Revision e1cbbfa5f5aaf40a1fe70856fac4dfcc33e0e651 authored by Josef Bacik on 17 March 2015, 14:52:28 UTC, committed by Josef Bacik on 17 March 2015, 20:36:35 UTC
We are keeping track of how many extents we need to reserve properly based on the amount we want to write, but we were still incrementing outstanding_extents if we wrote less than what we requested. This isn't quite right since we will be limited to our max extent size. So instead lets do something horrible! Keep track of how many outstanding_extents we reserved, and decrement each time we allocate an extent. If we use our entire reserve make sure to jack up outstanding_extents on the inode so the accounting works out properly. Thanks, Reported-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <jbacik@fb.com>
1 parent 6a3891c
balloc.c
/*
* linux/fs/sysv/balloc.c
*
* minix/bitmap.c
* Copyright (C) 1991, 1992 Linus Torvalds
*
* ext/freelists.c
* Copyright (C) 1992 Remy Card (card@masi.ibp.fr)
*
* xenix/alloc.c
* Copyright (C) 1992 Doug Evans
*
* coh/alloc.c
* Copyright (C) 1993 Pascal Haible, Bruno Haible
*
* sysv/balloc.c
* Copyright (C) 1993 Bruno Haible
*
* This file contains code for allocating/freeing blocks.
*/
#include <linux/buffer_head.h>
#include <linux/string.h>
#include "sysv.h"
/* We don't trust the value of
sb->sv_sbd2->s_tfree = *sb->sv_free_blocks
but we nevertheless keep it up to date. */
static inline sysv_zone_t *get_chunk(struct super_block *sb, struct buffer_head *bh)
{
char *bh_data = bh->b_data;
if (SYSV_SB(sb)->s_type == FSTYPE_SYSV4)
return (sysv_zone_t*)(bh_data+4);
else
return (sysv_zone_t*)(bh_data+2);
}
/* NOTE NOTE NOTE: nr is a block number _as_ _stored_ _on_ _disk_ */
void sysv_free_block(struct super_block * sb, sysv_zone_t nr)
{
struct sysv_sb_info * sbi = SYSV_SB(sb);
struct buffer_head * bh;
sysv_zone_t *blocks = sbi->s_bcache;
unsigned count;
unsigned block = fs32_to_cpu(sbi, nr);
/*
* This code does not work at all for AFS (it has a bitmap
* free list). As AFS is supposed to be read-only no one
* should call this for an AFS filesystem anyway...
*/
if (sbi->s_type == FSTYPE_AFS)
return;
if (block < sbi->s_firstdatazone || block >= sbi->s_nzones) {
printk("sysv_free_block: trying to free block not in datazone\n");
return;
}
mutex_lock(&sbi->s_lock);
count = fs16_to_cpu(sbi, *sbi->s_bcache_count);
if (count > sbi->s_flc_size) {
printk("sysv_free_block: flc_count > flc_size\n");
mutex_unlock(&sbi->s_lock);
return;
}
/* If the free list head in super-block is full, it is copied
* into this block being freed, ditto if it's completely empty
* (applies only on Coherent).
*/
if (count == sbi->s_flc_size || count == 0) {
block += sbi->s_block_base;
bh = sb_getblk(sb, block);
if (!bh) {
printk("sysv_free_block: getblk() failed\n");
mutex_unlock(&sbi->s_lock);
return;
}
memset(bh->b_data, 0, sb->s_blocksize);
*(__fs16*)bh->b_data = cpu_to_fs16(sbi, count);
memcpy(get_chunk(sb,bh), blocks, count * sizeof(sysv_zone_t));
mark_buffer_dirty(bh);
set_buffer_uptodate(bh);
brelse(bh);
count = 0;
}
sbi->s_bcache[count++] = nr;
*sbi->s_bcache_count = cpu_to_fs16(sbi, count);
fs32_add(sbi, sbi->s_free_blocks, 1);
dirty_sb(sb);
mutex_unlock(&sbi->s_lock);
}
sysv_zone_t sysv_new_block(struct super_block * sb)
{
struct sysv_sb_info *sbi = SYSV_SB(sb);
unsigned int block;
sysv_zone_t nr;
struct buffer_head * bh;
unsigned count;
mutex_lock(&sbi->s_lock);
count = fs16_to_cpu(sbi, *sbi->s_bcache_count);
if (count == 0) /* Applies only to Coherent FS */
goto Enospc;
nr = sbi->s_bcache[--count];
if (nr == 0) /* Applies only to Xenix FS, SystemV FS */
goto Enospc;
block = fs32_to_cpu(sbi, nr);
*sbi->s_bcache_count = cpu_to_fs16(sbi, count);
if (block < sbi->s_firstdatazone || block >= sbi->s_nzones) {
printk("sysv_new_block: new block %d is not in data zone\n",
block);
goto Enospc;
}
if (count == 0) { /* the last block continues the free list */
unsigned count;
block += sbi->s_block_base;
if (!(bh = sb_bread(sb, block))) {
printk("sysv_new_block: cannot read free-list block\n");
/* retry this same block next time */
*sbi->s_bcache_count = cpu_to_fs16(sbi, 1);
goto Enospc;
}
count = fs16_to_cpu(sbi, *(__fs16*)bh->b_data);
if (count > sbi->s_flc_size) {
printk("sysv_new_block: free-list block with >flc_size entries\n");
brelse(bh);
goto Enospc;
}
*sbi->s_bcache_count = cpu_to_fs16(sbi, count);
memcpy(sbi->s_bcache, get_chunk(sb, bh),
count * sizeof(sysv_zone_t));
brelse(bh);
}
/* Now the free list head in the superblock is valid again. */
fs32_add(sbi, sbi->s_free_blocks, -1);
dirty_sb(sb);
mutex_unlock(&sbi->s_lock);
return nr;
Enospc:
mutex_unlock(&sbi->s_lock);
return 0;
}
unsigned long sysv_count_free_blocks(struct super_block * sb)
{
struct sysv_sb_info * sbi = SYSV_SB(sb);
int sb_count;
int count;
struct buffer_head * bh = NULL;
sysv_zone_t *blocks;
unsigned block;
int n;
/*
* This code does not work at all for AFS (it has a bitmap
* free list). As AFS is supposed to be read-only we just
* lie and say it has no free block at all.
*/
if (sbi->s_type == FSTYPE_AFS)
return 0;
mutex_lock(&sbi->s_lock);
sb_count = fs32_to_cpu(sbi, *sbi->s_free_blocks);
if (0)
goto trust_sb;
/* this causes a lot of disk traffic ... */
count = 0;
n = fs16_to_cpu(sbi, *sbi->s_bcache_count);
blocks = sbi->s_bcache;
while (1) {
sysv_zone_t zone;
if (n > sbi->s_flc_size)
goto E2big;
zone = 0;
while (n && (zone = blocks[--n]) != 0)
count++;
if (zone == 0)
break;
block = fs32_to_cpu(sbi, zone);
if (bh)
brelse(bh);
if (block < sbi->s_firstdatazone || block >= sbi->s_nzones)
goto Einval;
block += sbi->s_block_base;
bh = sb_bread(sb, block);
if (!bh)
goto Eio;
n = fs16_to_cpu(sbi, *(__fs16*)bh->b_data);
blocks = get_chunk(sb, bh);
}
if (bh)
brelse(bh);
if (count != sb_count)
goto Ecount;
done:
mutex_unlock(&sbi->s_lock);
return count;
Einval:
printk("sysv_count_free_blocks: new block %d is not in data zone\n",
block);
goto trust_sb;
Eio:
printk("sysv_count_free_blocks: cannot read free-list block\n");
goto trust_sb;
E2big:
printk("sysv_count_free_blocks: >flc_size entries in free-list block\n");
if (bh)
brelse(bh);
trust_sb:
count = sb_count;
goto done;
Ecount:
printk("sysv_count_free_blocks: free block count was %d, "
"correcting to %d\n", sb_count, count);
if (!(sb->s_flags & MS_RDONLY)) {
*sbi->s_free_blocks = cpu_to_fs32(sbi, count);
dirty_sb(sb);
}
goto done;
}
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