minix/servers/vfs/open.c

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/* This file contains the procedures for creating, opening, closing, and
* seeking on files.
*
* The entry points into this file are
* do_creat: perform the CREAT system call
* do_open: perform the OPEN system call
* do_mknod: perform the MKNOD system call
* do_mkdir: perform the MKDIR system call
* do_close: perform the CLOSE system call
* do_lseek: perform the LSEEK system call
*
* Changes for VFS:
* Jul 2006 (Balazs Gerofi)
*/
#include "fs.h"
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/u64.h>
#include "file.h"
#include "fproc.h"
#include "lock.h"
#include "param.h"
#include <dirent.h>
Mostly bugfixes of bugs triggered by the test set. bugfixes: SYSTEM: . removed rc->p_priv->s_flags = 0; for the priv struct shared by all user processes in get_priv(). this should only be done once. doing a SYS_PRIV_USER in sys_privctl() caused the flags of all user processes to be reset, so they were no longer PREEMPTIBLE. this happened when RS executed a policy script. (this broke test1 in the test set) VFS/MFS: . chown can change the mode of a file, and chmod arguments are only part of the full file mode so the full filemode is slightly magic. changed these calls so that the final modes are returned to VFS, so that the vnode can be kept up-to-date. (this broke test11 in the test set) MFS: . lookup() checked for sizeof(string) instead of sizeof(user_path), truncating long path names (caught by test 23) . truncate functions neglected to update ctime (this broke test16) VFS: . corner case of an empty filename lookup caused fields of a request not to be filled in in the lookup functions, not making it clear that the lookup had failed, causing messages to garbage processes, causing strange failures. (caught by test 30) . trust v_size in vnode when doing reads or writes on non-special files, truncating i/o where necessary; this is necessary for pipes, as MFS can't tell when a pipe has been truncated without it being told explicitly each time. when the last reader/writer on a pipe closes, tell FS about the new size using truncate_vn(). (this broke test 25, among others) . permission check for chdir() had disappeared; added a forbidden() call (caught by test 23) new code, shouldn't change anything: . introduced RTS_SET, RTS_UNSET, and RTS_ISSET macro's, and their LOCK variants. These macros set and clear the p_rts_flags field, causing a lot of duplicated logic like old_flags = rp->p_rts_flags; /* save value of the flags */ rp->p_rts_flags &= ~NO_PRIV; if (old_flags != 0 && rp->p_rts_flags == 0) lock_enqueue(rp); to change into the simpler RTS_LOCK_UNSET(rp, NO_PRIV); so the macros take care of calling dequeue() and enqueue() (or lock_*()), as the case may be). This makes the code a bit more readable and a bit less fragile. . removed return code from do_clocktick in CLOCK as it currently never replies . removed some debug code from VFS . fixed grant debug message in device.c preemptive checks, tests, changes: . added return code checks of receive() to SYSTEM and CLOCK . O_TRUNC should never arrive at MFS (added sanity check and removed O_TRUNC code) . user_path declared with PATH_MAX+1 to let it be null-terminated . checks in MFS to see if strings passed by VFS are null-terminated IS: . static irq name table thrown out
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#include <assert.h>
#include <minix/vfsif.h>
#include "vnode.h"
#include "vmnt.h"
#define offset_lo m2_l1
#define offset_high m2_l2
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FORWARD _PROTOTYPE( int x_open, (int bits, int oflags, int omode,
char *lastc, struct vnode **vpp) );
FORWARD _PROTOTYPE( int common_open, (int oflags, mode_t omode) );
FORWARD _PROTOTYPE( int pipe_open, (struct vnode *vp,mode_t bits,int oflags));
/*===========================================================================*
* do_creat *
*===========================================================================*/
PUBLIC int do_creat()
{
/* Perform the creat(name, mode) system call. */
int r;
if (fetch_name(m_in.name, m_in.name_length, M3) != OK) return(err_code);
r = common_open(O_WRONLY | O_CREAT | O_TRUNC, (mode_t) m_in.mode);
return(r);
}
/*===========================================================================*
* do_open *
*===========================================================================*/
PUBLIC int do_open()
{
/* Perform the open(name, flags,...) system call. */
int create_mode = 0; /* is really mode_t but this gives problems */
int r;
/* If O_CREAT is set, open has three parameters, otherwise two. */
if (m_in.mode & O_CREAT) {
create_mode = m_in.c_mode;
r = fetch_name(m_in.c_name, m_in.name1_length, M1);
} else {
r = fetch_name(m_in.name, m_in.name_length, M3);
}
if (r != OK) {
return(err_code); /* name was bad */
}
r = common_open(m_in.mode, create_mode);
return(r);
}
/*===========================================================================*
* common_open *
*===========================================================================*/
PRIVATE int common_open(register int oflags, mode_t omode)
{
/* Common code from do_creat and do_open. */
int r, b, found;
dev_t dev;
mode_t bits;
off_t pos;
struct dmap *dp;
struct filp *fil_ptr, *filp2;
struct vnode *vp, *vp2;
struct vmnt *vmp;
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char Xlastc[NAME_MAX];
char *pathrem;
int m;
/* Request and response structures */
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struct lookup_req Xlookup_req;
struct open_req Xreq;
/* Remap the bottom two bits of oflags. */
m = oflags & O_ACCMODE;
switch(m) {
case O_RDONLY: bits = R_BIT; break;
case O_WRONLY: bits = W_BIT; break;
case O_RDWR: bits = R_BIT | W_BIT; break;
default: return EINVAL;
}
/* See if file descriptor and filp slots are available. */
if ((r = get_fd(0, bits, &m_in.fd, &fil_ptr)) != OK) return(r);
/* If O_CREATE, set umask */
if (oflags & O_CREAT) {
omode = I_REGULAR | (omode & ALL_MODES & fp->fp_umask);
}
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vp= NULL;
/* Fill in lookup request fields */
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Xlookup_req.path = user_fullpath;
Xlookup_req.lastc = Xlastc;
Xlookup_req.flags = oflags&O_CREAT ? (oflags&O_EXCL ? LAST_DIR :
LAST_DIR_EATSYM) : EAT_PATH;
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Xlookup_req.flags = ((oflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) ?
LAST_DIR : EAT_PATH;
Xlastc[0]= '\0'; /* Clear lastc, it will be filled with the part of the
* path that cannot be resolved.
*/
/* Request lookup */
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r = Xlookup_vp(&Xlookup_req, &vp, &pathrem);
if (r == OK && ((oflags & (O_CREAT|O_EXCL)) != (O_CREAT|O_EXCL)))
{
/* Clear lastc */
Xlastc[0]= '\0';
}
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/* Hide ENOENT for O_CREAT */
if (r == ENOENT && (oflags & O_CREAT))
{
if (pathrem == NULL)
panic(__FILE__, "no pathrem", NO_NUM);
Mostly bugfixes of bugs triggered by the test set. bugfixes: SYSTEM: . removed rc->p_priv->s_flags = 0; for the priv struct shared by all user processes in get_priv(). this should only be done once. doing a SYS_PRIV_USER in sys_privctl() caused the flags of all user processes to be reset, so they were no longer PREEMPTIBLE. this happened when RS executed a policy script. (this broke test1 in the test set) VFS/MFS: . chown can change the mode of a file, and chmod arguments are only part of the full file mode so the full filemode is slightly magic. changed these calls so that the final modes are returned to VFS, so that the vnode can be kept up-to-date. (this broke test11 in the test set) MFS: . lookup() checked for sizeof(string) instead of sizeof(user_path), truncating long path names (caught by test 23) . truncate functions neglected to update ctime (this broke test16) VFS: . corner case of an empty filename lookup caused fields of a request not to be filled in in the lookup functions, not making it clear that the lookup had failed, causing messages to garbage processes, causing strange failures. (caught by test 30) . trust v_size in vnode when doing reads or writes on non-special files, truncating i/o where necessary; this is necessary for pipes, as MFS can't tell when a pipe has been truncated without it being told explicitly each time. when the last reader/writer on a pipe closes, tell FS about the new size using truncate_vn(). (this broke test 25, among others) . permission check for chdir() had disappeared; added a forbidden() call (caught by test 23) new code, shouldn't change anything: . introduced RTS_SET, RTS_UNSET, and RTS_ISSET macro's, and their LOCK variants. These macros set and clear the p_rts_flags field, causing a lot of duplicated logic like old_flags = rp->p_rts_flags; /* save value of the flags */ rp->p_rts_flags &= ~NO_PRIV; if (old_flags != 0 && rp->p_rts_flags == 0) lock_enqueue(rp); to change into the simpler RTS_LOCK_UNSET(rp, NO_PRIV); so the macros take care of calling dequeue() and enqueue() (or lock_*()), as the case may be). This makes the code a bit more readable and a bit less fragile. . removed return code from do_clocktick in CLOCK as it currently never replies . removed some debug code from VFS . fixed grant debug message in device.c preemptive checks, tests, changes: . added return code checks of receive() to SYSTEM and CLOCK . O_TRUNC should never arrive at MFS (added sanity check and removed O_TRUNC code) . user_path declared with PATH_MAX+1 to let it be null-terminated . checks in MFS to see if strings passed by VFS are null-terminated IS: . static irq name table thrown out
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/* If any path remains, but no '/', O_CREAT can continue.
* If no path remains, a null filename was provided so ENOENT
* remains.
*/
if(*pathrem) {
if (strchr(pathrem, '/') == 0)
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r= OK;
Mostly bugfixes of bugs triggered by the test set. bugfixes: SYSTEM: . removed rc->p_priv->s_flags = 0; for the priv struct shared by all user processes in get_priv(). this should only be done once. doing a SYS_PRIV_USER in sys_privctl() caused the flags of all user processes to be reset, so they were no longer PREEMPTIBLE. this happened when RS executed a policy script. (this broke test1 in the test set) VFS/MFS: . chown can change the mode of a file, and chmod arguments are only part of the full file mode so the full filemode is slightly magic. changed these calls so that the final modes are returned to VFS, so that the vnode can be kept up-to-date. (this broke test11 in the test set) MFS: . lookup() checked for sizeof(string) instead of sizeof(user_path), truncating long path names (caught by test 23) . truncate functions neglected to update ctime (this broke test16) VFS: . corner case of an empty filename lookup caused fields of a request not to be filled in in the lookup functions, not making it clear that the lookup had failed, causing messages to garbage processes, causing strange failures. (caught by test 30) . trust v_size in vnode when doing reads or writes on non-special files, truncating i/o where necessary; this is necessary for pipes, as MFS can't tell when a pipe has been truncated without it being told explicitly each time. when the last reader/writer on a pipe closes, tell FS about the new size using truncate_vn(). (this broke test 25, among others) . permission check for chdir() had disappeared; added a forbidden() call (caught by test 23) new code, shouldn't change anything: . introduced RTS_SET, RTS_UNSET, and RTS_ISSET macro's, and their LOCK variants. These macros set and clear the p_rts_flags field, causing a lot of duplicated logic like old_flags = rp->p_rts_flags; /* save value of the flags */ rp->p_rts_flags &= ~NO_PRIV; if (old_flags != 0 && rp->p_rts_flags == 0) lock_enqueue(rp); to change into the simpler RTS_LOCK_UNSET(rp, NO_PRIV); so the macros take care of calling dequeue() and enqueue() (or lock_*()), as the case may be). This makes the code a bit more readable and a bit less fragile. . removed return code from do_clocktick in CLOCK as it currently never replies . removed some debug code from VFS . fixed grant debug message in device.c preemptive checks, tests, changes: . added return code checks of receive() to SYSTEM and CLOCK . O_TRUNC should never arrive at MFS (added sanity check and removed O_TRUNC code) . user_path declared with PATH_MAX+1 to let it be null-terminated . checks in MFS to see if strings passed by VFS are null-terminated IS: . static irq name table thrown out
2007-02-01 18:50:02 +01:00
else
{
printf("common_open: / in pathrem\n");
Mostly bugfixes of bugs triggered by the test set. bugfixes: SYSTEM: . removed rc->p_priv->s_flags = 0; for the priv struct shared by all user processes in get_priv(). this should only be done once. doing a SYS_PRIV_USER in sys_privctl() caused the flags of all user processes to be reset, so they were no longer PREEMPTIBLE. this happened when RS executed a policy script. (this broke test1 in the test set) VFS/MFS: . chown can change the mode of a file, and chmod arguments are only part of the full file mode so the full filemode is slightly magic. changed these calls so that the final modes are returned to VFS, so that the vnode can be kept up-to-date. (this broke test11 in the test set) MFS: . lookup() checked for sizeof(string) instead of sizeof(user_path), truncating long path names (caught by test 23) . truncate functions neglected to update ctime (this broke test16) VFS: . corner case of an empty filename lookup caused fields of a request not to be filled in in the lookup functions, not making it clear that the lookup had failed, causing messages to garbage processes, causing strange failures. (caught by test 30) . trust v_size in vnode when doing reads or writes on non-special files, truncating i/o where necessary; this is necessary for pipes, as MFS can't tell when a pipe has been truncated without it being told explicitly each time. when the last reader/writer on a pipe closes, tell FS about the new size using truncate_vn(). (this broke test 25, among others) . permission check for chdir() had disappeared; added a forbidden() call (caught by test 23) new code, shouldn't change anything: . introduced RTS_SET, RTS_UNSET, and RTS_ISSET macro's, and their LOCK variants. These macros set and clear the p_rts_flags field, causing a lot of duplicated logic like old_flags = rp->p_rts_flags; /* save value of the flags */ rp->p_rts_flags &= ~NO_PRIV; if (old_flags != 0 && rp->p_rts_flags == 0) lock_enqueue(rp); to change into the simpler RTS_LOCK_UNSET(rp, NO_PRIV); so the macros take care of calling dequeue() and enqueue() (or lock_*()), as the case may be). This makes the code a bit more readable and a bit less fragile. . removed return code from do_clocktick in CLOCK as it currently never replies . removed some debug code from VFS . fixed grant debug message in device.c preemptive checks, tests, changes: . added return code checks of receive() to SYSTEM and CLOCK . O_TRUNC should never arrive at MFS (added sanity check and removed O_TRUNC code) . user_path declared with PATH_MAX+1 to let it be null-terminated . checks in MFS to see if strings passed by VFS are null-terminated IS: . static irq name table thrown out
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}
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}
}
if (r != OK)
{
if (vp)
{
put_vnode(vp);
vp= NULL;
}
return r;
}
if (!vp) panic(__FILE__, "common_open: no vp", NO_NUM);
r= x_open(bits, oflags, omode, Xlastc, &vp);
if (r != OK)
{
if (vp)
{
put_vnode(vp);
vp= NULL;
}
return r;
}
#if 0
/* Lookup was okay, fill in request fields for
* the actual open request. */
req.inode_nr = res.inode_nr;
req.fs_e = res.fs_e;
req.oflags = oflags;
req.omode = omode;
req.lastc = lastc;
req.uid = fp->fp_effuid;
req.gid = fp->fp_effgid;
/* Issue request */
if ((r = req_open(&req, &res)) != OK) return r;
/* Check whether the vnode is already in use */
if ((vp2 = find_vnode(res.fs_e, res.inode_nr)) != NIL_VNODE) {
vp = vp2;
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vp->v_size = res.fsize; /* In case of trunc... */
vp->v_ref_count++;
vp->v_fs_count++;
}
/* Otherwise use the free one */
else {
vp->v_fs_e = res.fs_e;
if ( (vmp = find_vmnt(vp->v_fs_e)) == NIL_VMNT)
printf("VFS: vmnt not found by open()");
vp->v_dev = vmp->m_dev;
vp->v_inode_nr = res.inode_nr;
vp->v_mode = res.fmode;
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vp->v_uid = res.uid;
vp->v_gid = res.gid;
vp->v_size = res.fsize;
vp->v_sdev = res.dev;
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vp->v_fs_count = 1;
vp->v_ref_count = 1;
vp->v_vmnt = vmp;
vp->v_index = res.inode_index;
}
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#endif
/* Claim the file descriptor and filp slot and fill them in. */
fp->fp_filp[m_in.fd] = fil_ptr;
FD_SET(m_in.fd, &fp->fp_filp_inuse);
fil_ptr->filp_count = 1;
fil_ptr->filp_flags = oflags;
fil_ptr->filp_vno = vp;
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vp->v_isfifo= FALSE;
switch (vp->v_mode & I_TYPE) {
case I_CHAR_SPECIAL:
/* Invoke the driver for special processing. */
r = dev_open(vp->v_sdev, who_e, bits | (oflags & ~O_ACCMODE));
break;
case I_BLOCK_SPECIAL:
/* Invoke the driver for special processing. */
r = dev_open(vp->v_sdev, who_e, bits | (oflags & ~O_ACCMODE));
#if 0
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if (r != OK)
panic(__FILE__, "common_open: dev_open failed", r);
#endif
/* Check whether the device is mounted or not */
found = 0;
if (r == OK) {
for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) {
if (vmp->m_dev == vp->v_sdev) {
found = 1;
break;
}
}
/* Who is going to be responsible for this device? */
if (found) {
vp->v_bfs_e = vmp->m_fs_e;
vp->v_blocksize - vmp->m_block_size;
}
else { /* To be handled in the root FS proc if not mounted */
vp->v_bfs_e = ROOT_FS_E;
vp->v_blocksize = _MIN_BLOCK_SIZE;
}
/* Get the driver endpoint of the block spec device */
dp = &dmap[(vp->v_sdev >> MAJOR) & BYTE];
if (dp->dmap_driver == NONE) {
printf("VFSblock_spec_open: driver not found for device %d\n",
vp->v_sdev);
r = EINVAL;
break;
}
/* Send the driver endpoint (even if it is known already...) */
if ((r = req_newdriver(vp->v_bfs_e, vp->v_sdev, dp->dmap_driver))
!= OK) {
printf("VFSblock_spec_open: error sending driver endpoint\n");
}
}
break;
case I_NAMED_PIPE:
vp->v_pipe = I_PIPE;
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vp->v_isfifo= TRUE;
oflags |= O_APPEND; /* force append mode */
fil_ptr->filp_flags = oflags;
r = pipe_open(vp, bits, oflags);
if (r != ENXIO) {
/* See if someone else is doing a rd or wt on
* the FIFO. If so, use its filp entry so the
* file position will be automatically shared.
*/
b = (bits & R_BIT ? R_BIT : W_BIT);
Mostly bugfixes of bugs triggered by the test set. bugfixes: SYSTEM: . removed rc->p_priv->s_flags = 0; for the priv struct shared by all user processes in get_priv(). this should only be done once. doing a SYS_PRIV_USER in sys_privctl() caused the flags of all user processes to be reset, so they were no longer PREEMPTIBLE. this happened when RS executed a policy script. (this broke test1 in the test set) VFS/MFS: . chown can change the mode of a file, and chmod arguments are only part of the full file mode so the full filemode is slightly magic. changed these calls so that the final modes are returned to VFS, so that the vnode can be kept up-to-date. (this broke test11 in the test set) MFS: . lookup() checked for sizeof(string) instead of sizeof(user_path), truncating long path names (caught by test 23) . truncate functions neglected to update ctime (this broke test16) VFS: . corner case of an empty filename lookup caused fields of a request not to be filled in in the lookup functions, not making it clear that the lookup had failed, causing messages to garbage processes, causing strange failures. (caught by test 30) . trust v_size in vnode when doing reads or writes on non-special files, truncating i/o where necessary; this is necessary for pipes, as MFS can't tell when a pipe has been truncated without it being told explicitly each time. when the last reader/writer on a pipe closes, tell FS about the new size using truncate_vn(). (this broke test 25, among others) . permission check for chdir() had disappeared; added a forbidden() call (caught by test 23) new code, shouldn't change anything: . introduced RTS_SET, RTS_UNSET, and RTS_ISSET macro's, and their LOCK variants. These macros set and clear the p_rts_flags field, causing a lot of duplicated logic like old_flags = rp->p_rts_flags; /* save value of the flags */ rp->p_rts_flags &= ~NO_PRIV; if (old_flags != 0 && rp->p_rts_flags == 0) lock_enqueue(rp); to change into the simpler RTS_LOCK_UNSET(rp, NO_PRIV); so the macros take care of calling dequeue() and enqueue() (or lock_*()), as the case may be). This makes the code a bit more readable and a bit less fragile. . removed return code from do_clocktick in CLOCK as it currently never replies . removed some debug code from VFS . fixed grant debug message in device.c preemptive checks, tests, changes: . added return code checks of receive() to SYSTEM and CLOCK . O_TRUNC should never arrive at MFS (added sanity check and removed O_TRUNC code) . user_path declared with PATH_MAX+1 to let it be null-terminated . checks in MFS to see if strings passed by VFS are null-terminated IS: . static irq name table thrown out
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assert(fil_ptr->filp_count == 1);
fil_ptr->filp_count = 0; /* don't find self */
if ((filp2 = find_filp(vp, b)) != NIL_FILP) {
/* Co-reader or writer found. Use it.*/
fp->fp_filp[m_in.fd] = filp2;
filp2->filp_count++;
filp2->filp_vno = vp;
filp2->filp_flags = oflags;
/* v_count was incremented after the vnode has
* been found, i_count was incremented incorrectly
* by eatpath in FS, not knowing that we were going to
* use an existing filp entry. Correct this error.
*/
put_vnode(vp);
} else {
/* Nobody else found. Restore filp. */
fil_ptr->filp_count = 1;
if (fil_ptr->filp_mode == R_BIT)
fil_ptr->filp_pos = cvul64(vp->v_pipe_rd_pos);
else
fil_ptr->filp_pos = cvul64(vp->v_pipe_wr_pos);
}
}
break;
}
/* If error, release inode. */
if (r != OK) {
if (r == SUSPEND) return(r); /* Oops, just suspended */
fp->fp_filp[m_in.fd] = NIL_FILP;
FD_CLR(m_in.fd, &fp->fp_filp_inuse);
fil_ptr->filp_count= 0;
put_vnode(vp);
fil_ptr->filp_vno = NIL_VNODE;
return(r);
}
return(m_in.fd);
}
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/*===========================================================================*
* x_open *
*===========================================================================*/
PRIVATE int x_open(bits, oflags, omode, lastc, vpp)
mode_t bits;
int oflags;
mode_t omode;
char *lastc;
struct vnode **vpp;
{
int r, b, exist = TRUE;
struct vnode *vp, *dvp, *tmp_vp;
struct vmnt *vmp;
struct node_details res;
/* If O_CREATE is set, try to make the file. */
if ((oflags & O_CREAT) && lastc[0] != '\0') {
dvp= *vpp; /* Parent directory */
/* See if a free vnode is available */
if ((vp = get_free_vnode(__FILE__, __LINE__)) == NIL_VNODE) {
printf("VFS x_open: no free vnode available\n");
return EINVAL;
}
r= req_create(dvp->v_fs_e, dvp->v_inode_nr, omode, fp->fp_effuid,
fp->fp_effgid, lastc, &res);
if (r != OK)
return r;
exist = FALSE;
/* Check whether vnode is already in use or not */
if ((tmp_vp = find_vnode(res.fs_e, res.inode_nr)) != NIL_VNODE) {
vp= tmp_vp;
vp->v_ref_count++;
vp->v_fs_count++;
}
else
{
/* Fill in the free vnode's fields */
vp->v_fs_e = res.fs_e;
vp->v_inode_nr = res.inode_nr;
vp->v_mode = res.fmode;
vp->v_size = res.fsize;
vp->v_uid = res.uid;
vp->v_gid = res.gid;
vp->v_sdev = res.dev;
if ( (vmp = find_vmnt(vp->v_fs_e)) == NIL_VMNT)
panic(__FILE__, "lookup_vp: vmnt not found", NO_NUM);
vp->v_vmnt = vmp;
vp->v_dev = vmp->m_dev;
vp->v_fs_count = 1;
vp->v_ref_count = 1;
}
/* Release dvp */
put_vnode(dvp);
/* Update *vpp */
*vpp= vp;
}
else {
vp= *vpp;
}
/* Only do the normal open code if we didn't just create the file. */
if (!exist)
return OK;
/* Check protections. */
if ((r = forbidden(vp, bits)) != OK)
return r;
/* Opening reg. files directories and special files differ. */
switch (vp->v_mode & I_TYPE) {
case I_REGULAR:
/* Truncate regular file if O_TRUNC. */
if (oflags & O_TRUNC) {
if ((r = forbidden(vp, W_BIT)) !=OK) break;
truncate_vn(vp, 0);
}
break;
case I_DIRECTORY:
/* Directories may be read but not written. */
r = (bits & W_BIT ? EISDIR : OK);
break;
case I_CHAR_SPECIAL:
case I_BLOCK_SPECIAL:
if (vp->v_sdev == (dev_t)-1)
panic(__FILE__, "x_open: bad special", NO_NUM);
break;
case I_NAMED_PIPE:
if (vp->v_ref_count == 1)
{
if (vp->v_size != 0)
{
r= truncate_vn(vp, 0);
if (r != OK)
{
printf(
"x_open (fifo): truncate_vn failed: %d\n",
r);
}
}
}
break;
}
return(r);
}
/*===========================================================================*
* pipe_open *
*===========================================================================*/
PRIVATE int pipe_open(register struct vnode *vp, register mode_t bits,
register int oflags)
{
/* This function is called from common_open. It checks if
* there is at least one reader/writer pair for the pipe, if not
* it suspends the caller, otherwise it revives all other blocked
* processes hanging on the pipe.
*/
vp->v_pipe = I_PIPE;
if((bits & (R_BIT|W_BIT)) == (R_BIT|W_BIT)) {
printf("pipe opened RW.\n");
return ENXIO;
}
if (find_filp(vp, bits & W_BIT ? R_BIT : W_BIT) == NIL_FILP) {
if (oflags & O_NONBLOCK) {
if (bits & W_BIT) return(ENXIO);
} else {
suspend(XPOPEN); /* suspend caller */
return(SUSPEND);
}
} else if (susp_count > 0) {/* revive blocked processes */
release(vp, OPEN, susp_count);
release(vp, CREAT, susp_count);
}
return(OK);
}
/*===========================================================================*
* do_mknod *
*===========================================================================*/
PUBLIC int do_mknod()
{
/* Perform the mknod(name, mode, addr) system call. */
register mode_t bits, mode_bits;
char lastc[NAME_MAX]; /* last component of the path */
struct mknod_req req;
struct lookup_req lookup_req;
struct node_details res;
int r;
/* Only the super_user may make nodes other than fifos. */
mode_bits = (mode_t) m_in.mk_mode; /* mode of the inode */
if (!super_user && ((mode_bits & I_TYPE) != I_NAMED_PIPE)) return(EPERM);
if (fetch_name(m_in.name1, m_in.name1_length, M1) != OK) return(err_code);
bits = (mode_bits & I_TYPE) | (mode_bits & ALL_MODES & fp->fp_umask);
/* Fill in lookup request fields */
lookup_req.path = user_fullpath;
lookup_req.lastc = lastc;
lookup_req.flags = LAST_DIR;
/* Request lookup */
if ((r = lookup(&lookup_req, &res)) != OK) return r;
/* Lookup was okay, fill in request fields for the actual
* mknod request. */
req.fs_e = res.fs_e;
req.inode_nr = res.inode_nr;
req.rmode = bits;
req.dev = m_in.mk_z0;
req.lastc = lastc;
req.uid = fp->fp_effuid;
req.gid = fp->fp_effgid;
/* Issue request */
return req_mknod(&req);
}
/*===========================================================================*
* do_mkdir *
*===========================================================================*/
PUBLIC int do_mkdir()
{
/* Perform the mkdir(name, mode) system call. */
mode_t bits; /* mode bits for the new inode */
char lastc[NAME_MAX];
struct mkdir_req req;
struct lookup_req lookup_req;
struct node_details res;
int r;
/*printf("VFS: mkdir() START:");*/
if (fetch_name(m_in.name1, m_in.name1_length, M1) != OK) return(err_code);
bits = I_DIRECTORY | (m_in.mode & RWX_MODES & fp->fp_umask);
/* Fill in lookup request fields */
lookup_req.path = user_fullpath;
lookup_req.lastc = lastc;
lookup_req.flags = LAST_DIR;
/* Request lookup */
if ((r = lookup(&lookup_req, &res)) != OK) return r;
/* Lookup was okay, fill in request message fields
* for the actual mknod request. */
req.fs_e = res.fs_e;
req.d_inode_nr = res.inode_nr;
req.rmode = bits;
req.lastc = lastc;
req.uid = fp->fp_effuid;
req.gid = fp->fp_effgid;
/* Issue request */
return req_mkdir(&req);
}
/*===========================================================================*
* do_lseek *
*===========================================================================*/
PUBLIC int do_lseek()
{
/* Perform the lseek(ls_fd, offset, whence) system call. */
register struct filp *rfilp;
int r;
long offset;
u64_t pos, newpos;
struct node_req req;
/* Check to see if the file descriptor is valid. */
if ( (rfilp = get_filp(m_in.ls_fd)) == NIL_FILP) return(err_code);
/* No lseek on pipes. */
if (rfilp->filp_vno->v_pipe == I_PIPE) return(ESPIPE);
/* The value of 'whence' determines the start position to use. */
switch(m_in.whence) {
case SEEK_SET: pos = cvu64(0); break;
case SEEK_CUR: pos = rfilp->filp_pos; break;
case SEEK_END: pos = cvul64(rfilp->filp_vno->v_size); break;
default: return(EINVAL);
}
offset= m_in.offset_lo;
if (offset >= 0)
newpos= add64ul(pos, offset);
else
newpos= sub64ul(pos, -offset);
/* Check for overflow. */
if (ex64hi(newpos) != 0)
return EINVAL;
if (cmp64(newpos, rfilp->filp_pos) != 0) { /* Inhibit read ahead request */
/* Fill in request message */
req.fs_e = rfilp->filp_vno->v_fs_e;
req.inode_nr = rfilp->filp_vno->v_inode_nr;
/* Issue request */
if ((r = req_inhibread(&req)) != OK) return r;
}
rfilp->filp_pos = newpos;
/* insert the new position into the output message */
m_out.reply_l1 = ex64lo(newpos);
return(OK);
}
/*===========================================================================*
* do_llseek *
*===========================================================================*/
PUBLIC int do_llseek()
{
/* Perform the llseek(ls_fd, offset, whence) system call. */
register struct filp *rfilp;
u64_t pos, newpos;
struct node_req req;
int r;
/* Check to see if the file descriptor is valid. */
if ( (rfilp = get_filp(m_in.ls_fd)) == NIL_FILP) return(err_code);
/* No lseek on pipes. */
if (rfilp->filp_vno->v_pipe == I_PIPE) return(ESPIPE);
/* The value of 'whence' determines the start position to use. */
switch(m_in.whence) {
case SEEK_SET: pos = cvu64(0); break;
case SEEK_CUR: pos = rfilp->filp_pos; break;
case SEEK_END: pos = cvul64(rfilp->filp_vno->v_size); break;
default: return(EINVAL);
}
newpos= add64(pos, make64(m_in.offset_lo, m_in.offset_high));
/* Check for overflow. */
if (((long)m_in.offset_high > 0) && cmp64(newpos, pos) < 0)
return(EINVAL);
if (((long)m_in.offset_high < 0) && cmp64(newpos, pos) > 0)
return(EINVAL);
if (cmp64(newpos, rfilp->filp_pos) != 0) { /* Inhibit read ahead request */
/* Fill in request message */
req.fs_e = rfilp->filp_vno->v_fs_e;
req.inode_nr = rfilp->filp_vno->v_inode_nr;
/* Issue request */
if ((r = req_inhibread(&req)) != OK) return r;
}
rfilp->filp_pos = newpos;
m_out.reply_l1 = ex64lo(newpos);
m_out.reply_l2 = ex64hi(newpos);
return(OK);
}
/*===========================================================================*
* do_close *
*===========================================================================*/
PUBLIC int do_close()
{
/* Perform the close(fd) system call. */
return close_fd(fp, m_in.fd);
}
/*===========================================================================*
* close_fd *
*===========================================================================*/
PUBLIC int close_fd(rfp, fd_nr)
struct fproc *rfp;
int fd_nr;
{
/* Perform the close(fd) system call. */
register struct filp *rfilp;
register struct vnode *vp;
struct file_lock *flp;
int rw, mode_word, lock_count;
dev_t dev;
/* First locate the vnode that belongs to the file descriptor. */
if ( (rfilp = get_filp2(rfp, fd_nr)) == NIL_FILP) return(err_code);
vp = rfilp->filp_vno;
if (rfilp->filp_count - 1 == 0 && rfilp->filp_mode != FILP_CLOSED) {
/* Check to see if the file is special. */
mode_word = vp->v_mode & I_TYPE;
if (mode_word == I_CHAR_SPECIAL || mode_word == I_BLOCK_SPECIAL) {
dev = (dev_t) vp->v_sdev;
if (mode_word == I_BLOCK_SPECIAL) {
if (vp->v_bfs_e == ROOT_FS_E)
{
/* Invalidate the cache unless the special is
* mounted. Assume that the root filesystem's
* is open only for fsck.
*/
req_flush(vp->v_bfs_e, dev);
}
}
/* Do any special processing on device close. */
dev_close(dev);
}
}
/* If the inode being closed is a pipe, release everyone hanging on it. */
if (vp->v_pipe == I_PIPE) {
rw = (rfilp->filp_mode & R_BIT ? WRITE : READ);
release(vp, rw, NR_PROCS);
}
/* If a write has been done, the inode is already marked as DIRTY. */
if (--rfilp->filp_count == 0) {
Mostly bugfixes of bugs triggered by the test set. bugfixes: SYSTEM: . removed rc->p_priv->s_flags = 0; for the priv struct shared by all user processes in get_priv(). this should only be done once. doing a SYS_PRIV_USER in sys_privctl() caused the flags of all user processes to be reset, so they were no longer PREEMPTIBLE. this happened when RS executed a policy script. (this broke test1 in the test set) VFS/MFS: . chown can change the mode of a file, and chmod arguments are only part of the full file mode so the full filemode is slightly magic. changed these calls so that the final modes are returned to VFS, so that the vnode can be kept up-to-date. (this broke test11 in the test set) MFS: . lookup() checked for sizeof(string) instead of sizeof(user_path), truncating long path names (caught by test 23) . truncate functions neglected to update ctime (this broke test16) VFS: . corner case of an empty filename lookup caused fields of a request not to be filled in in the lookup functions, not making it clear that the lookup had failed, causing messages to garbage processes, causing strange failures. (caught by test 30) . trust v_size in vnode when doing reads or writes on non-special files, truncating i/o where necessary; this is necessary for pipes, as MFS can't tell when a pipe has been truncated without it being told explicitly each time. when the last reader/writer on a pipe closes, tell FS about the new size using truncate_vn(). (this broke test 25, among others) . permission check for chdir() had disappeared; added a forbidden() call (caught by test 23) new code, shouldn't change anything: . introduced RTS_SET, RTS_UNSET, and RTS_ISSET macro's, and their LOCK variants. These macros set and clear the p_rts_flags field, causing a lot of duplicated logic like old_flags = rp->p_rts_flags; /* save value of the flags */ rp->p_rts_flags &= ~NO_PRIV; if (old_flags != 0 && rp->p_rts_flags == 0) lock_enqueue(rp); to change into the simpler RTS_LOCK_UNSET(rp, NO_PRIV); so the macros take care of calling dequeue() and enqueue() (or lock_*()), as the case may be). This makes the code a bit more readable and a bit less fragile. . removed return code from do_clocktick in CLOCK as it currently never replies . removed some debug code from VFS . fixed grant debug message in device.c preemptive checks, tests, changes: . added return code checks of receive() to SYSTEM and CLOCK . O_TRUNC should never arrive at MFS (added sanity check and removed O_TRUNC code) . user_path declared with PATH_MAX+1 to let it be null-terminated . checks in MFS to see if strings passed by VFS are null-terminated IS: . static irq name table thrown out
2007-02-01 18:50:02 +01:00
if (vp->v_pipe == I_PIPE) {
/* Last reader or writer is going. Tell MFS about latest
* pipe size.
*/
truncate_vn(vp, vp->v_size);
}
2007-01-05 17:36:55 +01:00
if (vp->v_pipe == I_PIPE && vp->v_ref_count > 1) {
/* Save the file position in the v-node in case needed later.
* The read and write positions are saved separately.
*/
if (rfilp->filp_mode == R_BIT)
vp->v_pipe_rd_pos = ex64lo(rfilp->filp_pos);
else
vp->v_pipe_wr_pos = ex64lo(rfilp->filp_pos);
}
else {
/* Otherwise zero the pipe position fields */
vp->v_pipe_rd_pos = 0;
vp->v_pipe_wr_pos = 0;
}
put_vnode(rfilp->filp_vno);
}
FD_CLR(fd_nr, &rfp->fp_cloexec_set);
rfp->fp_filp[fd_nr] = NIL_FILP;
FD_CLR(fd_nr, &rfp->fp_filp_inuse);
/* Check to see if the file is locked. If so, release all locks. */
if (nr_locks == 0) return(OK);
lock_count = nr_locks; /* save count of locks */
for (flp = &file_lock[0]; flp < &file_lock[NR_LOCKS]; flp++) {
if (flp->lock_type == 0) continue; /* slot not in use */
if (flp->lock_vnode == vp && flp->lock_pid == rfp->fp_pid) {
flp->lock_type = 0;
nr_locks--;
}
}
if (nr_locks < lock_count) lock_revive(); /* lock released */
return(OK);
}