minix/servers/ext2/mount.c
Thomas Veerman a9d0ffbd0d Define protocol version of {mode,ino,uid,gid}_t
The next commit will make mode_t 32-bits, ino_t 64-bits, nlink_t
32-bits, and off_t 64-bits. However, in the protocol there is no
room for that.

When analyzing the usage of these data types we can see that of
mode_t we currently use 15 bits and that future flags (if copied
from NetBSD) are only of importance to VFS and not to the actual
file system on disk. Therefore we can get away with keeping the
protocol version of mode_t (pmode_t) 16 bits.

At this point it is unlikely that MINIX will support file systems
that can hold more than 2^32 files. Keeping the protocol version of
ino_t (pino_t) 32-bits and exposing it as 64-bits to the rest of the
system is fine.

uid_t and gid_t are already 32-bits, but in behind the scenes they're
16-bits. This is sufficient since we don't support uid/gids larger
than 2^16-1.

off_t will become 64-bits, but the protocol had room reserved
for that since it was revised years ago.

So to make the difference clear between what the protocol supports
and what is exposed to the system, we define protocol version of
these data types.

Change-Id: Ifb883aafb222142e69d6dcc3049a47170b78b3ee
2013-03-28 19:39:21 +00:00

251 lines
7.4 KiB
C

/* Created (MFS based):
* February 2010 (Evgeniy Ivanov)
*/
#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 <minix/vfsif.h>
#include <minix/bdev.h>
/*===========================================================================*
* fs_readsuper *
*===========================================================================*/
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 inode *root_ip;
cp_grant_id_t label_gid;
size_t label_len;
int r = OK;
int readonly, isroot;
u32_t mask;
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);
if (r != OK) {
printf("%s:%d fs_readsuper: safecopyfrom failed: %d\n",
__FILE__, __LINE__, r);
return(EINVAL);
}
/* Map the driver label for this major. */
bdev_driver(fs_dev, fs_dev_label);
/* Open the device the file system lives on. */
if (bdev_open(fs_dev, readonly ? R_BIT : (R_BIT|W_BIT)) != OK) {
return(EINVAL);
}
/* Fill in the super block. */
STATICINIT(superblock, 1);
if (!superblock)
panic("Can't allocate memory for superblock.");
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;
bdev_close(fs_dev);
return(r);
}
if (superblock->s_rev_level != EXT2_GOOD_OLD_REV) {
struct super_block *sp = superblock; /* just shorter name */
mask = ~SUPPORTED_INCOMPAT_FEATURES;
if (HAS_INCOMPAT_FEATURE(sp, mask)) {
if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_COMPRESSION & mask))
printf("ext2: fs compression is not supported by server\n");
if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_FILETYPE & mask))
printf("ext2: fs in dir filetype is not supported by server\n");
if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_RECOVER & mask))
printf("ext2: fs recovery is not supported by server\n");
if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_JOURNAL_DEV & mask))
printf("ext2: fs journal dev is not supported by server\n");
if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_META_BG & mask))
printf("ext2: fs meta bg is not supported by server\n");
return(EINVAL);
}
mask = ~SUPPORTED_RO_COMPAT_FEATURES;
if (HAS_RO_COMPAT_FEATURE(sp, mask)) {
if (HAS_RO_COMPAT_FEATURE(sp, RO_COMPAT_SPARSE_SUPER & mask)) {
printf("ext2: sparse super is not supported by server, \
remount read-only\n");
}
if (HAS_RO_COMPAT_FEATURE(sp, RO_COMPAT_LARGE_FILE & mask)) {
printf("ext2: large files are not supported by server, \
remount read-only\n");
}
if (HAS_RO_COMPAT_FEATURE(sp, RO_COMPAT_BTREE_DIR & mask)) {
printf("ext2: dir's btree is not supported by server, \
remount read-only\n");
}
return(EINVAL);
}
}
if (superblock->s_state == EXT2_ERROR_FS) {
printf("ext2: filesystem wasn't cleanly unmounted last time\n");
superblock->s_dev = NO_DEV;
bdev_close(fs_dev);
return(EINVAL);
}
lmfs_set_blocksize(superblock->s_block_size, major(fs_dev));
/* Get the root inode of the mounted file system. */
if ( (root_ip = get_inode(fs_dev, ROOT_INODE)) == NULL) {
printf("ext2: couldn't get root inode\n");
superblock->s_dev = NO_DEV;
bdev_close(fs_dev);
return(EINVAL);
}
if (root_ip != NULL && 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;
bdev_close(fs_dev);
return(EINVAL);
}
if (root_ip != NULL && (root_ip->i_mode & I_TYPE) != I_DIRECTORY) {
printf("%s:%d root inode has wrong type, it's not a DIR\n",
__FILE__, __LINE__);
put_inode(root_ip);
superblock->s_dev = NO_DEV;
bdev_close(fs_dev);
return(EINVAL);
}
superblock->s_rd_only = readonly;
superblock->s_is_root = isroot;
if (!readonly) {
superblock->s_state = EXT2_ERROR_FS;
superblock->s_mnt_count++;
superblock->s_mtime = clock_time();
write_super(superblock); /* Commit info, we just set above */
}
/* 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;
fs_m_out.RES_PROTO = 0;
VFS_FS_PROTO_PUT_VERSION(fs_m_out.RES_PROTO, VFS_FS_CURRENT_VERSION);
VFS_FS_PROTO_PUT_CONREQS(fs_m_out.RES_PROTO, 1);
return(r);
}
/*===========================================================================*
* fs_mountpoint *
*===========================================================================*/
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;
pmode_t bits;
/* Temporarily open the file. */
if( (rip = get_inode(fs_dev, fs_m_in.REQ_INODE_NR)) == NULL)
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 *
*===========================================================================*/
int fs_unmount()
{
/* Unmount a file system by device number. */
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)) == NULL) {
printf("ext2: couldn't find root inode. Unmount failed.\n");
panic("ext2: couldn't find root inode");
return(EINVAL);
}
/* Sync fs data before checking count. In some cases VFS can force unmounting
* and it will damage unsynced FS. We don't sync before checking root_ip since
* if it is missing then something strange happened with FS, so it's better
* to not use possibly corrupted data for syncing.
*/
if (!superblock->s_rd_only) {
/* force any cached blocks out of memory */
(void) fs_sync();
}
if (count > 1) return(EBUSY); /* can't umount a busy file system */
put_inode(root_ip);
if (!superblock->s_rd_only) {
superblock->s_wtime = clock_time();
superblock->s_state = EXT2_VALID_FS;
write_super(superblock); /* Commit info, we just set above */
}
/* Close the device the file system lives on. */
bdev_close(fs_dev);
/* Finish off the unmount. */
superblock->s_dev = NO_DEV;
unmountdone = TRUE;
return(OK);
}