minix/servers/mfs/mount.c
Cristiano Giuffrida d1fd04e72a Initialization protocol for system services.
SYSLIB CHANGES:
- SEF framework now supports a new SEF Init request type from RS. 3 different
callbacks are available (init_fresh, init_lu, init_restart) to specify
initialization code when a service starts fresh, starts after a live update,
or restarts.

SYSTEM SERVICE CHANGES:
- Initialization code for system services is now enclosed in a callback SEF will
automatically call at init time. The return code of the callback will
tell RS whether the initialization completed successfully.
- Each init callback can access information passed by RS to initialize. As of
now, each system service has access to the public entries of RS's system process
table to gather all the information required to initialize. This design
eliminates many existing or potential races at boot time and provides a uniform
initialization interface to system services. The same interface will be reused
for the upcoming publish/subscribe model to handle dynamic 
registration / deregistration of system services.

VM CHANGES:
- Uniform privilege management for all system services. Every service uses the
same call mask format. For boot services, VM copies the call mask from init
data. For dynamic services, VM still receives the call mask via rs_set_priv
call that will be soon replaced by the upcoming publish/subscribe model.

RS CHANGES:
- The system process table has been reorganized and split into private entries
and public entries. Only the latter ones are exposed to system services.
- VM call masks are now entirely configured in rs/table.c
- RS has now its own slot in the system process table. Only kernel tasks and
user processes not included in the boot image are now left out from the system
process table.
- RS implements the initialization protocol for system services.
- For services in the boot image, RS blocks till initialization is complete and
panics when failure is reported back. Services are initialized in their order of
appearance in the boot image priv table and RS blocks to implements synchronous
initialization for every system service having the flag SF_SYNCH_BOOT set.
- For services started dynamically, the initialization protocol is implemented
as though it were the first ping for the service. In this case, if the
system service fails to report back (or reports failure), RS brings the service
down rather than trying to restart it.
2010-01-08 01:20:42 +00:00

187 lines
5.3 KiB
C

#include "fs.h"
#include <fcntl.h>
#include <string.h>
#include <minix/com.h>
#include <sys/stat.h>
#include "buf.h"
#include "inode.h"
#include "super.h"
#include "drivers.h"
#include <minix/ds.h>
#include <minix/vfsif.h>
/*===========================================================================*
* fs_readsuper *
*===========================================================================*/
PUBLIC int fs_readsuper()
{
/* This function reads the superblock of the partition, gets the root inode
* and sends back the details of them. Note, that the FS process does not
* know the index of the vmnt object which refers to it, whenever the pathname
* lookup leaves a partition an ELEAVEMOUNT error is transferred back
* so that the VFS knows that it has to find the vnode on which this FS
* process' partition is mounted on.
*/
struct super_block *xp;
struct inode *root_ip;
cp_grant_id_t label_gid;
size_t label_len;
int r = OK;
unsigned long tasknr;
endpoint_t driver_e;
int readonly, isroot;
fs_dev = fs_m_in.REQ_DEV;
label_gid = fs_m_in.REQ_GRANT;
label_len = fs_m_in.REQ_PATH_LEN;
readonly = (fs_m_in.REQ_FLAGS & REQ_RDONLY) ? 1 : 0;
isroot = (fs_m_in.REQ_FLAGS & REQ_ISROOT) ? 1 : 0;
if (label_len > sizeof(fs_dev_label))
return(EINVAL);
r = sys_safecopyfrom(fs_m_in.m_source, label_gid, 0,
(vir_bytes)fs_dev_label, label_len, D);
if (r != OK) {
printf("%s:%d fs_readsuper: safecopyfrom failed: %d\n",
__FILE__, __LINE__, r);
return(EINVAL);
}
r = ds_retrieve_u32(fs_dev_label, &tasknr);
if (r != OK) {
printf("%s:%d fs_readsuper: ds_retrieve_u32 failed for '%s': %d\n",
__FILE__, __LINE__, fs_dev_label, r);
return(EINVAL);
}
driver_e = tasknr;
/* Map the driver endpoint for this major */
driver_endpoints[(fs_dev >> MAJOR) & BYTE].driver_e = driver_e;
use_getuptime2 = TRUE; /* Should be removed with old getuptime call. */
vfs_slink_storage = (char *)0xdeadbeef; /* Should be removed together
* with old lookup code.
*/;
/* Open the device the file system lives on. */
if (dev_open(driver_e, fs_dev, driver_e,
readonly ? R_BIT : (R_BIT|W_BIT)) != OK) {
return(EINVAL);
}
/* Fill in the super block. */
superblock.s_dev = fs_dev; /* read_super() needs to know which dev */
r = read_super(&superblock);
/* Is it recognized as a Minix filesystem? */
if (r != OK) {
superblock.s_dev = NO_DEV;
dev_close(driver_e, fs_dev);
return(r);
}
set_blocksize(superblock.s_block_size);
/* Get the root inode of the mounted file system. */
if( (root_ip = get_inode(fs_dev, ROOT_INODE)) == NIL_INODE) {
printf("MFS: couldn't get root inode\n");
superblock.s_dev = NO_DEV;
dev_close(driver_e, fs_dev);
return(EINVAL);
}
if(root_ip != NIL_INODE && root_ip->i_mode == 0) {
printf("%s:%d zero mode for root inode?\n", __FILE__, __LINE__);
put_inode(root_ip);
superblock.s_dev = NO_DEV;
dev_close(driver_e, fs_dev);
return(EINVAL);
}
superblock.s_rd_only = readonly;
superblock.s_is_root = isroot;
/* Root inode properties */
fs_m_out.RES_INODE_NR = root_ip->i_num;
fs_m_out.RES_MODE = root_ip->i_mode;
fs_m_out.RES_FILE_SIZE_LO = root_ip->i_size;
fs_m_out.RES_UID = root_ip->i_uid;
fs_m_out.RES_GID = root_ip->i_gid;
return(r);
}
/*===========================================================================*
* fs_mountpoint *
*===========================================================================*/
PUBLIC int fs_mountpoint()
{
/* This function looks up the mount point, it checks the condition whether
* the partition can be mounted on the inode or not.
*/
register struct inode *rip;
int r = OK;
mode_t bits;
/* Temporarily open the file. */
if( (rip = get_inode(fs_dev, fs_m_in.REQ_INODE_NR)) == NIL_INODE)
return(EINVAL);
if(rip->i_mountpoint) r = EBUSY;
/* It may not be special. */
bits = rip->i_mode & I_TYPE;
if (bits == I_BLOCK_SPECIAL || bits == I_CHAR_SPECIAL) r = ENOTDIR;
put_inode(rip);
if(r == OK) rip->i_mountpoint = TRUE;
return(r);
}
/*===========================================================================*
* fs_unmount *
*===========================================================================*/
PUBLIC int fs_unmount()
{
/* Unmount a file system by device number. */
struct super_block *sp1;
int count;
struct inode *rip, *root_ip;
if(superblock.s_dev != fs_dev) return(EINVAL);
/* See if the mounted device is busy. Only 1 inode using it should be
* open --the root inode-- and that inode only 1 time. */
count = 0;
for (rip = &inode[0]; rip < &inode[NR_INODES]; rip++)
if (rip->i_count > 0 && rip->i_dev == fs_dev) count += rip->i_count;
if ((root_ip = find_inode(fs_dev, ROOT_INODE)) == NIL_INODE) {
printf("MFS: couldn't find root inode. Unmount failed.\n");
panic(__FILE__, "MFS: couldn't find root inode", EINVAL);
return(EINVAL);
}
if (count > 1) return(EBUSY); /* can't umount a busy file system */
put_inode(root_ip);
/* force any cached blocks out of memory */
(void) fs_sync();
/* Close the device the file system lives on. */
dev_close(driver_endpoints[(fs_dev >> MAJOR) & BYTE].driver_e, fs_dev);
/* Finish off the unmount. */
superblock.s_dev = NO_DEV;
unmountdone = TRUE;
return(OK);
}