// SPDX-License-Identifier: GPL-2.0
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/*
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* fs/ext4/extents_status.c
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*
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* Written by Yongqiang Yang <xiaoqiangnk@gmail.com>
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* Modified by
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* Allison Henderson <achender@linux.vnet.ibm.com>
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* Hugh Dickins <hughd@google.com>
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* Zheng Liu <wenqing.lz@taobao.com>
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*
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* Ext4 extents status tree core functions.
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*/
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#include <linux/list_sort.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include "ext4.h"
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#include <trace/events/ext4.h>
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/*
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* According to previous discussion in Ext4 Developer Workshop, we
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* will introduce a new structure called io tree to track all extent
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* status in order to solve some problems that we have met
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* (e.g. Reservation space warning), and provide extent-level locking.
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* Delay extent tree is the first step to achieve this goal. It is
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* original built by Yongqiang Yang. At that time it is called delay
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* extent tree, whose goal is only track delayed extents in memory to
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* simplify the implementation of fiemap and bigalloc, and introduce
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* lseek SEEK_DATA/SEEK_HOLE support. That is why it is still called
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* delay extent tree at the first commit. But for better understand
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* what it does, it has been rename to extent status tree.
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*
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* Step1:
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* Currently the first step has been done. All delayed extents are
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* tracked in the tree. It maintains the delayed extent when a delayed
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* allocation is issued, and the delayed extent is written out or
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* invalidated. Therefore the implementation of fiemap and bigalloc
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* are simplified, and SEEK_DATA/SEEK_HOLE are introduced.
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*
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* The following comment describes the implemenmtation of extent
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* status tree and future works.
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*
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* Step2:
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* In this step all extent status are tracked by extent status tree.
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* Thus, we can first try to lookup a block mapping in this tree before
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* finding it in extent tree. Hence, single extent cache can be removed
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* because extent status tree can do a better job. Extents in status
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* tree are loaded on-demand. Therefore, the extent status tree may not
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* contain all of the extents in a file. Meanwhile we define a shrinker
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* to reclaim memory from extent status tree because fragmented extent
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* tree will make status tree cost too much memory. written/unwritten/-
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* hole extents in the tree will be reclaimed by this shrinker when we
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* are under high memory pressure. Delayed extents will not be
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* reclimed because fiemap, bigalloc, and seek_data/hole need it.
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*/
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/*
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* Extent status tree implementation for ext4.
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*
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*
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* ==========================================================================
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* Extent status tree tracks all extent status.
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*
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* 1. Why we need to implement extent status tree?
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*
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* Without extent status tree, ext4 identifies a delayed extent by looking
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* up page cache, this has several deficiencies - complicated, buggy,
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* and inefficient code.
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*
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* FIEMAP, SEEK_HOLE/DATA, bigalloc, and writeout all need to know if a
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* block or a range of blocks are belonged to a delayed extent.
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*
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* Let us have a look at how they do without extent status tree.
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* -- FIEMAP
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* FIEMAP looks up page cache to identify delayed allocations from holes.
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*
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* -- SEEK_HOLE/DATA
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* SEEK_HOLE/DATA has the same problem as FIEMAP.
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*
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* -- bigalloc
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* bigalloc looks up page cache to figure out if a block is
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* already under delayed allocation or not to determine whether
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* quota reserving is needed for the cluster.
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*
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* -- writeout
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* Writeout looks up whole page cache to see if a buffer is
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* mapped, If there are not very many delayed buffers, then it is
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* time consuming.
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*
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* With extent status tree implementation, FIEMAP, SEEK_HOLE/DATA,
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* bigalloc and writeout can figure out if a block or a range of
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* blocks is under delayed allocation(belonged to a delayed extent) or
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* not by searching the extent tree.
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*
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*
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* ==========================================================================
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* 2. Ext4 extent status tree impelmentation
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*
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* -- extent
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* A extent is a range of blocks which are contiguous logically and
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* physically. Unlike extent in extent tree, this extent in ext4 is
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* a in-memory struct, there is no corresponding on-disk data. There
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* is no limit on length of extent, so an extent can contain as many
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* blocks as they are contiguous logically and physically.
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*
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* -- extent status tree
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* Every inode has an extent status tree and all allocation blocks
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* are added to the tree with different status. The extent in the
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* tree are ordered by logical block no.
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*
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* -- operations on a extent status tree
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* There are three important operations on a delayed extent tree: find
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* next extent, adding a extent(a range of blocks) and removing a extent.
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*
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* -- race on a extent status tree
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* Extent status tree is protected by inode->i_es_lock.
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*
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* -- memory consumption
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* Fragmented extent tree will make extent status tree cost too much
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* memory. Hence, we will reclaim written/unwritten/hole extents from
|
* the tree under a heavy memory pressure.
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*
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*
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* ==========================================================================
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* 3. Performance analysis
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*
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* -- overhead
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* 1. There is a cache extent for write access, so if writes are
|
* not very random, adding space operaions are in O(1) time.
|
*
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* -- gain
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* 2. Code is much simpler, more readable, more maintainable and
|
* more efficient.
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*
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*
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* ==========================================================================
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* 4. TODO list
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*
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* -- Refactor delayed space reservation
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*
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* -- Extent-level locking
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*/
|
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static struct kmem_cache *ext4_es_cachep;
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static struct kmem_cache *ext4_pending_cachep;
|
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static int __es_insert_extent(struct inode *inode, struct extent_status *newes);
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static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
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ext4_lblk_t end, int *reserved);
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static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan);
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static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
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struct ext4_inode_info *locked_ei);
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static void __revise_pending(struct inode *inode, ext4_lblk_t lblk,
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ext4_lblk_t len);
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int __init ext4_init_es(void)
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{
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ext4_es_cachep = kmem_cache_create("ext4_extent_status",
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sizeof(struct extent_status),
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0, (SLAB_RECLAIM_ACCOUNT), NULL);
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if (ext4_es_cachep == NULL)
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return -ENOMEM;
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return 0;
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}
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void ext4_exit_es(void)
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{
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kmem_cache_destroy(ext4_es_cachep);
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}
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void ext4_es_init_tree(struct ext4_es_tree *tree)
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{
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tree->root = RB_ROOT;
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tree->cache_es = NULL;
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}
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#ifdef ES_DEBUG__
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static void ext4_es_print_tree(struct inode *inode)
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{
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struct ext4_es_tree *tree;
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struct rb_node *node;
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printk(KERN_DEBUG "status extents for inode %lu:", inode->i_ino);
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tree = &EXT4_I(inode)->i_es_tree;
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node = rb_first(&tree->root);
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while (node) {
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struct extent_status *es;
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es = rb_entry(node, struct extent_status, rb_node);
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printk(KERN_DEBUG " [%u/%u) %llu %x",
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es->es_lblk, es->es_len,
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ext4_es_pblock(es), ext4_es_status(es));
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node = rb_next(node);
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}
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printk(KERN_DEBUG "\n");
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}
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#else
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#define ext4_es_print_tree(inode)
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#endif
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static inline ext4_lblk_t ext4_es_end(struct extent_status *es)
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{
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BUG_ON(es->es_lblk + es->es_len < es->es_lblk);
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return es->es_lblk + es->es_len - 1;
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}
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/*
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* search through the tree for an delayed extent with a given offset. If
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* it can't be found, try to find next extent.
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*/
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static struct extent_status *__es_tree_search(struct rb_root *root,
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ext4_lblk_t lblk)
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{
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struct rb_node *node = root->rb_node;
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struct extent_status *es = NULL;
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while (node) {
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es = rb_entry(node, struct extent_status, rb_node);
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if (lblk < es->es_lblk)
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node = node->rb_left;
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else if (lblk > ext4_es_end(es))
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node = node->rb_right;
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else
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return es;
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}
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if (es && lblk < es->es_lblk)
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return es;
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if (es && lblk > ext4_es_end(es)) {
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node = rb_next(&es->rb_node);
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return node ? rb_entry(node, struct extent_status, rb_node) :
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NULL;
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}
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return NULL;
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}
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/*
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* ext4_es_find_extent_range - find extent with specified status within block
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* range or next extent following block range in
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* extents status tree
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*
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* @inode - file containing the range
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* @matching_fn - pointer to function that matches extents with desired status
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* @lblk - logical block defining start of range
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* @end - logical block defining end of range
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* @es - extent found, if any
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*
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* Find the first extent within the block range specified by @lblk and @end
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* in the extents status tree that satisfies @matching_fn. If a match
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* is found, it's returned in @es. If not, and a matching extent is found
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* beyond the block range, it's returned in @es. If no match is found, an
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* extent is returned in @es whose es_lblk, es_len, and es_pblk components
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* are 0.
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*/
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static void __es_find_extent_range(struct inode *inode,
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int (*matching_fn)(struct extent_status *es),
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ext4_lblk_t lblk, ext4_lblk_t end,
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struct extent_status *es)
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{
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struct ext4_es_tree *tree = NULL;
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struct extent_status *es1 = NULL;
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struct rb_node *node;
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WARN_ON(es == NULL);
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WARN_ON(end < lblk);
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tree = &EXT4_I(inode)->i_es_tree;
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/* see if the extent has been cached */
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es->es_lblk = es->es_len = es->es_pblk = 0;
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es1 = READ_ONCE(tree->cache_es);
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if (es1 && in_range(lblk, es1->es_lblk, es1->es_len)) {
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es_debug("%u cached by [%u/%u) %llu %x\n",
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lblk, es1->es_lblk, es1->es_len,
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ext4_es_pblock(es1), ext4_es_status(es1));
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goto out;
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}
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es1 = __es_tree_search(&tree->root, lblk);
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out:
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if (es1 && !matching_fn(es1)) {
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while ((node = rb_next(&es1->rb_node)) != NULL) {
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es1 = rb_entry(node, struct extent_status, rb_node);
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if (es1->es_lblk > end) {
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es1 = NULL;
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break;
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}
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if (matching_fn(es1))
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break;
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}
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}
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if (es1 && matching_fn(es1)) {
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WRITE_ONCE(tree->cache_es, es1);
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es->es_lblk = es1->es_lblk;
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es->es_len = es1->es_len;
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es->es_pblk = es1->es_pblk;
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}
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}
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/*
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* Locking for __es_find_extent_range() for external use
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*/
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void ext4_es_find_extent_range(struct inode *inode,
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int (*matching_fn)(struct extent_status *es),
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ext4_lblk_t lblk, ext4_lblk_t end,
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struct extent_status *es)
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{
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if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
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return;
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trace_ext4_es_find_extent_range_enter(inode, lblk);
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read_lock(&EXT4_I(inode)->i_es_lock);
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__es_find_extent_range(inode, matching_fn, lblk, end, es);
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read_unlock(&EXT4_I(inode)->i_es_lock);
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trace_ext4_es_find_extent_range_exit(inode, es);
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}
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/*
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* __es_scan_range - search block range for block with specified status
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* in extents status tree
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*
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* @inode - file containing the range
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* @matching_fn - pointer to function that matches extents with desired status
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* @lblk - logical block defining start of range
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* @end - logical block defining end of range
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*
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* Returns true if at least one block in the specified block range satisfies
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* the criterion specified by @matching_fn, and false if not. If at least
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* one extent has the specified status, then there is at least one block
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* in the cluster with that status. Should only be called by code that has
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* taken i_es_lock.
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*/
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static bool __es_scan_range(struct inode *inode,
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int (*matching_fn)(struct extent_status *es),
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ext4_lblk_t start, ext4_lblk_t end)
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{
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struct extent_status es;
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__es_find_extent_range(inode, matching_fn, start, end, &es);
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if (es.es_len == 0)
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return false; /* no matching extent in the tree */
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else if (es.es_lblk <= start &&
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start < es.es_lblk + es.es_len)
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return true;
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else if (start <= es.es_lblk && es.es_lblk <= end)
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return true;
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else
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return false;
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}
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/*
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* Locking for __es_scan_range() for external use
|
*/
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bool ext4_es_scan_range(struct inode *inode,
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int (*matching_fn)(struct extent_status *es),
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ext4_lblk_t lblk, ext4_lblk_t end)
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{
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bool ret;
|
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if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
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return false;
|
|
read_lock(&EXT4_I(inode)->i_es_lock);
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ret = __es_scan_range(inode, matching_fn, lblk, end);
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read_unlock(&EXT4_I(inode)->i_es_lock);
|
|
return ret;
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}
|
|
/*
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* __es_scan_clu - search cluster for block with specified status in
|
* extents status tree
|
*
|
* @inode - file containing the cluster
|
* @matching_fn - pointer to function that matches extents with desired status
|
* @lblk - logical block in cluster to be searched
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*
|
* Returns true if at least one extent in the cluster containing @lblk
|
* satisfies the criterion specified by @matching_fn, and false if not. If at
|
* least one extent has the specified status, then there is at least one block
|
* in the cluster with that status. Should only be called by code that has
|
* taken i_es_lock.
|
*/
|
static bool __es_scan_clu(struct inode *inode,
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int (*matching_fn)(struct extent_status *es),
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ext4_lblk_t lblk)
|
{
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struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
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ext4_lblk_t lblk_start, lblk_end;
|
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lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
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lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
|
|
return __es_scan_range(inode, matching_fn, lblk_start, lblk_end);
|
}
|
|
/*
|
* Locking for __es_scan_clu() for external use
|
*/
|
bool ext4_es_scan_clu(struct inode *inode,
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int (*matching_fn)(struct extent_status *es),
|
ext4_lblk_t lblk)
|
{
|
bool ret;
|
|
if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
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return false;
|
|
read_lock(&EXT4_I(inode)->i_es_lock);
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ret = __es_scan_clu(inode, matching_fn, lblk);
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read_unlock(&EXT4_I(inode)->i_es_lock);
|
|
return ret;
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}
|
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static void ext4_es_list_add(struct inode *inode)
|
{
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
|
if (!list_empty(&ei->i_es_list))
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return;
|
|
spin_lock(&sbi->s_es_lock);
|
if (list_empty(&ei->i_es_list)) {
|
list_add_tail(&ei->i_es_list, &sbi->s_es_list);
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sbi->s_es_nr_inode++;
|
}
|
spin_unlock(&sbi->s_es_lock);
|
}
|
|
static void ext4_es_list_del(struct inode *inode)
|
{
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
|
spin_lock(&sbi->s_es_lock);
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if (!list_empty(&ei->i_es_list)) {
|
list_del_init(&ei->i_es_list);
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sbi->s_es_nr_inode--;
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WARN_ON_ONCE(sbi->s_es_nr_inode < 0);
|
}
|
spin_unlock(&sbi->s_es_lock);
|
}
|
|
static struct extent_status *
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ext4_es_alloc_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len,
|
ext4_fsblk_t pblk)
|
{
|
struct extent_status *es;
|
es = kmem_cache_alloc(ext4_es_cachep, GFP_ATOMIC);
|
if (es == NULL)
|
return NULL;
|
es->es_lblk = lblk;
|
es->es_len = len;
|
es->es_pblk = pblk;
|
|
/*
|
* We don't count delayed extent because we never try to reclaim them
|
*/
|
if (!ext4_es_is_delayed(es)) {
|
if (!EXT4_I(inode)->i_es_shk_nr++)
|
ext4_es_list_add(inode);
|
percpu_counter_inc(&EXT4_SB(inode->i_sb)->
|
s_es_stats.es_stats_shk_cnt);
|
}
|
|
EXT4_I(inode)->i_es_all_nr++;
|
percpu_counter_inc(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
|
|
return es;
|
}
|
|
static void ext4_es_free_extent(struct inode *inode, struct extent_status *es)
|
{
|
EXT4_I(inode)->i_es_all_nr--;
|
percpu_counter_dec(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
|
|
/* Decrease the shrink counter when this es is not delayed */
|
if (!ext4_es_is_delayed(es)) {
|
BUG_ON(EXT4_I(inode)->i_es_shk_nr == 0);
|
if (!--EXT4_I(inode)->i_es_shk_nr)
|
ext4_es_list_del(inode);
|
percpu_counter_dec(&EXT4_SB(inode->i_sb)->
|
s_es_stats.es_stats_shk_cnt);
|
}
|
|
kmem_cache_free(ext4_es_cachep, es);
|
}
|
|
/*
|
* Check whether or not two extents can be merged
|
* Condition:
|
* - logical block number is contiguous
|
* - physical block number is contiguous
|
* - status is equal
|
*/
|
static int ext4_es_can_be_merged(struct extent_status *es1,
|
struct extent_status *es2)
|
{
|
if (ext4_es_type(es1) != ext4_es_type(es2))
|
return 0;
|
|
if (((__u64) es1->es_len) + es2->es_len > EXT_MAX_BLOCKS) {
|
pr_warn("ES assertion failed when merging extents. "
|
"The sum of lengths of es1 (%d) and es2 (%d) "
|
"is bigger than allowed file size (%d)\n",
|
es1->es_len, es2->es_len, EXT_MAX_BLOCKS);
|
WARN_ON(1);
|
return 0;
|
}
|
|
if (((__u64) es1->es_lblk) + es1->es_len != es2->es_lblk)
|
return 0;
|
|
if ((ext4_es_is_written(es1) || ext4_es_is_unwritten(es1)) &&
|
(ext4_es_pblock(es1) + es1->es_len == ext4_es_pblock(es2)))
|
return 1;
|
|
if (ext4_es_is_hole(es1))
|
return 1;
|
|
/* we need to check delayed extent is without unwritten status */
|
if (ext4_es_is_delayed(es1) && !ext4_es_is_unwritten(es1))
|
return 1;
|
|
return 0;
|
}
|
|
static struct extent_status *
|
ext4_es_try_to_merge_left(struct inode *inode, struct extent_status *es)
|
{
|
struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
|
struct extent_status *es1;
|
struct rb_node *node;
|
|
node = rb_prev(&es->rb_node);
|
if (!node)
|
return es;
|
|
es1 = rb_entry(node, struct extent_status, rb_node);
|
if (ext4_es_can_be_merged(es1, es)) {
|
es1->es_len += es->es_len;
|
if (ext4_es_is_referenced(es))
|
ext4_es_set_referenced(es1);
|
rb_erase(&es->rb_node, &tree->root);
|
ext4_es_free_extent(inode, es);
|
es = es1;
|
}
|
|
return es;
|
}
|
|
static struct extent_status *
|
ext4_es_try_to_merge_right(struct inode *inode, struct extent_status *es)
|
{
|
struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
|
struct extent_status *es1;
|
struct rb_node *node;
|
|
node = rb_next(&es->rb_node);
|
if (!node)
|
return es;
|
|
es1 = rb_entry(node, struct extent_status, rb_node);
|
if (ext4_es_can_be_merged(es, es1)) {
|
es->es_len += es1->es_len;
|
if (ext4_es_is_referenced(es1))
|
ext4_es_set_referenced(es);
|
rb_erase(node, &tree->root);
|
ext4_es_free_extent(inode, es1);
|
}
|
|
return es;
|
}
|
|
#ifdef ES_AGGRESSIVE_TEST
|
#include "ext4_extents.h" /* Needed when ES_AGGRESSIVE_TEST is defined */
|
|
static void ext4_es_insert_extent_ext_check(struct inode *inode,
|
struct extent_status *es)
|
{
|
struct ext4_ext_path *path = NULL;
|
struct ext4_extent *ex;
|
ext4_lblk_t ee_block;
|
ext4_fsblk_t ee_start;
|
unsigned short ee_len;
|
int depth, ee_status, es_status;
|
|
path = ext4_find_extent(inode, es->es_lblk, NULL, EXT4_EX_NOCACHE);
|
if (IS_ERR(path))
|
return;
|
|
depth = ext_depth(inode);
|
ex = path[depth].p_ext;
|
|
if (ex) {
|
|
ee_block = le32_to_cpu(ex->ee_block);
|
ee_start = ext4_ext_pblock(ex);
|
ee_len = ext4_ext_get_actual_len(ex);
|
|
ee_status = ext4_ext_is_unwritten(ex) ? 1 : 0;
|
es_status = ext4_es_is_unwritten(es) ? 1 : 0;
|
|
/*
|
* Make sure ex and es are not overlap when we try to insert
|
* a delayed/hole extent.
|
*/
|
if (!ext4_es_is_written(es) && !ext4_es_is_unwritten(es)) {
|
if (in_range(es->es_lblk, ee_block, ee_len)) {
|
pr_warn("ES insert assertion failed for "
|
"inode: %lu we can find an extent "
|
"at block [%d/%d/%llu/%c], but we "
|
"want to add a delayed/hole extent "
|
"[%d/%d/%llu/%x]\n",
|
inode->i_ino, ee_block, ee_len,
|
ee_start, ee_status ? 'u' : 'w',
|
es->es_lblk, es->es_len,
|
ext4_es_pblock(es), ext4_es_status(es));
|
}
|
goto out;
|
}
|
|
/*
|
* We don't check ee_block == es->es_lblk, etc. because es
|
* might be a part of whole extent, vice versa.
|
*/
|
if (es->es_lblk < ee_block ||
|
ext4_es_pblock(es) != ee_start + es->es_lblk - ee_block) {
|
pr_warn("ES insert assertion failed for inode: %lu "
|
"ex_status [%d/%d/%llu/%c] != "
|
"es_status [%d/%d/%llu/%c]\n", inode->i_ino,
|
ee_block, ee_len, ee_start,
|
ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
|
ext4_es_pblock(es), es_status ? 'u' : 'w');
|
goto out;
|
}
|
|
if (ee_status ^ es_status) {
|
pr_warn("ES insert assertion failed for inode: %lu "
|
"ex_status [%d/%d/%llu/%c] != "
|
"es_status [%d/%d/%llu/%c]\n", inode->i_ino,
|
ee_block, ee_len, ee_start,
|
ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
|
ext4_es_pblock(es), es_status ? 'u' : 'w');
|
}
|
} else {
|
/*
|
* We can't find an extent on disk. So we need to make sure
|
* that we don't want to add an written/unwritten extent.
|
*/
|
if (!ext4_es_is_delayed(es) && !ext4_es_is_hole(es)) {
|
pr_warn("ES insert assertion failed for inode: %lu "
|
"can't find an extent at block %d but we want "
|
"to add a written/unwritten extent "
|
"[%d/%d/%llu/%x]\n", inode->i_ino,
|
es->es_lblk, es->es_lblk, es->es_len,
|
ext4_es_pblock(es), ext4_es_status(es));
|
}
|
}
|
out:
|
ext4_ext_drop_refs(path);
|
kfree(path);
|
}
|
|
static void ext4_es_insert_extent_ind_check(struct inode *inode,
|
struct extent_status *es)
|
{
|
struct ext4_map_blocks map;
|
int retval;
|
|
/*
|
* Here we call ext4_ind_map_blocks to lookup a block mapping because
|
* 'Indirect' structure is defined in indirect.c. So we couldn't
|
* access direct/indirect tree from outside. It is too dirty to define
|
* this function in indirect.c file.
|
*/
|
|
map.m_lblk = es->es_lblk;
|
map.m_len = es->es_len;
|
|
retval = ext4_ind_map_blocks(NULL, inode, &map, 0);
|
if (retval > 0) {
|
if (ext4_es_is_delayed(es) || ext4_es_is_hole(es)) {
|
/*
|
* We want to add a delayed/hole extent but this
|
* block has been allocated.
|
*/
|
pr_warn("ES insert assertion failed for inode: %lu "
|
"We can find blocks but we want to add a "
|
"delayed/hole extent [%d/%d/%llu/%x]\n",
|
inode->i_ino, es->es_lblk, es->es_len,
|
ext4_es_pblock(es), ext4_es_status(es));
|
return;
|
} else if (ext4_es_is_written(es)) {
|
if (retval != es->es_len) {
|
pr_warn("ES insert assertion failed for "
|
"inode: %lu retval %d != es_len %d\n",
|
inode->i_ino, retval, es->es_len);
|
return;
|
}
|
if (map.m_pblk != ext4_es_pblock(es)) {
|
pr_warn("ES insert assertion failed for "
|
"inode: %lu m_pblk %llu != "
|
"es_pblk %llu\n",
|
inode->i_ino, map.m_pblk,
|
ext4_es_pblock(es));
|
return;
|
}
|
} else {
|
/*
|
* We don't need to check unwritten extent because
|
* indirect-based file doesn't have it.
|
*/
|
BUG();
|
}
|
} else if (retval == 0) {
|
if (ext4_es_is_written(es)) {
|
pr_warn("ES insert assertion failed for inode: %lu "
|
"We can't find the block but we want to add "
|
"a written extent [%d/%d/%llu/%x]\n",
|
inode->i_ino, es->es_lblk, es->es_len,
|
ext4_es_pblock(es), ext4_es_status(es));
|
return;
|
}
|
}
|
}
|
|
static inline void ext4_es_insert_extent_check(struct inode *inode,
|
struct extent_status *es)
|
{
|
/*
|
* We don't need to worry about the race condition because
|
* caller takes i_data_sem locking.
|
*/
|
BUG_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
|
if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
|
ext4_es_insert_extent_ext_check(inode, es);
|
else
|
ext4_es_insert_extent_ind_check(inode, es);
|
}
|
#else
|
static inline void ext4_es_insert_extent_check(struct inode *inode,
|
struct extent_status *es)
|
{
|
}
|
#endif
|
|
static int __es_insert_extent(struct inode *inode, struct extent_status *newes)
|
{
|
struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
|
struct rb_node **p = &tree->root.rb_node;
|
struct rb_node *parent = NULL;
|
struct extent_status *es;
|
|
while (*p) {
|
parent = *p;
|
es = rb_entry(parent, struct extent_status, rb_node);
|
|
if (newes->es_lblk < es->es_lblk) {
|
if (ext4_es_can_be_merged(newes, es)) {
|
/*
|
* Here we can modify es_lblk directly
|
* because it isn't overlapped.
|
*/
|
es->es_lblk = newes->es_lblk;
|
es->es_len += newes->es_len;
|
if (ext4_es_is_written(es) ||
|
ext4_es_is_unwritten(es))
|
ext4_es_store_pblock(es,
|
newes->es_pblk);
|
es = ext4_es_try_to_merge_left(inode, es);
|
goto out;
|
}
|
p = &(*p)->rb_left;
|
} else if (newes->es_lblk > ext4_es_end(es)) {
|
if (ext4_es_can_be_merged(es, newes)) {
|
es->es_len += newes->es_len;
|
es = ext4_es_try_to_merge_right(inode, es);
|
goto out;
|
}
|
p = &(*p)->rb_right;
|
} else {
|
BUG();
|
return -EINVAL;
|
}
|
}
|
|
es = ext4_es_alloc_extent(inode, newes->es_lblk, newes->es_len,
|
newes->es_pblk);
|
if (!es)
|
return -ENOMEM;
|
rb_link_node(&es->rb_node, parent, p);
|
rb_insert_color(&es->rb_node, &tree->root);
|
|
out:
|
tree->cache_es = es;
|
return 0;
|
}
|
|
/*
|
* ext4_es_insert_extent() adds information to an inode's extent
|
* status tree.
|
*
|
* Return 0 on success, error code on failure.
|
*/
|
int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
|
ext4_lblk_t len, ext4_fsblk_t pblk,
|
unsigned int status)
|
{
|
struct extent_status newes;
|
ext4_lblk_t end = lblk + len - 1;
|
int err = 0;
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
|
if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
|
return 0;
|
|
es_debug("add [%u/%u) %llu %x to extent status tree of inode %lu\n",
|
lblk, len, pblk, status, inode->i_ino);
|
|
if (!len)
|
return 0;
|
|
BUG_ON(end < lblk);
|
|
if ((status & EXTENT_STATUS_DELAYED) &&
|
(status & EXTENT_STATUS_WRITTEN)) {
|
ext4_warning(inode->i_sb, "Inserting extent [%u/%u] as "
|
" delayed and written which can potentially "
|
" cause data loss.", lblk, len);
|
WARN_ON(1);
|
}
|
|
newes.es_lblk = lblk;
|
newes.es_len = len;
|
ext4_es_store_pblock_status(&newes, pblk, status);
|
trace_ext4_es_insert_extent(inode, &newes);
|
|
ext4_es_insert_extent_check(inode, &newes);
|
|
write_lock(&EXT4_I(inode)->i_es_lock);
|
err = __es_remove_extent(inode, lblk, end, NULL);
|
if (err != 0)
|
goto error;
|
retry:
|
err = __es_insert_extent(inode, &newes);
|
if (err == -ENOMEM && __es_shrink(EXT4_SB(inode->i_sb),
|
128, EXT4_I(inode)))
|
goto retry;
|
if (err == -ENOMEM && !ext4_es_is_delayed(&newes))
|
err = 0;
|
|
if (sbi->s_cluster_ratio > 1 && test_opt(inode->i_sb, DELALLOC) &&
|
(status & EXTENT_STATUS_WRITTEN ||
|
status & EXTENT_STATUS_UNWRITTEN))
|
__revise_pending(inode, lblk, len);
|
|
error:
|
write_unlock(&EXT4_I(inode)->i_es_lock);
|
|
ext4_es_print_tree(inode);
|
|
return err;
|
}
|
|
/*
|
* ext4_es_cache_extent() inserts information into the extent status
|
* tree if and only if there isn't information about the range in
|
* question already.
|
*/
|
void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
|
ext4_lblk_t len, ext4_fsblk_t pblk,
|
unsigned int status)
|
{
|
struct extent_status *es;
|
struct extent_status newes;
|
ext4_lblk_t end = lblk + len - 1;
|
|
if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
|
return;
|
|
newes.es_lblk = lblk;
|
newes.es_len = len;
|
ext4_es_store_pblock_status(&newes, pblk, status);
|
trace_ext4_es_cache_extent(inode, &newes);
|
|
if (!len)
|
return;
|
|
BUG_ON(end < lblk);
|
|
write_lock(&EXT4_I(inode)->i_es_lock);
|
|
es = __es_tree_search(&EXT4_I(inode)->i_es_tree.root, lblk);
|
if (!es || es->es_lblk > end)
|
__es_insert_extent(inode, &newes);
|
write_unlock(&EXT4_I(inode)->i_es_lock);
|
}
|
|
/*
|
* ext4_es_lookup_extent() looks up an extent in extent status tree.
|
*
|
* ext4_es_lookup_extent is called by ext4_map_blocks/ext4_da_map_blocks.
|
*
|
* Return: 1 on found, 0 on not
|
*/
|
int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
|
ext4_lblk_t *next_lblk,
|
struct extent_status *es)
|
{
|
struct ext4_es_tree *tree;
|
struct ext4_es_stats *stats;
|
struct extent_status *es1 = NULL;
|
struct rb_node *node;
|
int found = 0;
|
|
if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
|
return 0;
|
|
trace_ext4_es_lookup_extent_enter(inode, lblk);
|
es_debug("lookup extent in block %u\n", lblk);
|
|
tree = &EXT4_I(inode)->i_es_tree;
|
read_lock(&EXT4_I(inode)->i_es_lock);
|
|
/* find extent in cache firstly */
|
es->es_lblk = es->es_len = es->es_pblk = 0;
|
es1 = READ_ONCE(tree->cache_es);
|
if (es1 && in_range(lblk, es1->es_lblk, es1->es_len)) {
|
es_debug("%u cached by [%u/%u)\n",
|
lblk, es1->es_lblk, es1->es_len);
|
found = 1;
|
goto out;
|
}
|
|
node = tree->root.rb_node;
|
while (node) {
|
es1 = rb_entry(node, struct extent_status, rb_node);
|
if (lblk < es1->es_lblk)
|
node = node->rb_left;
|
else if (lblk > ext4_es_end(es1))
|
node = node->rb_right;
|
else {
|
found = 1;
|
break;
|
}
|
}
|
|
out:
|
stats = &EXT4_SB(inode->i_sb)->s_es_stats;
|
if (found) {
|
BUG_ON(!es1);
|
es->es_lblk = es1->es_lblk;
|
es->es_len = es1->es_len;
|
es->es_pblk = es1->es_pblk;
|
if (!ext4_es_is_referenced(es1))
|
ext4_es_set_referenced(es1);
|
percpu_counter_inc(&stats->es_stats_cache_hits);
|
if (next_lblk) {
|
node = rb_next(&es1->rb_node);
|
if (node) {
|
es1 = rb_entry(node, struct extent_status,
|
rb_node);
|
*next_lblk = es1->es_lblk;
|
} else
|
*next_lblk = 0;
|
}
|
} else {
|
percpu_counter_inc(&stats->es_stats_cache_misses);
|
}
|
|
read_unlock(&EXT4_I(inode)->i_es_lock);
|
|
trace_ext4_es_lookup_extent_exit(inode, es, found);
|
return found;
|
}
|
|
struct rsvd_count {
|
int ndelonly;
|
bool first_do_lblk_found;
|
ext4_lblk_t first_do_lblk;
|
ext4_lblk_t last_do_lblk;
|
struct extent_status *left_es;
|
bool partial;
|
ext4_lblk_t lclu;
|
};
|
|
/*
|
* init_rsvd - initialize reserved count data before removing block range
|
* in file from extent status tree
|
*
|
* @inode - file containing range
|
* @lblk - first block in range
|
* @es - pointer to first extent in range
|
* @rc - pointer to reserved count data
|
*
|
* Assumes es is not NULL
|
*/
|
static void init_rsvd(struct inode *inode, ext4_lblk_t lblk,
|
struct extent_status *es, struct rsvd_count *rc)
|
{
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
struct rb_node *node;
|
|
rc->ndelonly = 0;
|
|
/*
|
* for bigalloc, note the first delonly block in the range has not
|
* been found, record the extent containing the block to the left of
|
* the region to be removed, if any, and note that there's no partial
|
* cluster to track
|
*/
|
if (sbi->s_cluster_ratio > 1) {
|
rc->first_do_lblk_found = false;
|
if (lblk > es->es_lblk) {
|
rc->left_es = es;
|
} else {
|
node = rb_prev(&es->rb_node);
|
rc->left_es = node ? rb_entry(node,
|
struct extent_status,
|
rb_node) : NULL;
|
}
|
rc->partial = false;
|
}
|
}
|
|
/*
|
* count_rsvd - count the clusters containing delayed and not unwritten
|
* (delonly) blocks in a range within an extent and add to
|
* the running tally in rsvd_count
|
*
|
* @inode - file containing extent
|
* @lblk - first block in range
|
* @len - length of range in blocks
|
* @es - pointer to extent containing clusters to be counted
|
* @rc - pointer to reserved count data
|
*
|
* Tracks partial clusters found at the beginning and end of extents so
|
* they aren't overcounted when they span adjacent extents
|
*/
|
static void count_rsvd(struct inode *inode, ext4_lblk_t lblk, long len,
|
struct extent_status *es, struct rsvd_count *rc)
|
{
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
ext4_lblk_t i, end, nclu;
|
|
if (!ext4_es_is_delonly(es))
|
return;
|
|
WARN_ON(len <= 0);
|
|
if (sbi->s_cluster_ratio == 1) {
|
rc->ndelonly += (int) len;
|
return;
|
}
|
|
/* bigalloc */
|
|
i = (lblk < es->es_lblk) ? es->es_lblk : lblk;
|
end = lblk + (ext4_lblk_t) len - 1;
|
end = (end > ext4_es_end(es)) ? ext4_es_end(es) : end;
|
|
/* record the first block of the first delonly extent seen */
|
if (!rc->first_do_lblk_found) {
|
rc->first_do_lblk = i;
|
rc->first_do_lblk_found = true;
|
}
|
|
/* update the last lblk in the region seen so far */
|
rc->last_do_lblk = end;
|
|
/*
|
* if we're tracking a partial cluster and the current extent
|
* doesn't start with it, count it and stop tracking
|
*/
|
if (rc->partial && (rc->lclu != EXT4_B2C(sbi, i))) {
|
rc->ndelonly++;
|
rc->partial = false;
|
}
|
|
/*
|
* if the first cluster doesn't start on a cluster boundary but
|
* ends on one, count it
|
*/
|
if (EXT4_LBLK_COFF(sbi, i) != 0) {
|
if (end >= EXT4_LBLK_CFILL(sbi, i)) {
|
rc->ndelonly++;
|
rc->partial = false;
|
i = EXT4_LBLK_CFILL(sbi, i) + 1;
|
}
|
}
|
|
/*
|
* if the current cluster starts on a cluster boundary, count the
|
* number of whole delonly clusters in the extent
|
*/
|
if ((i + sbi->s_cluster_ratio - 1) <= end) {
|
nclu = (end - i + 1) >> sbi->s_cluster_bits;
|
rc->ndelonly += nclu;
|
i += nclu << sbi->s_cluster_bits;
|
}
|
|
/*
|
* start tracking a partial cluster if there's a partial at the end
|
* of the current extent and we're not already tracking one
|
*/
|
if (!rc->partial && i <= end) {
|
rc->partial = true;
|
rc->lclu = EXT4_B2C(sbi, i);
|
}
|
}
|
|
/*
|
* __pr_tree_search - search for a pending cluster reservation
|
*
|
* @root - root of pending reservation tree
|
* @lclu - logical cluster to search for
|
*
|
* Returns the pending reservation for the cluster identified by @lclu
|
* if found. If not, returns a reservation for the next cluster if any,
|
* and if not, returns NULL.
|
*/
|
static struct pending_reservation *__pr_tree_search(struct rb_root *root,
|
ext4_lblk_t lclu)
|
{
|
struct rb_node *node = root->rb_node;
|
struct pending_reservation *pr = NULL;
|
|
while (node) {
|
pr = rb_entry(node, struct pending_reservation, rb_node);
|
if (lclu < pr->lclu)
|
node = node->rb_left;
|
else if (lclu > pr->lclu)
|
node = node->rb_right;
|
else
|
return pr;
|
}
|
if (pr && lclu < pr->lclu)
|
return pr;
|
if (pr && lclu > pr->lclu) {
|
node = rb_next(&pr->rb_node);
|
return node ? rb_entry(node, struct pending_reservation,
|
rb_node) : NULL;
|
}
|
return NULL;
|
}
|
|
/*
|
* get_rsvd - calculates and returns the number of cluster reservations to be
|
* released when removing a block range from the extent status tree
|
* and releases any pending reservations within the range
|
*
|
* @inode - file containing block range
|
* @end - last block in range
|
* @right_es - pointer to extent containing next block beyond end or NULL
|
* @rc - pointer to reserved count data
|
*
|
* The number of reservations to be released is equal to the number of
|
* clusters containing delayed and not unwritten (delonly) blocks within
|
* the range, minus the number of clusters still containing delonly blocks
|
* at the ends of the range, and minus the number of pending reservations
|
* within the range.
|
*/
|
static unsigned int get_rsvd(struct inode *inode, ext4_lblk_t end,
|
struct extent_status *right_es,
|
struct rsvd_count *rc)
|
{
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
struct pending_reservation *pr;
|
struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree;
|
struct rb_node *node;
|
ext4_lblk_t first_lclu, last_lclu;
|
bool left_delonly, right_delonly, count_pending;
|
struct extent_status *es;
|
|
if (sbi->s_cluster_ratio > 1) {
|
/* count any remaining partial cluster */
|
if (rc->partial)
|
rc->ndelonly++;
|
|
if (rc->ndelonly == 0)
|
return 0;
|
|
first_lclu = EXT4_B2C(sbi, rc->first_do_lblk);
|
last_lclu = EXT4_B2C(sbi, rc->last_do_lblk);
|
|
/*
|
* decrease the delonly count by the number of clusters at the
|
* ends of the range that still contain delonly blocks -
|
* these clusters still need to be reserved
|
*/
|
left_delonly = right_delonly = false;
|
|
es = rc->left_es;
|
while (es && ext4_es_end(es) >=
|
EXT4_LBLK_CMASK(sbi, rc->first_do_lblk)) {
|
if (ext4_es_is_delonly(es)) {
|
rc->ndelonly--;
|
left_delonly = true;
|
break;
|
}
|
node = rb_prev(&es->rb_node);
|
if (!node)
|
break;
|
es = rb_entry(node, struct extent_status, rb_node);
|
}
|
if (right_es && (!left_delonly || first_lclu != last_lclu)) {
|
if (end < ext4_es_end(right_es)) {
|
es = right_es;
|
} else {
|
node = rb_next(&right_es->rb_node);
|
es = node ? rb_entry(node, struct extent_status,
|
rb_node) : NULL;
|
}
|
while (es && es->es_lblk <=
|
EXT4_LBLK_CFILL(sbi, rc->last_do_lblk)) {
|
if (ext4_es_is_delonly(es)) {
|
rc->ndelonly--;
|
right_delonly = true;
|
break;
|
}
|
node = rb_next(&es->rb_node);
|
if (!node)
|
break;
|
es = rb_entry(node, struct extent_status,
|
rb_node);
|
}
|
}
|
|
/*
|
* Determine the block range that should be searched for
|
* pending reservations, if any. Clusters on the ends of the
|
* original removed range containing delonly blocks are
|
* excluded. They've already been accounted for and it's not
|
* possible to determine if an associated pending reservation
|
* should be released with the information available in the
|
* extents status tree.
|
*/
|
if (first_lclu == last_lclu) {
|
if (left_delonly | right_delonly)
|
count_pending = false;
|
else
|
count_pending = true;
|
} else {
|
if (left_delonly)
|
first_lclu++;
|
if (right_delonly)
|
last_lclu--;
|
if (first_lclu <= last_lclu)
|
count_pending = true;
|
else
|
count_pending = false;
|
}
|
|
/*
|
* a pending reservation found between first_lclu and last_lclu
|
* represents an allocated cluster that contained at least one
|
* delonly block, so the delonly total must be reduced by one
|
* for each pending reservation found and released
|
*/
|
if (count_pending) {
|
pr = __pr_tree_search(&tree->root, first_lclu);
|
while (pr && pr->lclu <= last_lclu) {
|
rc->ndelonly--;
|
node = rb_next(&pr->rb_node);
|
rb_erase(&pr->rb_node, &tree->root);
|
kmem_cache_free(ext4_pending_cachep, pr);
|
if (!node)
|
break;
|
pr = rb_entry(node, struct pending_reservation,
|
rb_node);
|
}
|
}
|
}
|
return rc->ndelonly;
|
}
|
|
|
/*
|
* __es_remove_extent - removes block range from extent status tree
|
*
|
* @inode - file containing range
|
* @lblk - first block in range
|
* @end - last block in range
|
* @reserved - number of cluster reservations released
|
*
|
* If @reserved is not NULL and delayed allocation is enabled, counts
|
* block/cluster reservations freed by removing range and if bigalloc
|
* enabled cancels pending reservations as needed. Returns 0 on success,
|
* error code on failure.
|
*/
|
static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
|
ext4_lblk_t end, int *reserved)
|
{
|
struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
|
struct rb_node *node;
|
struct extent_status *es;
|
struct extent_status orig_es;
|
ext4_lblk_t len1, len2;
|
ext4_fsblk_t block;
|
int err;
|
bool count_reserved = true;
|
struct rsvd_count rc;
|
|
if (reserved == NULL || !test_opt(inode->i_sb, DELALLOC))
|
count_reserved = false;
|
retry:
|
err = 0;
|
|
es = __es_tree_search(&tree->root, lblk);
|
if (!es)
|
goto out;
|
if (es->es_lblk > end)
|
goto out;
|
|
/* Simply invalidate cache_es. */
|
tree->cache_es = NULL;
|
if (count_reserved)
|
init_rsvd(inode, lblk, es, &rc);
|
|
orig_es.es_lblk = es->es_lblk;
|
orig_es.es_len = es->es_len;
|
orig_es.es_pblk = es->es_pblk;
|
|
len1 = lblk > es->es_lblk ? lblk - es->es_lblk : 0;
|
len2 = ext4_es_end(es) > end ? ext4_es_end(es) - end : 0;
|
if (len1 > 0)
|
es->es_len = len1;
|
if (len2 > 0) {
|
if (len1 > 0) {
|
struct extent_status newes;
|
|
newes.es_lblk = end + 1;
|
newes.es_len = len2;
|
block = 0x7FDEADBEEFULL;
|
if (ext4_es_is_written(&orig_es) ||
|
ext4_es_is_unwritten(&orig_es))
|
block = ext4_es_pblock(&orig_es) +
|
orig_es.es_len - len2;
|
ext4_es_store_pblock_status(&newes, block,
|
ext4_es_status(&orig_es));
|
err = __es_insert_extent(inode, &newes);
|
if (err) {
|
es->es_lblk = orig_es.es_lblk;
|
es->es_len = orig_es.es_len;
|
if ((err == -ENOMEM) &&
|
__es_shrink(EXT4_SB(inode->i_sb),
|
128, EXT4_I(inode)))
|
goto retry;
|
goto out;
|
}
|
} else {
|
es->es_lblk = end + 1;
|
es->es_len = len2;
|
if (ext4_es_is_written(es) ||
|
ext4_es_is_unwritten(es)) {
|
block = orig_es.es_pblk + orig_es.es_len - len2;
|
ext4_es_store_pblock(es, block);
|
}
|
}
|
if (count_reserved)
|
count_rsvd(inode, lblk, orig_es.es_len - len1 - len2,
|
&orig_es, &rc);
|
goto out_get_reserved;
|
}
|
|
if (len1 > 0) {
|
if (count_reserved)
|
count_rsvd(inode, lblk, orig_es.es_len - len1,
|
&orig_es, &rc);
|
node = rb_next(&es->rb_node);
|
if (node)
|
es = rb_entry(node, struct extent_status, rb_node);
|
else
|
es = NULL;
|
}
|
|
while (es && ext4_es_end(es) <= end) {
|
if (count_reserved)
|
count_rsvd(inode, es->es_lblk, es->es_len, es, &rc);
|
node = rb_next(&es->rb_node);
|
rb_erase(&es->rb_node, &tree->root);
|
ext4_es_free_extent(inode, es);
|
if (!node) {
|
es = NULL;
|
break;
|
}
|
es = rb_entry(node, struct extent_status, rb_node);
|
}
|
|
if (es && es->es_lblk < end + 1) {
|
ext4_lblk_t orig_len = es->es_len;
|
|
len1 = ext4_es_end(es) - end;
|
if (count_reserved)
|
count_rsvd(inode, es->es_lblk, orig_len - len1,
|
es, &rc);
|
es->es_lblk = end + 1;
|
es->es_len = len1;
|
if (ext4_es_is_written(es) || ext4_es_is_unwritten(es)) {
|
block = es->es_pblk + orig_len - len1;
|
ext4_es_store_pblock(es, block);
|
}
|
}
|
|
out_get_reserved:
|
if (count_reserved)
|
*reserved = get_rsvd(inode, end, es, &rc);
|
out:
|
return err;
|
}
|
|
/*
|
* ext4_es_remove_extent - removes block range from extent status tree
|
*
|
* @inode - file containing range
|
* @lblk - first block in range
|
* @len - number of blocks to remove
|
*
|
* Reduces block/cluster reservation count and for bigalloc cancels pending
|
* reservations as needed. Returns 0 on success, error code on failure.
|
*/
|
int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
|
ext4_lblk_t len)
|
{
|
ext4_lblk_t end;
|
int err = 0;
|
int reserved = 0;
|
|
if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
|
return 0;
|
|
trace_ext4_es_remove_extent(inode, lblk, len);
|
es_debug("remove [%u/%u) from extent status tree of inode %lu\n",
|
lblk, len, inode->i_ino);
|
|
if (!len)
|
return err;
|
|
end = lblk + len - 1;
|
BUG_ON(end < lblk);
|
|
/*
|
* ext4_clear_inode() depends on us taking i_es_lock unconditionally
|
* so that we are sure __es_shrink() is done with the inode before it
|
* is reclaimed.
|
*/
|
write_lock(&EXT4_I(inode)->i_es_lock);
|
err = __es_remove_extent(inode, lblk, end, &reserved);
|
write_unlock(&EXT4_I(inode)->i_es_lock);
|
ext4_es_print_tree(inode);
|
ext4_da_release_space(inode, reserved);
|
return err;
|
}
|
|
static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
|
struct ext4_inode_info *locked_ei)
|
{
|
struct ext4_inode_info *ei;
|
struct ext4_es_stats *es_stats;
|
ktime_t start_time;
|
u64 scan_time;
|
int nr_to_walk;
|
int nr_shrunk = 0;
|
int retried = 0, nr_skipped = 0;
|
|
es_stats = &sbi->s_es_stats;
|
start_time = ktime_get();
|
|
retry:
|
spin_lock(&sbi->s_es_lock);
|
nr_to_walk = sbi->s_es_nr_inode;
|
while (nr_to_walk-- > 0) {
|
if (list_empty(&sbi->s_es_list)) {
|
spin_unlock(&sbi->s_es_lock);
|
goto out;
|
}
|
ei = list_first_entry(&sbi->s_es_list, struct ext4_inode_info,
|
i_es_list);
|
/* Move the inode to the tail */
|
list_move_tail(&ei->i_es_list, &sbi->s_es_list);
|
|
/*
|
* Normally we try hard to avoid shrinking precached inodes,
|
* but we will as a last resort.
|
*/
|
if (!retried && ext4_test_inode_state(&ei->vfs_inode,
|
EXT4_STATE_EXT_PRECACHED)) {
|
nr_skipped++;
|
continue;
|
}
|
|
if (ei == locked_ei || !write_trylock(&ei->i_es_lock)) {
|
nr_skipped++;
|
continue;
|
}
|
/*
|
* Now we hold i_es_lock which protects us from inode reclaim
|
* freeing inode under us
|
*/
|
spin_unlock(&sbi->s_es_lock);
|
|
nr_shrunk += es_reclaim_extents(ei, &nr_to_scan);
|
write_unlock(&ei->i_es_lock);
|
|
if (nr_to_scan <= 0)
|
goto out;
|
spin_lock(&sbi->s_es_lock);
|
}
|
spin_unlock(&sbi->s_es_lock);
|
|
/*
|
* If we skipped any inodes, and we weren't able to make any
|
* forward progress, try again to scan precached inodes.
|
*/
|
if ((nr_shrunk == 0) && nr_skipped && !retried) {
|
retried++;
|
goto retry;
|
}
|
|
if (locked_ei && nr_shrunk == 0)
|
nr_shrunk = es_reclaim_extents(locked_ei, &nr_to_scan);
|
|
out:
|
scan_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
|
if (likely(es_stats->es_stats_scan_time))
|
es_stats->es_stats_scan_time = (scan_time +
|
es_stats->es_stats_scan_time*3) / 4;
|
else
|
es_stats->es_stats_scan_time = scan_time;
|
if (scan_time > es_stats->es_stats_max_scan_time)
|
es_stats->es_stats_max_scan_time = scan_time;
|
if (likely(es_stats->es_stats_shrunk))
|
es_stats->es_stats_shrunk = (nr_shrunk +
|
es_stats->es_stats_shrunk*3) / 4;
|
else
|
es_stats->es_stats_shrunk = nr_shrunk;
|
|
trace_ext4_es_shrink(sbi->s_sb, nr_shrunk, scan_time,
|
nr_skipped, retried);
|
return nr_shrunk;
|
}
|
|
static unsigned long ext4_es_count(struct shrinker *shrink,
|
struct shrink_control *sc)
|
{
|
unsigned long nr;
|
struct ext4_sb_info *sbi;
|
|
sbi = container_of(shrink, struct ext4_sb_info, s_es_shrinker);
|
nr = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
|
trace_ext4_es_shrink_count(sbi->s_sb, sc->nr_to_scan, nr);
|
return nr;
|
}
|
|
static unsigned long ext4_es_scan(struct shrinker *shrink,
|
struct shrink_control *sc)
|
{
|
struct ext4_sb_info *sbi = container_of(shrink,
|
struct ext4_sb_info, s_es_shrinker);
|
int nr_to_scan = sc->nr_to_scan;
|
int ret, nr_shrunk;
|
|
ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
|
trace_ext4_es_shrink_scan_enter(sbi->s_sb, nr_to_scan, ret);
|
|
nr_shrunk = __es_shrink(sbi, nr_to_scan, NULL);
|
|
ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
|
trace_ext4_es_shrink_scan_exit(sbi->s_sb, nr_shrunk, ret);
|
return nr_shrunk;
|
}
|
|
int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v)
|
{
|
struct ext4_sb_info *sbi = EXT4_SB((struct super_block *) seq->private);
|
struct ext4_es_stats *es_stats = &sbi->s_es_stats;
|
struct ext4_inode_info *ei, *max = NULL;
|
unsigned int inode_cnt = 0;
|
|
if (v != SEQ_START_TOKEN)
|
return 0;
|
|
/* here we just find an inode that has the max nr. of objects */
|
spin_lock(&sbi->s_es_lock);
|
list_for_each_entry(ei, &sbi->s_es_list, i_es_list) {
|
inode_cnt++;
|
if (max && max->i_es_all_nr < ei->i_es_all_nr)
|
max = ei;
|
else if (!max)
|
max = ei;
|
}
|
spin_unlock(&sbi->s_es_lock);
|
|
seq_printf(seq, "stats:\n %lld objects\n %lld reclaimable objects\n",
|
percpu_counter_sum_positive(&es_stats->es_stats_all_cnt),
|
percpu_counter_sum_positive(&es_stats->es_stats_shk_cnt));
|
seq_printf(seq, " %lld/%lld cache hits/misses\n",
|
percpu_counter_sum_positive(&es_stats->es_stats_cache_hits),
|
percpu_counter_sum_positive(&es_stats->es_stats_cache_misses));
|
if (inode_cnt)
|
seq_printf(seq, " %d inodes on list\n", inode_cnt);
|
|
seq_printf(seq, "average:\n %llu us scan time\n",
|
div_u64(es_stats->es_stats_scan_time, 1000));
|
seq_printf(seq, " %lu shrunk objects\n", es_stats->es_stats_shrunk);
|
if (inode_cnt)
|
seq_printf(seq,
|
"maximum:\n %lu inode (%u objects, %u reclaimable)\n"
|
" %llu us max scan time\n",
|
max->vfs_inode.i_ino, max->i_es_all_nr, max->i_es_shk_nr,
|
div_u64(es_stats->es_stats_max_scan_time, 1000));
|
|
return 0;
|
}
|
|
int ext4_es_register_shrinker(struct ext4_sb_info *sbi)
|
{
|
int err;
|
|
/* Make sure we have enough bits for physical block number */
|
BUILD_BUG_ON(ES_SHIFT < 48);
|
INIT_LIST_HEAD(&sbi->s_es_list);
|
sbi->s_es_nr_inode = 0;
|
spin_lock_init(&sbi->s_es_lock);
|
sbi->s_es_stats.es_stats_shrunk = 0;
|
err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_hits, 0,
|
GFP_KERNEL);
|
if (err)
|
return err;
|
err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_misses, 0,
|
GFP_KERNEL);
|
if (err)
|
goto err1;
|
sbi->s_es_stats.es_stats_scan_time = 0;
|
sbi->s_es_stats.es_stats_max_scan_time = 0;
|
err = percpu_counter_init(&sbi->s_es_stats.es_stats_all_cnt, 0, GFP_KERNEL);
|
if (err)
|
goto err2;
|
err = percpu_counter_init(&sbi->s_es_stats.es_stats_shk_cnt, 0, GFP_KERNEL);
|
if (err)
|
goto err3;
|
|
sbi->s_es_shrinker.scan_objects = ext4_es_scan;
|
sbi->s_es_shrinker.count_objects = ext4_es_count;
|
sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
|
err = register_shrinker(&sbi->s_es_shrinker);
|
if (err)
|
goto err4;
|
|
return 0;
|
err4:
|
percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
|
err3:
|
percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
|
err2:
|
percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses);
|
err1:
|
percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits);
|
return err;
|
}
|
|
void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi)
|
{
|
percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits);
|
percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses);
|
percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
|
percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
|
unregister_shrinker(&sbi->s_es_shrinker);
|
}
|
|
/*
|
* Shrink extents in given inode from ei->i_es_shrink_lblk till end. Scan at
|
* most *nr_to_scan extents, update *nr_to_scan accordingly.
|
*
|
* Return 0 if we hit end of tree / interval, 1 if we exhausted nr_to_scan.
|
* Increment *nr_shrunk by the number of reclaimed extents. Also update
|
* ei->i_es_shrink_lblk to where we should continue scanning.
|
*/
|
static int es_do_reclaim_extents(struct ext4_inode_info *ei, ext4_lblk_t end,
|
int *nr_to_scan, int *nr_shrunk)
|
{
|
struct inode *inode = &ei->vfs_inode;
|
struct ext4_es_tree *tree = &ei->i_es_tree;
|
struct extent_status *es;
|
struct rb_node *node;
|
|
es = __es_tree_search(&tree->root, ei->i_es_shrink_lblk);
|
if (!es)
|
goto out_wrap;
|
|
while (*nr_to_scan > 0) {
|
if (es->es_lblk > end) {
|
ei->i_es_shrink_lblk = end + 1;
|
return 0;
|
}
|
|
(*nr_to_scan)--;
|
node = rb_next(&es->rb_node);
|
/*
|
* We can't reclaim delayed extent from status tree because
|
* fiemap, bigallic, and seek_data/hole need to use it.
|
*/
|
if (ext4_es_is_delayed(es))
|
goto next;
|
if (ext4_es_is_referenced(es)) {
|
ext4_es_clear_referenced(es);
|
goto next;
|
}
|
|
rb_erase(&es->rb_node, &tree->root);
|
ext4_es_free_extent(inode, es);
|
(*nr_shrunk)++;
|
next:
|
if (!node)
|
goto out_wrap;
|
es = rb_entry(node, struct extent_status, rb_node);
|
}
|
ei->i_es_shrink_lblk = es->es_lblk;
|
return 1;
|
out_wrap:
|
ei->i_es_shrink_lblk = 0;
|
return 0;
|
}
|
|
static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan)
|
{
|
struct inode *inode = &ei->vfs_inode;
|
int nr_shrunk = 0;
|
ext4_lblk_t start = ei->i_es_shrink_lblk;
|
static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
|
DEFAULT_RATELIMIT_BURST);
|
|
if (ei->i_es_shk_nr == 0)
|
return 0;
|
|
if (ext4_test_inode_state(inode, EXT4_STATE_EXT_PRECACHED) &&
|
__ratelimit(&_rs))
|
ext4_warning(inode->i_sb, "forced shrink of precached extents");
|
|
if (!es_do_reclaim_extents(ei, EXT_MAX_BLOCKS, nr_to_scan, &nr_shrunk) &&
|
start != 0)
|
es_do_reclaim_extents(ei, start - 1, nr_to_scan, &nr_shrunk);
|
|
ei->i_es_tree.cache_es = NULL;
|
return nr_shrunk;
|
}
|
|
/*
|
* Called to support EXT4_IOC_CLEAR_ES_CACHE. We can only remove
|
* discretionary entries from the extent status cache. (Some entries
|
* must be present for proper operations.)
|
*/
|
void ext4_clear_inode_es(struct inode *inode)
|
{
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
struct extent_status *es;
|
struct ext4_es_tree *tree;
|
struct rb_node *node;
|
|
write_lock(&ei->i_es_lock);
|
tree = &EXT4_I(inode)->i_es_tree;
|
tree->cache_es = NULL;
|
node = rb_first(&tree->root);
|
while (node) {
|
es = rb_entry(node, struct extent_status, rb_node);
|
node = rb_next(node);
|
if (!ext4_es_is_delayed(es)) {
|
rb_erase(&es->rb_node, &tree->root);
|
ext4_es_free_extent(inode, es);
|
}
|
}
|
ext4_clear_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
|
write_unlock(&ei->i_es_lock);
|
}
|
|
#ifdef ES_DEBUG__
|
static void ext4_print_pending_tree(struct inode *inode)
|
{
|
struct ext4_pending_tree *tree;
|
struct rb_node *node;
|
struct pending_reservation *pr;
|
|
printk(KERN_DEBUG "pending reservations for inode %lu:", inode->i_ino);
|
tree = &EXT4_I(inode)->i_pending_tree;
|
node = rb_first(&tree->root);
|
while (node) {
|
pr = rb_entry(node, struct pending_reservation, rb_node);
|
printk(KERN_DEBUG " %u", pr->lclu);
|
node = rb_next(node);
|
}
|
printk(KERN_DEBUG "\n");
|
}
|
#else
|
#define ext4_print_pending_tree(inode)
|
#endif
|
|
int __init ext4_init_pending(void)
|
{
|
ext4_pending_cachep = kmem_cache_create("ext4_pending_reservation",
|
sizeof(struct pending_reservation),
|
0, (SLAB_RECLAIM_ACCOUNT), NULL);
|
if (ext4_pending_cachep == NULL)
|
return -ENOMEM;
|
return 0;
|
}
|
|
void ext4_exit_pending(void)
|
{
|
kmem_cache_destroy(ext4_pending_cachep);
|
}
|
|
void ext4_init_pending_tree(struct ext4_pending_tree *tree)
|
{
|
tree->root = RB_ROOT;
|
}
|
|
/*
|
* __get_pending - retrieve a pointer to a pending reservation
|
*
|
* @inode - file containing the pending cluster reservation
|
* @lclu - logical cluster of interest
|
*
|
* Returns a pointer to a pending reservation if it's a member of
|
* the set, and NULL if not. Must be called holding i_es_lock.
|
*/
|
static struct pending_reservation *__get_pending(struct inode *inode,
|
ext4_lblk_t lclu)
|
{
|
struct ext4_pending_tree *tree;
|
struct rb_node *node;
|
struct pending_reservation *pr = NULL;
|
|
tree = &EXT4_I(inode)->i_pending_tree;
|
node = (&tree->root)->rb_node;
|
|
while (node) {
|
pr = rb_entry(node, struct pending_reservation, rb_node);
|
if (lclu < pr->lclu)
|
node = node->rb_left;
|
else if (lclu > pr->lclu)
|
node = node->rb_right;
|
else if (lclu == pr->lclu)
|
return pr;
|
}
|
return NULL;
|
}
|
|
/*
|
* __insert_pending - adds a pending cluster reservation to the set of
|
* pending reservations
|
*
|
* @inode - file containing the cluster
|
* @lblk - logical block in the cluster to be added
|
*
|
* Returns 0 on successful insertion and -ENOMEM on failure. If the
|
* pending reservation is already in the set, returns successfully.
|
*/
|
static int __insert_pending(struct inode *inode, ext4_lblk_t lblk)
|
{
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree;
|
struct rb_node **p = &tree->root.rb_node;
|
struct rb_node *parent = NULL;
|
struct pending_reservation *pr;
|
ext4_lblk_t lclu;
|
int ret = 0;
|
|
lclu = EXT4_B2C(sbi, lblk);
|
/* search to find parent for insertion */
|
while (*p) {
|
parent = *p;
|
pr = rb_entry(parent, struct pending_reservation, rb_node);
|
|
if (lclu < pr->lclu) {
|
p = &(*p)->rb_left;
|
} else if (lclu > pr->lclu) {
|
p = &(*p)->rb_right;
|
} else {
|
/* pending reservation already inserted */
|
goto out;
|
}
|
}
|
|
pr = kmem_cache_alloc(ext4_pending_cachep, GFP_ATOMIC);
|
if (pr == NULL) {
|
ret = -ENOMEM;
|
goto out;
|
}
|
pr->lclu = lclu;
|
|
rb_link_node(&pr->rb_node, parent, p);
|
rb_insert_color(&pr->rb_node, &tree->root);
|
|
out:
|
return ret;
|
}
|
|
/*
|
* __remove_pending - removes a pending cluster reservation from the set
|
* of pending reservations
|
*
|
* @inode - file containing the cluster
|
* @lblk - logical block in the pending cluster reservation to be removed
|
*
|
* Returns successfully if pending reservation is not a member of the set.
|
*/
|
static void __remove_pending(struct inode *inode, ext4_lblk_t lblk)
|
{
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
struct pending_reservation *pr;
|
struct ext4_pending_tree *tree;
|
|
pr = __get_pending(inode, EXT4_B2C(sbi, lblk));
|
if (pr != NULL) {
|
tree = &EXT4_I(inode)->i_pending_tree;
|
rb_erase(&pr->rb_node, &tree->root);
|
kmem_cache_free(ext4_pending_cachep, pr);
|
}
|
}
|
|
/*
|
* ext4_remove_pending - removes a pending cluster reservation from the set
|
* of pending reservations
|
*
|
* @inode - file containing the cluster
|
* @lblk - logical block in the pending cluster reservation to be removed
|
*
|
* Locking for external use of __remove_pending.
|
*/
|
void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk)
|
{
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
|
write_lock(&ei->i_es_lock);
|
__remove_pending(inode, lblk);
|
write_unlock(&ei->i_es_lock);
|
}
|
|
/*
|
* ext4_is_pending - determine whether a cluster has a pending reservation
|
* on it
|
*
|
* @inode - file containing the cluster
|
* @lblk - logical block in the cluster
|
*
|
* Returns true if there's a pending reservation for the cluster in the
|
* set of pending reservations, and false if not.
|
*/
|
bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk)
|
{
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
bool ret;
|
|
read_lock(&ei->i_es_lock);
|
ret = (bool)(__get_pending(inode, EXT4_B2C(sbi, lblk)) != NULL);
|
read_unlock(&ei->i_es_lock);
|
|
return ret;
|
}
|
|
/*
|
* ext4_es_insert_delayed_block - adds a delayed block to the extents status
|
* tree, adding a pending reservation where
|
* needed
|
*
|
* @inode - file containing the newly added block
|
* @lblk - logical block to be added
|
* @allocated - indicates whether a physical cluster has been allocated for
|
* the logical cluster that contains the block
|
*
|
* Returns 0 on success, negative error code on failure.
|
*/
|
int ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
|
bool allocated)
|
{
|
struct extent_status newes;
|
int err = 0;
|
|
if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
|
return 0;
|
|
es_debug("add [%u/1) delayed to extent status tree of inode %lu\n",
|
lblk, inode->i_ino);
|
|
newes.es_lblk = lblk;
|
newes.es_len = 1;
|
ext4_es_store_pblock_status(&newes, ~0, EXTENT_STATUS_DELAYED);
|
trace_ext4_es_insert_delayed_block(inode, &newes, allocated);
|
|
ext4_es_insert_extent_check(inode, &newes);
|
|
write_lock(&EXT4_I(inode)->i_es_lock);
|
|
err = __es_remove_extent(inode, lblk, lblk, NULL);
|
if (err != 0)
|
goto error;
|
retry:
|
err = __es_insert_extent(inode, &newes);
|
if (err == -ENOMEM && __es_shrink(EXT4_SB(inode->i_sb),
|
128, EXT4_I(inode)))
|
goto retry;
|
if (err != 0)
|
goto error;
|
|
if (allocated)
|
__insert_pending(inode, lblk);
|
|
error:
|
write_unlock(&EXT4_I(inode)->i_es_lock);
|
|
ext4_es_print_tree(inode);
|
ext4_print_pending_tree(inode);
|
|
return err;
|
}
|
|
/*
|
* __es_delayed_clu - count number of clusters containing blocks that
|
* are delayed only
|
*
|
* @inode - file containing block range
|
* @start - logical block defining start of range
|
* @end - logical block defining end of range
|
*
|
* Returns the number of clusters containing only delayed (not delayed
|
* and unwritten) blocks in the range specified by @start and @end. Any
|
* cluster or part of a cluster within the range and containing a delayed
|
* and not unwritten block within the range is counted as a whole cluster.
|
*/
|
static unsigned int __es_delayed_clu(struct inode *inode, ext4_lblk_t start,
|
ext4_lblk_t end)
|
{
|
struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
|
struct extent_status *es;
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
struct rb_node *node;
|
ext4_lblk_t first_lclu, last_lclu;
|
unsigned long long last_counted_lclu;
|
unsigned int n = 0;
|
|
/* guaranteed to be unequal to any ext4_lblk_t value */
|
last_counted_lclu = ~0ULL;
|
|
es = __es_tree_search(&tree->root, start);
|
|
while (es && (es->es_lblk <= end)) {
|
if (ext4_es_is_delonly(es)) {
|
if (es->es_lblk <= start)
|
first_lclu = EXT4_B2C(sbi, start);
|
else
|
first_lclu = EXT4_B2C(sbi, es->es_lblk);
|
|
if (ext4_es_end(es) >= end)
|
last_lclu = EXT4_B2C(sbi, end);
|
else
|
last_lclu = EXT4_B2C(sbi, ext4_es_end(es));
|
|
if (first_lclu == last_counted_lclu)
|
n += last_lclu - first_lclu;
|
else
|
n += last_lclu - first_lclu + 1;
|
last_counted_lclu = last_lclu;
|
}
|
node = rb_next(&es->rb_node);
|
if (!node)
|
break;
|
es = rb_entry(node, struct extent_status, rb_node);
|
}
|
|
return n;
|
}
|
|
/*
|
* ext4_es_delayed_clu - count number of clusters containing blocks that
|
* are both delayed and unwritten
|
*
|
* @inode - file containing block range
|
* @lblk - logical block defining start of range
|
* @len - number of blocks in range
|
*
|
* Locking for external use of __es_delayed_clu().
|
*/
|
unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
|
ext4_lblk_t len)
|
{
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
ext4_lblk_t end;
|
unsigned int n;
|
|
if (len == 0)
|
return 0;
|
|
end = lblk + len - 1;
|
WARN_ON(end < lblk);
|
|
read_lock(&ei->i_es_lock);
|
|
n = __es_delayed_clu(inode, lblk, end);
|
|
read_unlock(&ei->i_es_lock);
|
|
return n;
|
}
|
|
/*
|
* __revise_pending - makes, cancels, or leaves unchanged pending cluster
|
* reservations for a specified block range depending
|
* upon the presence or absence of delayed blocks
|
* outside the range within clusters at the ends of the
|
* range
|
*
|
* @inode - file containing the range
|
* @lblk - logical block defining the start of range
|
* @len - length of range in blocks
|
*
|
* Used after a newly allocated extent is added to the extents status tree.
|
* Requires that the extents in the range have either written or unwritten
|
* status. Must be called while holding i_es_lock.
|
*/
|
static void __revise_pending(struct inode *inode, ext4_lblk_t lblk,
|
ext4_lblk_t len)
|
{
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
ext4_lblk_t end = lblk + len - 1;
|
ext4_lblk_t first, last;
|
bool f_del = false, l_del = false;
|
|
if (len == 0)
|
return;
|
|
/*
|
* Two cases - block range within single cluster and block range
|
* spanning two or more clusters. Note that a cluster belonging
|
* to a range starting and/or ending on a cluster boundary is treated
|
* as if it does not contain a delayed extent. The new range may
|
* have allocated space for previously delayed blocks out to the
|
* cluster boundary, requiring that any pre-existing pending
|
* reservation be canceled. Because this code only looks at blocks
|
* outside the range, it should revise pending reservations
|
* correctly even if the extent represented by the range can't be
|
* inserted in the extents status tree due to ENOSPC.
|
*/
|
|
if (EXT4_B2C(sbi, lblk) == EXT4_B2C(sbi, end)) {
|
first = EXT4_LBLK_CMASK(sbi, lblk);
|
if (first != lblk)
|
f_del = __es_scan_range(inode, &ext4_es_is_delonly,
|
first, lblk - 1);
|
if (f_del) {
|
__insert_pending(inode, first);
|
} else {
|
last = EXT4_LBLK_CMASK(sbi, end) +
|
sbi->s_cluster_ratio - 1;
|
if (last != end)
|
l_del = __es_scan_range(inode,
|
&ext4_es_is_delonly,
|
end + 1, last);
|
if (l_del)
|
__insert_pending(inode, last);
|
else
|
__remove_pending(inode, last);
|
}
|
} else {
|
first = EXT4_LBLK_CMASK(sbi, lblk);
|
if (first != lblk)
|
f_del = __es_scan_range(inode, &ext4_es_is_delonly,
|
first, lblk - 1);
|
if (f_del)
|
__insert_pending(inode, first);
|
else
|
__remove_pending(inode, first);
|
|
last = EXT4_LBLK_CMASK(sbi, end) + sbi->s_cluster_ratio - 1;
|
if (last != end)
|
l_del = __es_scan_range(inode, &ext4_es_is_delonly,
|
end + 1, last);
|
if (l_del)
|
__insert_pending(inode, last);
|
else
|
__remove_pending(inode, last);
|
}
|
}
|
