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minix/servers/vfs/request.c
Thomas Veerman 13ef7f1f38 Prepare VFS to support back calls from PFS. For security reasons and to support 
file descriptor passing, PFS does some back calls to VFS. For example, to
verify the validity of a path provided by a process and to tell VFS it must
copy file descriptors from one process to another.
2010-08-30 13:44:07 +00:00

1176 lines
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/* This file contains the wrapper functions for issueing a request
* and receiving response from FS processes.
* Each function builds a request message according to the request
* parameter, calls the most low-level fs_sendrec and copies
* back the response.
* The low-level fs_sendrec handles the recovery mechanism from
* a dead driver and reissues the request.
*/
#include "fs.h"
#include <string.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <sys/statvfs.h>
#include <minix/vfsif.h>
#include <minix/com.h>
#include <minix/const.h>
#include <minix/endpoint.h>
#include <minix/u64.h>
#include <unistd.h>
#include <minix/vfsif.h>
#include "fproc.h"
#include "vmnt.h"
#include "vnode.h"
#include "param.h"
FORWARD _PROTOTYPE(int fs_sendrec_f, (char *file, int line, endpoint_t fs_e,
message *reqm) );
#define fs_sendrec(e, m) fs_sendrec_f(__FILE__, __LINE__, (e), (m))
/*===========================================================================*
* req_breadwrite *
*===========================================================================*/
PUBLIC int req_breadwrite(
endpoint_t fs_e,
endpoint_t user_e,
dev_t dev,
u64_t pos,
unsigned int num_of_bytes,
char *user_addr,
int rw_flag,
u64_t *new_posp,
unsigned int *cum_iop
)
{
int r;
cp_grant_id_t grant_id;
message m;
grant_id = cpf_grant_magic(fs_e, user_e, (vir_bytes) user_addr, num_of_bytes,
(rw_flag == READING ? CPF_WRITE : CPF_READ));
if(grant_id == -1)
panic("req_breadwrite: cpf_grant_magic failed");
/* Fill in request message */
m.m_type = rw_flag == READING ? REQ_BREAD : REQ_BWRITE;
m.REQ_DEV2 = dev;
m.REQ_GRANT = grant_id;
m.REQ_SEEK_POS_LO = ex64lo(pos);
m.REQ_SEEK_POS_HI = ex64hi(pos);
m.REQ_NBYTES = num_of_bytes;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
if (r != OK) return(r);
/* Fill in response structure */
*new_posp = make64(m.RES_SEEK_POS_LO, m.RES_SEEK_POS_HI);
*cum_iop = m.RES_NBYTES;
return(OK);
}
/*===========================================================================*
* req_chmod *
*===========================================================================*/
PUBLIC int req_chmod(
int fs_e,
ino_t inode_nr,
mode_t rmode,
mode_t *new_modep
)
{
message m;
int r;
/* Fill in request message */
m.m_type = REQ_CHMOD;
m.REQ_INODE_NR = inode_nr;
m.REQ_MODE = rmode;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
/* Copy back actual mode. */
*new_modep = m.RES_MODE;
return(r);
}
/*===========================================================================*
* req_chown *
*===========================================================================*/
PUBLIC int req_chown(
endpoint_t fs_e,
ino_t inode_nr,
uid_t newuid,
gid_t newgid,
mode_t *new_modep
)
{
message m;
int r;
/* Fill in request message */
m.m_type = REQ_CHOWN;
m.REQ_INODE_NR = inode_nr;
m.REQ_UID = newuid;
m.REQ_GID = newgid;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
/* Return new mode to caller. */
*new_modep = m.RES_MODE;
return(r);
}
/*===========================================================================*
* req_create *
*===========================================================================*/
PUBLIC int req_create(
int fs_e,
ino_t inode_nr,
int omode,
uid_t uid,
gid_t gid,
char *path,
node_details_t *res
)
{
int r;
cp_grant_id_t grant_id;
size_t len;
message m;
if (path[0] == '/')
panic("req_create: filename starts with '/'");
len = strlen(path) + 1;
grant_id = cpf_grant_direct(fs_e, (vir_bytes) path, len, CPF_READ);
if (grant_id == -1)
panic("req_create: cpf_grant_direct failed");
/* Fill in request message */
m.m_type = REQ_CREATE;
m.REQ_INODE_NR = inode_nr;
m.REQ_MODE = omode;
m.REQ_UID = uid;
m.REQ_GID = gid;
m.REQ_GRANT = grant_id;
m.REQ_PATH_LEN = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
if (r != OK) return(r);
/* Fill in response structure */
res->fs_e = m.m_source;
res->inode_nr = m.RES_INODE_NR;
res->fmode = m.RES_MODE;
res->fsize = m.RES_FILE_SIZE_LO;
res->uid = m.RES_UID;
res->gid = m.RES_GID;
res->dev = m.RES_DEV;
return(OK);
}
/*===========================================================================*
* req_flush *
*===========================================================================*/
PUBLIC int req_flush(endpoint_t fs_e, dev_t dev)
{
message m;
/* Fill in request message */
m.m_type = REQ_FLUSH;
m.REQ_DEV = dev;
/* Send/rec request */
return fs_sendrec(fs_e, &m);
}
/*===========================================================================*
* req_fstatfs *
*===========================================================================*/
PUBLIC int req_fstatfs(int fs_e, int who_e, char *buf)
{
int r;
cp_grant_id_t grant_id;
message m;
grant_id = cpf_grant_magic(fs_e, who_e, (vir_bytes) buf, sizeof(struct statfs),
CPF_WRITE);
if(grant_id == -1)
panic("req_fstatfs: cpf_grant_magic failed");
/* Fill in request message */
m.m_type = REQ_FSTATFS;
m.REQ_GRANT = grant_id;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
return(r);
}
/*===========================================================================*
* req_statvfs *
*===========================================================================*/
PUBLIC int req_statvfs(int fs_e, int who_e, char *buf)
{
int r;
cp_grant_id_t grant_id;
message m;
grant_id = cpf_grant_magic(fs_e, who_e, (vir_bytes) buf, sizeof(struct statvfs),
CPF_WRITE);
if(grant_id == -1)
panic("req_statvfs: cpf_grant_magic failed");
/* Fill in request message */
m.m_type = REQ_STATVFS;
m.REQ_GRANT = grant_id;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
return(r);
}
/*===========================================================================*
* req_ftrunc *
*===========================================================================*/
PUBLIC int req_ftrunc(endpoint_t fs_e, ino_t inode_nr, off_t start, off_t end)
{
message m;
/* Fill in request message */
m.m_type = REQ_FTRUNC;
m.REQ_INODE_NR = inode_nr;
m.REQ_TRC_START_LO = start;
m.REQ_TRC_START_HI = 0; /* Not used for now, so clear it. */
m.REQ_TRC_END_LO = end;
m.REQ_TRC_END_HI = 0; /* Not used for now, so clear it. */
/* Send/rec request */
return fs_sendrec(fs_e, &m);
}
/*===========================================================================*
* req_getdents *
*===========================================================================*/
PUBLIC int req_getdents(
endpoint_t fs_e,
ino_t inode_nr,
u64_t pos,
char *buf,
size_t size,
u64_t *new_pos,
int direct
)
{
int r;
message m;
cp_grant_id_t grant_id;
if (direct) {
grant_id = cpf_grant_direct(fs_e, (vir_bytes) buf, size,
CPF_WRITE);
} else {
grant_id = cpf_grant_magic(fs_e, who_e, (vir_bytes) buf, size,
CPF_WRITE);
}
if (grant_id < 0)
panic("req_getdents: cpf_grant_direct/cpf_grant_magic failed: %d",
grant_id);
m.m_type = REQ_GETDENTS;
m.REQ_INODE_NR = inode_nr;
m.REQ_GRANT = grant_id;
m.REQ_MEM_SIZE = size;
m.REQ_SEEK_POS_LO = ex64lo(pos);
m.REQ_SEEK_POS_HI = 0; /* Not used for now, so clear it. */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
if (r == OK) {
*new_pos = cvul64(m.RES_SEEK_POS_LO);
r = m.RES_NBYTES;
}
return(r);
}
/*===========================================================================*
* req_inhibread *
*===========================================================================*/
PUBLIC int req_inhibread(endpoint_t fs_e, ino_t inode_nr)
{
message m;
/* Fill in request message */
m.m_type = REQ_INHIBREAD;
m.REQ_INODE_NR = inode_nr;
/* Send/rec request */
return fs_sendrec(fs_e, &m);
}
/*===========================================================================*
* req_link *
*===========================================================================*/
PUBLIC int req_link(
endpoint_t fs_e,
ino_t link_parent,
char *lastc,
ino_t linked_file
)
{
int r;
cp_grant_id_t grant_id;
const size_t len = strlen(lastc) + 1;
message m;
grant_id = cpf_grant_direct(fs_e, (vir_bytes)lastc, len, CPF_READ);
if(grant_id == -1)
panic("req_link: cpf_grant_direct failed");
/* Fill in request message */
m.m_type = REQ_LINK;
m.REQ_INODE_NR = linked_file;
m.REQ_DIR_INO = link_parent;
m.REQ_GRANT = grant_id;
m.REQ_PATH_LEN = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
return(r);
}
/*===========================================================================*
* req_lookup *
*===========================================================================*/
PUBLIC int req_lookup(
endpoint_t fs_e,
ino_t dir_ino,
ino_t root_ino,
uid_t uid,
gid_t gid,
int flags,
lookup_res_t *res,
struct fproc *rfp
)
{
int r;
size_t len;
cp_grant_id_t grant_id, grant_id2;
message m;
vfs_ucred_t credentials;
grant_id = cpf_grant_direct(fs_e, (vir_bytes) user_fullpath,
sizeof(user_fullpath), CPF_READ | CPF_WRITE);
if(grant_id == -1)
panic("req_lookup: cpf_grant_direct failed");
len = strlen(user_fullpath) + 1;
m.m_type = REQ_LOOKUP;
m.REQ_GRANT = grant_id;
m.REQ_PATH_LEN = len;
m.REQ_PATH_SIZE = sizeof(user_fullpath);
m.REQ_DIR_INO = dir_ino;
m.REQ_ROOT_INO = root_ino;
if(rfp->fp_ngroups > 0) { /* Is the process member of multiple groups? */
/* In that case the FS has to copy the uid/gid credentials */
int i;
/* Set credentials */
credentials.vu_uid = rfp->fp_effuid;
credentials.vu_gid = rfp->fp_effgid;
credentials.vu_ngroups = rfp->fp_ngroups;
for (i = 0; i < rfp->fp_ngroups; i++)
credentials.vu_sgroups[i] = rfp->fp_sgroups[i];
grant_id2 = cpf_grant_direct(fs_e, (vir_bytes) &credentials,
sizeof(credentials), CPF_READ);
if(grant_id2 == -1)
panic("req_lookup: cpf_grant_direct failed");
m.REQ_GRANT2 = grant_id2;
m.REQ_UCRED_SIZE= sizeof(credentials);
flags |= PATH_GET_UCRED;
} else {
/* When there's only one gid, we can send it directly */
m.REQ_UID = uid;
m.REQ_GID = gid;
flags &= ~PATH_GET_UCRED;
}
m.REQ_FLAGS = flags;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
if(rfp->fp_ngroups > 0) cpf_revoke(grant_id2);
/* Fill in response according to the return value */
res->fs_e = m.m_source;
switch (r) {
case OK:
res->inode_nr = m.RES_INODE_NR;
res->fmode = m.RES_MODE;
res->fsize = m.RES_FILE_SIZE_LO;
res->dev = m.RES_DEV;
res->uid= m.RES_UID;
res->gid= m.RES_GID;
break;
case EENTERMOUNT:
res->inode_nr = m.RES_INODE_NR;
res->char_processed = m.RES_OFFSET;
res->symloop = m.RES_SYMLOOP;
break;
case ELEAVEMOUNT:
res->char_processed = m.RES_OFFSET;
res->symloop = m.RES_SYMLOOP;
break;
case ESYMLINK:
res->char_processed = m.RES_OFFSET;
res->symloop = m.RES_SYMLOOP;
break;
default:
break;
}
return(r);
}
/*===========================================================================*
* req_mkdir *
*===========================================================================*/
PUBLIC int req_mkdir(
endpoint_t fs_e,
ino_t inode_nr,
char *lastc,
uid_t uid,
gid_t gid,
mode_t dmode
)
{
int r;
cp_grant_id_t grant_id;
size_t len;
message m;
len = strlen(lastc) + 1;
grant_id = cpf_grant_direct(fs_e, (vir_bytes)lastc, len, CPF_READ);
if(grant_id == -1)
panic("req_mkdir: cpf_grant_direct failed");
/* Fill in request message */
m.m_type = REQ_MKDIR;
m.REQ_INODE_NR = inode_nr;
m.REQ_MODE = dmode;
m.REQ_UID = uid;
m.REQ_GID = gid;
m.REQ_GRANT = grant_id;
m.REQ_PATH_LEN = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
return(r);
}
/*===========================================================================*
* req_mknod *
*===========================================================================*/
PUBLIC int req_mknod(
endpoint_t fs_e,
ino_t inode_nr,
char *lastc,
uid_t uid,
gid_t gid,
mode_t dmode,
dev_t dev
)
{
int r;
size_t len;
cp_grant_id_t grant_id;
message m;
len = strlen(lastc) + 1;
grant_id = cpf_grant_direct(fs_e, (vir_bytes)lastc, len, CPF_READ);
if(grant_id == -1)
panic("req_mknod: cpf_grant_direct failed");
/* Fill in request message */
m.m_type = REQ_MKNOD;
m.REQ_INODE_NR = inode_nr;
m.REQ_MODE = dmode;
m.REQ_DEV = dev;
m.REQ_UID = uid;
m.REQ_GID = gid;
m.REQ_GRANT = grant_id;
m.REQ_PATH_LEN = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
return(r);
}
/*===========================================================================*
* req_mountpoint *
*===========================================================================*/
PUBLIC int req_mountpoint(endpoint_t fs_e, ino_t inode_nr)
{
message m;
/* Fill in request message */
m.m_type = REQ_MOUNTPOINT;
m.REQ_INODE_NR = inode_nr;
/* Send/rec request */
return fs_sendrec(fs_e, &m);
}
/*===========================================================================*
* req_newnode *
*===========================================================================*/
PUBLIC int req_newnode(
endpoint_t fs_e,
uid_t uid,
gid_t gid,
mode_t dmode,
dev_t dev,
struct node_details *res
)
{
int r;
message m;
/* Fill in request message */
m.m_type = REQ_NEWNODE;
m.REQ_MODE = dmode;
m.REQ_DEV = dev;
m.REQ_UID = uid;
m.REQ_GID = gid;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
res->fs_e = m.m_source;
res->inode_nr = m.RES_INODE_NR;
res->fmode = m.RES_MODE;
res->fsize = m.RES_FILE_SIZE_LO;
res->dev = m.RES_DEV;
res->uid = m.RES_UID;
res->gid = m.RES_GID;
return(r);
}
/*===========================================================================*
* req_newdriver *
*===========================================================================*/
PUBLIC int req_newdriver(
endpoint_t fs_e,
dev_t dev,
endpoint_t driver_e
)
{
/* Note: this is the only request function that doesn't use the
* fs_sendrec internal routine, since we want to avoid the dead
* driver recovery mechanism here. This function is actually called
* during the recovery.
*/
message m;
int r;
/* Fill in request message */
m.m_type = REQ_NEW_DRIVER;
m.REQ_DEV = dev;
m.REQ_DRIVER_E = driver_e;
/* Issue request */
if((r = sendrec(fs_e, &m)) != OK) {
printf("%s:%d VFS req_newdriver: error sending message %d to %d\n",
__FILE__, __LINE__, r, fs_e);
util_stacktrace();
return(r);
}
return(OK);
}
/*===========================================================================*
* req_putnode *
*===========================================================================*/
PUBLIC int req_putnode(fs_e, inode_nr, count)
int fs_e;
ino_t inode_nr;
int count;
{
message m;
/* Fill in request message */
m.m_type = REQ_PUTNODE;
m.REQ_INODE_NR = inode_nr;
m.REQ_COUNT = count;
/* Send/rec request */
return fs_sendrec(fs_e, &m);
}
/*===========================================================================*
* req_rdlink *
*===========================================================================*/
PUBLIC int req_rdlink(fs_e, inode_nr, who_e, buf, len, direct)
endpoint_t fs_e;
ino_t inode_nr;
endpoint_t who_e;
char *buf;
size_t len;
int direct; /* set to 1 to use direct grants instead of magic grants */
{
message m;
int r;
cp_grant_id_t grant_id;
if (direct) {
grant_id = cpf_grant_direct(fs_e, (vir_bytes) buf, len, CPF_WRITE);
} else {
grant_id = cpf_grant_magic(fs_e, who_e, (vir_bytes) buf, len,
CPF_WRITE);
}
if(grant_id == -1)
panic("req_rdlink: cpf_grant_magic failed");
/* Fill in request message */
m.m_type = REQ_RDLINK;
m.REQ_INODE_NR = inode_nr;
m.REQ_GRANT = grant_id;
m.REQ_MEM_SIZE = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
if(r == OK) r = m.RES_NBYTES;
return(r);
}
/*===========================================================================*
* req_readsuper *
*===========================================================================*/
PUBLIC int req_readsuper(
endpoint_t fs_e,
char *label,
dev_t dev,
int readonly,
int isroot,
struct node_details *res_nodep
)
{
int r;
cp_grant_id_t grant_id;
size_t len;
message m;
len = strlen(label)+1;
grant_id = cpf_grant_direct(fs_e, (vir_bytes) label, len, CPF_READ);
if (grant_id == -1)
panic("req_readsuper: cpf_grant_direct failed");
/* Fill in request message */
m.m_type = REQ_READSUPER;
m.REQ_FLAGS = 0;
if(readonly) m.REQ_FLAGS |= REQ_RDONLY;
if(isroot) m.REQ_FLAGS |= REQ_ISROOT;
m.REQ_GRANT = grant_id;
m.REQ_DEV = dev;
m.REQ_PATH_LEN = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
if(r == OK) {
/* Fill in response structure */
res_nodep->fs_e = m.m_source;
res_nodep->inode_nr = m.RES_INODE_NR;
res_nodep->fmode = m.RES_MODE;
res_nodep->fsize = m.RES_FILE_SIZE_LO;
res_nodep->uid = m.RES_UID;
res_nodep->gid = m.RES_GID;
}
return(r);
}
/*===========================================================================*
* req_readwrite *
*===========================================================================*/
PUBLIC int req_readwrite(fs_e, inode_nr, pos, rw_flag, user_e,
user_addr, num_of_bytes, new_posp, cum_iop)
endpoint_t fs_e;
ino_t inode_nr;
u64_t pos;
int rw_flag;
endpoint_t user_e;
char *user_addr;
unsigned int num_of_bytes;
u64_t *new_posp;
unsigned int *cum_iop;
{
int r;
cp_grant_id_t grant_id;
message m;
if (ex64hi(pos) != 0)
panic("req_readwrite: pos too large");
grant_id = cpf_grant_magic(fs_e, user_e, (vir_bytes) user_addr, num_of_bytes,
(rw_flag==READING ? CPF_WRITE:CPF_READ));
if (grant_id == -1)
panic("req_readwrite: cpf_grant_magic failed");
/* Fill in request message */
m.m_type = rw_flag == READING ? REQ_READ : REQ_WRITE;
m.REQ_INODE_NR = inode_nr;
m.REQ_GRANT = grant_id;
m.REQ_SEEK_POS_LO = ex64lo(pos);
m.REQ_SEEK_POS_HI = 0; /* Not used for now, so clear it. */
m.REQ_NBYTES = num_of_bytes;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
if (r == OK) {
/* Fill in response structure */
*new_posp = cvul64(m.RES_SEEK_POS_LO);
*cum_iop = m.RES_NBYTES;
}
return(r);
}
/*===========================================================================*
* req_rename *
*===========================================================================*/
PUBLIC int req_rename(fs_e, old_dir, old_name, new_dir, new_name)
endpoint_t fs_e;
ino_t old_dir;
char *old_name;
ino_t new_dir;
char *new_name;
{
int r;
cp_grant_id_t gid_old, gid_new;
size_t len_old, len_new;
message m;
len_old = strlen(old_name) + 1;
gid_old = cpf_grant_direct(fs_e, (vir_bytes) old_name, len_old, CPF_READ);
if(gid_old == -1)
panic("req_rename: cpf_grant_direct failed");
len_new = strlen(new_name) + 1;
gid_new = cpf_grant_direct(fs_e, (vir_bytes) new_name, len_new, CPF_READ);
if(gid_new == -1)
panic("req_rename: cpf_grant_direct failed");
/* Fill in request message */
m.m_type = REQ_RENAME;
m.REQ_REN_OLD_DIR = old_dir;
m.REQ_REN_NEW_DIR = new_dir;
m.REQ_REN_GRANT_OLD = gid_old;
m.REQ_REN_LEN_OLD = len_old;
m.REQ_REN_GRANT_NEW = gid_new;
m.REQ_REN_LEN_NEW = len_new;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(gid_old);
cpf_revoke(gid_new);
return(r);
}
/*===========================================================================*
* req_rmdir *
*===========================================================================*/
PUBLIC int req_rmdir(fs_e, inode_nr, lastc)
endpoint_t fs_e;
ino_t inode_nr;
char *lastc;
{
int r;
cp_grant_id_t grant_id;
size_t len;
message m;
len = strlen(lastc) + 1;
grant_id = cpf_grant_direct(fs_e, (vir_bytes) lastc, len, CPF_READ);
if(grant_id == -1)
panic("req_rmdir: cpf_grant_direct failed");
/* Fill in request message */
m.m_type = REQ_RMDIR;
m.REQ_INODE_NR = inode_nr;
m.REQ_GRANT = grant_id;
m.REQ_PATH_LEN = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
return(r);
}
/*===========================================================================*
* req_slink *
*===========================================================================*/
PUBLIC int req_slink(
endpoint_t fs_e,
ino_t inode_nr,
char *lastc,
endpoint_t who_e,
char *path_addr,
unsigned short path_length,
uid_t uid,
gid_t gid
)
{
int r;
size_t len;
cp_grant_id_t gid_name, gid_buf;
message m;
len = strlen(lastc) + 1;
gid_name = cpf_grant_direct(fs_e, (vir_bytes) lastc, len, CPF_READ);
if(gid_name == -1)
panic("req_slink: cpf_grant_direct failed");
gid_buf = cpf_grant_magic(fs_e, who_e, (vir_bytes) path_addr, path_length,
CPF_READ);
if(gid_buf == -1) {
cpf_revoke(gid_name);
panic("req_slink: cpf_grant_magic failed");
}
/* Fill in request message */
m.m_type = REQ_SLINK;
m.REQ_INODE_NR = inode_nr;
m.REQ_UID = uid;
m.REQ_GID = gid;
m.REQ_GRANT = gid_name;
m.REQ_PATH_LEN = len;
m.REQ_GRANT3 = gid_buf;
m.REQ_MEM_SIZE = path_length;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(gid_name);
cpf_revoke(gid_buf);
return(r);
}
/*===========================================================================*
* req_stat *
*===========================================================================*/
PUBLIC int req_stat(fs_e, inode_nr, who_e, buf, pos)
int fs_e;
ino_t inode_nr;
int who_e;
char *buf;
int pos;
{
cp_grant_id_t grant_id;
int r;
message m;
struct stat sb;
if (pos != 0)
grant_id = cpf_grant_direct(fs_e, (vir_bytes) &sb,
sizeof(struct stat), CPF_WRITE);
else
grant_id = cpf_grant_magic(fs_e, who_e, (vir_bytes) buf,
sizeof(struct stat), CPF_WRITE);
if (grant_id < 0)
panic("req_stat: cpf_grant_* failed");
/* Fill in request message */
m.m_type = REQ_STAT;
m.REQ_INODE_NR = inode_nr;
m.REQ_GRANT = grant_id;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
if (r == OK && pos != 0) {
sb.st_size -= pos;
r = sys_vircopy(SELF, D, (vir_bytes) &sb, who_e, D, (vir_bytes) buf,
sizeof(struct stat));
}
return(r);
}
/*===========================================================================*
* req_sync *
*===========================================================================*/
PUBLIC int req_sync(fs_e)
endpoint_t fs_e;
{
message m;
/* Fill in request message */
m.m_type = REQ_SYNC;
/* Send/rec request */
return fs_sendrec(fs_e, &m);
}
/*===========================================================================*
* req_unlink *
*===========================================================================*/
PUBLIC int req_unlink(fs_e, inode_nr, lastc)
endpoint_t fs_e;
ino_t inode_nr;
char *lastc;
{
cp_grant_id_t grant_id;
size_t len;
int r;
message m;
len = strlen(lastc) + 1;
grant_id = cpf_grant_direct(fs_e, (vir_bytes) lastc, len, CPF_READ);
if(grant_id == -1)
panic("req_unlink: cpf_grant_direct failed");
/* Fill in request message */
m.m_type = REQ_UNLINK;
m.REQ_INODE_NR = inode_nr;
m.REQ_GRANT = grant_id;
m.REQ_PATH_LEN = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
return(r);
}
/*===========================================================================*
* req_unmount *
*===========================================================================*/
PUBLIC int req_unmount(fs_e)
endpoint_t fs_e;
{
message m;
/* Fill in request message */
m.m_type = REQ_UNMOUNT;
/* Send/rec request */
return fs_sendrec(fs_e, &m);
}
/*===========================================================================*
* req_utime *
*===========================================================================*/
PUBLIC int req_utime(fs_e, inode_nr, actime, modtime)
endpoint_t fs_e;
ino_t inode_nr;
time_t actime;
time_t modtime;
{
message m;
/* Fill in request message */
m.m_type = REQ_UTIME;
m.REQ_INODE_NR = inode_nr;
m.REQ_ACTIME = actime;
m.REQ_MODTIME = modtime;
/* Send/rec request */
return fs_sendrec(fs_e, &m);
}
/*===========================================================================*
* fs_sendrec *
*===========================================================================*/
PRIVATE int fs_sendrec_f(char *file, int line, endpoint_t fs_e, message *reqm)
{
/* This is the low level function that sends requests to FS processes.
* It also handles driver recovery mechanism and reissuing the
* request which failed due to a dead driver.
*/
int r, old_driver_e;
message origm, m;
if(fs_e <= 0 || fs_e == NONE)
panic("talking to bogus endpoint: %d", fs_e);
/* Make a copy of the request so that we can load it back in
* case of a dead driver */
origm = *reqm;
/* In response to the request we sent, some file systems may send back their
* own VFS request, instead of a reply. VFS currently offers limited support
* for this. As long as the FS keeps sending requests, we process them and
* send back a reply. We break out of the loop as soon as the FS sends a
* reply to the original request.
*
* There is no form of locking or whatever on global data structures, so it
* is quite easy to mess things up; hence, 'limited' support. A future async
* VFS will solve this problem for good.
*/
for (;;) {
/* Do the actual send, receive */
if (OK != (r = sendrec(fs_e, reqm))) {
printf("VFS:fs_sendrec:%s:%d: error sending message. "
"FS_e: %d req_nr: %d err: %d\n", file, line, fs_e,
reqm->m_type, r);
util_stacktrace();
return(r);
}
/* If the type field is 0 (OK) or negative (E*), this is a reply. If it
* contains a positive nonzero value, this is a request.
*/
if (reqm->m_type <= 0)
break; /* Reply */
if (reqm->m_type == -EENTERMOUNT || reqm->m_type == -ELEAVEMOUNT ||
reqm->m_type == -ESYMLINK) {
reqm->m_type = -reqm->m_type;
break; /* Reply */
}
/* Request */
nested_fs_call(reqm);
}
#if 0
if(r == OK) {
/* Sendrec was okay */
break;
}
/* Dead driver */
if (r == EDEADSRCDST || r == EDSTDIED || r == ESRCDIED) {
old_driver_e = NONE;
/* Find old driver by endpoint */
for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) {
if (vmp->m_fs_e == fs_e) { /* found FS */
#if 0
old_driver_e = vmp->m_driver_e;
#endif
dmap_unmap_by_endpt(old_driver_e); /* unmap driver */
break;
}
}
/* No FS ?? */
if (old_driver_e == NONE)
panic("VFSdead_driver: couldn't find FS: %d", fs_e);
/* Wait for a new driver. */
for (;;) {
new_driver_e = 0;
printf("VFSdead_driver: waiting for new driver\n");
r = sef_receive(RS_PROC_NR, &m);
if (r != OK) {
panic("VFSdead_driver: unable to receive from RS: %d", r);
}
if (m.m_type == DEVCTL) {
/* Map new driver */
r = fs_devctl(m.ctl_req, m.dev_nr, m.driver_nr,
m.dev_style, m.m_force);
if (m.ctl_req == DEV_MAP && r == OK) {
new_driver_e = m.driver_nr;
printf("VFSdead_driver: new driver endpoint: %d\n",
new_driver_e);
}
}
else {
panic("VFSdead_driver: got message from RS type: %d", m.m_type);
}
m.m_type = r;
if ((r = send(RS_PROC_NR, &m)) != OK) {
panic("VFSdead_driver: unable to send to RS: %d", r);
}
/* New driver is ready */
if (new_driver_e) break;
}
/* Copy back original request */
*reqm = origm;
continue;
}
printf("fs_sendrec: unhandled error %d sending to %d\n", r, fs_e);
panic("fs_sendrec: unhandled error");
}
#endif
/* Return message type */
return(reqm->m_type);
}
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