ac2e5327a5
Currently, sizeof(struct parsed_partitions) may be 64KB in 32bit arch, so it is easy to trigger page allocation failure by check_partition, especially in hotplug block device situation(such as, USB mass storage, MMC card, ...), and Felipe Balbi has observed the failure. This patch does below optimizations on the allocation of struct parsed_partitions to try to address the issue: - make parsed_partitions.parts as pointer so that the pointed memory can fit in 32KB buffer, then approximate 32KB memory can be saved - vmalloc the buffer pointed by parsed_partitions.parts because 32KB is still a bit big for kmalloc - given that many devices have the partition count limit, so only allocate disk_max_parts() partitions instead of 256 partitions always Signed-off-by: Ming Lei <ming.lei@canonical.com> Reported-by: Felipe Balbi <balbi@ti.com> Cc: Jens Axboe <axboe@kernel.dk> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
194 lines
4.2 KiB
C
194 lines
4.2 KiB
C
/*
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* fs/partitions/check.c
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*
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* Code extracted from drivers/block/genhd.c
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* Copyright (C) 1991-1998 Linus Torvalds
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* Re-organised Feb 1998 Russell King
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*
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* We now have independent partition support from the
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* block drivers, which allows all the partition code to
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* be grouped in one location, and it to be mostly self
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* contained.
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*
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* Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
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*/
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/ctype.h>
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#include <linux/genhd.h>
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#include "check.h"
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#include "acorn.h"
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#include "amiga.h"
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#include "atari.h"
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#include "ldm.h"
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#include "mac.h"
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#include "msdos.h"
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#include "osf.h"
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#include "sgi.h"
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#include "sun.h"
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#include "ibm.h"
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#include "ultrix.h"
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#include "efi.h"
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#include "karma.h"
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#include "sysv68.h"
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int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
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static int (*check_part[])(struct parsed_partitions *) = {
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/*
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* Probe partition formats with tables at disk address 0
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* that also have an ADFS boot block at 0xdc0.
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*/
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#ifdef CONFIG_ACORN_PARTITION_ICS
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adfspart_check_ICS,
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#endif
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#ifdef CONFIG_ACORN_PARTITION_POWERTEC
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adfspart_check_POWERTEC,
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#endif
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#ifdef CONFIG_ACORN_PARTITION_EESOX
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adfspart_check_EESOX,
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#endif
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/*
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* Now move on to formats that only have partition info at
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* disk address 0xdc0. Since these may also have stale
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* PC/BIOS partition tables, they need to come before
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* the msdos entry.
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*/
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#ifdef CONFIG_ACORN_PARTITION_CUMANA
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adfspart_check_CUMANA,
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#endif
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#ifdef CONFIG_ACORN_PARTITION_ADFS
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adfspart_check_ADFS,
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#endif
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#ifdef CONFIG_EFI_PARTITION
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efi_partition, /* this must come before msdos */
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#endif
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#ifdef CONFIG_SGI_PARTITION
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sgi_partition,
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#endif
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#ifdef CONFIG_LDM_PARTITION
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ldm_partition, /* this must come before msdos */
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#endif
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#ifdef CONFIG_MSDOS_PARTITION
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msdos_partition,
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#endif
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#ifdef CONFIG_OSF_PARTITION
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osf_partition,
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#endif
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#ifdef CONFIG_SUN_PARTITION
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sun_partition,
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#endif
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#ifdef CONFIG_AMIGA_PARTITION
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amiga_partition,
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#endif
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#ifdef CONFIG_ATARI_PARTITION
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atari_partition,
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#endif
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#ifdef CONFIG_MAC_PARTITION
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mac_partition,
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#endif
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#ifdef CONFIG_ULTRIX_PARTITION
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ultrix_partition,
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#endif
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#ifdef CONFIG_IBM_PARTITION
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ibm_partition,
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#endif
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#ifdef CONFIG_KARMA_PARTITION
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karma_partition,
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#endif
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#ifdef CONFIG_SYSV68_PARTITION
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sysv68_partition,
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#endif
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NULL
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};
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static struct parsed_partitions *allocate_partitions(struct gendisk *hd)
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{
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struct parsed_partitions *state;
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int nr;
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state = kzalloc(sizeof(*state), GFP_KERNEL);
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if (!state)
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return NULL;
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nr = disk_max_parts(hd);
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state->parts = vzalloc(nr * sizeof(state->parts[0]));
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if (!state->parts) {
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kfree(state);
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return NULL;
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}
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state->limit = nr;
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return state;
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}
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void free_partitions(struct parsed_partitions *state)
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{
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vfree(state->parts);
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kfree(state);
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}
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struct parsed_partitions *
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check_partition(struct gendisk *hd, struct block_device *bdev)
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{
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struct parsed_partitions *state;
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int i, res, err;
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state = allocate_partitions(hd);
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if (!state)
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return NULL;
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state->pp_buf = (char *)__get_free_page(GFP_KERNEL);
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if (!state->pp_buf) {
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free_partitions(state);
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return NULL;
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}
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state->pp_buf[0] = '\0';
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state->bdev = bdev;
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disk_name(hd, 0, state->name);
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snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
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if (isdigit(state->name[strlen(state->name)-1]))
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sprintf(state->name, "p");
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i = res = err = 0;
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while (!res && check_part[i]) {
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memset(state->parts, 0, state->limit * sizeof(state->parts[0]));
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res = check_part[i++](state);
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if (res < 0) {
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/* We have hit an I/O error which we don't report now.
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* But record it, and let the others do their job.
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*/
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err = res;
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res = 0;
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}
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}
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if (res > 0) {
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printk(KERN_INFO "%s", state->pp_buf);
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free_page((unsigned long)state->pp_buf);
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return state;
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}
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if (state->access_beyond_eod)
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err = -ENOSPC;
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if (err)
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/* The partition is unrecognized. So report I/O errors if there were any */
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res = err;
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if (!res)
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strlcat(state->pp_buf, " unknown partition table\n", PAGE_SIZE);
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else if (warn_no_part)
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strlcat(state->pp_buf, " unable to read partition table\n", PAGE_SIZE);
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printk(KERN_INFO "%s", state->pp_buf);
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free_page((unsigned long)state->pp_buf);
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free_partitions(state);
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return ERR_PTR(res);
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}
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