Revision 58fc73d10f3e92bfcd1e9a8391eb3e49b68df8e5 authored by Christoph Hellwig on 26 August 2011, 16:25:38 UTC, committed by Nicholas Bellinger on 16 September 2011, 09:50:09 UTC
Problem: Changed from wake_up_interruptible -> wake_up_process and wait_event_interruptible-> schedule_timeout_interruptible broke the FCoE target. Earlier approach of wake_up_interruptible was also looking at 'queue_cnt' which is not necessary, because it increment of 'queue_cnt' with wake_up_inetrriptible / waker_up_process introduces race condition. Fix: Instead of fixing the code which used wake_up_process and remove 'queue_cnt', using work_queue based approach is cleaner and acheives same result. As well, work queue based approach has less programming overhead and OS manages threads which processes work queues. This patch is developed by Christoph Hellwig and reviwed+validated by Kiran Patil. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kiran Patil <kiran.patil@intel.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
1 parent 079587b
do_mounts.c
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include <linux/fd.h>
#include <linux/tty.h>
#include <linux/suspend.h>
#include <linux/root_dev.h>
#include <linux/security.h>
#include <linux/delay.h>
#include <linux/genhd.h>
#include <linux/mount.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/initrd.h>
#include <linux/async.h>
#include <linux/fs_struct.h>
#include <linux/slab.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/nfs_mount.h>
#include "do_mounts.h"
int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
int root_mountflags = MS_RDONLY | MS_SILENT;
static char * __initdata root_device_name;
static char __initdata saved_root_name[64];
static int __initdata root_wait;
dev_t ROOT_DEV;
static int __init load_ramdisk(char *str)
{
rd_doload = simple_strtol(str,NULL,0) & 3;
return 1;
}
__setup("load_ramdisk=", load_ramdisk);
static int __init readonly(char *str)
{
if (*str)
return 0;
root_mountflags |= MS_RDONLY;
return 1;
}
static int __init readwrite(char *str)
{
if (*str)
return 0;
root_mountflags &= ~MS_RDONLY;
return 1;
}
__setup("ro", readonly);
__setup("rw", readwrite);
#ifdef CONFIG_BLOCK
/**
* match_dev_by_uuid - callback for finding a partition using its uuid
* @dev: device passed in by the caller
* @data: opaque pointer to a 36 byte char array with a UUID
*
* Returns 1 if the device matches, and 0 otherwise.
*/
static int match_dev_by_uuid(struct device *dev, void *data)
{
u8 *uuid = data;
struct hd_struct *part = dev_to_part(dev);
if (!part->info)
goto no_match;
if (memcmp(uuid, part->info->uuid, sizeof(part->info->uuid)))
goto no_match;
return 1;
no_match:
return 0;
}
/**
* devt_from_partuuid - looks up the dev_t of a partition by its UUID
* @uuid: 36 byte char array containing a hex ascii UUID
*
* The function will return the first partition which contains a matching
* UUID value in its partition_meta_info struct. This does not search
* by filesystem UUIDs.
*
* Returns the matching dev_t on success or 0 on failure.
*/
static dev_t devt_from_partuuid(char *uuid_str)
{
dev_t res = 0;
struct device *dev = NULL;
u8 uuid[16];
/* Pack the requested UUID in the expected format. */
part_pack_uuid(uuid_str, uuid);
dev = class_find_device(&block_class, NULL, uuid, &match_dev_by_uuid);
if (!dev)
goto done;
res = dev->devt;
put_device(dev);
done:
return res;
}
#endif
/*
* Convert a name into device number. We accept the following variants:
*
* 1) device number in hexadecimal represents itself
* 2) /dev/nfs represents Root_NFS (0xff)
* 3) /dev/<disk_name> represents the device number of disk
* 4) /dev/<disk_name><decimal> represents the device number
* of partition - device number of disk plus the partition number
* 5) /dev/<disk_name>p<decimal> - same as the above, that form is
* used when disk name of partitioned disk ends on a digit.
* 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
* unique id of a partition if the partition table provides it.
*
* If name doesn't have fall into the categories above, we return (0,0).
* block_class is used to check if something is a disk name. If the disk
* name contains slashes, the device name has them replaced with
* bangs.
*/
dev_t name_to_dev_t(char *name)
{
char s[32];
char *p;
dev_t res = 0;
int part;
#ifdef CONFIG_BLOCK
if (strncmp(name, "PARTUUID=", 9) == 0) {
name += 9;
if (strlen(name) != 36)
goto fail;
res = devt_from_partuuid(name);
if (!res)
goto fail;
goto done;
}
#endif
if (strncmp(name, "/dev/", 5) != 0) {
unsigned maj, min;
if (sscanf(name, "%u:%u", &maj, &min) == 2) {
res = MKDEV(maj, min);
if (maj != MAJOR(res) || min != MINOR(res))
goto fail;
} else {
res = new_decode_dev(simple_strtoul(name, &p, 16));
if (*p)
goto fail;
}
goto done;
}
name += 5;
res = Root_NFS;
if (strcmp(name, "nfs") == 0)
goto done;
res = Root_RAM0;
if (strcmp(name, "ram") == 0)
goto done;
if (strlen(name) > 31)
goto fail;
strcpy(s, name);
for (p = s; *p; p++)
if (*p == '/')
*p = '!';
res = blk_lookup_devt(s, 0);
if (res)
goto done;
/*
* try non-existent, but valid partition, which may only exist
* after revalidating the disk, like partitioned md devices
*/
while (p > s && isdigit(p[-1]))
p--;
if (p == s || !*p || *p == '0')
goto fail;
/* try disk name without <part number> */
part = simple_strtoul(p, NULL, 10);
*p = '\0';
res = blk_lookup_devt(s, part);
if (res)
goto done;
/* try disk name without p<part number> */
if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
goto fail;
p[-1] = '\0';
res = blk_lookup_devt(s, part);
if (res)
goto done;
fail:
return 0;
done:
return res;
}
static int __init root_dev_setup(char *line)
{
strlcpy(saved_root_name, line, sizeof(saved_root_name));
return 1;
}
__setup("root=", root_dev_setup);
static int __init rootwait_setup(char *str)
{
if (*str)
return 0;
root_wait = 1;
return 1;
}
__setup("rootwait", rootwait_setup);
static char * __initdata root_mount_data;
static int __init root_data_setup(char *str)
{
root_mount_data = str;
return 1;
}
static char * __initdata root_fs_names;
static int __init fs_names_setup(char *str)
{
root_fs_names = str;
return 1;
}
static unsigned int __initdata root_delay;
static int __init root_delay_setup(char *str)
{
root_delay = simple_strtoul(str, NULL, 0);
return 1;
}
__setup("rootflags=", root_data_setup);
__setup("rootfstype=", fs_names_setup);
__setup("rootdelay=", root_delay_setup);
static void __init get_fs_names(char *page)
{
char *s = page;
if (root_fs_names) {
strcpy(page, root_fs_names);
while (*s++) {
if (s[-1] == ',')
s[-1] = '\0';
}
} else {
int len = get_filesystem_list(page);
char *p, *next;
page[len] = '\0';
for (p = page-1; p; p = next) {
next = strchr(++p, '\n');
if (*p++ != '\t')
continue;
while ((*s++ = *p++) != '\n')
;
s[-1] = '\0';
}
}
*s = '\0';
}
static int __init do_mount_root(char *name, char *fs, int flags, void *data)
{
int err = sys_mount(name, "/root", fs, flags, data);
if (err)
return err;
sys_chdir((const char __user __force *)"/root");
ROOT_DEV = current->fs->pwd.mnt->mnt_sb->s_dev;
printk(KERN_INFO
"VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
current->fs->pwd.mnt->mnt_sb->s_type->name,
current->fs->pwd.mnt->mnt_sb->s_flags & MS_RDONLY ?
" readonly" : "", MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
return 0;
}
void __init mount_block_root(char *name, int flags)
{
char *fs_names = __getname_gfp(GFP_KERNEL
| __GFP_NOTRACK_FALSE_POSITIVE);
char *p;
#ifdef CONFIG_BLOCK
char b[BDEVNAME_SIZE];
#else
const char *b = name;
#endif
get_fs_names(fs_names);
retry:
for (p = fs_names; *p; p += strlen(p)+1) {
int err = do_mount_root(name, p, flags, root_mount_data);
switch (err) {
case 0:
goto out;
case -EACCES:
flags |= MS_RDONLY;
goto retry;
case -EINVAL:
continue;
}
/*
* Allow the user to distinguish between failed sys_open
* and bad superblock on root device.
* and give them a list of the available devices
*/
#ifdef CONFIG_BLOCK
__bdevname(ROOT_DEV, b);
#endif
printk("VFS: Cannot open root device \"%s\" or %s\n",
root_device_name, b);
printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
printk_all_partitions();
#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
"explicit textual name for \"root=\" boot option.\n");
#endif
panic("VFS: Unable to mount root fs on %s", b);
}
printk("List of all partitions:\n");
printk_all_partitions();
printk("No filesystem could mount root, tried: ");
for (p = fs_names; *p; p += strlen(p)+1)
printk(" %s", p);
printk("\n");
#ifdef CONFIG_BLOCK
__bdevname(ROOT_DEV, b);
#endif
panic("VFS: Unable to mount root fs on %s", b);
out:
putname(fs_names);
}
#ifdef CONFIG_ROOT_NFS
static int __init mount_nfs_root(void)
{
char *root_dev, *root_data;
if (nfs_root_data(&root_dev, &root_data) != 0)
return 0;
if (do_mount_root(root_dev, "nfs", root_mountflags, root_data) != 0)
return 0;
return 1;
}
#endif
#if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
void __init change_floppy(char *fmt, ...)
{
struct termios termios;
char buf[80];
char c;
int fd;
va_list args;
va_start(args, fmt);
vsprintf(buf, fmt, args);
va_end(args);
fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
if (fd >= 0) {
sys_ioctl(fd, FDEJECT, 0);
sys_close(fd);
}
printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
fd = sys_open("/dev/console", O_RDWR, 0);
if (fd >= 0) {
sys_ioctl(fd, TCGETS, (long)&termios);
termios.c_lflag &= ~ICANON;
sys_ioctl(fd, TCSETSF, (long)&termios);
sys_read(fd, &c, 1);
termios.c_lflag |= ICANON;
sys_ioctl(fd, TCSETSF, (long)&termios);
sys_close(fd);
}
}
#endif
void __init mount_root(void)
{
#ifdef CONFIG_ROOT_NFS
if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
if (mount_nfs_root())
return;
printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
ROOT_DEV = Root_FD0;
}
#endif
#ifdef CONFIG_BLK_DEV_FD
if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
/* rd_doload is 2 for a dual initrd/ramload setup */
if (rd_doload==2) {
if (rd_load_disk(1)) {
ROOT_DEV = Root_RAM1;
root_device_name = NULL;
}
} else
change_floppy("root floppy");
}
#endif
#ifdef CONFIG_BLOCK
create_dev("/dev/root", ROOT_DEV);
mount_block_root("/dev/root", root_mountflags);
#endif
}
/*
* Prepare the namespace - decide what/where to mount, load ramdisks, etc.
*/
void __init prepare_namespace(void)
{
int is_floppy;
if (root_delay) {
printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
root_delay);
ssleep(root_delay);
}
/*
* wait for the known devices to complete their probing
*
* Note: this is a potential source of long boot delays.
* For example, it is not atypical to wait 5 seconds here
* for the touchpad of a laptop to initialize.
*/
wait_for_device_probe();
md_run_setup();
if (saved_root_name[0]) {
root_device_name = saved_root_name;
if (!strncmp(root_device_name, "mtd", 3) ||
!strncmp(root_device_name, "ubi", 3)) {
mount_block_root(root_device_name, root_mountflags);
goto out;
}
ROOT_DEV = name_to_dev_t(root_device_name);
if (strncmp(root_device_name, "/dev/", 5) == 0)
root_device_name += 5;
}
if (initrd_load())
goto out;
/* wait for any asynchronous scanning to complete */
if ((ROOT_DEV == 0) && root_wait) {
printk(KERN_INFO "Waiting for root device %s...\n",
saved_root_name);
while (driver_probe_done() != 0 ||
(ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
msleep(100);
async_synchronize_full();
}
is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
if (is_floppy && rd_doload && rd_load_disk(0))
ROOT_DEV = Root_RAM0;
mount_root();
out:
devtmpfs_mount("dev");
sys_mount(".", "/", NULL, MS_MOVE, NULL);
sys_chroot((const char __user __force *)".");
}
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