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minix/servers/vfs/request.c
David van Moolenbroek 0ac1aaccca Limited support for nested FS->VFS requests during VFS->FS call. 
- Changed VFS-FS protocol to only store OK or negative error code in
  m_type field of reply messages.
- Changed VFS to treat nonzero positive replies from FS as requests.
- Added backwards compatibility to VFS and MFS.
No protection of global data structures is provided in VFS, so many
VFS calls cannot be made safely by FS servers during many FS calls.
Use with caution (or, preferably, not at all).
2009-05-11 10:02:28 +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.
*
* Sep 2006 (Balazs Gerofi)
*/
#include "fs.h"
#include <string.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/keymap.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(fs_e, user_e, dev, pos, num_of_bytes, user_addr,
rw_flag, new_posp, cum_iop)
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 gid;
message m;
gid= cpf_grant_magic(fs_e, user_e, (vir_bytes)user_addr,
num_of_bytes, (rw_flag == READING ? CPF_WRITE : CPF_READ));
if (gid == -1)
panic(__FILE__, "req_breadwrite: cpf_grant_magic failed", NO_NUM);
/* Fill in request message */
m.m_type = rw_flag == READING ? REQ_BREAD_S : REQ_BWRITE_S;
m.REQ_XFD_BDEV = dev;
m.REQ_XFD_GID = gid;
m.REQ_XFD_POS_LO = ex64lo(pos);
m.REQ_XFD_POS_HI = ex64hi(pos);
m.REQ_XFD_NBYTES = num_of_bytes;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(gid);
if (r != OK) return r;
/* Fill in response structure */
*new_posp = make64(m.RES_XFD_POS_LO, m.RES_XFD_POS_HI);
*cum_iop = m.RES_XFD_CUM_IO;
return OK;
}
/*===========================================================================*
* req_chmod *
*===========================================================================*/
PUBLIC int req_chmod(fs_e, inode_nr, rmode, new_modep)
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;
m.REQ_UID = fp->fp_effuid;
m.REQ_GID = fp->fp_effgid;
/* 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(fs_e, inode_nr, newuid, newgid, new_modep)
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 = fp->fp_effuid;
m.REQ_GID = fp->fp_effgid;
m.REQ_NEW_UID = newuid;
m.REQ_NEW_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 *
*===========================================================================*/
int req_create(fs_e, inode_nr, omode, uid, gid, path, res)
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;
len= strlen(path) + 1;
grant_id= cpf_grant_direct(fs_e, (vir_bytes)path, len, CPF_READ);
if (grant_id == -1)
panic(__FILE__, "req_create: cpf_grant_direct failed", NO_NUM);
/* Fill in request message */
m.m_type = REQ_CREATE_S;
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;
res->uid = m.RES_UID;
res->gid = m.RES_GID;
res->dev = m.RES_DEV;
res->inode_index = m.RES_INODE_INDEX;
return OK;
}
/*===========================================================================*
* req_flush *
*===========================================================================*/
PUBLIC int req_flush(fs_e, dev)
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(fs_e, who_e, buf)
int fs_e;
int who_e;
char *buf;
{
int r;
cp_grant_id_t gid;
message m;
gid= cpf_grant_magic(fs_e, who_e, (vir_bytes)buf, sizeof(struct statfs),
CPF_WRITE);
if (gid < 0)
return gid;
/* Fill in request message */
m.m_type = REQ_FSTATFS;
m.REQ_GRANT = gid;
/* Send/rec request */
r= fs_sendrec(fs_e, &m);
cpf_revoke(gid);
return r;
}
/*===========================================================================*
* req_ftrunc *
*===========================================================================*/
PUBLIC int req_ftrunc(fs_e, inode_nr, start, end)
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_FD_INODE_NR = inode_nr;
m.REQ_FD_START = start;
m.REQ_FD_END = end;
/* Send/rec request */
return fs_sendrec(fs_e, &m);
}
/*===========================================================================*
* req_getdents *
*===========================================================================*/
PUBLIC int req_getdents(fs_e, inode_nr, pos, gid, size, pos_change)
endpoint_t fs_e;
ino_t inode_nr;
off_t pos;
cp_grant_id_t gid;
size_t size;
off_t *pos_change;
{
int r;
message m;
m.m_type= REQ_GETDENTS;
m.REQ_GDE_INODE= inode_nr;
m.REQ_GDE_GRANT= gid;
m.REQ_GDE_SIZE= size;
m.REQ_GDE_POS= pos;
r = fs_sendrec(fs_e, &m);
if (r != ENOSYS && r != EINVAL) {
*pos_change= m.RES_GDE_POS_CHANGE;
if (r == OK)
r = m.RES_GDE_CUM_IO;
return r;
}
/* Legacy support: try the old getdents */
m.m_type = REQ_GETDENTS_O;
m.REQ_GDE_INODE= inode_nr;
m.REQ_GDE_GRANT= gid;
m.REQ_GDE_SIZE= size;
m.REQ_GDE_POS= pos;
r = fs_sendrec(fs_e, &m);
*pos_change= m.RES_GDE_POS_CHANGE;
return r;
}
/*===========================================================================*
* req_inhibread *
*===========================================================================*/
PUBLIC int req_inhibread(fs_e, inode_nr)
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(fs_e, link_parent, lastc, linked_file)
endpoint_t fs_e;
ino_t link_parent;
char *lastc;
ino_t linked_file;
{
int r;
cp_grant_id_t gid;
size_t len;
message m;
len= strlen(lastc) + 1;
gid= cpf_grant_direct(fs_e, (vir_bytes)lastc, len, CPF_READ);
if (gid == -1)
panic(__FILE__, "req_link: cpf_grant_direct failed", NO_NUM);
/* Fill in request message */
m.m_type = REQ_LINK_S;
m.REQ_LINKED_FILE = linked_file;
m.REQ_LINK_PARENT = link_parent;
m.REQ_GRANT = gid;
m.REQ_PATH_LEN = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(gid);
return r;
}
/*===========================================================================*
* req_lookup *
*===========================================================================*/
PUBLIC int req_lookup(fs_e, path_off, dir_ino, root_ino, uid, gid, flags, res)
endpoint_t fs_e;
size_t path_off;
ino_t dir_ino;
ino_t root_ino;
uid_t uid;
gid_t gid;
int flags;
lookup_res_t *res;
{
int r;
size_t len;
cp_grant_id_t grant_id;
message m;
#if 0
printf("req_lookup_s: fs %d, ino %d, root %d, string (off %d) '%s'\n",
fs_e, dir_ino, root_ino, path_off, user_fullpath+path_off);
#endif
grant_id= cpf_grant_direct(fs_e, (vir_bytes)user_fullpath,
sizeof(user_fullpath), CPF_READ|CPF_WRITE);
if (grant_id == -1)
panic(__FILE__, "req_lookup_s: cpf_grant_direct failed", NO_NUM);
len= strlen(user_fullpath+path_off) + 1;
/* Fill in request message */
m.m_type = REQ_LOOKUP_S;
m.REQ_L_GRANT = grant_id;
m.REQ_L_PATH_LEN = len;
m.REQ_L_PATH_SIZE = sizeof(user_fullpath);
m.REQ_L_PATH_OFF = path_off;
m.REQ_L_DIR_INO = dir_ino;
m.REQ_L_ROOT_INO = root_ino;
m.REQ_L_FLAGS = flags;
m.REQ_L_UID = uid;
m.REQ_L_GID = gid;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(grant_id);
/* 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;
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_SYMLOOP2;
break;
case ELEAVEMOUNT:
res->char_processed = m.RES_OFFSET;
res->symloop = m.RES_SYMLOOP2;
break;
case ESYMLINK:
res->char_processed = m.RES_OFFSET;
res->symloop = m.RES_SYMLOOP2;
break;
default:
break;
}
return r;
}
/*===========================================================================*
* req_mkdir *
*===========================================================================*/
PUBLIC int req_mkdir(fs_e, inode_nr, lastc, uid, gid, dmode)
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(__FILE__, "req_mkdir: cpf_grant_direct failed", NO_NUM);
/* Fill in request message */
m.m_type = REQ_MKDIR_S;
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(fs_e, inode_nr, lastc, uid, gid, dmode, dev)
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(__FILE__, "req_mknod: cpf_grant_direct failed", NO_NUM);
/* Fill in request message */
m.m_type = REQ_MKNOD_S;
m.REQ_INODE_NR = inode_nr;
m.REQ_MODE = dmode;
m.REQ_DEVx = 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(fs_e, inode_nr)
endpoint_t fs_e;
ino_t inode_nr;
{
int r;
message m;
/* Fill in request message */
m.m_type = REQ_MOUNTPOINT_S;
m.REQ_INODE_NR = inode_nr;
/* Send/rec request */
return fs_sendrec(fs_e, &m);
}
/*===========================================================================*
* req_newnode *
*===========================================================================*/
PUBLIC int req_newnode(fs_e, uid, gid, dmode, dev, res)
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_DEVx = 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;
res->dev = m.RES_DEV;
res->uid= m.RES_UID;
res->gid= m.RES_GID;
return r;
}
/*===========================================================================*
* req_newdriver *
*===========================================================================*/
PUBLIC int req_newdriver(fs_e, dev, driver_e)
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("VFSreq_newdriver: error sending message to %d: %d\n", fs_e, r);
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)
endpoint_t fs_e;
ino_t inode_nr;
endpoint_t who_e;
vir_bytes buf;
size_t len;
{
message m;
int r;
cp_grant_id_t gid;
gid= cpf_grant_magic(fs_e, who_e, buf, len, CPF_WRITE);
if (gid == -1)
panic(__FILE__, "req_rdlink: cpf_grant_magic failed", NO_NUM);
/* Fill in request message */
m.m_type = REQ_RDLINK_S;
m.REQ_INODE_NR = inode_nr;
m.REQ_GRANT = gid;
m.REQ_SLENGTH = len;
/* Send/rec request */
r= fs_sendrec(fs_e, &m);
if (r != ENOSYS && r != EINVAL) {
cpf_revoke(gid);
if (r == OK)
r = m.RES_RDL_LENGTH;
return r;
}
/* Legacy support: try the old rdlink */
m.m_type = REQ_RDLINK_SO;
m.REQ_INODE_NR = inode_nr;
m.REQ_GRANT = gid;
m.REQ_SLENGTH = len;
r= fs_sendrec(fs_e, &m);
cpf_revoke(gid);
return r;
}
/*===========================================================================*
* req_readsuper *
*===========================================================================*/
PUBLIC int req_readsuper(fs_e, label, dev, readonly, isroot, res_nodep)
endpoint_t fs_e;
char *label;
dev_t dev;
int readonly;
int isroot;
struct node_details *res_nodep;
{
int r;
cp_grant_id_t gid;
size_t len;
message m;
len= strlen(label)+1;
gid= cpf_grant_direct(fs_e, (vir_bytes)label, len, CPF_READ);
if (gid == -1)
panic(__FILE__, "req_req_readsuper: cpf_grant_direct failed", NO_NUM);
/* Fill in request message */
m.m_type = REQ_READSUPER_S;
m.REQ_READONLY = readonly;
m.REQ_GRANT2 = gid;
m.REQ_DEV = dev;
m.REQ_ISROOT = isroot;
m.REQ_PATH_LEN = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(gid);
if(r != OK) return r;
/* 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;
res_nodep->uid = m.RES_UID;
res_nodep->gid = m.RES_GID;
return OK;
}
/*===========================================================================*
* req_readwrite *
*===========================================================================*/
PUBLIC int req_readwrite(fs_e, inode_nr, inode_index, pos, rw_flag, user_e,
user_addr, num_of_bytes, new_posp, cum_iop)
endpoint_t fs_e;
ino_t inode_nr;
unsigned short inode_index;
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 gid;
message m;
if (ex64hi(pos) != 0)
panic(__FILE__, "req_readwrite: pos too large", NO_NUM);
gid= cpf_grant_magic(fs_e, user_e, (vir_bytes)user_addr,
num_of_bytes, (rw_flag == READING ? CPF_WRITE : CPF_READ));
if (gid == -1)
panic(__FILE__, "req_readwrite: cpf_grant_magic failed", NO_NUM);
/* Fill in request message */
m.m_type = rw_flag == READING ? REQ_READ_S : REQ_WRITE_S;
m.REQ_FD_INODE_NR = inode_nr;
m.REQ_FD_GID = gid;
m.REQ_FD_POS = ex64lo(pos);
m.REQ_FD_NBYTES = num_of_bytes;
m.REQ_FD_INODE_INDEX = inode_index;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(gid);
if (r != OK) return r;
/* Fill in response structure */
*new_posp = cvul64(m.RES_FD_POS);
*cum_iop = m.RES_FD_CUM_IO;
return OK;
}
/*===========================================================================*
* 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(__FILE__, "req_rename: cpf_grant_direct failed", NO_NUM);
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(__FILE__, "req_rename: cpf_grant_direct failed", NO_NUM);
/* Fill in request message */
m.m_type = REQ_RENAME_S;
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 gid;
size_t len;
message m;
len= strlen(lastc) + 1;
gid= cpf_grant_direct(fs_e, (vir_bytes)lastc, len, CPF_READ);
if (gid == -1)
panic(__FILE__, "req_rmdir: cpf_grant_direct failed", NO_NUM);
/* Fill in request message */
m.m_type = REQ_RMDIR_S;
m.REQ_INODE_NR = inode_nr;
m.REQ_GRANT = gid;
m.REQ_PATH_LEN = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(gid);
return r;
}
/*===========================================================================*
* req_slink *
*===========================================================================*/
PUBLIC int req_slink(fs_e, inode_nr, lastc, who_e, path_addr, path_length,
uid, gid)
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(__FILE__, "req_slink: cpf_grant_direct failed", NO_NUM);
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(__FILE__, "req_slink: cpf_grant_magic failed", NO_NUM);
}
/* Fill in request message */
m.m_type = REQ_SLINK_S;
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_GRANT2 = gid_buf;
m.REQ_SLENGTH = 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 gid;
int r;
message m;
struct stat sb;
if (pos != 0)
{
gid= cpf_grant_direct(fs_e, (vir_bytes)&sb, sizeof(struct stat),
CPF_WRITE);
}
else
{
gid= cpf_grant_magic(fs_e, who_e, (vir_bytes)buf, sizeof(struct stat),
CPF_WRITE);
}
if (gid < 0)
panic(__FILE__, "req_stat: cpf_grant_* failed", NO_NUM);
/* Fill in request message */
m.m_type = REQ_STAT;
m.REQ_INODE_NR = inode_nr;
m.REQ_GRANT = gid;
/* Send/rec request */
r= fs_sendrec(fs_e, &m);
cpf_revoke(gid);
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 gid;
size_t len;
int r;
message m;
len= strlen(lastc) + 1;
gid= cpf_grant_direct(fs_e, (vir_bytes)lastc, len, CPF_READ);
if (gid == -1)
panic(__FILE__, "req_unlink: cpf_grant_direct failed", NO_NUM);
/* Fill in request message */
m.m_type = REQ_UNLINK_S;
m.REQ_INODE_NR = inode_nr;
m.REQ_GRANT = gid;
m.REQ_PATH_LEN = len;
/* Send/rec request */
r = fs_sendrec(fs_e, &m);
cpf_revoke(gid);
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, new_driver_e;
message origm, m;
struct vmnt *vmp;
if(fs_e <= 0 || fs_e == NONE)
panic(__FILE__, "talking to bogus endpoint", 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 */
/* Legacy support: hacks for old nonzero nonnegative replies */
if (origm.m_type == REQ_GETDENTS_O || origm.m_type == REQ_RDLINK_SO)
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(__FILE__, "VFSdead_driver: couldn't find FS\n", fs_e);
/* Wait for a new driver. */
for (;;) {
new_driver_e = 0;
printf("VFSdead_driver: waiting for new driver\n");
r = receive(RS_PROC_NR, &m);
if (r != OK) {
panic(__FILE__, "VFSdead_driver: unable to receive from RS",
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(__FILE__, "VFSdead_driver: got message from RS, type",
m.m_type);
}
m.m_type = r;
if ((r = send(RS_PROC_NR, &m)) != OK) {
panic(__FILE__, "VFSdead_driver: unable to send to RS",
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(__FILE__, "fs_sendrec: unhandled error", NO_NUM);
}
#endif
/* Return message type */
return reqm->m_type;
}
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