- 根目录:
- fs
- ocfs2
- localalloc.c
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* localalloc.c
*
* Node local data allocation
*
* Copyright (C) 2002, 2004 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/bitops.h>
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "alloc.h"
#include "blockcheck.h"
#include "dlmglue.h"
#include "inode.h"
#include "journal.h"
#include "localalloc.h"
#include "suballoc.h"
#include "super.h"
#include "sysfile.h"
#include "ocfs2_trace.h"
#include "buffer_head_io.h"
#define OCFS2_LOCAL_ALLOC(dinode) (&((dinode)->id2.i_lab))
static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc);
static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
struct ocfs2_dinode *alloc,
u32 *numbits,
struct ocfs2_alloc_reservation *resv);
static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc);
static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
handle_t *handle,
struct ocfs2_dinode *alloc,
struct inode *main_bm_inode,
struct buffer_head *main_bm_bh);
static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
struct ocfs2_alloc_context **ac,
struct inode **bitmap_inode,
struct buffer_head **bitmap_bh);
static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
handle_t *handle,
struct ocfs2_alloc_context *ac);
static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
struct inode *local_alloc_inode);
/*
* ocfs2_la_default_mb() - determine a default size, in megabytes of
* the local alloc.
*
* Generally, we'd like to pick as large a local alloc as
* possible. Performance on large workloads tends to scale
* proportionally to la size. In addition to that, the reservations
* code functions more efficiently as it can reserve more windows for
* write.
*
* Some things work against us when trying to choose a large local alloc:
*
* - We need to ensure our sizing is picked to leave enough space in
* group descriptors for other allocations (such as block groups,
* etc). Picking default sizes which are a multiple of 4 could help
* - block groups are allocated in 2mb and 4mb chunks.
*
* - Likewise, we don't want to starve other nodes of bits on small
* file systems. This can easily be taken care of by limiting our
* default to a reasonable size (256M) on larger cluster sizes.
*
* - Some file systems can't support very large sizes - 4k and 8k in
* particular are limited to less than 128 and 256 megabytes respectively.
*
* The following reference table shows group descriptor and local
* alloc maximums at various cluster sizes (4k blocksize)
*
* csize: 4K group: 126M la: 121M
* csize: 8K group: 252M la: 243M
* csize: 16K group: 504M la: 486M
* csize: 32K group: 1008M la: 972M
* csize: 64K group: 2016M la: 1944M
* csize: 128K group: 4032M la: 3888M
* csize: 256K group: 8064M la: 7776M
* csize: 512K group: 16128M la: 15552M
* csize: 1024K group: 32256M la: 31104M
*/
#define OCFS2_LA_MAX_DEFAULT_MB 256
#define OCFS2_LA_OLD_DEFAULT 8
unsigned int ocfs2_la_default_mb(struct ocfs2_super *osb)
{
unsigned int la_mb;
unsigned int gd_mb;
unsigned int la_max_mb;
unsigned int megs_per_slot;
struct super_block *sb = osb->sb;
gd_mb = ocfs2_clusters_to_megabytes(osb->sb,
8 * ocfs2_group_bitmap_size(sb, 0, osb->s_feature_incompat));
/*
* This takes care of files systems with very small group
* descriptors - 512 byte blocksize at cluster sizes lower
* than 16K and also 1k blocksize with 4k cluster size.
*/
if ((sb->s_blocksize == 512 && osb->s_clustersize <= 8192)
|| (sb->s_blocksize == 1024 && osb->s_clustersize == 4096))
return OCFS2_LA_OLD_DEFAULT;
/*
* Leave enough room for some block groups and make the final
* value we work from a multiple of 4.
*/
gd_mb -= 16;
gd_mb &= 0xFFFFFFFB;
la_mb = gd_mb;
/*
* Keep window sizes down to a reasonable default
*/
if (la_mb > OCFS2_LA_MAX_DEFAULT_MB) {
/*
* Some clustersize / blocksize combinations will have
* given us a larger than OCFS2_LA_MAX_DEFAULT_MB
* default size, but get poor distribution when
* limited to exactly 256 megabytes.
*
* As an example, 16K clustersize at 4K blocksize
* gives us a cluster group size of 504M. Paring the
* local alloc size down to 256 however, would give us
* only one window and around 200MB left in the
* cluster group. Instead, find the first size below
* 256 which would give us an even distribution.
*
* Larger cluster group sizes actually work out pretty
* well when pared to 256, so we don't have to do this
* for any group that fits more than two
* OCFS2_LA_MAX_DEFAULT_MB windows.
*/
if (gd_mb > (2 * OCFS2_LA_MAX_DEFAULT_MB))
la_mb = 256;
else {
unsigned int gd_mult = gd_mb;
while (gd_mult > 256)
gd_mult = gd_mult >> 1;
la_mb = gd_mult;
}
}
megs_per_slot = osb->osb_clusters_at_boot / osb->max_slots;
megs_per_slot = ocfs2_clusters_to_megabytes(osb->sb, megs_per_slot);
/* Too many nodes, too few disk clusters. */
if (megs_per_slot < la_mb)
la_mb = megs_per_slot;
/* We can't store more bits than we can in a block. */
la_max_mb = ocfs2_clusters_to_megabytes(osb->sb,
ocfs2_local_alloc_size(sb) * 8);
if (la_mb > la_max_mb)
la_mb = la_max_mb;
return la_mb;
}
void ocfs2_la_set_sizes(struct ocfs2_super *osb, int requested_mb)
{
struct super_block *sb = osb->sb;
unsigned int la_default_mb = ocfs2_la_default_mb(osb);
unsigned int la_max_mb;
la_max_mb = ocfs2_clusters_to_megabytes(sb,
ocfs2_local_alloc_size(sb) * 8);
trace_ocfs2_la_set_sizes(requested_mb, la_max_mb, la_default_mb);
if (requested_mb == -1) {
/* No user request - use defaults */
osb->local_alloc_default_bits =
ocfs2_megabytes_to_clusters(sb, la_default_mb);
} else if (requested_mb > la_max_mb) {
/* Request is too big, we give the maximum available */
osb->local_alloc_default_bits =
ocfs2_megabytes_to_clusters(sb, la_max_mb);
} else {
osb->local_alloc_default_bits =
ocfs2_megabytes_to_clusters(sb, requested_mb);
}
osb->local_alloc_bits = osb->local_alloc_default_bits;
}
static inline int ocfs2_la_state_enabled(struct ocfs2_super *osb)
{
return (osb->local_alloc_state == OCFS2_LA_THROTTLED ||
osb->local_alloc_state == OCFS2_LA_ENABLED);
}
void ocfs2_local_alloc_seen_free_bits(struct ocfs2_super *osb,
unsigned int num_clusters)
{
spin_lock(&osb->osb_lock);
if (osb->local_alloc_state == OCFS2_LA_DISABLED ||
osb->local_alloc_state == OCFS2_LA_THROTTLED)
if (num_clusters >= osb->local_alloc_default_bits) {
cancel_delayed_work(&osb->la_enable_wq);
osb->local_alloc_state = OCFS2_LA_ENABLED;
}
spin_unlock(&osb->osb_lock);
}
void ocfs2_la_enable_worker(struct work_struct *work)
{
struct ocfs2_super *osb =
container_of(work, struct ocfs2_super,
la_enable_wq.work);
spin_lock(&osb->osb_lock);
osb->local_alloc_state = OCFS2_LA_ENABLED;
spin_unlock(&osb->osb_lock);
}
/*
* Tell us whether a given allocation should use the local alloc
* file. Otherwise, it has to go to the main bitmap.
*
* This function does semi-dirty reads of local alloc size and state!
* This is ok however, as the values are re-checked once under mutex.
*/
int ocfs2_alloc_should_use_local(struct ocfs2_super *osb, u64 bits)
{
int ret = 0;
int la_bits;
spin_lock(&osb->osb_lock);
la_bits = osb->local_alloc_bits;
if (!ocfs2_la_state_enabled(osb))
goto bail;
/* la_bits should be at least twice the size (in clusters) of
* a new block group. We want to be sure block group
* allocations go through the local alloc, so allow an
* allocation to take up to half the bitmap. */
if (bits > (la_bits / 2))
goto bail;
ret = 1;
bail:
trace_ocfs2_alloc_should_use_local(
(unsigned long long)bits, osb->local_alloc_state, la_bits, ret);
spin_unlock(&osb->osb_lock);
return ret;
}
int ocfs2_load_local_alloc(struct ocfs2_super *osb)
{
int status = 0;
struct ocfs2_dinode *alloc = NULL;
struct buffer_head *alloc_bh = NULL;
u32 num_used;
struct inode *inode = NULL;
struct ocfs2_local_alloc *la;
if (osb->local_alloc_bits == 0)
goto bail;
if (osb->local_alloc_bits >= osb->bitmap_cpg) {
mlog(ML_NOTICE, "Requested local alloc window %d is larger "
"than max possible %u. Using defaults.\n",
osb->local_alloc_bits, (osb->bitmap_cpg - 1));
osb->local_alloc_bits =
ocfs2_megabytes_to_clusters(osb->sb,
ocfs2_la_default_mb(osb));
}
/* read the alloc off disk */
inode = ocfs2_get_system_file_inode(osb, LOCAL_ALLOC_SYSTEM_INODE,
osb->slot_num);
if (!inode) {
status = -EINVAL;
mlog_errno(status);
goto bail;
}
status = ocfs2_read_inode_block_full(inode, &alloc_bh,
OCFS2_BH_IGNORE_CACHE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
alloc = (struct ocfs2_dinode *) alloc_bh->b_data;
la = OCFS2_LOCAL_ALLOC(alloc);
if (!(le32_to_cpu(alloc->i_flags) &
(OCFS2_LOCAL_ALLOC_FL|OCFS2_BITMAP_FL))) {
mlog(ML_ERROR, "Invalid local alloc inode, %llu\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
status = -EINVAL;
goto bail;
}
if ((la->la_size == 0) ||
(le16_to_cpu(la->la_size) > ocfs2_local_alloc_size(inode->i_sb))) {
mlog(ML_ERROR, "Local alloc size is invalid (la_size = %u)\n",
le16_to_cpu(la->la_size));
status = -EINVAL;
goto bail;
}
/* do a little verification. */
num_used = ocfs2_local_alloc_count_bits(alloc);
/* hopefully the local alloc has always been recovered before
* we load it. */
if (num_used
|| alloc->id1.bitmap1.i_used
|| alloc->id1.bitmap1.i_total
|| la->la_bm_off)
mlog(ML_ERROR, "Local alloc hasn't been recovered!\n"
"found = %u, set = %u, taken = %u, off = %u\n",
num_used, le32_to_cpu(alloc->id1.bitmap1.i_used),
le32_to_cpu(alloc->id1.bitmap1.i_total),
OCFS2_LOCAL_ALLOC(alloc)->la_bm_off);
osb->local_alloc_bh = alloc_bh;
osb->local_alloc_state = OCFS2_LA_ENABLED;
bail:
if (status < 0)
brelse(alloc_bh);
if (inode)
iput(inode);
trace_ocfs2_load_local_alloc(osb->local_alloc_bits);
if (status)
mlog_errno(status);
return status;
}
/*
* return any unused bits to the bitmap and write out a clean
* local_alloc.
*
* local_alloc_bh is optional. If not passed, we will simply use the
* one off osb. If you do pass it however, be warned that it *will* be
* returned brelse'd and NULL'd out.*/
void ocfs2_shutdown_local_alloc(struct ocfs2_super *osb)
{
int status;
handle_t *handle;
struct inode *local_alloc_inode = NULL;
struct buffer_head *bh = NULL;
struct buffer_head *main_bm_bh = NULL;
struct inode *main_bm_inode = NULL;
struct ocfs2_dinode *alloc_copy = NULL;
struct ocfs2_dinode *alloc = NULL;
cancel_delayed_work(&osb->la_enable_wq);
flush_workqueue(ocfs2_wq);
if (osb->local_alloc_state == OCFS2_LA_UNUSED)
goto out;
local_alloc_inode =
ocfs2_get_system_file_inode(osb,
LOCAL_ALLOC_SYSTEM_INODE,
osb->slot_num);
if (!local_alloc_inode) {
status = -ENOENT;
mlog_errno(status);
goto out;
}
osb->local_alloc_state = OCFS2_LA_DISABLED;
ocfs2_resmap_uninit(&osb->osb_la_resmap);
main_bm_inode = ocfs2_get_system_file_inode(osb,
GLOBAL_BITMAP_SYSTEM_INODE,
OCFS2_INVALID_SLOT);
if (!main_bm_inode) {
status = -EINVAL;
mlog_errno(status);
goto out;
}
mutex_lock(&main_bm_inode->i_mutex);
status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
if (status < 0) {
mlog_errno(status);
goto out_mutex;
}
/* WINDOW_MOVE_CREDITS is a bit heavy... */
handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
if (IS_ERR(handle)) {
mlog_errno(PTR_ERR(handle));
handle = NULL;
goto out_unlock;
}
bh = osb->local_alloc_bh;
alloc = (struct ocfs2_dinode *) bh->b_data;
alloc_copy = kmalloc(bh->b_size, GFP_NOFS);
if (!alloc_copy) {
status = -ENOMEM;
goto out_commit;
}
memcpy(alloc_copy, alloc, bh->b_size);
status = ocfs2_journal_access_di(handle, INODE_CACHE(local_alloc_inode),
bh, OCFS2_JOURNAL_ACCESS_WRITE);
if (status < 0) {
mlog_errno(status);
goto out_commit;
}
ocfs2_clear_local_alloc(alloc);
ocfs2_journal_dirty(handle, bh);
brelse(bh);
osb->local_alloc_bh = NULL;
osb->local_alloc_state = OCFS2_LA_UNUSED;
status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
main_bm_inode, main_bm_bh);
if (status < 0)
mlog_errno(status);
out_commit:
ocfs2_commit_trans(osb, handle);
out_unlock:
brelse(main_bm_bh);
ocfs2_inode_unlock(main_bm_inode, 1);
out_mutex:
mutex_unlock(&main_bm_inode->i_mutex);
iput(main_bm_inode);
out:
if (local_alloc_inode)
iput(local_alloc_inode);
if (alloc_copy)
kfree(alloc_copy);
}
/*
* We want to free the bitmap bits outside of any recovery context as
* we'll need a cluster lock to do so, but we must clear the local
* alloc before giving up the recovered nodes journal. To solve this,
* we kmalloc a copy of the local alloc before it's change for the
* caller to process with ocfs2_complete_local_alloc_recovery
*/
int ocfs2_begin_local_alloc_recovery(struct ocfs2_super *osb,
int slot_num,
struct ocfs2_dinode **alloc_copy)
{
int status = 0;
struct buffer_head *alloc_bh = NULL;
struct inode *inode = NULL;
struct ocfs2_dinode *alloc;
trace_ocfs2_begin_local_alloc_recovery(slot_num);
*alloc_copy = NULL;
inode = ocfs2_get_system_file_inode(osb,
LOCAL_ALLOC_SYSTEM_INODE,
slot_num);
if (!inode) {
status = -EINVAL;
mlog_errno(status);
goto bail;
}
mutex_lock(&inode->i_mutex);
status = ocfs2_read_inode_block_full(inode, &alloc_bh,
OCFS2_BH_IGNORE_CACHE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
*alloc_copy = kmalloc(alloc_bh->b_size, GFP_KERNEL);
if (!(*alloc_copy)) {
status = -ENOMEM;
goto bail;
}
memcpy((*alloc_copy), alloc_bh->b_data, alloc_bh->b_size);
alloc = (struct ocfs2_dinode *) alloc_bh->b_data;
ocfs2_clear_local_alloc(alloc);
ocfs2_compute_meta_ecc(osb->sb, alloc_bh->b_data, &alloc->i_check);
status = ocfs2_write_block(osb, alloc_bh, INODE_CACHE(inode));
if (status < 0)
mlog_errno(status);
bail:
if ((status < 0) && (*alloc_copy)) {
kfree(*alloc_copy);
*alloc_copy = NULL;
}
brelse(alloc_bh);
if (inode) {
mutex_unlock(&inode->i_mutex);
iput(inode);
}
if (status)
mlog_errno(status);
return status;
}
/*
* Step 2: By now, we've completed the journal recovery, we've stamped
* a clean local alloc on disk and dropped the node out of the
* recovery map. Dlm locks will no longer stall, so lets clear out the
* main bitmap.
*/
int ocfs2_complete_local_alloc_recovery(struct ocfs2_super *osb,
struct ocfs2_dinode *alloc)
{
int status;
handle_t *handle;
struct buffer_head *main_bm_bh = NULL;
struct inode *main_bm_inode;
main_bm_inode = ocfs2_get_system_file_inode(osb,
GLOBAL_BITMAP_SYSTEM_INODE,
OCFS2_INVALID_SLOT);
if (!main_bm_inode) {
status = -EINVAL;
mlog_errno(status);
goto out;
}
mutex_lock(&main_bm_inode->i_mutex);
status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
if (status < 0) {
mlog_errno(status);
goto out_mutex;
}
handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
if (IS_ERR(handle)) {
status = PTR_ERR(handle);
handle = NULL;
mlog_errno(status);
goto out_unlock;
}
/* we want the bitmap change to be recorded on disk asap */
handle->h_sync = 1;
status = ocfs2_sync_local_to_main(osb, handle, alloc,
main_bm_inode, main_bm_bh);
if (status < 0)
mlog_errno(status);
ocfs2_commit_trans(osb, handle);
out_unlock:
ocfs2_inode_unlock(main_bm_inode, 1);
out_mutex:
mutex_unlock(&main_bm_inode->i_mutex);
brelse(main_bm_bh);
iput(main_bm_inode);
out:
if (!status)
ocfs2_init_steal_slots(osb);
if (status)
mlog_errno(status);
return status;
}
/*
* make sure we've got at least bits_wanted contiguous bits in the
* local alloc. You lose them when you drop i_mutex.
*
* We will add ourselves to the transaction passed in, but may start
* our own in order to shift windows.
*/
int ocfs2_reserve_local_alloc_bits(struct ocfs2_super *osb,
u32 bits_wanted,
struct ocfs2_alloc_context *ac)
{
int status;
struct ocfs2_dinode *alloc;
struct inode *local_alloc_inode;
unsigned int free_bits;
BUG_ON(!ac);
local_alloc_inode =
ocfs2_get_system_file_inode(osb,
LOCAL_ALLOC_SYSTEM_INODE,
osb->slot_num);
if (!local_alloc_inode) {
status = -ENOENT;
mlog_errno(status);
goto bail;
}
mutex_lock(&local_alloc_inode->i_mutex);
/*
* We must double check state and allocator bits because
* another process may have changed them while holding i_mutex.
*/
spin_lock(&osb->osb_lock);
if (!ocfs2_la_state_enabled(osb) ||
(bits_wanted > osb->local_alloc_bits)) {
spin_unlock(&osb->osb_lock);
status = -ENOSPC;
goto bail;
}
spin_unlock(&osb->osb_lock);
alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
#ifdef CONFIG_OCFS2_DEBUG_FS
if (le32_to_cpu(alloc->id1.bitmap1.i_used) !=
ocfs2_local_alloc_count_bits(alloc)) {
ocfs2_error(osb->sb, "local alloc inode %llu says it has "
"%u free bits, but a count shows %u",
(unsigned long long)le64_to_cpu(alloc->i_blkno),
le32_to_cpu(alloc->id1.bitmap1.i_used),
ocfs2_local_alloc_count_bits(alloc));
status = -EIO;
goto bail;
}
#endif
free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
le32_to_cpu(alloc->id1.bitmap1.i_used);
if (bits_wanted > free_bits) {
/* uhoh, window change time. */
status =
ocfs2_local_alloc_slide_window(osb, local_alloc_inode);
if (status < 0) {
if (status != -ENOSPC)
mlog_errno(status);
goto bail;
}
/*
* Under certain conditions, the window slide code
* might have reduced the number of bits available or
* disabled the the local alloc entirely. Re-check
* here and return -ENOSPC if necessary.
*/
status = -ENOSPC;
if (!ocfs2_la_state_enabled(osb))
goto bail;
free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
le32_to_cpu(alloc->id1.bitmap1.i_used);
if (bits_wanted > free_bits)
goto bail;
}
ac->ac_inode = local_alloc_inode;
/* We should never use localalloc from another slot */
ac->ac_alloc_slot = osb->slot_num;
ac->ac_which = OCFS2_AC_USE_LOCAL;
get_bh(osb->local_alloc_bh);
ac->ac_bh = osb->local_alloc_bh;
status = 0;
bail:
if (status < 0 && local_alloc_inode) {
mutex_unlock(&local_alloc_inode->i_mutex);
iput(local_alloc_inode);
}
trace_ocfs2_reserve_local_alloc_bits(
(unsigned long long)ac->ac_max_block,
bits_wanted, osb->slot_num, status);
if (status)
mlog_errno(status);
return status;
}
int ocfs2_claim_local_alloc_bits(struct ocfs2_super *osb,
handle_t *handle,
struct ocfs2_alloc_context *ac,
u32 bits_wanted,
u32 *bit_off,
u32 *num_bits)
{
int status, start;
struct inode *local_alloc_inode;
void *bitmap;
struct ocfs2_dinode *alloc;
struct ocfs2_local_alloc *la;
BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL);
local_alloc_inode = ac->ac_inode;
alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
la = OCFS2_LOCAL_ALLOC(alloc);
start = ocfs2_local_alloc_find_clear_bits(osb, alloc, &bits_wanted,
ac->ac_resv);
if (start == -1) {
/* TODO: Shouldn't we just BUG here? */
status = -ENOSPC;
mlog_errno(status);
goto bail;
}
bitmap = la->la_bitmap;
*bit_off = le32_to_cpu(la->la_bm_off) + start;
*num_bits = bits_wanted;
status = ocfs2_journal_access_di(handle,
INODE_CACHE(local_alloc_inode),
osb->local_alloc_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
ocfs2_resmap_claimed_bits(&osb->osb_la_resmap, ac->ac_resv, start,
bits_wanted);
while(bits_wanted--)
ocfs2_set_bit(start++, bitmap);
le32_add_cpu(&alloc->id1.bitmap1.i_used, *num_bits);
ocfs2_journal_dirty(handle, osb->local_alloc_bh);
bail:
if (status)
mlog_errno(status);
return status;
}
static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc)
{
int i;
u8 *buffer;
u32 count = 0;
struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
buffer = la->la_bitmap;
for (i = 0; i < le16_to_cpu(la->la_size); i++)
count += hweight8(buffer[i]);
trace_ocfs2_local_alloc_count_bits(count);
return count;
}
static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
struct ocfs2_dinode *alloc,
u32 *numbits,
struct ocfs2_alloc_reservation *resv)
{
int numfound, bitoff, left, startoff, lastzero;
int local_resv = 0;
struct ocfs2_alloc_reservation r;
void *bitmap = NULL;
struct ocfs2_reservation_map *resmap = &osb->osb_la_resmap;
if (!alloc->id1.bitmap1.i_total) {
bitoff = -1;
goto bail;
}
if (!resv) {
local_resv = 1;
ocfs2_resv_init_once(&r);
ocfs2_resv_set_type(&r, OCFS2_RESV_FLAG_TMP);
resv = &r;
}
numfound = *numbits;
if (ocfs2_resmap_resv_bits(resmap, resv, &bitoff, &numfound) == 0) {
if (numfound < *numbits)
*numbits = numfound;
goto bail;
}
/*
* Code error. While reservations are enabled, local
* allocation should _always_ go through them.
*/
BUG_ON(osb->osb_resv_level != 0);
/*
* Reservations are disabled. Handle this the old way.
*/
bitmap = OCFS2_LOCAL_ALLOC(alloc)->la_bitmap;
numfound = bitoff = startoff = 0;
lastzero = -1;
left = le32_to_cpu(alloc->id1.bitmap1.i_total);
while ((bitoff = ocfs2_find_next_zero_bit(bitmap, left, startoff)) != -1) {
if (bitoff == left) {
/* mlog(0, "bitoff (%d) == left", bitoff); */
break;
}
/* mlog(0, "Found a zero: bitoff = %d, startoff = %d, "
"numfound = %d\n", bitoff, startoff, numfound);*/
/* Ok, we found a zero bit... is it contig. or do we
* start over?*/
if (bitoff == startoff) {
/* we found a zero */
numfound++;
startoff++;
} else {
/* got a zero after some ones */
numfound = 1;
startoff = bitoff+1;
}
/* we got everything we needed */
if (numfound == *numbits) {
/* mlog(0, "Found it all!\n"); */
break;
}
}
trace_ocfs2_local_alloc_find_clear_bits_search_bitmap(bitoff, numfound);
if (numfound == *numbits)
bitoff = startoff - numfound;
else
bitoff = -1;
bail:
if (local_resv)
ocfs2_resv_discard(resmap, resv);
trace_ocfs2_local_alloc_find_clear_bits(*numbits,
le32_to_cpu(alloc->id1.bitmap1.i_total),
bitoff, numfound);
return bitoff;
}
static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc)
{
struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
int i;
alloc->id1.bitmap1.i_total = 0;
alloc->id1.bitmap1.i_used = 0;
la->la_bm_off = 0;
for(i = 0; i < le16_to_cpu(la->la_size); i++)
la->la_bitmap[i] = 0;
}
#if 0
/* turn this on and uncomment below to aid debugging window shifts. */
static void ocfs2_verify_zero_bits(unsigned long *bitmap,
unsigned int start,
unsigned int count)
{
unsigned int tmp = count;
while(tmp--) {
if (ocfs2_test_bit(start + tmp, bitmap)) {
printk("ocfs2_verify_zero_bits: start = %u, count = "
"%u\n", start, count);
printk("ocfs2_verify_zero_bits: bit %u is set!",
start + tmp);
BUG();
}
}
}
#endif
/*
* sync the local alloc to main bitmap.
*
* assumes you've already locked the main bitmap -- the bitmap inode
* passed is used for caching.
*/
static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
handle_t *handle,
struct ocfs2_dinode *alloc,
struct inode *main_bm_inode,
struct buffer_head *main_bm_bh)
{
int status = 0;
int bit_off, left, count, start;
u64 la_start_blk;
u64 blkno;
void *bitmap;
struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
trace_ocfs2_sync_local_to_main(
le32_to_cpu(alloc->id1.bitmap1.i_total),
le32_to_cpu(alloc->id1.bitmap1.i_used));
if (!alloc->id1.bitmap1.i_total) {
goto bail;
}
if (le32_to_cpu(alloc->id1.bitmap1.i_used) ==
le32_to_cpu(alloc->id1.bitmap1.i_total)) {
goto bail;
}
la_start_blk = ocfs2_clusters_to_blocks(osb->sb,
le32_to_cpu(la->la_bm_off));
bitmap = la->la_bitmap;
start = count = bit_off = 0;
left = le32_to_cpu(alloc->id1.bitmap1.i_total);
while ((bit_off = ocfs2_find_next_zero_bit(bitmap, left, start))
!= -1) {
if ((bit_off < left) && (bit_off == start)) {
count++;
start++;
continue;
}
if (count) {
blkno = la_start_blk +
ocfs2_clusters_to_blocks(osb->sb,
start - count);
trace_ocfs2_sync_local_to_main_free(
count, start - count,
(unsigned long long)la_start_blk,
(unsigned long long)blkno);
status = ocfs2_release_clusters(handle,
main_bm_inode,
main_bm_bh, blkno,
count);
if (status < 0) {
mlog_errno(status);
goto bail;
}
}
if (bit_off >= left)
break;
count = 1;
start = bit_off + 1;
}
bail:
if (status)
mlog_errno(status);
return status;
}
enum ocfs2_la_event {
OCFS2_LA_EVENT_SLIDE, /* Normal window slide. */
OCFS2_LA_EVENT_FRAGMENTED, /* The global bitmap has
* enough bits theoretically
* free, but a contiguous
* allocation could not be
* found. */
OCFS2_LA_EVENT_ENOSPC, /* Global bitmap doesn't have
* enough bits free to satisfy
* our request. */
};
#define OCFS2_LA_ENABLE_INTERVAL (30 * HZ)
/*
* Given an event, calculate the size of our next local alloc window.
*
* This should always be called under i_mutex of the local alloc inode
* so that local alloc disabling doesn't race with processes trying to
* use the allocator.
*
* Returns the state which the local alloc was left in. This value can
* be ignored by some paths.
*/
static int ocfs2_recalc_la_window(struct ocfs2_super *osb,
enum ocfs2_la_event event)
{
unsigned int bits;
int state;
spin_lock(&osb->osb_lock);
if (osb->local_alloc_state == OCFS2_LA_DISABLED) {
WARN_ON_ONCE(osb->local_alloc_state == OCFS2_LA_DISABLED);
goto out_unlock;
}
/*
* ENOSPC and fragmentation are treated similarly for now.
*/
if (event == OCFS2_LA_EVENT_ENOSPC ||
event == OCFS2_LA_EVENT_FRAGMENTED) {
/*
* We ran out of contiguous space in the primary
* bitmap. Drastically reduce the number of bits used
* by local alloc until we have to disable it.
*/
bits = osb->local_alloc_bits >> 1;
if (bits > ocfs2_megabytes_to_clusters(osb->sb, 1)) {
/*
* By setting state to THROTTLED, we'll keep
* the number of local alloc bits used down
* until an event occurs which would give us
* reason to assume the bitmap situation might
* have changed.
*/
osb->local_alloc_state = OCFS2_LA_THROTTLED;
osb->local_alloc_bits = bits;
} else {
osb->local_alloc_state = OCFS2_LA_DISABLED;
}
queue_delayed_work(ocfs2_wq, &osb->la_enable_wq,
OCFS2_LA_ENABLE_INTERVAL);
goto out_unlock;
}
/*
* Don't increase the size of the local alloc window until we
* know we might be able to fulfill the request. Otherwise, we
* risk bouncing around the global bitmap during periods of
* low space.
*/
if (osb->local_alloc_state != OCFS2_LA_THROTTLED)
osb->local_alloc_bits = osb->local_alloc_default_bits;
out_unlock:
state = osb->local_alloc_state;
spin_unlock(&osb->osb_lock);
return state;
}
static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
struct ocfs2_alloc_context **ac,
struct inode **bitmap_inode,
struct buffer_head **bitmap_bh)
{
int status;
*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
if (!(*ac)) {
status = -ENOMEM;
mlog_errno(status);
goto bail;
}
retry_enospc:
(*ac)->ac_bits_wanted = osb->local_alloc_default_bits;
status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
if (status == -ENOSPC) {
if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_ENOSPC) ==
OCFS2_LA_DISABLED)
goto bail;
ocfs2_free_ac_resource(*ac);
memset(*ac, 0, sizeof(struct ocfs2_alloc_context));
goto retry_enospc;
}
if (status < 0) {
mlog_errno(status);
goto bail;
}
*bitmap_inode = (*ac)->ac_inode;
igrab(*bitmap_inode);
*bitmap_bh = (*ac)->ac_bh;
get_bh(*bitmap_bh);
status = 0;
bail:
if ((status < 0) && *ac) {
ocfs2_free_alloc_context(*ac);
*ac = NULL;
}
if (status)
mlog_errno(status);
return status;
}
/*
* pass it the bitmap lock in lock_bh if you have it.
*/
static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
handle_t *handle,
struct ocfs2_alloc_context *ac)
{
int status = 0;
u32 cluster_off, cluster_count;
struct ocfs2_dinode *alloc = NULL;
struct ocfs2_local_alloc *la;
alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
la = OCFS2_LOCAL_ALLOC(alloc);
trace_ocfs2_local_alloc_new_window(
le32_to_cpu(alloc->id1.bitmap1.i_total),
osb->local_alloc_bits);
/* Instruct the allocation code to try the most recently used
* cluster group. We'll re-record the group used this pass
* below. */
ac->ac_last_group = osb->la_last_gd;
/* we used the generic suballoc reserve function, but we set
* everything up nicely, so there's no reason why we can't use
* the more specific cluster api to claim bits. */
status = ocfs2_claim_clusters(handle, ac, osb->local_alloc_bits,
&cluster_off, &cluster_count);
if (status == -ENOSPC) {
retry_enospc:
/*
* Note: We could also try syncing the journal here to
* allow use of any free bits which the current
* transaction can't give us access to. --Mark
*/
if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_FRAGMENTED) ==
OCFS2_LA_DISABLED)
goto bail;
ac->ac_bits_wanted = osb->local_alloc_default_bits;
status = ocfs2_claim_clusters(handle, ac,
osb->local_alloc_bits,
&cluster_off,
&cluster_count);
if (status == -ENOSPC)
goto retry_enospc;
/*
* We only shrunk the *minimum* number of in our
* request - it's entirely possible that the allocator
* might give us more than we asked for.
*/
if (status == 0) {
spin_lock(&osb->osb_lock);
osb->local_alloc_bits = cluster_count;
spin_unlock(&osb->osb_lock);
}
}
if (status < 0) {
if (status != -ENOSPC)
mlog_errno(status);
goto bail;
}
osb->la_last_gd = ac->ac_last_group;
la->la_bm_off = cpu_to_le32(cluster_off);
alloc->id1.bitmap1.i_total = cpu_to_le32(cluster_count);
/* just in case... In the future when we find space ourselves,
* we don't have to get all contiguous -- but we'll have to
* set all previously used bits in bitmap and update
* la_bits_set before setting the bits in the main bitmap. */
alloc->id1.bitmap1.i_used = 0;
memset(OCFS2_LOCAL_ALLOC(alloc)->la_bitmap, 0,
le16_to_cpu(la->la_size));
ocfs2_resmap_restart(&osb->osb_la_resmap, cluster_count,
OCFS2_LOCAL_ALLOC(alloc)->la_bitmap);
trace_ocfs2_local_alloc_new_window_result(
OCFS2_LOCAL_ALLOC(alloc)->la_bm_off,
le32_to_cpu(alloc->id1.bitmap1.i_total));
bail:
if (status)
mlog_errno(status);
return status;
}
/* Note that we do *NOT* lock the local alloc inode here as
* it's been locked already for us. */
static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
struct inode *local_alloc_inode)
{
int status = 0;
struct buffer_head *main_bm_bh = NULL;
struct inode *main_bm_inode = NULL;
handle_t *handle = NULL;
struct ocfs2_dinode *alloc;
struct ocfs2_dinode *alloc_copy = NULL;
struct ocfs2_alloc_context *ac = NULL;
ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_SLIDE);
/* This will lock the main bitmap for us. */
status = ocfs2_local_alloc_reserve_for_window(osb,
&ac,
&main_bm_inode,
&main_bm_bh);
if (status < 0) {
if (status != -ENOSPC)
mlog_errno(status);
goto bail;
}
handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
if (IS_ERR(handle)) {
status = PTR_ERR(handle);
handle = NULL;
mlog_errno(status);
goto bail;
}
alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
/* We want to clear the local alloc before doing anything
* else, so that if we error later during this operation,
* local alloc shutdown won't try to double free main bitmap
* bits. Make a copy so the sync function knows which bits to
* free. */
alloc_copy = kmalloc(osb->local_alloc_bh->b_size, GFP_NOFS);
if (!alloc_copy) {
status = -ENOMEM;
mlog_errno(status);
goto bail;
}
memcpy(alloc_copy, alloc, osb->local_alloc_bh->b_size);
status = ocfs2_journal_access_di(handle,
INODE_CACHE(local_alloc_inode),
osb->local_alloc_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
ocfs2_clear_local_alloc(alloc);
ocfs2_journal_dirty(handle, osb->local_alloc_bh);
status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
main_bm_inode, main_bm_bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
status = ocfs2_local_alloc_new_window(osb, handle, ac);
if (status < 0) {
if (status != -ENOSPC)
mlog_errno(status);
goto bail;
}
atomic_inc(&osb->alloc_stats.moves);
bail:
if (handle)
ocfs2_commit_trans(osb, handle);
brelse(main_bm_bh);
if (main_bm_inode)
iput(main_bm_inode);
if (alloc_copy)
kfree(alloc_copy);
if (ac)
ocfs2_free_alloc_context(ac);
if (status)
mlog_errno(status);
return status;
}