Revision c4f675cd40d955d539180506c09515c90169b15b authored by Sergei Trofimovich on 20 May 2011, 20:20:30 UTC, committed by Chris Mason on 23 May 2011, 17:24:14 UTC
Observed as a large delay when --mixed filesystem is filled up. Test example: 1. create tiny --mixed FS: $ dd if=/dev/zero of=2G.img seek=$((2048 * 1024 * 1024 - 1)) count=1 bs=1 $ mkfs.btrfs --mixed 2G.img $ mount -oloop 2G.img /mnt/ut/ 2. Try to fill it up: $ dd if=/dev/urandom of=10M.file bs=10240 count=1024 $ seq 1 256 | while read file_no; do echo $file_no; time cp 10M.file ${file_no}.copy; done Up to '200.copy' it goes fast, but when disk fills-up each -ENOSPC message takes 3 seconds to pop-up _every_ ENOSPC (and in usermode linux it's even more: 30-60 seconds!). (Maybe, time depends on kernel's timer resolution). No IO, no CPU load, just rescheduling. Some debugging revealed busy spinning in shrink_delalloc. Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> Reviewed-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
1 parent 0f3b708
ibm.c
/*
* File...........: linux/fs/partitions/ibm.c
* Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
* Volker Sameske <sameske@de.ibm.com>
* Bugreports.to..: <Linux390@de.ibm.com>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
*/
#include <linux/buffer_head.h>
#include <linux/hdreg.h>
#include <linux/slab.h>
#include <asm/dasd.h>
#include <asm/ebcdic.h>
#include <asm/uaccess.h>
#include <asm/vtoc.h>
#include "check.h"
#include "ibm.h"
/*
* compute the block number from a
* cyl-cyl-head-head structure
*/
static sector_t
cchh2blk (struct vtoc_cchh *ptr, struct hd_geometry *geo) {
sector_t cyl;
__u16 head;
/*decode cylinder and heads for large volumes */
cyl = ptr->hh & 0xFFF0;
cyl <<= 12;
cyl |= ptr->cc;
head = ptr->hh & 0x000F;
return cyl * geo->heads * geo->sectors +
head * geo->sectors;
}
/*
* compute the block number from a
* cyl-cyl-head-head-block structure
*/
static sector_t
cchhb2blk (struct vtoc_cchhb *ptr, struct hd_geometry *geo) {
sector_t cyl;
__u16 head;
/*decode cylinder and heads for large volumes */
cyl = ptr->hh & 0xFFF0;
cyl <<= 12;
cyl |= ptr->cc;
head = ptr->hh & 0x000F;
return cyl * geo->heads * geo->sectors +
head * geo->sectors +
ptr->b;
}
/*
*/
int ibm_partition(struct parsed_partitions *state)
{
struct block_device *bdev = state->bdev;
int blocksize, res;
loff_t i_size, offset, size, fmt_size;
dasd_information2_t *info;
struct hd_geometry *geo;
char type[5] = {0,};
char name[7] = {0,};
union label_t {
struct vtoc_volume_label_cdl vol;
struct vtoc_volume_label_ldl lnx;
struct vtoc_cms_label cms;
} *label;
unsigned char *data;
Sector sect;
sector_t labelsect;
char tmp[64];
res = 0;
blocksize = bdev_logical_block_size(bdev);
if (blocksize <= 0)
goto out_exit;
i_size = i_size_read(bdev->bd_inode);
if (i_size == 0)
goto out_exit;
info = kmalloc(sizeof(dasd_information2_t), GFP_KERNEL);
if (info == NULL)
goto out_exit;
geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL);
if (geo == NULL)
goto out_nogeo;
label = kmalloc(sizeof(union label_t), GFP_KERNEL);
if (label == NULL)
goto out_nolab;
if (ioctl_by_bdev(bdev, BIODASDINFO2, (unsigned long)info) != 0 ||
ioctl_by_bdev(bdev, HDIO_GETGEO, (unsigned long)geo) != 0)
goto out_freeall;
/*
* Special case for FBA disks: label sector does not depend on
* blocksize.
*/
if ((info->cu_type == 0x6310 && info->dev_type == 0x9336) ||
(info->cu_type == 0x3880 && info->dev_type == 0x3370))
labelsect = info->label_block;
else
labelsect = info->label_block * (blocksize >> 9);
/*
* Get volume label, extract name and type.
*/
data = read_part_sector(state, labelsect, §);
if (data == NULL)
goto out_readerr;
memcpy(label, data, sizeof(union label_t));
put_dev_sector(sect);
if ((!info->FBA_layout) && (!strcmp(info->type, "ECKD"))) {
strncpy(type, label->vol.vollbl, 4);
strncpy(name, label->vol.volid, 6);
} else {
strncpy(type, label->lnx.vollbl, 4);
strncpy(name, label->lnx.volid, 6);
}
EBCASC(type, 4);
EBCASC(name, 6);
res = 1;
/*
* Three different formats: LDL, CDL and unformated disk
*
* identified by info->format
*
* unformated disks we do not have to care about
*/
if (info->format == DASD_FORMAT_LDL) {
if (strncmp(type, "CMS1", 4) == 0) {
/*
* VM style CMS1 labeled disk
*/
blocksize = label->cms.block_size;
if (label->cms.disk_offset != 0) {
snprintf(tmp, sizeof(tmp), "CMS1/%8s(MDSK):", name);
strlcat(state->pp_buf, tmp, PAGE_SIZE);
/* disk is reserved minidisk */
offset = label->cms.disk_offset;
size = (label->cms.block_count - 1)
* (blocksize >> 9);
} else {
snprintf(tmp, sizeof(tmp), "CMS1/%8s:", name);
strlcat(state->pp_buf, tmp, PAGE_SIZE);
offset = (info->label_block + 1);
size = label->cms.block_count
* (blocksize >> 9);
}
put_partition(state, 1, offset*(blocksize >> 9),
size-offset*(blocksize >> 9));
} else {
if (strncmp(type, "LNX1", 4) == 0) {
snprintf(tmp, sizeof(tmp), "LNX1/%8s:", name);
strlcat(state->pp_buf, tmp, PAGE_SIZE);
if (label->lnx.ldl_version == 0xf2) {
fmt_size = label->lnx.formatted_blocks
* (blocksize >> 9);
} else if (!strcmp(info->type, "ECKD")) {
/* formated w/o large volume support */
fmt_size = geo->cylinders * geo->heads
* geo->sectors * (blocksize >> 9);
} else {
/* old label and no usable disk geometry
* (e.g. DIAG) */
fmt_size = i_size >> 9;
}
size = i_size >> 9;
if (fmt_size < size)
size = fmt_size;
offset = (info->label_block + 1);
} else {
/* unlabeled disk */
strlcat(state->pp_buf, "(nonl)", PAGE_SIZE);
size = i_size >> 9;
offset = (info->label_block + 1);
}
put_partition(state, 1, offset*(blocksize >> 9),
size-offset*(blocksize >> 9));
}
} else if (info->format == DASD_FORMAT_CDL) {
/*
* New style CDL formatted disk
*/
sector_t blk;
int counter;
/*
* check if VOL1 label is available
* if not, something is wrong, skipping partition detection
*/
if (strncmp(type, "VOL1", 4) == 0) {
snprintf(tmp, sizeof(tmp), "VOL1/%8s:", name);
strlcat(state->pp_buf, tmp, PAGE_SIZE);
/*
* get block number and read then go through format1
* labels
*/
blk = cchhb2blk(&label->vol.vtoc, geo) + 1;
counter = 0;
data = read_part_sector(state, blk * (blocksize/512),
§);
while (data != NULL) {
struct vtoc_format1_label f1;
memcpy(&f1, data,
sizeof(struct vtoc_format1_label));
put_dev_sector(sect);
/* skip FMT4 / FMT5 / FMT7 labels */
if (f1.DS1FMTID == _ascebc['4']
|| f1.DS1FMTID == _ascebc['5']
|| f1.DS1FMTID == _ascebc['7']
|| f1.DS1FMTID == _ascebc['9']) {
blk++;
data = read_part_sector(state,
blk * (blocksize/512), §);
continue;
}
/* only FMT1 and 8 labels valid at this point */
if (f1.DS1FMTID != _ascebc['1'] &&
f1.DS1FMTID != _ascebc['8'])
break;
/* OK, we got valid partition data */
offset = cchh2blk(&f1.DS1EXT1.llimit, geo);
size = cchh2blk(&f1.DS1EXT1.ulimit, geo) -
offset + geo->sectors;
if (counter >= state->limit)
break;
put_partition(state, counter + 1,
offset * (blocksize >> 9),
size * (blocksize >> 9));
counter++;
blk++;
data = read_part_sector(state,
blk * (blocksize/512), §);
}
if (!data)
/* Are we not supposed to report this ? */
goto out_readerr;
} else
printk(KERN_WARNING "Warning, expected Label VOL1 not "
"found, treating as CDL formated Disk");
}
strlcat(state->pp_buf, "\n", PAGE_SIZE);
goto out_freeall;
out_readerr:
res = -1;
out_freeall:
kfree(label);
out_nolab:
kfree(geo);
out_nogeo:
kfree(info);
out_exit:
return res;
}
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