NetBSD/sys/msdosfs/msdosfs_lookup.c

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brought in fixed/renamed/matching MS-DOS FS code, from Jeff Polk <polk@bsdi.com>. His notes are as follows: ------------------------------------------------------------------------------ July 22, 1993 - Changed name of entire package from PCFS to MSDOSFS - Fixed bugs: root directory size in clusters instead of bytes growing directory didn't update in-core size link, symlink, mknod didn't free locked parent (deadlock) lookup returned real error on create and rename instead of EJUSTRETURN rename changed `.' entry in child instead of name entry in parent rename removed `.' entry in child instead of removing entry in parent when moving a directory from one dir to another createde() left new node locked when write of parent failed (deadlock) removede() decremented refcount even on error (rmdir's which failed due to write errors left in-core cache entries inconsistent) changed validation for filesystem to not check for the boot signature since some disks (e.g., mtools) aren't bootable directories are always show current time as modify time (needed for NFS export since DOS never updates dir mod times -- ctime is true create time). - Added support for cookies changes to the readdir() vnode interface (#ifdef __bsdi__) - Punted on the whole problem of inode generation numbers. This means that there's a chance of using a stale file handle to access a new file, but it doesn't appear to be the common case, and I don't see how to generate reasonable generation numbers without changing something on the disk (which is the way the SVR4 filesystem survival kit guys did it). I don't think it would be very safe to change the on-disk format. Jeff Polk (polk@BSDI.COM) ------------------------------------------------------------------------------
1993-08-13 15:35:13 +04:00
/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*
* $Id: msdosfs_lookup.c,v 1.2 1993/09/03 04:36:25 cgd Exp $
brought in fixed/renamed/matching MS-DOS FS code, from Jeff Polk <polk@bsdi.com>. His notes are as follows: ------------------------------------------------------------------------------ July 22, 1993 - Changed name of entire package from PCFS to MSDOSFS - Fixed bugs: root directory size in clusters instead of bytes growing directory didn't update in-core size link, symlink, mknod didn't free locked parent (deadlock) lookup returned real error on create and rename instead of EJUSTRETURN rename changed `.' entry in child instead of name entry in parent rename removed `.' entry in child instead of removing entry in parent when moving a directory from one dir to another createde() left new node locked when write of parent failed (deadlock) removede() decremented refcount even on error (rmdir's which failed due to write errors left in-core cache entries inconsistent) changed validation for filesystem to not check for the boot signature since some disks (e.g., mtools) aren't bootable directories are always show current time as modify time (needed for NFS export since DOS never updates dir mod times -- ctime is true create time). - Added support for cookies changes to the readdir() vnode interface (#ifdef __bsdi__) - Punted on the whole problem of inode generation numbers. This means that there's a chance of using a stale file handle to access a new file, but it doesn't appear to be the common case, and I don't see how to generate reasonable generation numbers without changing something on the disk (which is the way the SVR4 filesystem survival kit guys did it). I don't think it would be very safe to change the on-disk format. Jeff Polk (polk@BSDI.COM) ------------------------------------------------------------------------------
1993-08-13 15:35:13 +04:00
*/
#include "param.h"
#include "namei.h"
#include "buf.h"
#include "vnode.h"
#include "mount.h"
#include "bpb.h"
#include "direntry.h"
#include "denode.h"
#include "msdosfsmount.h"
#include "fat.h"
/*
* When we search a directory the blocks containing directory entries are
* read and examined. The directory entries contain information that would
* normally be in the inode of a unix filesystem. This means that some of
* a directory's contents may also be in memory resident denodes (sort of
* an inode). This can cause problems if we are searching while some other
* process is modifying a directory. To prevent one process from accessing
* incompletely modified directory information we depend upon being the
* soul owner of a directory block. bread/brelse provide this service.
* This being the case, when a process modifies a directory it must first
* acquire the disk block that contains the directory entry to be modified.
* Then update the disk block and the denode, and then write the disk block
* out to disk. This way disk blocks containing directory entries and in
* memory denode's will be in synch.
*/
int
msdosfs_lookup(vdp, ndp, p)
struct vnode *vdp; /* vnode of directory to search */
struct nameidata *ndp;
struct proc *p;
{
daddr_t bn;
int flag;
int error;
int lockparent;
int wantparent;
int slotstatus;
#define NONE 0
#define FOUND 1
int slotoffset;
int slotcluster;
int frcn;
u_long cluster;
int rootreloff;
int diroff;
int isadir; /* ~0 if found direntry is a directory */
u_long scn; /* starting cluster number */
struct denode *dp;
struct denode *pdp;
struct denode *tdp;
struct msdosfsmount *pmp;
struct buf *bp = 0;
struct direntry *dep;
u_char dosfilename[12];
#if defined(MSDOSFSDEBUG)
printf("msdosfs_lookup(): looking for %s\n", ndp->ni_ptr);
#endif /* defined(MSDOSFSDEBUG) */
ndp->ni_dvp = vdp;
ndp->ni_vp = NULL;
dp = VTODE(vdp);
pmp = dp->de_pmp;
lockparent = ndp->ni_nameiop & LOCKPARENT;
flag = ndp->ni_nameiop & OPMASK;
wantparent = ndp->ni_nameiop & (LOCKPARENT | WANTPARENT);
#if defined(MSDOSFSDEBUG)
printf("msdosfs_lookup(): vdp %08x, dp %08x, Attr %02x\n",
vdp, dp, dp->de_Attributes);
#endif /* defined(MSDOSFSDEBUG) */
/*
* Be sure vdp is a directory. Since dos filesystems don't have
* the concept of execute permission anybody can search a
* directory.
*/
if ((dp->de_Attributes & ATTR_DIRECTORY) == 0)
return ENOTDIR;
/*
* See if the component of the pathname we are looking for is in
* the directory cache. If so then do a few things and return.
*/
if (error = cache_lookup(ndp)) {
int vpid;
if (error == ENOENT)
return error;
#ifdef PARANOID
if (vdp == ndp->ni_rdir && ndp->ni_isdotdot)
panic("msdosfs_lookup: .. thru root");
#endif /* PARANOID */
pdp = dp;
vdp = ndp->ni_vp;
dp = VTODE(vdp);
vpid = vdp->v_id;
if (pdp == dp) {
VREF(vdp);
error = 0;
}
else if (ndp->ni_isdotdot) {
DEUNLOCK(pdp);
error = vget(vdp);
if (!error && lockparent && *ndp->ni_next == '\0')
DELOCK(pdp);
}
else {
error = vget(vdp);
if (!lockparent || error || *ndp->ni_next != '\0')
DEUNLOCK(pdp);
}
if (!error) {
if (vpid == vdp->v_id) {
#if defined(MSDOSFSDEBUG)
printf("msdosfs_lookup(): cache hit, vnode %08x, file %s\n", vdp, dp->de_Name);
#endif /* defined(MSDOSFSDEBUG) */
return 0;
}
deput(dp);
if (lockparent && pdp != dp && *ndp->ni_next == '\0')
DEUNLOCK(pdp);
}
DELOCK(pdp);
dp = pdp;
vdp = DETOV(dp);
ndp->ni_vp = NULL;
}
/*
* If they are going after the . or .. entry in the root directory,
* they won't find it. DOS filesystems don't have them in the root
* directory. So, we fake it. deget() is in on this scam too.
*/
if ((vdp->v_flag & VROOT) && ndp->ni_ptr[0] == '.' &&
(ndp->ni_namelen == 1 ||
(ndp->ni_namelen == 2 && ndp->ni_ptr[1] == '.'))) {
isadir = ATTR_DIRECTORY;
scn = MSDOSFSROOT;
#if defined(MSDOSFSDEBUG)
printf("msdosfs_lookup(): looking for . or .. in root directory\n");
#endif /* defined(MSDOSFSDEBUG) */
cluster == MSDOSFSROOT;
diroff = MSDOSFSROOT_OFS;
goto foundroot;
}
/*
* Don't search for free slots unless we are creating a filename
* and we are at the end of the pathname.
*/
slotstatus = FOUND;
if ((flag == CREATE || flag == RENAME) && *ndp->ni_next == '\0') {
slotstatus = NONE;
slotoffset = -1;
}
unix2dosfn((u_char *) ndp->ni_ptr, dosfilename, ndp->ni_namelen);
dosfilename[11] = 0;
#if defined(MSDOSFSDEBUG)
printf("msdosfs_lookup(): dos version of filename %s, length %d\n",
dosfilename, ndp->ni_namelen);
#endif /* defined(MSDOSFSDEBUG) */
/*
* Search the directory pointed at by vdp for the name pointed at
* by ndp->ni_ptr.
*/
tdp = NULL;
/*
* The outer loop ranges over the clusters that make up the
* directory. Note that the root directory is different from all
* other directories. It has a fixed number of blocks that are not
* part of the pool of allocatable clusters. So, we treat it a
* little differently. The root directory starts at "cluster" 0.
*/
rootreloff = 0;
for (frcn = 0;; frcn++) {
if (error = pcbmap(dp, frcn, &bn, &cluster)) {
if (error == E2BIG)
break;
return error;
}
if (error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, NOCRED, &bp))
return error;
for (diroff = 0; diroff < pmp->pm_depclust; diroff++) {
dep = (struct direntry *) bp->b_un.b_addr + diroff;
/*
* If the slot is empty and we are still looking
* for an empty then remember this one. If the
* slot is not empty then check to see if it
* matches what we are looking for. If the slot
* has never been filled with anything, then the
* remainder of the directory has never been used,
* so there is no point in searching it.
*/
if (dep->deName[0] == SLOT_EMPTY ||
dep->deName[0] == SLOT_DELETED) {
if (slotstatus != FOUND) {
slotstatus = FOUND;
if (cluster == MSDOSFSROOT)
slotoffset = rootreloff;
else
slotoffset = diroff;
slotcluster = cluster;
}
if (dep->deName[0] == SLOT_EMPTY) {
brelse(bp);
goto notfound;
}
}
else {
/*
* Ignore volume labels (anywhere, not just
* the root directory).
*/
if ((dep->deAttributes & ATTR_VOLUME) == 0 &&
bcmp(dosfilename, dep->deName, 11) == 0) {
#if defined(MSDOSFSDEBUG)
printf("msdosfs_lookup(): match diroff %d, rootreloff %d\n", diroff, rootreloff);
#endif /* defined(MSDOSFSDEBUG) */
/*
* Remember where this directory
* entry came from for whoever did
* this lookup. If this is the root
* directory we are interested in
* the offset relative to the
* beginning of the directory (not
* the beginning of the cluster).
*/
if (cluster == MSDOSFSROOT)
diroff = rootreloff;
ndp->ni_msdosfs.msdosfs_offset = diroff;
ndp->ni_msdosfs.msdosfs_cluster = cluster;
goto found;
}
}
rootreloff++;
} /* for (diroff = 0; .... */
/*
* Release the buffer holding the directory cluster just
* searched.
*/
brelse(bp);
} /* for (frcn = 0; ; frcn++) */
notfound:;
/*
* We hold no disk buffers at this point.
*/
/*
* If we get here we didn't find the entry we were looking for. But
* that's ok if we are creating or renaming and are at the end of
* the pathname and the directory hasn't been removed.
*/
#if defined(MSDOSFSDEBUG)
printf("msdosfs_lookup(): flag %d, refcnt %d, slotstatus %d\n",
flag, dp->de_refcnt, slotstatus);
printf(" slotoffset %d, slotcluster %d\n",
slotoffset, slotcluster);
#endif /* defined(MSDOSFSDEBUG) */
if ((flag == CREATE || flag == RENAME) &&
*ndp->ni_next == '\0' && dp->de_refcnt != 0) {
if (slotstatus == NONE) {
ndp->ni_msdosfs.msdosfs_offset = 0;
ndp->ni_msdosfs.msdosfs_cluster = 0;
ndp->ni_msdosfs.msdosfs_count = 0;
}
else {
#if defined(MSDOSFSDEBUG)
printf("msdosfs_lookup(): saving empty slot location\n");
#endif /* defined(MSDOSFSDEBUG) */
ndp->ni_msdosfs.msdosfs_offset = slotoffset;
ndp->ni_msdosfs.msdosfs_cluster = slotcluster;
ndp->ni_msdosfs.msdosfs_count = 1;
}
/* dp->de_flag |= DEUPD; /* never update dos directories */
ndp->ni_nameiop |= SAVENAME;
if (!lockparent)/* leave searched dir locked? */
DEUNLOCK(dp);
}
/*
* Insert name in cache as non-existant if not trying to create it.
*/
if (ndp->ni_makeentry && flag != CREATE)
cache_enter(ndp);
#ifdef __bsdi__
brought in fixed/renamed/matching MS-DOS FS code, from Jeff Polk <polk@bsdi.com>. His notes are as follows: ------------------------------------------------------------------------------ July 22, 1993 - Changed name of entire package from PCFS to MSDOSFS - Fixed bugs: root directory size in clusters instead of bytes growing directory didn't update in-core size link, symlink, mknod didn't free locked parent (deadlock) lookup returned real error on create and rename instead of EJUSTRETURN rename changed `.' entry in child instead of name entry in parent rename removed `.' entry in child instead of removing entry in parent when moving a directory from one dir to another createde() left new node locked when write of parent failed (deadlock) removede() decremented refcount even on error (rmdir's which failed due to write errors left in-core cache entries inconsistent) changed validation for filesystem to not check for the boot signature since some disks (e.g., mtools) aren't bootable directories are always show current time as modify time (needed for NFS export since DOS never updates dir mod times -- ctime is true create time). - Added support for cookies changes to the readdir() vnode interface (#ifdef __bsdi__) - Punted on the whole problem of inode generation numbers. This means that there's a chance of using a stale file handle to access a new file, but it doesn't appear to be the common case, and I don't see how to generate reasonable generation numbers without changing something on the disk (which is the way the SVR4 filesystem survival kit guys did it). I don't think it would be very safe to change the on-disk format. Jeff Polk (polk@BSDI.COM) ------------------------------------------------------------------------------
1993-08-13 15:35:13 +04:00
if (flag == CREATE || flag == RENAME)
return EJUSTRETURN;
#endif
brought in fixed/renamed/matching MS-DOS FS code, from Jeff Polk <polk@bsdi.com>. His notes are as follows: ------------------------------------------------------------------------------ July 22, 1993 - Changed name of entire package from PCFS to MSDOSFS - Fixed bugs: root directory size in clusters instead of bytes growing directory didn't update in-core size link, symlink, mknod didn't free locked parent (deadlock) lookup returned real error on create and rename instead of EJUSTRETURN rename changed `.' entry in child instead of name entry in parent rename removed `.' entry in child instead of removing entry in parent when moving a directory from one dir to another createde() left new node locked when write of parent failed (deadlock) removede() decremented refcount even on error (rmdir's which failed due to write errors left in-core cache entries inconsistent) changed validation for filesystem to not check for the boot signature since some disks (e.g., mtools) aren't bootable directories are always show current time as modify time (needed for NFS export since DOS never updates dir mod times -- ctime is true create time). - Added support for cookies changes to the readdir() vnode interface (#ifdef __bsdi__) - Punted on the whole problem of inode generation numbers. This means that there's a chance of using a stale file handle to access a new file, but it doesn't appear to be the common case, and I don't see how to generate reasonable generation numbers without changing something on the disk (which is the way the SVR4 filesystem survival kit guys did it). I don't think it would be very safe to change the on-disk format. Jeff Polk (polk@BSDI.COM) ------------------------------------------------------------------------------
1993-08-13 15:35:13 +04:00
return ENOENT;
found: ;
/*
* NOTE: We still have the buffer with matched directory entry at
* this point.
*/
isadir = dep->deAttributes & ATTR_DIRECTORY;
scn = dep->deStartCluster;
foundroot:;
/*
* If we entered at foundroot, then we are looking for the . or ..
* entry of the filesystems root directory. isadir and scn were
* setup before jumping here. And, bp is null. There is no buf
* header.
*/
/*
* If deleting and at the end of the path, then if we matched on
* "." then don't deget() we would probably panic(). Otherwise
* deget() the directory entry.
*/
if (flag == DELETE && ndp->ni_next == '\0') {
if (dp->de_StartCluster == scn &&
isadir) { /* "." */
VREF(vdp);
ndp->ni_vp = vdp;
if (bp)
brelse(bp);
return 0;
}
error = deget(pmp, cluster, diroff, dep, &tdp);
if (error) {
if (bp)
brelse(bp);
return error;
}
ndp->ni_vp = DETOV(tdp);
if (!lockparent)
DEUNLOCK(dp);
if (bp)
brelse(bp);
return 0;
}
/*
* If renaming.
*/
if (flag == RENAME && wantparent && *ndp->ni_next == '\0') {
if (dp->de_StartCluster == scn &&
isadir) {
if (bp)
brelse(bp);
return EISDIR;
}
error = deget(pmp, cluster, diroff, dep, &tdp);
if (error) {
if (bp)
brelse(bp);
return error;
}
ndp->ni_vp = DETOV(tdp);
ndp->ni_nameiop |= SAVENAME;
if (!lockparent)
DEUNLOCK(dp);
if (bp)
brelse(bp);
return 0;
}
/*
* ?
*/
pdp = dp;
if (ndp->ni_isdotdot) {
DEUNLOCK(pdp);
error = deget(pmp, cluster, diroff, dep, &tdp);
if (error) {
DELOCK(pdp);
if (bp)
brelse(bp);
return error;
}
if (lockparent && *ndp->ni_next == '\0')
DELOCK(pdp);
ndp->ni_vp = DETOV(tdp);
}
else if (dp->de_StartCluster == scn &&
isadir) { /* "." */
VREF(vdp);
ndp->ni_vp = vdp;
}
else {
error = deget(pmp, cluster, diroff, dep, &tdp);
if (error) {
if (bp)
brelse(bp);
return error;
}
if (!lockparent || *ndp->ni_next != '\0')
DEUNLOCK(pdp);
ndp->ni_vp = DETOV(tdp);
}
if (bp)
brelse(bp);
/*
* Insert name in cache if wanted.
*/
if (ndp->ni_makeentry)
cache_enter(ndp);
return 0;
}
/*
* dep - directory to copy into the directory ndp - nameidata structure
* containing info on where to put the directory entry in the directory.
* depp - return the address of the denode for the created directory entry
* if depp != 0
*/
int
createde(dep, ndp, depp)
struct denode *dep;
struct nameidata *ndp;
struct denode **depp;
{
int bn;
int error;
u_long dirclust, diroffset;
struct direntry *ndep;
struct denode *ddep = VTODE(ndp->ni_dvp); /* directory to add to */
struct msdosfsmount *pmp = dep->de_pmp;
struct buf *bp;
#if defined(MSDOSFSDEBUG)
printf("createde(dep %08x, ndp %08x, depp %08x)\n", dep, ndp, depp);
#endif /* defined(MSDOSFSDEBUG) */
/*
* If no space left in the directory then allocate another cluster
* and chain it onto the end of the file. There is one exception
* to this. That is, if the root directory has no more space it
* can NOT be expanded. extendfile() checks for and fails attempts
* to extend the root directory. We just return an error in that
* case.
*/
if (ndp->ni_msdosfs.msdosfs_count == 0) {
if (error = extendfile(ddep, &bp, &dirclust))
return error;
ndep = (struct direntry *) bp->b_un.b_addr;
/*
* Let caller know where we put the directory entry.
*/
ndp->ni_msdosfs.msdosfs_cluster = dirclust;
ndp->ni_msdosfs.msdosfs_offset = diroffset = 0;
/*
* Update the size of the directory
*/
ddep->de_FileSize += pmp->pm_bpcluster;
}
else {
/*
* There is space in the existing directory. So, we just
* read in the cluster with space. Copy the new directory
* entry in. Then write it to disk. NOTE: DOS directories
* do not get smaller as clusters are emptied.
*/
dirclust = ndp->ni_msdosfs.msdosfs_cluster;
diroffset = ndp->ni_msdosfs.msdosfs_offset;
error = readep(pmp, dirclust, diroffset, &bp, &ndep);
if (error)
return error;
}
*ndep = dep->de_de;
/*
* If they want us to return with the denode gotten.
*/
if (depp) {
error = deget(pmp, dirclust, diroffset, ndep, depp);
if (error)
return error;
}
if (error = bwrite(bp)) {
deput(*depp); /* free the vnode we got on error */
return error;
}
return 0;
}
/*
* Read in a directory entry and mark it as being deleted.
*/
int
markdeleted(pmp, dirclust, diroffset)
struct msdosfsmount *pmp;
u_long dirclust;
u_long diroffset;
{
int error;
struct direntry *ep;
struct buf *bp;
error = readep(pmp, dirclust, diroffset, &bp, &ep);
if (error)
return error;
ep->deName[0] = SLOT_DELETED;
return bwrite(bp);
}
/*
* Remove a directory entry. At this point the file represented by the
* directory entry to be removed is still full length until no one has it
* open. When the file no longer being used msdosfs_inactive() is called
* and will truncate the file to 0 length. When the vnode containing the
* denode is needed for some other purpose by VFS it will call
* msdosfs_reclaim() which will remove the denode from the denode cache.
*/
int
removede(ndp)
struct nameidata *ndp;
{
struct denode *dep = VTODE(ndp->ni_vp); /* the file being removed */
struct msdosfsmount *pmp = dep->de_pmp;
int error;
#if defined(MSDOSFSDEBUG)
/*
* printf("removede(): filename %s\n", dep->de_Name);
* printf("rmde(): dep %08x, ndpcluster %d, ndpoffset %d\n", dep,
* ndp->ni_msdosfs.msdosfs_cluster,
* ndp->ni_msdosfs.msdosfs_offset);
*/
#endif /* defined(MSDOSFSDEBUG) */
/*
* Read the directory block containing the directory entry we are
* to make free. The nameidata structure holds the cluster number
* and directory entry index number of the entry to free.
*/
error = markdeleted(pmp, ndp->ni_msdosfs.msdosfs_cluster,
ndp->ni_msdosfs.msdosfs_offset);
if (error == 0)
dep->de_refcnt--;
return error;
}
/*
* Be sure a directory is empty except for "." and "..". Return 1 if empty,
* return 0 if not empty or error.
*/
int
dosdirempty(dep)
struct denode *dep;
{
int dei;
int error;
u_long cn;
daddr_t bn;
struct buf *bp;
struct msdosfsmount *pmp = dep->de_pmp;
struct direntry *dentp;
/*
* Since the filesize field in directory entries for a directory is
* zero, we just have to feel our way through the directory until
* we hit end of file.
*/
for (cn = 0;; cn++) {
error = pcbmap(dep, cn, &bn, 0);
if (error == E2BIG)
return 1; /* it's empty */
error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, NOCRED,
&bp);
if (error)
return error;
dentp = (struct direntry *) bp->b_un.b_addr;
for (dei = 0; dei < pmp->pm_depclust; dei++) {
if (dentp->deName[0] != SLOT_DELETED) {
/*
* In dos directories an entry whose name
* starts with SLOT_EMPTY (0) starts the
* beginning of the unused part of the
* directory, so we can just return that it
* is empty.
*/
if (dentp->deName[0] == SLOT_EMPTY) {
brelse(bp);
return 1;
}
/*
* Any names other than "." and ".." in a
* directory mean it is not empty.
*/
if (bcmp(dentp->deName, ". ", 11) &&
bcmp(dentp->deName, ".. ", 11)) {
brelse(bp);
#if defined(MSDOSFSDEBUG)
printf("dosdirempty(): entry %d found %02x, %02x\n", dei, dentp->deName[0],
dentp->deName[1]);
#endif /* defined(MSDOSFSDEBUG) */
return 0; /* not empty */
}
}
dentp++;
}
brelse(bp);
}
/* NOTREACHED */
}
/*
* Check to see if the directory described by target is in some
* subdirectory of source. This prevents something like the following from
* succeeding and leaving a bunch or files and directories orphaned. mv
* /a/b/c /a/b/c/d/e/f Where c and f are directories. source - the inode
* for /a/b/c target - the inode for /a/b/c/d/e/f Returns 0 if target is
* NOT a subdirectory of source. Otherwise returns a non-zero error number.
* The target inode is always unlocked on return.
*/
int
doscheckpath(source, target)
struct denode *source;
struct denode *target;
{
daddr_t scn;
struct denode dummy;
struct msdosfsmount *pmp;
struct direntry *ep;
struct denode *dep;
struct buf *bp = NULL;
int error = 0;
dep = target;
if ((target->de_Attributes & ATTR_DIRECTORY) == 0 ||
(source->de_Attributes & ATTR_DIRECTORY) == 0) {
error = ENOTDIR;
goto out;
}
if (dep->de_StartCluster == source->de_StartCluster) {
error = EEXIST;
goto out;
}
if (dep->de_StartCluster == MSDOSFSROOT)
goto out;
for (;;) {
if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) {
error = ENOTDIR;
goto out;
}
pmp = dep->de_pmp;
scn = dep->de_StartCluster;
error = bread(pmp->pm_devvp, cntobn(pmp, scn),
pmp->pm_bpcluster, NOCRED, &bp);
if (error) {
break;
}
ep = (struct direntry *) bp->b_un.b_addr + 1;
if ((ep->deAttributes & ATTR_DIRECTORY) == 0 ||
bcmp(ep->deName, ".. ", 11) != 0) {
error = ENOTDIR;
break;
}
if (ep->deStartCluster == source->de_StartCluster) {
error = EINVAL;
break;
}
if (ep->deStartCluster == MSDOSFSROOT)
break;
deput(dep);
/* NOTE: deget() clears dep on error */
error = deget(pmp, ep->deStartCluster, 0, ep, &dep);
brelse(bp);
bp = NULL;
if (error)
break;
}
out: ;
if (bp)
brelse(bp);
if (error == ENOTDIR)
printf("doscheckpath(): .. not a directory?\n");
if (dep != NULL)
deput(dep);
return error;
}
/*
* Read in the disk block containing the directory entry (dirclu, dirofs)
* and return the address of the buf header, and the address of the
* directory entry within the block.
*/
int
readep(pmp, dirclu, dirofs, bpp, epp)
struct msdosfsmount *pmp;
u_long dirclu, dirofs;
struct buf **bpp;
struct direntry **epp;
{
int error;
daddr_t bn;
bn = detobn(pmp, dirclu, dirofs);
if (error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, NOCRED, bpp)) {
*bpp = NULL;
return error;
}
if (epp)
*epp = bptoep(pmp, *bpp, dirofs);
return 0;
}
/*
* Read in the disk block containing the directory entry dep came from and
* return the address of the buf header, and the address of the directory
* entry within the block.
*/
int
readde(dep, bpp, epp)
struct denode *dep;
struct buf **bpp;
struct direntry **epp;
{
return readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset,
bpp, epp);
}