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
osf.c
/*
* fs/partitions/osf.c
*
* Code extracted from drivers/block/genhd.c
*
* Copyright (C) 1991-1998 Linus Torvalds
* Re-organised Feb 1998 Russell King
*/
#include "check.h"
#include "osf.h"
#define MAX_OSF_PARTITIONS 18
int osf_partition(struct parsed_partitions *state)
{
int i;
int slot = 1;
unsigned int npartitions;
Sector sect;
unsigned char *data;
struct disklabel {
__le32 d_magic;
__le16 d_type,d_subtype;
u8 d_typename[16];
u8 d_packname[16];
__le32 d_secsize;
__le32 d_nsectors;
__le32 d_ntracks;
__le32 d_ncylinders;
__le32 d_secpercyl;
__le32 d_secprtunit;
__le16 d_sparespertrack;
__le16 d_sparespercyl;
__le32 d_acylinders;
__le16 d_rpm, d_interleave, d_trackskew, d_cylskew;
__le32 d_headswitch, d_trkseek, d_flags;
__le32 d_drivedata[5];
__le32 d_spare[5];
__le32 d_magic2;
__le16 d_checksum;
__le16 d_npartitions;
__le32 d_bbsize, d_sbsize;
struct d_partition {
__le32 p_size;
__le32 p_offset;
__le32 p_fsize;
u8 p_fstype;
u8 p_frag;
__le16 p_cpg;
} d_partitions[MAX_OSF_PARTITIONS];
} * label;
struct d_partition * partition;
data = read_part_sector(state, 0, §);
if (!data)
return -1;
label = (struct disklabel *) (data+64);
partition = label->d_partitions;
if (le32_to_cpu(label->d_magic) != DISKLABELMAGIC) {
put_dev_sector(sect);
return 0;
}
if (le32_to_cpu(label->d_magic2) != DISKLABELMAGIC) {
put_dev_sector(sect);
return 0;
}
npartitions = le16_to_cpu(label->d_npartitions);
if (npartitions > MAX_OSF_PARTITIONS) {
put_dev_sector(sect);
return 0;
}
for (i = 0 ; i < npartitions; i++, partition++) {
if (slot == state->limit)
break;
if (le32_to_cpu(partition->p_size))
put_partition(state, slot,
le32_to_cpu(partition->p_offset),
le32_to_cpu(partition->p_size));
slot++;
}
strlcat(state->pp_buf, "\n", PAGE_SIZE);
put_dev_sector(sect);
return 1;
}
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