--- /dev/null
+/*
+ * fs/ext4/mballoc.h
+ *
+ * Written by: Alex Tomas <alex@clusterfs.com>
+ *
+ */
+#ifndef _EXT4_MBALLOC_H
+#define _EXT4_MBALLOC_H
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include <linux/module.h>
+#include <linux/swap.h>
+#include <linux/proc_fs.h>
+#include <linux/pagemap.h>
+#include <linux/seq_file.h>
+#include <linux/blkdev.h>
+#include <linux/mutex.h>
+#include "ext4_jbd2.h"
+#include "ext4.h"
+
+/*
+ * with AGGRESSIVE_CHECK allocator runs consistency checks over
+ * structures. these checks slow things down a lot
+ */
+#define AGGRESSIVE_CHECK__
+
+/*
+ * with DOUBLE_CHECK defined mballoc creates persistent in-core
+ * bitmaps, maintains and uses them to check for double allocations
+ */
+#define DOUBLE_CHECK__
+
+/*
+ */
+#ifdef CONFIG_EXT4_DEBUG
+extern ushort ext4_mballoc_debug;
+
+#define mb_debug(n, fmt, a...) \
+ do { \
+ if ((n) <= ext4_mballoc_debug) { \
+ printk(KERN_DEBUG "(%s, %d): %s: ", \
+ __FILE__, __LINE__, __func__); \
+ printk(fmt, ## a); \
+ } \
+ } while (0)
+#else
+#define mb_debug(n, fmt, a...) no_printk(fmt, ## a)
+#endif
+
+#define EXT4_MB_HISTORY_ALLOC 1 /* allocation */
+#define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */
+
+/*
+ * How long mballoc can look for a best extent (in found extents)
+ */
+#define MB_DEFAULT_MAX_TO_SCAN 200
+
+/*
+ * How long mballoc must look for a best extent
+ */
+#define MB_DEFAULT_MIN_TO_SCAN 10
+
+/*
+ * with 'ext4_mb_stats' allocator will collect stats that will be
+ * shown at umount. The collecting costs though!
+ */
+#define MB_DEFAULT_STATS 0
+
+/*
+ * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served
+ * by the stream allocator, which purpose is to pack requests
+ * as close each to other as possible to produce smooth I/O traffic
+ * We use locality group prealloc space for stream request.
+ * We can tune the same via /proc/fs/ext4/<parition>/stream_req
+ */
+#define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */
+
+/*
+ * for which requests use 2^N search using buddies
+ */
+#define MB_DEFAULT_ORDER2_REQS 2
+
+/*
+ * default group prealloc size 512 blocks
+ */
+#define MB_DEFAULT_GROUP_PREALLOC 512
+
+
+struct ext4_free_data {
+ /* MUST be the first member */
+ struct ext4_journal_cb_entry efd_jce;
+
+ /* ext4_free_data private data starts from here */
+
+ /* this links the free block information from group_info */
+ struct rb_node efd_node;
+
+ /* group which free block extent belongs */
+ ext4_group_t efd_group;
+
+ /* free block extent */
+ ext4_grpblk_t efd_start_cluster;
+ ext4_grpblk_t efd_count;
+
+ /* transaction which freed this extent */
+ tid_t efd_tid;
+};
+
+struct ext4_prealloc_space {
+ struct list_head pa_inode_list;
+ struct list_head pa_group_list;
+ union {
+ struct list_head pa_tmp_list;
+ struct rcu_head pa_rcu;
+ } u;
+ spinlock_t pa_lock;
+ atomic_t pa_count;
+ unsigned pa_deleted;
+ ext4_fsblk_t pa_pstart; /* phys. block */
+ ext4_lblk_t pa_lstart; /* log. block */
+ ext4_grpblk_t pa_len; /* len of preallocated chunk */
+ ext4_grpblk_t pa_free; /* how many blocks are free */
+ unsigned short pa_type; /* pa type. inode or group */
+ spinlock_t *pa_obj_lock;
+ struct inode *pa_inode; /* hack, for history only */
+};
+
+enum {
+ MB_INODE_PA = 0,
+ MB_GROUP_PA = 1
+};
+
+struct ext4_free_extent {
+ ext4_lblk_t fe_logical;
+ ext4_grpblk_t fe_start; /* In cluster units */
+ ext4_group_t fe_group;
+ ext4_grpblk_t fe_len; /* In cluster units */
+};
+
+/*
+ * Locality group:
+ * we try to group all related changes together
+ * so that writeback can flush/allocate them together as well
+ * Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC
+ * (512). We store prealloc space into the hash based on the pa_free blocks
+ * order value.ie, fls(pa_free)-1;
+ */
+#define PREALLOC_TB_SIZE 10
+struct ext4_locality_group {
+ /* for allocator */
+ /* to serialize allocates */
+ struct mutex lg_mutex;
+ /* list of preallocations */
+ struct list_head lg_prealloc_list[PREALLOC_TB_SIZE];
+ spinlock_t lg_prealloc_lock;
+};
+
+struct ext4_allocation_context {
+ struct inode *ac_inode;
+ struct super_block *ac_sb;
+
+ /* original request */
+ struct ext4_free_extent ac_o_ex;
+
+ /* goal request (normalized ac_o_ex) */
+ struct ext4_free_extent ac_g_ex;
+
+ /* the best found extent */
+ struct ext4_free_extent ac_b_ex;
+
+ /* copy of the best found extent taken before preallocation efforts */
+ struct ext4_free_extent ac_f_ex;
+
+ __u16 ac_groups_scanned;
+ __u16 ac_found;
+ __u16 ac_tail;
+ __u16 ac_buddy;
+ __u16 ac_flags; /* allocation hints */
+ __u8 ac_status;
+ __u8 ac_criteria;
+ __u8 ac_2order; /* if request is to allocate 2^N blocks and
+ * N > 0, the field stores N, otherwise 0 */
+ __u8 ac_op; /* operation, for history only */
+ struct page *ac_bitmap_page;
+ struct page *ac_buddy_page;
+ struct ext4_prealloc_space *ac_pa;
+ struct ext4_locality_group *ac_lg;
+};
+
+#define AC_STATUS_CONTINUE 1
+#define AC_STATUS_FOUND 2
+#define AC_STATUS_BREAK 3
+
+struct ext4_buddy {
+ struct page *bd_buddy_page;
+ void *bd_buddy;
+ struct page *bd_bitmap_page;
+ void *bd_bitmap;
+ struct ext4_group_info *bd_info;
+ struct super_block *bd_sb;
+ __u16 bd_blkbits;
+ ext4_group_t bd_group;
+};
+
+static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
+ struct ext4_free_extent *fex)
+{
+ return ext4_group_first_block_no(sb, fex->fe_group) +
+ (fex->fe_start << EXT4_SB(sb)->s_cluster_bits);
+}
+#endif
Code Review / kvmfornfv.git / blobdiff