linux/fs/ocfs2/localalloc.c

1295 lines
32 KiB
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 <linux/debugfs.h>
#define MLOG_MASK_PREFIX ML_DISK_ALLOC
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "alloc.h"
#include "dlmglue.h"
#include "inode.h"
#include "journal.h"
#include "localalloc.h"
#include "suballoc.h"
#include "super.h"
#include "sysfile.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);
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);
#ifdef CONFIG_OCFS2_FS_STATS
static int ocfs2_la_debug_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
#define LA_DEBUG_BUF_SZ PAGE_CACHE_SIZE
#define LA_DEBUG_VER 1
static ssize_t ocfs2_la_debug_read(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos)
{
static DEFINE_MUTEX(la_debug_mutex);
struct ocfs2_super *osb = file->private_data;
int written, ret;
char *buf = osb->local_alloc_debug_buf;
mutex_lock(&la_debug_mutex);
memset(buf, 0, LA_DEBUG_BUF_SZ);
written = snprintf(buf, LA_DEBUG_BUF_SZ,
"0x%x\t0x%llx\t%u\t%u\t0x%x\n",
LA_DEBUG_VER,
(unsigned long long)osb->la_last_gd,
osb->local_alloc_default_bits,
osb->local_alloc_bits, osb->local_alloc_state);
ret = simple_read_from_buffer(userbuf, count, ppos, buf, written);
mutex_unlock(&la_debug_mutex);
return ret;
}
static const struct file_operations ocfs2_la_debug_fops = {
.open = ocfs2_la_debug_open,
.read = ocfs2_la_debug_read,
};
static void ocfs2_init_la_debug(struct ocfs2_super *osb)
{
osb->local_alloc_debug_buf = kmalloc(LA_DEBUG_BUF_SZ, GFP_NOFS);
if (!osb->local_alloc_debug_buf)
return;
osb->local_alloc_debug = debugfs_create_file("local_alloc_stats",
S_IFREG|S_IRUSR,
osb->osb_debug_root,
osb,
&ocfs2_la_debug_fops);
if (!osb->local_alloc_debug) {
kfree(osb->local_alloc_debug_buf);
osb->local_alloc_debug_buf = NULL;
}
}
static void ocfs2_shutdown_la_debug(struct ocfs2_super *osb)
{
if (osb->local_alloc_debug)
debugfs_remove(osb->local_alloc_debug);
if (osb->local_alloc_debug_buf)
kfree(osb->local_alloc_debug_buf);
osb->local_alloc_debug_buf = NULL;
osb->local_alloc_debug = NULL;
}
#else /* CONFIG_OCFS2_FS_STATS */
static void ocfs2_init_la_debug(struct ocfs2_super *osb)
{
return;
}
static void ocfs2_shutdown_la_debug(struct ocfs2_super *osb)
{
return;
}
#endif
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:
mlog(0, "state=%d, bits=%llu, la_bits=%d, ret=%d\n",
osb->local_alloc_state, (unsigned long long)bits, 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;
mlog_entry_void();
ocfs2_init_la_debug(osb);
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_DEFAULT_LOCAL_ALLOC_SIZE);
}
/* 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_blocks(inode, OCFS2_I(inode)->ip_blkno, 1,
&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);
if (status < 0)
ocfs2_shutdown_la_debug(osb);
mlog(0, "Local alloc window bits = %d\n", osb->local_alloc_bits);
mlog_exit(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;
mlog_entry_void();
cancel_delayed_work(&osb->la_enable_wq);
flush_workqueue(ocfs2_wq);
ocfs2_shutdown_la_debug(osb);
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;
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(handle, local_alloc_inode, bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (status < 0) {
mlog_errno(status);
goto out_commit;
}
ocfs2_clear_local_alloc(alloc);
status = ocfs2_journal_dirty(handle, bh);
if (status < 0) {
mlog_errno(status);
goto out_commit;
}
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);
mlog_exit_void();
}
/*
* 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;
mlog_entry("(slot_num = %d)\n", 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_blocks(inode, OCFS2_I(inode)->ip_blkno, 1,
&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);
status = ocfs2_write_block(osb, alloc_bh, 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);
}
mlog_exit(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;
mlog_entry_void();
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_inode_steal_slot(osb);
mlog_exit(status);
return status;
}
/* Check to see if the local alloc window is within ac->ac_max_block */
static int ocfs2_local_alloc_in_range(struct inode *inode,
struct ocfs2_alloc_context *ac,
u32 bits_wanted)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct ocfs2_dinode *alloc;
struct ocfs2_local_alloc *la;
int start;
u64 block_off;
if (!ac->ac_max_block)
return 1;
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);
if (start == -1) {
mlog_errno(-ENOSPC);
return 0;
}
/*
* Converting (bm_off + start + bits_wanted) to blocks gives us
* the blkno just past our actual allocation. This is perfect
* to compare with ac_max_block.
*/
block_off = ocfs2_clusters_to_blocks(inode->i_sb,
le32_to_cpu(la->la_bm_off) +
start + bits_wanted);
mlog(0, "Checking %llu against %llu\n",
(unsigned long long)block_off,
(unsigned long long)ac->ac_max_block);
if (block_off > ac->ac_max_block)
return 0;
return 1;
}
/*
* 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;
mlog_entry_void();
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;
}
if (ac->ac_max_block)
mlog(0, "Calling in_range for max block %llu\n",
(unsigned long long)ac->ac_max_block);
if (!ocfs2_local_alloc_in_range(local_alloc_inode, ac,
bits_wanted)) {
/*
* The window is outside ac->ac_max_block.
* This errno tells the caller to keep localalloc enabled
* but to get the allocation from the main bitmap.
*/
status = -EFBIG;
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);
}
mlog(0, "bits=%d, slot=%d, ret=%d\n", bits_wanted, osb->slot_num,
status);
mlog_exit(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;
mlog_entry_void();
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);
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;
/* local alloc is always contiguous by nature -- we never
* delete bits from it! */
*num_bits = bits_wanted;
status = ocfs2_journal_access(handle, local_alloc_inode,
osb->local_alloc_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
while(bits_wanted--)
ocfs2_set_bit(start++, bitmap);
le32_add_cpu(&alloc->id1.bitmap1.i_used, *num_bits);
status = ocfs2_journal_dirty(handle, osb->local_alloc_bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
status = 0;
bail:
mlog_exit(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);
mlog_entry_void();
buffer = la->la_bitmap;
for (i = 0; i < le16_to_cpu(la->la_size); i++)
count += hweight8(buffer[i]);
mlog_exit(count);
return count;
}
static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
struct ocfs2_dinode *alloc,
u32 numbits)
{
int numfound, bitoff, left, startoff, lastzero;
void *bitmap = NULL;
mlog_entry("(numbits wanted = %u)\n", numbits);
if (!alloc->id1.bitmap1.i_total) {
mlog(0, "No bits in my window!\n");
bitoff = -1;
goto bail;
}
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;
}
}
mlog(0, "Exiting loop, bitoff = %d, numfound = %d\n", bitoff,
numfound);
if (numfound == numbits)
bitoff = startoff - numfound;
else
bitoff = -1;
bail:
mlog_exit(bitoff);
return bitoff;
}
static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc)
{
struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
int i;
mlog_entry_void();
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;
mlog_exit_void();
}
#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);
mlog_entry("total = %u, used = %u\n",
le32_to_cpu(alloc->id1.bitmap1.i_total),
le32_to_cpu(alloc->id1.bitmap1.i_used));
if (!alloc->id1.bitmap1.i_total) {
mlog(0, "nothing to sync!\n");
goto bail;
}
if (le32_to_cpu(alloc->id1.bitmap1.i_used) ==
le32_to_cpu(alloc->id1.bitmap1.i_total)) {
mlog(0, "all bits were taken!\n");
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);
mlog(0, "freeing %u bits starting at local alloc bit "
"%u (la_start_blk = %llu, blkno = %llu)\n",
count, start - count,
(unsigned long long)la_start_blk,
(unsigned long long)blkno);
status = ocfs2_free_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:
mlog_exit(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_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;
}
mlog_exit(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;
mlog_entry_void();
alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
la = OCFS2_LOCAL_ALLOC(alloc);
if (alloc->id1.bitmap1.i_total)
mlog(0, "asking me to alloc a new window over a non-empty "
"one\n");
mlog(0, "Allocating %u clusters for a new window.\n",
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(osb, 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;
status = ocfs2_claim_clusters(osb, 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));
mlog(0, "New window allocated:\n");
mlog(0, "window la_bm_off = %u\n",
OCFS2_LOCAL_ALLOC(alloc)->la_bm_off);
mlog(0, "window bits = %u\n", le32_to_cpu(alloc->id1.bitmap1.i_total));
bail:
mlog_exit(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;
mlog_entry_void();
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(handle, local_alloc_inode,
osb->local_alloc_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
ocfs2_clear_local_alloc(alloc);
status = ocfs2_journal_dirty(handle, osb->local_alloc_bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
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);
status = 0;
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);
mlog_exit(status);
return status;
}