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rgrp.c
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rgrp.c
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/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License version 2.
*/
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/fs.h>
#include <linux/gfs2_ondisk.h>
#include <linux/lm_interface.h>
#include "gfs2.h"
#include "incore.h"
#include "glock.h"
#include "glops.h"
#include "lops.h"
#include "meta_io.h"
#include "quota.h"
#include "rgrp.h"
#include "super.h"
#include "trans.h"
#include "ops_file.h"
#include "util.h"
#define BFITNOENT ((u32)~0)
/*
* These routines are used by the resource group routines (rgrp.c)
* to keep track of block allocation. Each block is represented by two
* bits. So, each byte represents GFS2_NBBY (i.e. 4) blocks.
*
* 0 = Free
* 1 = Used (not metadata)
* 2 = Unlinked (still in use) inode
* 3 = Used (metadata)
*/
static const char valid_change[16] = {
/* current */
/* n */ 0, 1, 1, 1,
/* e */ 1, 0, 0, 0,
/* w */ 0, 0, 0, 1,
1, 0, 0, 0
};
/**
* gfs2_setbit - Set a bit in the bitmaps
* @buffer: the buffer that holds the bitmaps
* @buflen: the length (in bytes) of the buffer
* @block: the block to set
* @new_state: the new state of the block
*
*/
static void gfs2_setbit(struct gfs2_rgrpd *rgd, unsigned char *buffer,
unsigned int buflen, u32 block,
unsigned char new_state)
{
unsigned char *byte, *end, cur_state;
unsigned int bit;
byte = buffer + (block / GFS2_NBBY);
bit = (block % GFS2_NBBY) * GFS2_BIT_SIZE;
end = buffer + buflen;
gfs2_assert(rgd->rd_sbd, byte < end);
cur_state = (*byte >> bit) & GFS2_BIT_MASK;
if (valid_change[new_state * 4 + cur_state]) {
*byte ^= cur_state << bit;
*byte |= new_state << bit;
} else
gfs2_consist_rgrpd(rgd);
}
/**
* gfs2_testbit - test a bit in the bitmaps
* @buffer: the buffer that holds the bitmaps
* @buflen: the length (in bytes) of the buffer
* @block: the block to read
*
*/
static unsigned char gfs2_testbit(struct gfs2_rgrpd *rgd, unsigned char *buffer,
unsigned int buflen, u32 block)
{
unsigned char *byte, *end, cur_state;
unsigned int bit;
byte = buffer + (block / GFS2_NBBY);
bit = (block % GFS2_NBBY) * GFS2_BIT_SIZE;
end = buffer + buflen;
gfs2_assert(rgd->rd_sbd, byte < end);
cur_state = (*byte >> bit) & GFS2_BIT_MASK;
return cur_state;
}
/**
* gfs2_bitfit - Search an rgrp's bitmap buffer to find a bit-pair representing
* a block in a given allocation state.
* @buffer: the buffer that holds the bitmaps
* @buflen: the length (in bytes) of the buffer
* @goal: start search at this block's bit-pair (within @buffer)
* @old_state: GFS2_BLKST_XXX the state of the block we're looking for;
* bit 0 = alloc(1)/free(0), bit 1 = meta(1)/data(0)
*
* Scope of @goal and returned block number is only within this bitmap buffer,
* not entire rgrp or filesystem. @buffer will be offset from the actual
* beginning of a bitmap block buffer, skipping any header structures.
*
* Return: the block number (bitmap buffer scope) that was found
*/
static u32 gfs2_bitfit(struct gfs2_rgrpd *rgd, unsigned char *buffer,
unsigned int buflen, u32 goal,
unsigned char old_state)
{
unsigned char *byte, *end, alloc;
u32 blk = goal;
unsigned int bit;
byte = buffer + (goal / GFS2_NBBY);
bit = (goal % GFS2_NBBY) * GFS2_BIT_SIZE;
end = buffer + buflen;
alloc = (old_state & 1) ? 0 : 0x55;
while (byte < end) {
if ((*byte & 0x55) == alloc) {
blk += (8 - bit) >> 1;
bit = 0;
byte++;
continue;
}
if (((*byte >> bit) & GFS2_BIT_MASK) == old_state)
return blk;
bit += GFS2_BIT_SIZE;
if (bit >= 8) {
bit = 0;
byte++;
}
blk++;
}
return BFITNOENT;
}
/**
* gfs2_bitcount - count the number of bits in a certain state
* @buffer: the buffer that holds the bitmaps
* @buflen: the length (in bytes) of the buffer
* @state: the state of the block we're looking for
*
* Returns: The number of bits
*/
static u32 gfs2_bitcount(struct gfs2_rgrpd *rgd, unsigned char *buffer,
unsigned int buflen, unsigned char state)
{
unsigned char *byte = buffer;
unsigned char *end = buffer + buflen;
unsigned char state1 = state << 2;
unsigned char state2 = state << 4;
unsigned char state3 = state << 6;
u32 count = 0;
for (; byte < end; byte++) {
if (((*byte) & 0x03) == state)
count++;
if (((*byte) & 0x0C) == state1)
count++;
if (((*byte) & 0x30) == state2)
count++;
if (((*byte) & 0xC0) == state3)
count++;
}
return count;
}
/**
* gfs2_rgrp_verify - Verify that a resource group is consistent
* @sdp: the filesystem
* @rgd: the rgrp
*
*/
void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd)
{
struct gfs2_sbd *sdp = rgd->rd_sbd;
struct gfs2_bitmap *bi = NULL;
u32 length = rgd->rd_ri.ri_length;
u32 count[4], tmp;
int buf, x;
memset(count, 0, 4 * sizeof(u32));
/* Count # blocks in each of 4 possible allocation states */
for (buf = 0; buf < length; buf++) {
bi = rgd->rd_bits + buf;
for (x = 0; x < 4; x++)
count[x] += gfs2_bitcount(rgd,
bi->bi_bh->b_data +
bi->bi_offset,
bi->bi_len, x);
}
if (count[0] != rgd->rd_rg.rg_free) {
if (gfs2_consist_rgrpd(rgd))
fs_err(sdp, "free data mismatch: %u != %u\n",
count[0], rgd->rd_rg.rg_free);
return;
}
tmp = rgd->rd_ri.ri_data -
rgd->rd_rg.rg_free -
rgd->rd_rg.rg_dinodes;
if (count[1] + count[2] != tmp) {
if (gfs2_consist_rgrpd(rgd))
fs_err(sdp, "used data mismatch: %u != %u\n",
count[1], tmp);
return;
}
if (count[3] != rgd->rd_rg.rg_dinodes) {
if (gfs2_consist_rgrpd(rgd))
fs_err(sdp, "used metadata mismatch: %u != %u\n",
count[3], rgd->rd_rg.rg_dinodes);
return;
}
if (count[2] > count[3]) {
if (gfs2_consist_rgrpd(rgd))
fs_err(sdp, "unlinked inodes > inodes: %u\n",
count[2]);
return;
}
}
static inline int rgrp_contains_block(struct gfs2_rindex_host *ri, u64 block)
{
u64 first = ri->ri_data0;
u64 last = first + ri->ri_data;
return first <= block && block < last;
}
/**
* gfs2_blk2rgrpd - Find resource group for a given data/meta block number
* @sdp: The GFS2 superblock
* @n: The data block number
*
* Returns: The resource group, or NULL if not found
*/
struct gfs2_rgrpd *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, u64 blk)
{
struct gfs2_rgrpd *rgd;
spin_lock(&sdp->sd_rindex_spin);
list_for_each_entry(rgd, &sdp->sd_rindex_mru_list, rd_list_mru) {
if (rgrp_contains_block(&rgd->rd_ri, blk)) {
list_move(&rgd->rd_list_mru, &sdp->sd_rindex_mru_list);
spin_unlock(&sdp->sd_rindex_spin);
return rgd;
}
}
spin_unlock(&sdp->sd_rindex_spin);
return NULL;
}
/**
* gfs2_rgrpd_get_first - get the first Resource Group in the filesystem
* @sdp: The GFS2 superblock
*
* Returns: The first rgrp in the filesystem
*/
struct gfs2_rgrpd *gfs2_rgrpd_get_first(struct gfs2_sbd *sdp)
{
gfs2_assert(sdp, !list_empty(&sdp->sd_rindex_list));
return list_entry(sdp->sd_rindex_list.next, struct gfs2_rgrpd, rd_list);
}
/**
* gfs2_rgrpd_get_next - get the next RG
* @rgd: A RG
*
* Returns: The next rgrp
*/
struct gfs2_rgrpd *gfs2_rgrpd_get_next(struct gfs2_rgrpd *rgd)
{
if (rgd->rd_list.next == &rgd->rd_sbd->sd_rindex_list)
return NULL;
return list_entry(rgd->rd_list.next, struct gfs2_rgrpd, rd_list);
}
static void clear_rgrpdi(struct gfs2_sbd *sdp)
{
struct list_head *head;
struct gfs2_rgrpd *rgd;
struct gfs2_glock *gl;
spin_lock(&sdp->sd_rindex_spin);
sdp->sd_rindex_forward = NULL;
head = &sdp->sd_rindex_recent_list;
while (!list_empty(head)) {
rgd = list_entry(head->next, struct gfs2_rgrpd, rd_recent);
list_del(&rgd->rd_recent);
}
spin_unlock(&sdp->sd_rindex_spin);
head = &sdp->sd_rindex_list;
while (!list_empty(head)) {
rgd = list_entry(head->next, struct gfs2_rgrpd, rd_list);
gl = rgd->rd_gl;
list_del(&rgd->rd_list);
list_del(&rgd->rd_list_mru);
if (gl) {
gl->gl_object = NULL;
gfs2_glock_put(gl);
}
kfree(rgd->rd_bits);
kfree(rgd);
}
}
void gfs2_clear_rgrpd(struct gfs2_sbd *sdp)
{
mutex_lock(&sdp->sd_rindex_mutex);
clear_rgrpdi(sdp);
mutex_unlock(&sdp->sd_rindex_mutex);
}
/**
* gfs2_compute_bitstructs - Compute the bitmap sizes
* @rgd: The resource group descriptor
*
* Calculates bitmap descriptors, one for each block that contains bitmap data
*
* Returns: errno
*/
static int compute_bitstructs(struct gfs2_rgrpd *rgd)
{
struct gfs2_sbd *sdp = rgd->rd_sbd;
struct gfs2_bitmap *bi;
u32 length = rgd->rd_ri.ri_length; /* # blocks in hdr & bitmap */
u32 bytes_left, bytes;
int x;
if (!length)
return -EINVAL;
rgd->rd_bits = kcalloc(length, sizeof(struct gfs2_bitmap), GFP_NOFS);
if (!rgd->rd_bits)
return -ENOMEM;
bytes_left = rgd->rd_ri.ri_bitbytes;
for (x = 0; x < length; x++) {
bi = rgd->rd_bits + x;
/* small rgrp; bitmap stored completely in header block */
if (length == 1) {
bytes = bytes_left;
bi->bi_offset = sizeof(struct gfs2_rgrp);
bi->bi_start = 0;
bi->bi_len = bytes;
/* header block */
} else if (x == 0) {
bytes = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_rgrp);
bi->bi_offset = sizeof(struct gfs2_rgrp);
bi->bi_start = 0;
bi->bi_len = bytes;
/* last block */
} else if (x + 1 == length) {
bytes = bytes_left;
bi->bi_offset = sizeof(struct gfs2_meta_header);
bi->bi_start = rgd->rd_ri.ri_bitbytes - bytes_left;
bi->bi_len = bytes;
/* other blocks */
} else {
bytes = sdp->sd_sb.sb_bsize -
sizeof(struct gfs2_meta_header);
bi->bi_offset = sizeof(struct gfs2_meta_header);
bi->bi_start = rgd->rd_ri.ri_bitbytes - bytes_left;
bi->bi_len = bytes;
}
bytes_left -= bytes;
}
if (bytes_left) {
gfs2_consist_rgrpd(rgd);
return -EIO;
}
bi = rgd->rd_bits + (length - 1);
if ((bi->bi_start + bi->bi_len) * GFS2_NBBY != rgd->rd_ri.ri_data) {
if (gfs2_consist_rgrpd(rgd)) {
gfs2_rindex_print(&rgd->rd_ri);
fs_err(sdp, "start=%u len=%u offset=%u\n",
bi->bi_start, bi->bi_len, bi->bi_offset);
}
return -EIO;
}
return 0;
}
/**
* gfs2_ri_update - Pull in a new resource index from the disk
* @gl: The glock covering the rindex inode
*
* Returns: 0 on successful update, error code otherwise
*/
static int gfs2_ri_update(struct gfs2_inode *ip)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct inode *inode = &ip->i_inode;
struct gfs2_rgrpd *rgd;
char buf[sizeof(struct gfs2_rindex)];
struct file_ra_state ra_state;
u64 junk = ip->i_di.di_size;
int error;
if (do_div(junk, sizeof(struct gfs2_rindex))) {
gfs2_consist_inode(ip);
return -EIO;
}
clear_rgrpdi(sdp);
file_ra_state_init(&ra_state, inode->i_mapping);
for (sdp->sd_rgrps = 0;; sdp->sd_rgrps++) {
loff_t pos = sdp->sd_rgrps * sizeof(struct gfs2_rindex);
error = gfs2_internal_read(ip, &ra_state, buf, &pos,
sizeof(struct gfs2_rindex));
if (!error)
break;
if (error != sizeof(struct gfs2_rindex)) {
if (error > 0)
error = -EIO;
goto fail;
}
rgd = kzalloc(sizeof(struct gfs2_rgrpd), GFP_NOFS);
error = -ENOMEM;
if (!rgd)
goto fail;
mutex_init(&rgd->rd_mutex);
lops_init_le(&rgd->rd_le, &gfs2_rg_lops);
rgd->rd_sbd = sdp;
list_add_tail(&rgd->rd_list, &sdp->sd_rindex_list);
list_add_tail(&rgd->rd_list_mru, &sdp->sd_rindex_mru_list);
gfs2_rindex_in(&rgd->rd_ri, buf);
error = compute_bitstructs(rgd);
if (error)
goto fail;
error = gfs2_glock_get(sdp, rgd->rd_ri.ri_addr,
&gfs2_rgrp_glops, CREATE, &rgd->rd_gl);
if (error)
goto fail;
rgd->rd_gl->gl_object = rgd;
rgd->rd_rg_vn = rgd->rd_gl->gl_vn - 1;
}
sdp->sd_rindex_vn = ip->i_gl->gl_vn;
return 0;
fail:
clear_rgrpdi(sdp);
return error;
}
/**
* gfs2_rindex_hold - Grab a lock on the rindex
* @sdp: The GFS2 superblock
* @ri_gh: the glock holder
*
* We grab a lock on the rindex inode to make sure that it doesn't
* change whilst we are performing an operation. We keep this lock
* for quite long periods of time compared to other locks. This
* doesn't matter, since it is shared and it is very, very rarely
* accessed in the exclusive mode (i.e. only when expanding the filesystem).
*
* This makes sure that we're using the latest copy of the resource index
* special file, which might have been updated if someone expanded the
* filesystem (via gfs2_grow utility), which adds new resource groups.
*
* Returns: 0 on success, error code otherwise
*/
int gfs2_rindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ri_gh)
{
struct gfs2_inode *ip = GFS2_I(sdp->sd_rindex);
struct gfs2_glock *gl = ip->i_gl;
int error;
error = gfs2_glock_nq_init(gl, LM_ST_SHARED, 0, ri_gh);
if (error)
return error;
/* Read new copy from disk if we don't have the latest */
if (sdp->sd_rindex_vn != gl->gl_vn) {
mutex_lock(&sdp->sd_rindex_mutex);
if (sdp->sd_rindex_vn != gl->gl_vn) {
error = gfs2_ri_update(ip);
if (error)
gfs2_glock_dq_uninit(ri_gh);
}
mutex_unlock(&sdp->sd_rindex_mutex);
}
return error;
}
/**
* gfs2_rgrp_bh_get - Read in a RG's header and bitmaps
* @rgd: the struct gfs2_rgrpd describing the RG to read in
*
* Read in all of a Resource Group's header and bitmap blocks.
* Caller must eventually call gfs2_rgrp_relse() to free the bitmaps.
*
* Returns: errno
*/
int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd)
{
struct gfs2_sbd *sdp = rgd->rd_sbd;
struct gfs2_glock *gl = rgd->rd_gl;
unsigned int length = rgd->rd_ri.ri_length;
struct gfs2_bitmap *bi;
unsigned int x, y;
int error;
mutex_lock(&rgd->rd_mutex);
spin_lock(&sdp->sd_rindex_spin);
if (rgd->rd_bh_count) {
rgd->rd_bh_count++;
spin_unlock(&sdp->sd_rindex_spin);
mutex_unlock(&rgd->rd_mutex);
return 0;
}
spin_unlock(&sdp->sd_rindex_spin);
for (x = 0; x < length; x++) {
bi = rgd->rd_bits + x;
error = gfs2_meta_read(gl, rgd->rd_ri.ri_addr + x, 0, &bi->bi_bh);
if (error)
goto fail;
}
for (y = length; y--;) {
bi = rgd->rd_bits + y;
error = gfs2_meta_wait(sdp, bi->bi_bh);
if (error)
goto fail;
if (gfs2_metatype_check(sdp, bi->bi_bh, y ? GFS2_METATYPE_RB :
GFS2_METATYPE_RG)) {
error = -EIO;
goto fail;
}
}
if (rgd->rd_rg_vn != gl->gl_vn) {
gfs2_rgrp_in(&rgd->rd_rg, (rgd->rd_bits[0].bi_bh)->b_data);
rgd->rd_rg_vn = gl->gl_vn;
}
spin_lock(&sdp->sd_rindex_spin);
rgd->rd_free_clone = rgd->rd_rg.rg_free;
rgd->rd_bh_count++;
spin_unlock(&sdp->sd_rindex_spin);
mutex_unlock(&rgd->rd_mutex);
return 0;
fail:
while (x--) {
bi = rgd->rd_bits + x;
brelse(bi->bi_bh);
bi->bi_bh = NULL;
gfs2_assert_warn(sdp, !bi->bi_clone);
}
mutex_unlock(&rgd->rd_mutex);
return error;
}
void gfs2_rgrp_bh_hold(struct gfs2_rgrpd *rgd)
{
struct gfs2_sbd *sdp = rgd->rd_sbd;
spin_lock(&sdp->sd_rindex_spin);
gfs2_assert_warn(rgd->rd_sbd, rgd->rd_bh_count);
rgd->rd_bh_count++;
spin_unlock(&sdp->sd_rindex_spin);
}
/**
* gfs2_rgrp_bh_put - Release RG bitmaps read in with gfs2_rgrp_bh_get()
* @rgd: the struct gfs2_rgrpd describing the RG to read in
*
*/
void gfs2_rgrp_bh_put(struct gfs2_rgrpd *rgd)
{
struct gfs2_sbd *sdp = rgd->rd_sbd;
int x, length = rgd->rd_ri.ri_length;
spin_lock(&sdp->sd_rindex_spin);
gfs2_assert_warn(rgd->rd_sbd, rgd->rd_bh_count);
if (--rgd->rd_bh_count) {
spin_unlock(&sdp->sd_rindex_spin);
return;
}
for (x = 0; x < length; x++) {
struct gfs2_bitmap *bi = rgd->rd_bits + x;
kfree(bi->bi_clone);
bi->bi_clone = NULL;
brelse(bi->bi_bh);
bi->bi_bh = NULL;
}
spin_unlock(&sdp->sd_rindex_spin);
}
void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd)
{
struct gfs2_sbd *sdp = rgd->rd_sbd;
unsigned int length = rgd->rd_ri.ri_length;
unsigned int x;
for (x = 0; x < length; x++) {
struct gfs2_bitmap *bi = rgd->rd_bits + x;
if (!bi->bi_clone)
continue;
memcpy(bi->bi_clone + bi->bi_offset,
bi->bi_bh->b_data + bi->bi_offset, bi->bi_len);
}
spin_lock(&sdp->sd_rindex_spin);
rgd->rd_free_clone = rgd->rd_rg.rg_free;
spin_unlock(&sdp->sd_rindex_spin);
}
/**
* gfs2_alloc_get - get the struct gfs2_alloc structure for an inode
* @ip: the incore GFS2 inode structure
*
* Returns: the struct gfs2_alloc
*/
struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip)
{
struct gfs2_alloc *al = &ip->i_alloc;
/* FIXME: Should assert that the correct locks are held here... */
memset(al, 0, sizeof(*al));
return al;
}
/**
* try_rgrp_fit - See if a given reservation will fit in a given RG
* @rgd: the RG data
* @al: the struct gfs2_alloc structure describing the reservation
*
* If there's room for the requested blocks to be allocated from the RG:
* Sets the $al_reserved_data field in @al.
* Sets the $al_reserved_meta field in @al.
* Sets the $al_rgd field in @al.
*
* Returns: 1 on success (it fits), 0 on failure (it doesn't fit)
*/
static int try_rgrp_fit(struct gfs2_rgrpd *rgd, struct gfs2_alloc *al)
{
struct gfs2_sbd *sdp = rgd->rd_sbd;
int ret = 0;
spin_lock(&sdp->sd_rindex_spin);
if (rgd->rd_free_clone >= al->al_requested) {
al->al_rgd = rgd;
ret = 1;
}
spin_unlock(&sdp->sd_rindex_spin);
return ret;
}
/**
* recent_rgrp_first - get first RG from "recent" list
* @sdp: The GFS2 superblock
* @rglast: address of the rgrp used last
*
* Returns: The first rgrp in the recent list
*/
static struct gfs2_rgrpd *recent_rgrp_first(struct gfs2_sbd *sdp,
u64 rglast)
{
struct gfs2_rgrpd *rgd = NULL;
spin_lock(&sdp->sd_rindex_spin);
if (list_empty(&sdp->sd_rindex_recent_list))
goto out;
if (!rglast)
goto first;
list_for_each_entry(rgd, &sdp->sd_rindex_recent_list, rd_recent) {
if (rgd->rd_ri.ri_addr == rglast)
goto out;
}
first:
rgd = list_entry(sdp->sd_rindex_recent_list.next, struct gfs2_rgrpd,
rd_recent);
out:
spin_unlock(&sdp->sd_rindex_spin);
return rgd;
}
/**
* recent_rgrp_next - get next RG from "recent" list
* @cur_rgd: current rgrp
* @remove:
*
* Returns: The next rgrp in the recent list
*/
static struct gfs2_rgrpd *recent_rgrp_next(struct gfs2_rgrpd *cur_rgd,
int remove)
{
struct gfs2_sbd *sdp = cur_rgd->rd_sbd;
struct list_head *head;
struct gfs2_rgrpd *rgd;
spin_lock(&sdp->sd_rindex_spin);
head = &sdp->sd_rindex_recent_list;
list_for_each_entry(rgd, head, rd_recent) {
if (rgd == cur_rgd) {
if (cur_rgd->rd_recent.next != head)
rgd = list_entry(cur_rgd->rd_recent.next,
struct gfs2_rgrpd, rd_recent);
else
rgd = NULL;
if (remove)
list_del(&cur_rgd->rd_recent);
goto out;
}
}
rgd = NULL;
if (!list_empty(head))
rgd = list_entry(head->next, struct gfs2_rgrpd, rd_recent);
out:
spin_unlock(&sdp->sd_rindex_spin);
return rgd;
}
/**
* recent_rgrp_add - add an RG to tail of "recent" list
* @new_rgd: The rgrp to add
*
*/
static void recent_rgrp_add(struct gfs2_rgrpd *new_rgd)
{
struct gfs2_sbd *sdp = new_rgd->rd_sbd;
struct gfs2_rgrpd *rgd;
unsigned int count = 0;
unsigned int max = sdp->sd_rgrps / gfs2_jindex_size(sdp);
spin_lock(&sdp->sd_rindex_spin);
list_for_each_entry(rgd, &sdp->sd_rindex_recent_list, rd_recent) {
if (rgd == new_rgd)
goto out;
if (++count >= max)
goto out;
}
list_add_tail(&new_rgd->rd_recent, &sdp->sd_rindex_recent_list);
out:
spin_unlock(&sdp->sd_rindex_spin);
}
/**
* forward_rgrp_get - get an rgrp to try next from full list
* @sdp: The GFS2 superblock
*
* Returns: The rgrp to try next
*/
static struct gfs2_rgrpd *forward_rgrp_get(struct gfs2_sbd *sdp)
{
struct gfs2_rgrpd *rgd;
unsigned int journals = gfs2_jindex_size(sdp);
unsigned int rg = 0, x;
spin_lock(&sdp->sd_rindex_spin);
rgd = sdp->sd_rindex_forward;
if (!rgd) {
if (sdp->sd_rgrps >= journals)
rg = sdp->sd_rgrps * sdp->sd_jdesc->jd_jid / journals;
for (x = 0, rgd = gfs2_rgrpd_get_first(sdp); x < rg;
x++, rgd = gfs2_rgrpd_get_next(rgd))
/* Do Nothing */;
sdp->sd_rindex_forward = rgd;
}
spin_unlock(&sdp->sd_rindex_spin);
return rgd;
}
/**
* forward_rgrp_set - set the forward rgrp pointer
* @sdp: the filesystem
* @rgd: The new forward rgrp
*
*/
static void forward_rgrp_set(struct gfs2_sbd *sdp, struct gfs2_rgrpd *rgd)
{
spin_lock(&sdp->sd_rindex_spin);
sdp->sd_rindex_forward = rgd;
spin_unlock(&sdp->sd_rindex_spin);
}
/**
* get_local_rgrp - Choose and lock a rgrp for allocation
* @ip: the inode to reserve space for
* @rgp: the chosen and locked rgrp
*
* Try to acquire rgrp in way which avoids contending with others.
*
* Returns: errno
*/
static int get_local_rgrp(struct gfs2_inode *ip)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct gfs2_rgrpd *rgd, *begin = NULL;
struct gfs2_alloc *al = &ip->i_alloc;
int flags = LM_FLAG_TRY;
int skipped = 0;
int loops = 0;
int error;
/* Try recently successful rgrps */
rgd = recent_rgrp_first(sdp, ip->i_last_rg_alloc);
while (rgd) {
error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE,
LM_FLAG_TRY, &al->al_rgd_gh);
switch (error) {
case 0:
if (try_rgrp_fit(rgd, al))
goto out;
gfs2_glock_dq_uninit(&al->al_rgd_gh);
rgd = recent_rgrp_next(rgd, 1);
break;
case GLR_TRYFAILED:
rgd = recent_rgrp_next(rgd, 0);
break;
default:
return error;
}
}
/* Go through full list of rgrps */
begin = rgd = forward_rgrp_get(sdp);
for (;;) {
error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, flags,
&al->al_rgd_gh);
switch (error) {
case 0:
if (try_rgrp_fit(rgd, al))
goto out;
gfs2_glock_dq_uninit(&al->al_rgd_gh);
break;
case GLR_TRYFAILED:
skipped++;
break;
default:
return error;
}
rgd = gfs2_rgrpd_get_next(rgd);
if (!rgd)
rgd = gfs2_rgrpd_get_first(sdp);
if (rgd == begin) {
if (++loops >= 2 || !skipped)
return -ENOSPC;
flags = 0;
}
}
out:
ip->i_last_rg_alloc = rgd->rd_ri.ri_addr;
if (begin) {
recent_rgrp_add(rgd);
rgd = gfs2_rgrpd_get_next(rgd);
if (!rgd)
rgd = gfs2_rgrpd_get_first(sdp);
forward_rgrp_set(sdp, rgd);
}
return 0;
}
/**
* gfs2_inplace_reserve_i - Reserve space in the filesystem
* @ip: the inode to reserve space for
*
* Returns: errno
*/
int gfs2_inplace_reserve_i(struct gfs2_inode *ip, char *file, unsigned int line)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct gfs2_alloc *al = &ip->i_alloc;
int error;
if (gfs2_assert_warn(sdp, al->al_requested))
return -EINVAL;
error = gfs2_rindex_hold(sdp, &al->al_ri_gh);
if (error)
return error;
error = get_local_rgrp(ip);
if (error) {
gfs2_glock_dq_uninit(&al->al_ri_gh);
return error;
}
al->al_file = file;
al->al_line = line;
return 0;
}
/**
* gfs2_inplace_release - release an inplace reservation
* @ip: the inode the reservation was taken out on
*
* Release a reservation made by gfs2_inplace_reserve().