_extents(struct inode *inode,
|
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struct list_head *logged_list)
|
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{
|
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struct btrfs_ordered_inode_tree *tree;
|
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struct btrfs_ordered_extent *ordered;
|
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struct rb_node *n;
|
|
|
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tree = &BTRFS_I(inode)->ordered_tree;
|
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spin_lock_irq(&tree->lock);
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for (n = rb_first(&tree->tree); n; n = rb_next(n)) {
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ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
|
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if (!list_empty(&ordered->log_list))
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continue;
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list_add_tail(&ordered->log_list, logged_list);
|
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atomic_inc(&ordered->refs);
|
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}
|
|
spin_unlock_irq(&tree->lock);
|
|
}
|
|
|
|
void btrfs_put_logged_extents(struct list_head *logged_list)
|
|
{
|
|
struct btrfs_ordered_extent *ordered;
|
|
|
|
while (!list_empty(logged_list)) {
|
|
ordered = list_first_entry(logged_list,
|
|
struct btrfs_ordered_extent,
|
|
log_list);
|
|
list_del_init(&ordered->log_list);
|
|
btrfs_put_ordered_extent(ordered);
|
|
}
|
|
}
|
|
|
|
void btrfs_submit_logged_extents(struct list_head *logged_list,
|
|
struct btrfs_root *log)
|
|
{
|
|
int index = log->log_transid % 2;
|
|
|
|
spin_lock_irq(&log->log_extents_lock[index]);
|
|
list_splice_tail(logged_list, &log->logged_list[index]);
|
|
spin_unlock_irq(&log->log_extents_lock[index]);
|
|
}
|
|
|
|
void btrfs_wait_logged_extents(struct btrfs_root *log, u64 transid)
|
|
{
|
|
struct btrfs_ordered_extent *ordered;
|
|
int index = transid % 2;
|
|
|
|
spin_lock_irq(&log->log_extents_lock[index]);
|
|
while (!list_empty(&log->logged_list[index])) {
|
|
ordered = list_first_entry(&log->logged_list[index],
|
|
struct btrfs_ordered_extent,
|
|
log_list);
|
|
list_del_init(&ordered->log_list);
|
|
spin_unlock_irq(&log->log_extents_lock[index]);
|
|
|
|
if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
|
|
!test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
|
|
struct inode *inode = ordered->inode;
|
|
u64 start = ordered->file_offset;
|
|
u64 end = ordered->file_offset + ordered->len - 1;
|
|
|
|
WARN_ON(!inode);
|
|
filemap_fdatawrite_range(inode->i_mapping, start, end);
|
|
}
|
|
wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE,
|
|
&ordered->flags));
|
|
|
|
btrfs_put_ordered_extent(ordered);
|
|
spin_lock_irq(&log->log_extents_lock[index]);
|
|
}
|
|
spin_unlock_irq(&log->log_extents_lock[index]);
|
|
}
|
|
|
|
void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid)
|
|
{
|
|
struct btrfs_ordered_extent *ordered;
|
|
int index = transid % 2;
|
|
|
|
spin_lock_irq(&log->log_extents_lock[index]);
|
|
while (!list_empty(&log->logged_list[index])) {
|
|
ordered = list_first_entry(&log->logged_list[index],
|
|
struct btrfs_ordered_extent,
|
|
log_list);
|
|
list_del_init(&ordered->log_list);
|
|
spin_unlock_irq(&log->log_extents_lock[index]);
|
|
btrfs_put_ordered_extent(ordered);
|
|
spin_lock_irq(&log->log_extents_lock[index]);
|
|
}
|
|
spin_unlock_irq(&log->log_extents_lock[index]);
|
|
}
|
|
|
|
/*
|
|
* used to drop a reference on an ordered extent. This will free
|
|
* the extent if the last reference is dropped
|
|
*/
|
|
void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
|
|
{
|
|
struct list_head *cur;
|
|
struct btrfs_ordered_sum *sum;
|
|
|
|
trace_btrfs_ordered_extent_put(entry->inode, entry);
|
|
|
|
if (atomic_dec_and_test(&entry->refs)) {
|
|
if (entry->inode)
|
|
btrfs_add_delayed_iput(entry->inode);
|
|
while (!list_empty(&entry->list)) {
|
|
cur = entry->list.next;
|
|
sum = list_entry(cur, struct btrfs_ordered_sum, list);
|
|
list_del(&sum->list);
|
|
kfree(sum);
|
|
}
|
|
kmem_cache_free(btrfs_ordered_extent_cache, entry);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* remove an ordered extent from the tree. No references are dropped
|
|
* and waiters are woken up.
|
|
*/
|
|
void btrfs_remove_ordered_extent(struct inode *inode,
|
|
struct btrfs_ordered_extent *entry)
|
|
{
|
|
struct btrfs_ordered_inode_tree *tree;
|
|
struct btrfs_root *root = BTRFS_I(inode)->root;
|
|
struct rb_node *node;
|
|
|
|
tree = &BTRFS_I(inode)->ordered_tree;
|
|
spin_lock_irq(&tree->lock);
|
|
node = &entry->rb_node;
|
|
rb_erase(node, &tree->tree);
|
|
if (tree->last == node)
|
|
tree->last = NULL;
|
|
set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
|
|
spin_unlock_irq(&tree->lock);
|
|
|
|
spin_lock(&root->ordered_extent_lock);
|
|
list_del_init(&entry->root_extent_list);
|
|
root->nr_ordered_extents--;
|
|
|
|
trace_btrfs_ordered_extent_remove(inode, entry);
|
|
|
|
if (!root->nr_ordered_extents) {
|
|
spin_lock(&root->fs_info->ordered_root_lock);
|
|
BUG_ON(list_empty(&root->ordered_root));
|
|
list_del_init(&root->ordered_root);
|
|
spin_unlock(&root->fs_info->ordered_root_lock);
|
|
}
|
|
spin_unlock(&root->ordered_extent_lock);
|
|
wake_up(&entry->wait);
|
|
}
|
|
|
|
static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
|
|
{
|
|
struct btrfs_ordered_extent *ordered;
|
|
|
|
ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
|
|
btrfs_start_ordered_extent(ordered->inode, ordered, 1);
|
|
complete(&ordered->completion);
|
|
}
|
|
|
|
/*
|
|
* wait for all the ordered extents in a root. This is done when balancing
|
|
* space between drives.
|
|
*/
|
|
int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
|
|
{
|
|
struct list_head splice, works;
|
|
struct btrfs_ordered_extent *ordered, *next;
|
|
int count = 0;
|
|
|
|
INIT_LIST_HEAD(&splice);
|
|
INIT_LIST_HEAD(&works);
|
|
|
|
mutex_lock(&root->ordered_extent_mutex);
|
|
spin_lock(&root->ordered_extent_lock);
|
|
list_splice_init(&root->ordered_extents, &splice);
|
|
while (!list_empty(&splice) && nr) {
|
|
ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
|
|
root_extent_list);
|
|
list_move_tail(&ordered->root_extent_list,
|
|
&root->ordered_extents);
|
|
atomic_inc(&ordered->refs);
|
|
spin_unlock(&root->ordered_extent_lock);
|
|
|
|
btrfs_init_work(&ordered->flush_work,
|
|
btrfs_flush_delalloc_helper,
|
|
btrfs_run_ordered_extent_work, NULL, NULL);
|
|
list_add_tail(&ordered->work_list, &works);
|
|
btrfs_queue_work(root->fs_info->flush_workers,
|
|
&ordered->flush_work);
|
|
|
|
cond_resched();
|
|
spin_lock(&root->ordered_extent_lock);
|
|
if (nr != -1)
|
|
nr--;
|
|
count++;
|
|
}
|
|
list_splice_tail(&splice, &root->ordered_extents);
|
|
spin_unlock(&root->ordered_extent_lock);
|
|
|
|
list_for_each_entry_safe(ordered, next, &works, work_list) {
|
|
list_del_init(&ordered->work_list);
|
|
wait_for_completion(&ordered->completion);
|
|
btrfs_put_ordered_extent(ordered);
|
|
cond_resched();
|
|
}
|
|
mutex_unlock(&root->ordered_extent_mutex);
|
|
|
|
return count;
|
|
}
|
|
|
|
void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr)
|
|
{
|
|
struct btrfs_root *root;
|
|
struct list_head splice;
|
|
int done;
|
|
|
|
INIT_LIST_HEAD(&splice);
|
|
|
|
mutex_lock(&fs_info->ordered_operations_mutex);
|
|
spin_lock(&fs_info->ordered_root_lock);
|
|
list_splice_init(&fs_info->ordered_roots, &splice);
|
|
while (!list_empty(&splice) && nr) {
|
|
root = list_first_entry(&splice, struct btrfs_root,
|
|
ordered_root);
|
|
root = btrfs_grab_fs_root(root);
|
|
BUG_ON(!root);
|
|
list_move_tail(&root->ordered_root,
|
|
&fs_info->ordered_roots);
|
|
spin_unlock(&fs_info->ordered_root_lock);
|
|
|
|
done = btrfs_wait_ordered_extents(root, nr);
|
|
btrfs_put_fs_root(root);
|
|
|
|
spin_lock(&fs_info->ordered_root_lock);
|
|
if (nr != -1) {
|
|
nr -= done;
|
|
WARN_ON(nr < 0);
|
|
}
|
|
}
|
|
list_splice_tail(&splice, &fs_info->ordered_roots);
|
|
spin_unlock(&fs_info->ordered_root_lock);
|
|
mutex_unlock(&fs_info->ordered_operations_mutex);
|
|
}
|
|
|
|
/*
|
|
* Used to start IO or wait for a given ordered extent to finish.
|
|
*
|
|
* If wait is one, this effectively waits on page writeback for all the pages
|
|
* in the extent, and it waits on the io completion code to insert
|
|
* metadata into the btree corresponding to the extent
|
|
*/
|
|
void btrfs_start_ordered_extent(struct inode *inode,
|
|
struct btrfs_ordered_extent *entry,
|
|
int wait)
|
|
{
|
|
u64 start = entry->file_offset;
|
|
u64 end = start + entry->len - 1;
|
|
|
|
trace_btrfs_ordered_extent_start(inode, entry);
|
|
|
|
/*
|
|
* pages in the range can be dirty, clean or writeback. We
|
|
* start IO on any dirty ones so the wait doesn't stall waiting
|
|
* for the flusher thread to find them
|
|
*/
|
|
if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
|
|
filemap_fdatawrite_range(inode->i_mapping, start, end);
|
|
if (wait) {
|
|
wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
|
|
&entry->flags));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Used to wait on ordered extents across a large range of bytes.
|
|
*/
|
|
int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
|
|
{
|
|
int ret = 0;
|
|
u64 end;
|
|
u64 orig_end;
|
|
struct btrfs_ordered_extent *ordered;
|
|
|
|
if (start + len < start) {
|
|
orig_end = INT_LIMIT(loff_t);
|
|
} else {
|
|
orig_end = start + len - 1;
|
|
if (orig_end > INT_LIMIT(loff_t))
|
|
orig_end = INT_LIMIT(loff_t);
|
|
}
|
|
|
|
/* start IO across the range first to instantiate any delalloc
|
|
* extents
|
|
*/
|
|
ret = filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
|
|
if (ret)
|
|
return ret;
|
|
/*
|
|
* So with compression we will find and lock a dirty page and clear the
|
|
* first one as dirty, setup an async extent, and immediately return
|
|
* with the entire range locked but with nobody actually marked with
|
|
* writeback. So we can't just filemap_write_and_wait_range() and
|
|
* expect it to work since it will just kick off a thread to do the
|
|
* actual work. So we need to call filemap_fdatawrite_range _again_
|
|
* since it will wait on the page lock, which won't be unlocked until
|
|
* after the pages have been marked as writeback and so we're good to go
|
|
* from there. We have to do this otherwise we'll miss the ordered
|
|
* extents and that results in badness. Please Josef, do not think you
|
|
* know better and pull this out at some point in the future, it is
|
|
* right and you are wrong.
|
|
*/
|
|
if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
|
|
&BTRFS_I(inode)->runtime_flags)) {
|
|
ret = filemap_fdatawrite_range(inode->i_mapping, start,
|
|
orig_end);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
ret = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
|
|
if (ret)
|
|
return ret;
|
|
|
|
end = orig_end;
|
|
while (1) {
|
|
ordered = btrfs_lookup_first_ordered_extent(inode, end);
|
|
if (!ordered)
|
|
break;
|
|
if (ordered->file_offset > orig_end) {
|
|
btrfs_put_ordered_extent(ordered);
|
|
break;
|
|
}
|
|
if (ordered->file_offset + ordered->len <= start) {
|
|
btrfs_put_ordered_extent(ordered);
|
|
break;
|
|
}
|
|
btrfs_start_ordered_extent(inode, ordered, 1);
|
|
end = ordered->file_offset;
|
|
if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
|
|
ret = -EIO;
|
|
btrfs_put_ordered_extent(ordered);
|
|
if (ret || end == 0 || end == start)
|
|
break;
|
|
end--;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* find an ordered extent corresponding to file_offset. return NULL if
|
|
* nothing is found, otherwise take a reference on the extent and return it
|
|
*/
|
|
struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
|
|
u64 file_offset)
|
|
{
|
|
struct btrfs_ordered_inode_tree *tree;
|
|
struct rb_node *node;
|
|
struct btrfs_ordered_extent *entry = NULL;
|
|
|
|
tree = &BTRFS_I(inode)->ordered_tree;
|
|
spin_lock_irq(&tree->lock);
|
|
node = tree_search(tree, file_offset);
|
|
if (!node)
|
|
goto out;
|
|
|
|
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
|
|
if (!offset_in_entry(entry, file_offset))
|
|
entry = NULL;
|
|
if (entry)
|
|
atomic_inc(&entry->refs);
|
|
out:
|
|
spin_unlock_irq(&tree->lock);
|
|
return entry;
|
|
}
|
|
|
|
/* Since the DIO code tries to lock a wide area we need to look for any ordered
|
|
* extents that exist in the range, rather than just the start of the range.
|
|
*/
|
|
struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
|
|
u64 file_offset,
|
|
u64 len)
|
|
{
|
|
struct btrfs_ordered_inode_tree *tree;
|
|
struct rb_node *node;
|
|
struct btrfs_ordered_extent *entry = NULL;
|
|
|
|
tree = &BTRFS_I(inode)->ordered_tree;
|
|
spin_lock_irq(&tree->lock);
|
|
node = tree_search(tree, file_offset);
|
|
if (!node) {
|
|
node = tree_search(tree, file_offset + len);
|
|
if (!node)
|
|
goto out;
|
|
}
|
|
|
|
while (1) {
|
|
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
|
|
if (range_overlaps(entry, file_offset, len))
|
|
break;
|
|
|
|
if (entry->file_offset >= file_offset + len) {
|
|
entry = NULL;
|
|
break;
|
|
}
|
|
entry = NULL;
|
|
node = rb_next(node);
|
|
if (!node)
|
|
break;
|
|
}
|
|
out:
|
|
if (entry)
|
|
atomic_inc(&entry->refs);
|
|
spin_unlock_irq(&tree->lock);
|
|
return entry;
|
|
}
|
|
|
|
/*
|
|
* lookup and return any extent before 'file_offset'. NULL is returned
|
|
* if none is found
|
|
*/
|
|
struct btrfs_ordered_extent *
|
|
btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
|
|
{
|
|
struct btrfs_ordered_inode_tree *tree;
|
|
struct rb_node *node;
|
|
struct btrfs_ordered_extent *entry = NULL;
|
|
|
|
tree = &BTRFS_I(inode)->ordered_tree;
|
|
spin_lock_irq(&tree->lock);
|
|
node = tree_search(tree, file_offset);
|
|
if (!node)
|
|
goto out;
|
|
|
|
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
|
|
atomic_inc(&entry->refs);
|
|
out:
|
|
spin_unlock_irq(&tree->lock);
|
|
return entry;
|
|
}
|
|
|
|
/*
|
|
* After an extent is done, call this to conditionally update the on disk
|
|
* i_size. i_size is updated to cover any fully written part of the file.
|
|
*/
|
|
int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
|
|
struct btrfs_ordered_extent *ordered)
|
|
{
|
|
struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
|
|
u64 disk_i_size;
|
|
u64 new_i_size;
|
|
u64 i_size = i_size_read(inode);
|
|
struct rb_node *node;
|
|
struct rb_node *prev = NULL;
|
|
struct btrfs_ordered_extent *test;
|
|
int ret = 1;
|
|
|
|
spin_lock_irq(&tree->lock);
|
|
if (ordered) {
|
|
offset = entry_end(ordered);
|
|
if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
|
|
offset = min(offset,
|
|
ordered->file_offset +
|
|
ordered->truncated_len);
|
|
} else {
|
|
offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
|
|
}
|
|
disk_i_size = BTRFS_I(inode)->disk_i_size;
|
|
|
|
/* truncate file */
|
|
if (disk_i_size > i_size) {
|
|
BTRFS_I(inode)->disk_i_size = i_size;
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* if the disk i_size is already at the inode->i_size, or
|
|
* this ordered extent is inside the disk i_size, we're done
|
|
*/
|
|
if (disk_i_size == i_size)
|
|
goto out;
|
|
|
|
/*
|
|
* We still need to update disk_i_size if outstanding_isize is greater
|
|
* than disk_i_size.
|
|
*/
|
|
if (offset <= disk_i_size &&
|
|
(!ordered || ordered->outstanding_isize <= disk_i_size))
|
|
goto out;
|
|
|
|
/*
|
|
* walk backward from this ordered extent to disk_i_size.
|
|
* if we find an ordered extent then we can't update disk i_size
|
|
* yet
|
|
*/
|
|
if (ordered) {
|
|
node = rb_prev(&ordered->rb_node);
|
|
} else {
|
|
prev = tree_search(tree, offset);
|
|
/*
|
|
* we insert file extents without involving ordered struct,
|
|
* so there should be no ordered struct cover this offset
|
|
*/
|
|
if (prev) {
|
|
test = rb_entry(prev, struct btrfs_ordered_extent,
|
|
rb_node);
|
|
BUG_ON(offset_in_entry(test, offset));
|
|
}
|
|
node = prev;
|
|
}
|
|
for (; node; node = rb_prev(node)) {
|
|
test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
|
|
|
|
/* We treat this entry as if it doesnt exist */
|
|
if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
|
|
continue;
|
|
if (test->file_offset + test->len <= disk_i_size)
|
|
break;
|
|
if (test->file_offset >= i_size)
|
|
break;
|
|
if (entry_end(test) > disk_i_size) {
|
|
/*
|
|
* we don't update disk_i_size now, so record this
|
|
* undealt i_size. Or we will not know the real
|
|
* i_size.
|
|
*/
|
|
if (test->outstanding_isize < offset)
|
|
test->outstanding_isize = offset;
|
|
if (ordered &&
|
|
ordered->outstanding_isize >
|
|
test->outstanding_isize)
|
|
test->outstanding_isize =
|
|
ordered->outstanding_isize;
|
|
goto out;
|
|
}
|
|
}
|
|
new_i_size = min_t(u64, offset, i_size);
|
|
|
|
/*
|
|
* Some ordered extents may completed before the current one, and
|
|
* we hold the real i_size in ->outstanding_isize.
|
|
*/
|
|
if (ordered && ordered->outstanding_isize > new_i_size)
|
|
new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
|
|
BTRFS_I(inode)->disk_i_size = new_i_size;
|
|
ret = 0;
|
|
out:
|
|
/*
|
|
* We need to do this because we can't remove ordered extents until
|
|
* after the i_disk_size has been updated and then the inode has been
|
|
* updated to reflect the change, so we need to tell anybody who finds
|
|
* this ordered extent that we've already done all the real work, we
|
|
* just haven't completed all the other work.
|
|
*/
|
|
if (ordered)
|
|
set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
|
|
spin_unlock_irq(&tree->lock);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* search the ordered extents for one corresponding to 'offset' and
|
|
* try to find a checksum. This is used because we allow pages to
|
|
* be reclaimed before their checksum is actually put into the btree
|
|
*/
|
|
int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
|
|
u32 *sum, int len)
|
|
{
|
|
struct btrfs_ordered_sum *ordered_sum;
|
|
struct btrfs_ordered_extent *ordered;
|
|
struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
|
|
unsigned long num_sectors;
|
|
unsigned long i;
|
|
u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
|
|
int index = 0;
|
|
|
|
ordered = btrfs_lookup_ordered_extent(inode, offset);
|
|
if (!ordered)
|
|
return 0;
|
|
|
|
spin_lock_irq(&tree->lock);
|
|
list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
|
|
if (disk_bytenr >= ordered_sum->bytenr &&
|
|
disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
|
|
i = (disk_bytenr - ordered_sum->bytenr) >>
|
|
inode->i_sb->s_blocksize_bits;
|
|
num_sectors = ordered_sum->len >>
|
|
inode->i_sb->s_blocksize_bits;
|
|
num_sectors = min_t(int, len - index, num_sectors - i);
|
|
memcpy(sum + index, ordered_sum->sums + i,
|
|
num_sectors);
|
|
|
|
index += (int)num_sectors;
|
|
if (index == len)
|
|
goto out;
|
|
disk_bytenr += num_sectors * sectorsize;
|
|
}
|
|
}
|
|
out:
|
|
spin_unlock_irq(&tree->lock);
|
|
btrfs_put_ordered_extent(ordered);
|
|
return index;
|
|
}
|
|
|
|
int __init ordered_data_init(void)
|
|
{
|
|
btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
|
|
sizeof(struct btrfs_ordered_extent), 0,
|
|
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
|
|
NULL);
|
|
if (!btrfs_ordered_extent_cache)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void ordered_data_exit(void)
|
|
{
|
|
if (btrfs_ordered_extent_cache)
|
|
kmem_cache_destroy(btrfs_ordered_extent_cache);
|
|
}
|