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After we mark the blocks in the buddy cache as allocated, we need to ensure that we don't reinit the buddy cache until the block bitmap is updated. This commit achieves this by holding the group_info alloc_semaphore till ext4_mb_release_context Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@kernel.org
262 lines
6.7 KiB
C
262 lines
6.7 KiB
C
/*
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* fs/ext4/mballoc.h
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*
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* Written by: Alex Tomas <alex@clusterfs.com>
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*
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*/
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#ifndef _EXT4_MBALLOC_H
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#define _EXT4_MBALLOC_H
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#include <linux/time.h>
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#include <linux/fs.h>
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#include <linux/namei.h>
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#include <linux/quotaops.h>
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#include <linux/buffer_head.h>
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#include <linux/module.h>
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#include <linux/swap.h>
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#include <linux/proc_fs.h>
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#include <linux/pagemap.h>
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#include <linux/seq_file.h>
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#include <linux/version.h>
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#include <linux/blkdev.h>
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#include <linux/marker.h>
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#include <linux/mutex.h>
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#include "ext4_jbd2.h"
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#include "ext4.h"
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#include "group.h"
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/*
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* with AGGRESSIVE_CHECK allocator runs consistency checks over
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* structures. these checks slow things down a lot
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*/
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#define AGGRESSIVE_CHECK__
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/*
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* with DOUBLE_CHECK defined mballoc creates persistent in-core
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* bitmaps, maintains and uses them to check for double allocations
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*/
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#define DOUBLE_CHECK__
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/*
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*/
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#define MB_DEBUG__
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#ifdef MB_DEBUG
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#define mb_debug(fmt, a...) printk(fmt, ##a)
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#else
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#define mb_debug(fmt, a...)
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#endif
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/*
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* with EXT4_MB_HISTORY mballoc stores last N allocations in memory
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* and you can monitor it in /proc/fs/ext4/<dev>/mb_history
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*/
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#define EXT4_MB_HISTORY
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#define EXT4_MB_HISTORY_ALLOC 1 /* allocation */
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#define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */
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#define EXT4_MB_HISTORY_DISCARD 4 /* preallocation discarded */
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#define EXT4_MB_HISTORY_FREE 8 /* free */
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#define EXT4_MB_HISTORY_DEFAULT (EXT4_MB_HISTORY_ALLOC | \
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EXT4_MB_HISTORY_PREALLOC)
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/*
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* How long mballoc can look for a best extent (in found extents)
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*/
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#define MB_DEFAULT_MAX_TO_SCAN 200
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/*
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* How long mballoc must look for a best extent
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*/
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#define MB_DEFAULT_MIN_TO_SCAN 10
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/*
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* How many groups mballoc will scan looking for the best chunk
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*/
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#define MB_DEFAULT_MAX_GROUPS_TO_SCAN 5
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/*
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* with 'ext4_mb_stats' allocator will collect stats that will be
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* shown at umount. The collecting costs though!
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*/
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#define MB_DEFAULT_STATS 1
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/*
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* files smaller than MB_DEFAULT_STREAM_THRESHOLD are served
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* by the stream allocator, which purpose is to pack requests
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* as close each to other as possible to produce smooth I/O traffic
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* We use locality group prealloc space for stream request.
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* We can tune the same via /proc/fs/ext4/<parition>/stream_req
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*/
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#define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */
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/*
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* for which requests use 2^N search using buddies
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*/
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#define MB_DEFAULT_ORDER2_REQS 2
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/*
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* default group prealloc size 512 blocks
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*/
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#define MB_DEFAULT_GROUP_PREALLOC 512
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struct ext4_free_data {
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/* this links the free block information from group_info */
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struct rb_node node;
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/* this links the free block information from ext4_sb_info */
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struct list_head list;
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/* group which free block extent belongs */
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ext4_group_t group;
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/* free block extent */
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ext4_grpblk_t start_blk;
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ext4_grpblk_t count;
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/* transaction which freed this extent */
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tid_t t_tid;
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};
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struct ext4_prealloc_space {
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struct list_head pa_inode_list;
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struct list_head pa_group_list;
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union {
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struct list_head pa_tmp_list;
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struct rcu_head pa_rcu;
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} u;
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spinlock_t pa_lock;
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atomic_t pa_count;
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unsigned pa_deleted;
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ext4_fsblk_t pa_pstart; /* phys. block */
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ext4_lblk_t pa_lstart; /* log. block */
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unsigned short pa_len; /* len of preallocated chunk */
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unsigned short pa_free; /* how many blocks are free */
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unsigned short pa_linear; /* consumed in one direction
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* strictly, for grp prealloc */
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spinlock_t *pa_obj_lock;
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struct inode *pa_inode; /* hack, for history only */
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};
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struct ext4_free_extent {
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ext4_lblk_t fe_logical;
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ext4_grpblk_t fe_start;
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ext4_group_t fe_group;
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int fe_len;
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};
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/*
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* Locality group:
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* we try to group all related changes together
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* so that writeback can flush/allocate them together as well
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* Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC
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* (512). We store prealloc space into the hash based on the pa_free blocks
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* order value.ie, fls(pa_free)-1;
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*/
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#define PREALLOC_TB_SIZE 10
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struct ext4_locality_group {
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/* for allocator */
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/* to serialize allocates */
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struct mutex lg_mutex;
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/* list of preallocations */
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struct list_head lg_prealloc_list[PREALLOC_TB_SIZE];
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spinlock_t lg_prealloc_lock;
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};
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struct ext4_allocation_context {
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struct inode *ac_inode;
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struct super_block *ac_sb;
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/* original request */
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struct ext4_free_extent ac_o_ex;
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/* goal request (after normalization) */
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struct ext4_free_extent ac_g_ex;
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/* the best found extent */
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struct ext4_free_extent ac_b_ex;
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/* copy of the bext found extent taken before preallocation efforts */
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struct ext4_free_extent ac_f_ex;
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/* number of iterations done. we have to track to limit searching */
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unsigned long ac_ex_scanned;
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__u16 ac_groups_scanned;
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__u16 ac_found;
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__u16 ac_tail;
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__u16 ac_buddy;
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__u16 ac_flags; /* allocation hints */
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__u8 ac_status;
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__u8 ac_criteria;
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__u8 ac_repeats;
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__u8 ac_2order; /* if request is to allocate 2^N blocks and
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* N > 0, the field stores N, otherwise 0 */
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__u8 ac_op; /* operation, for history only */
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struct page *ac_bitmap_page;
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struct page *ac_buddy_page;
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/*
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* pointer to the held semaphore upon successful
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* block allocation
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*/
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struct rw_semaphore *alloc_semp;
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struct ext4_prealloc_space *ac_pa;
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struct ext4_locality_group *ac_lg;
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};
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#define AC_STATUS_CONTINUE 1
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#define AC_STATUS_FOUND 2
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#define AC_STATUS_BREAK 3
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struct ext4_mb_history {
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struct ext4_free_extent orig; /* orig allocation */
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struct ext4_free_extent goal; /* goal allocation */
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struct ext4_free_extent result; /* result allocation */
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unsigned pid;
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unsigned ino;
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__u16 found; /* how many extents have been found */
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__u16 groups; /* how many groups have been scanned */
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__u16 tail; /* what tail broke some buddy */
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__u16 buddy; /* buddy the tail ^^^ broke */
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__u16 flags;
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__u8 cr:3; /* which phase the result extent was found at */
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__u8 op:4;
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__u8 merged:1;
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};
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struct ext4_buddy {
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struct page *bd_buddy_page;
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void *bd_buddy;
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struct page *bd_bitmap_page;
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void *bd_bitmap;
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struct ext4_group_info *bd_info;
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struct super_block *bd_sb;
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__u16 bd_blkbits;
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ext4_group_t bd_group;
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struct rw_semaphore *alloc_semp;
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};
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#define EXT4_MB_BITMAP(e4b) ((e4b)->bd_bitmap)
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#define EXT4_MB_BUDDY(e4b) ((e4b)->bd_buddy)
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#ifndef EXT4_MB_HISTORY
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static inline void ext4_mb_store_history(struct ext4_allocation_context *ac)
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{
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return;
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}
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#endif
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#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
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struct buffer_head *read_block_bitmap(struct super_block *, ext4_group_t);
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static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
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struct ext4_free_extent *fex)
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{
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ext4_fsblk_t block;
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block = (ext4_fsblk_t) fex->fe_group * EXT4_BLOCKS_PER_GROUP(sb)
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+ fex->fe_start
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+ le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
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return block;
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}
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#endif
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