/*
* Lookup gets a vnode for a pathname.
*/
static
int
sfs_lookup(struct vnode *v, char *path, struct vnode **ret)
{
struct sfs_vnode *sv = v->vn_data;
struct sfs_vnode *parent, *child;
char name[SFS_NAMELEN];
int i, err;
if (sv->sv_i.sfi_type != SFS_TYPE_DIR) {
return ENOTDIR;
}
parent = sv;
VOP_INCREF(&parent->sv_v);
child = NULL; //just to be safe
while(1){
i = 0;
while(path[i] != '/' && path[i] != '\0' && i < SFS_NAMELEN) i++;
if(i >= SFS_NAMELEN){
VOP_DECREF(&parent->sv_v);
return ENAMETOOLONG;
}
else if(path[i] == '/'){
path[i] = 0;
strcpy(name, path);
path = &path[i + 1];
err = sfs_lookonce(parent, name, &child, NULL);
if(err){
VOP_DECREF(&parent->sv_v);
return err;
}
VOP_DECREF(&parent->sv_v);
parent = child;
if(parent->sv_i.sfi_type != SFS_TYPE_DIR) return ENOTDIR;
} else{ /* Hit NULL, so this is our last time through */
assert(path[i] == '\0');
err = sfs_lookonce(parent, path, &child, NULL);
if(err){
VOP_DECREF(&parent->sv_v);
return err;
}
VOP_DECREF(&parent->sv_v);
break;
}
}
*ret = &child->sv_v;
return 0;
}
/*
* Delete a file.
*/
static
int
sfs_remove(struct vnode *dir, const char *name)
{
struct sfs_vnode *sv = dir->vn_data;
struct sfs_vnode *victim;
int slot;
int result;
/* Look for the file and fetch a vnode for it. */
result = sfs_lookonce(sv, name, &victim, &slot);
if (result) {
return result;
}
/* Erase its directory entry. */
result = sfs_dir_unlink(sv, slot);
if (result==0) {
/* If we succeeded, decrement the link count. */
assert(victim->sv_i.sfi_linkcount > 0);
victim->sv_i.sfi_linkcount--;
victim->sv_dirty = 1;
}
/* Discard the reference that sfs_lookonce got us */
VOP_DECREF(&victim->sv_v);
return result;
}
static
int
sfs_lookparent_internal(struct vnode *v, char *path, struct vnode **ret,
char *buf, size_t buflen)
{
struct sfs_vnode *sv = v->vn_data;
struct sfs_vnode *next;
char *s;
int result;
VOP_INCREF(&sv->sv_absvn);
while (1) {
/* Don't need lock to check vnode type; it's constant */
if (sv->sv_type != SFS_TYPE_DIR) {
VOP_DECREF(&sv->sv_absvn);
return ENOTDIR;
}
s = strchr(path, '/');
if (!s) {
/* Last component. */
break;
}
*s = 0;
s++;
lock_acquire(sv->sv_lock);
result = sfs_lookonce(sv, path, &next, NULL);
lock_release(sv->sv_lock);
if (result) {
VOP_DECREF(&sv->sv_absvn);
return result;
}
VOP_DECREF(&sv->sv_absvn);
sv = next;
path = s;
}
if (strlen(path)+1 > buflen) {
VOP_DECREF(&sv->sv_absvn);
return ENAMETOOLONG;
}
strcpy(buf, path);
*ret = &sv->sv_absvn;
return 0;
}
/*
* Helper function for rename. Make sure COMPARE is not a direct
* ancestor of (or the same as) CHILD.
*
* Note: acquires locks as it goes up.
*/
static
int
check_parent(struct sfs_vnode *lookfor, struct sfs_vnode *failon,
struct sfs_vnode *child, int *found)
{
struct sfs_vnode *up;
int result;
*found = 0;
VOP_INCREF(&child->sv_absvn);
while (1) {
if (failon == child) {
/* Bad */
VOP_DECREF(&child->sv_absvn);
return EINVAL;
}
if (lookfor == child) {
*found = 1;
}
lock_acquire(child->sv_lock);
result = sfs_lookonce(child, "..", &up, NULL);
lock_release(child->sv_lock);
if (result) {
VOP_DECREF(&child->sv_absvn);
return result;
}
if (child == up) {
/* Hit root, done */
VOP_DECREF(&up->sv_absvn);
break;
}
VOP_DECREF(&child->sv_absvn);
child = up;
}
VOP_DECREF(&child->sv_absvn);
return 0;
}
static
int
sfs_rmdir(struct vnode *vv, const char *name){
struct sfs_vnode *sv = vv->vn_data;
struct sfs_vnode *victim;
struct sfs_dir tsd;
int slot, slot2, nentries;
int result;
/* Look for the directory and fetch a vnode for it. */
result = sfs_lookonce(sv, name, &victim, &slot);
if (result) {
return result;
}
/* Make sure it's a directory and that only . and .. are left */
if(victim->sv_i.sfi_type != SFS_TYPE_DIR){
VOP_DECREF(&victim->sv_v);
return ENOTDIR;
}
nentries = sfs_dir_nentries(victim);
if(nentries != 2){
slot2 = 2;
while(slot2 < nentries){
/* Ensure all other entries are blank */
result = sfs_readdir(victim, &tsd, slot2);
if(result){
VOP_DECREF(&victim->sv_v);
return result;
}
if(tsd.sfd_ino != SFS_NOINO){
VOP_DECREF(&victim->sv_v);
return ENOTEMPTY;
}
slot2++;
}
}
/* Get rid of . and .. (should always be in slot 0 and 1) */
result = sfs_dir_unlink(victim, 0);
if(result){
VOP_DECREF(&victim->sv_v);
return result;
}
assert(victim->sv_i.sfi_linkcount > 0);
victim->sv_i.sfi_linkcount--;
victim->sv_dirty = 1;
result = sfs_dir_unlink(victim, 1);
if(result){
VOP_DECREF(&victim->sv_v);
return result;
}
assert(sv->sv_i.sfi_linkcount > 0);
sv->sv_i.sfi_linkcount--;
sv->sv_dirty = 1;
/* Erase its directory entry. */
result = sfs_dir_unlink(sv, slot);
if (result==0) {
/* If we succeeded, decrement the link count. */
assert(victim->sv_i.sfi_linkcount > 0);
victim->sv_i.sfi_linkcount--;
victim->sv_dirty = 1;
}
/* Discard the reference that sfs_lookonce got us */
VOP_DECREF(&victim->sv_v);
return result;
}
/*
* Rename a file.
*/
static
int
sfs_rename(struct vnode *d1, const char *n1,
struct vnode *d2, const char *n2)
{
struct sfs_vnode *sv1 = d1->vn_data;
struct sfs_vnode *sv2 = d2->vn_data;
struct sfs_vnode *g1;
int slot1, slot2;
int result, result2;
/* Look up the old name of the file and get its inode and slot number*/
result = sfs_lookonce(sv1, n1, &g1, &slot1);
if (result) {
return result;
}
/*
* Link it to the 'new' directory under the new name.
*
* We could theoretically just overwrite the original
* directory entry, except that we need to check to make sure
* the new name doesn't already exist; might as well use the
* existing link routine.
*/
result = sfs_dir_link(sv2, n2, g1->sv_ino, &slot2);
if (result) {
goto puke;
}
/* Increment the link count, and mark inode dirty */
g1->sv_i.sfi_linkcount++;
g1->sv_dirty = 1;
/* Unlink the old slot */
result = sfs_dir_unlink(sv1, slot1);
if (result) {
goto puke_harder;
}
/*
* Decrement the link count again, and mark the inode dirty again,
* in case it's been synced behind our back.
*/
assert(g1->sv_i.sfi_linkcount>0);
g1->sv_i.sfi_linkcount--;
g1->sv_dirty = 1;
/* Let go of the reference to g1 */
VOP_DECREF(&g1->sv_v);
return 0;
puke_harder:
/*
* Error recovery: try to undo what we already did
*/
result2 = sfs_dir_unlink(sv2, slot2);
if (result2) {
kprintf("sfs: rename: %s\n", strerror(result));
kprintf("sfs: rename: while cleaning up: %s\n",
strerror(result2));
panic("sfs: rename: Cannot recover\n");
}
g1->sv_i.sfi_linkcount--;
puke:
/* Let go of the reference to g1 */
VOP_DECREF(&g1->sv_v);
return result;
}
/*
* Delete a file.
*
* Locking: locks the directory, then the file. Unlocks both.
* This follows the hierarchical locking order imposed by the directory tree.
*
* Requires up to 4 buffers.
*/
static
int
sfs_remove(struct vnode *dir, const char *name)
{
struct sfs_vnode *sv = dir->vn_data;
struct sfs_vnode *victim;
struct sfs_dinode *victim_inodeptr;
struct sfs_dinode *dir_inodeptr;
int slot;
int result;
/* need to check this to avoid deadlock even in error condition */
if (!strcmp(name, ".") || !strcmp(name, "..")) {
return EISDIR;
}
lock_acquire(sv->sv_lock);
reserve_buffers(SFS_BLOCKSIZE);
result = sfs_dinode_load(sv);
if (result) {
goto out_buffers;
}
dir_inodeptr = sfs_dinode_map(sv);
if (dir_inodeptr->sfi_linkcount == 0) {
result = ENOENT;
goto out_loadsv;
}
/* Look for the file and fetch a vnode for it. */
result = sfs_lookonce(sv, name, &victim, &slot);
if (result) {
goto out_loadsv;
}
lock_acquire(victim->sv_lock);
result = sfs_dinode_load(victim);
if (result) {
lock_release(victim->sv_lock);
VOP_DECREF(&victim->sv_absvn);
goto out_loadsv;
}
victim_inodeptr = sfs_dinode_map(victim);
KASSERT(victim_inodeptr->sfi_linkcount > 0);
/* Not allowed on directories */
if (victim_inodeptr->sfi_type == SFS_TYPE_DIR) {
result = EISDIR;
goto out_reference;
}
/* Erase its directory entry. */
result = sfs_dir_unlink(sv, slot);
if (result) {
goto out_reference;
}
/* Decrement the link count. */
KASSERT(victim_inodeptr->sfi_linkcount > 0);
victim_inodeptr->sfi_linkcount--;
sfs_dinode_mark_dirty(victim);
out_reference:
/* Discard the reference that sfs_lookonce got us */
sfs_dinode_unload(victim);
lock_release(victim->sv_lock);
VOP_DECREF(&victim->sv_absvn);
out_loadsv:
sfs_dinode_unload(sv);
out_buffers:
lock_release(sv->sv_lock);
unreserve_buffers(SFS_BLOCKSIZE);
return result;
}
/*
* Delete a directory.
*
* Locking: Acquires vnode lock for parent dir and then vnode lock for
* victim dir. Releases both.
*
* Requires 4 buffers.
*/
static
int
sfs_rmdir(struct vnode *v, const char *name)
{
struct sfs_vnode *sv = v->vn_data;
struct sfs_fs *sfs = sv->sv_absvn.vn_fs->fs_data;
struct sfs_vnode *victim;
struct sfs_dinode *dir_inodeptr;
struct sfs_dinode *victim_inodeptr;
int result, result2;
int slot;
/* Cannot remove the . or .. entries from a directory! */
if (!strcmp(name, ".") || !strcmp(name, "..")) {
return EINVAL;
}
lock_acquire(sv->sv_lock);
reserve_buffers(SFS_BLOCKSIZE);
result = sfs_dinode_load(sv);
if (result) {
goto die_loadsv;
}
dir_inodeptr = sfs_dinode_map(sv);
if (dir_inodeptr->sfi_linkcount == 0) {
result = ENOENT;
goto die_linkcount;
}
result = sfs_lookonce(sv, name, &victim, &slot);
if (result) {
goto die_linkcount;
}
lock_acquire(victim->sv_lock);
result = sfs_dinode_load(victim);
if (result) {
goto die_loadvictim;
}
victim_inodeptr = sfs_dinode_map(victim);
if (victim->sv_ino == SFS_ROOTDIR_INO) {
result = EPERM;
goto die_total;
}
/* Only allowed on directories */
if (victim_inodeptr->sfi_type != SFS_TYPE_DIR) {
result = ENOTDIR;
goto die_total;
}
result = sfs_dir_checkempty(victim);
if (result) {
goto die_total;
}
result = sfs_dir_unlink(sv, slot);
if (result) {
goto die_total;
}
KASSERT(dir_inodeptr->sfi_linkcount > 1);
KASSERT(victim_inodeptr->sfi_linkcount==2);
dir_inodeptr->sfi_linkcount--;
sfs_dinode_mark_dirty(sv);
victim_inodeptr->sfi_linkcount -= 2;
sfs_dinode_mark_dirty(victim);
result = sfs_itrunc(victim, 0);
if (result) {
victim_inodeptr->sfi_linkcount += 2;
dir_inodeptr->sfi_linkcount++;
result2 = sfs_dir_link(sv, name, victim->sv_ino, NULL);
if (result2) {
/* XXX: would be better if this case didn't exist */
panic("sfs: %s: rmdir: %s; while recovering: %s\n",
sfs->sfs_sb.sb_volname,
strerror(result), strerror(result2));
}
goto die_total;
}
die_total:
sfs_dinode_unload(victim);
die_loadvictim:
lock_release(victim->sv_lock);
VOP_DECREF(&victim->sv_absvn);
die_linkcount:
sfs_dinode_unload(sv);
die_loadsv:
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sv->sv_lock);
return result;
}
/*
* Get the full pathname for a file. This only needs to work on directories.
*
* Locking: Gets/releases vnode locks, but only one at a time.
*
* Requires up to 3 buffers.
*/
static
int
sfs_namefile(struct vnode *vv, struct uio *uio)
{
struct sfs_vnode *sv = vv->vn_data;
struct sfs_vnode *parent = NULL;
int result;
char *buf;
size_t bufpos, bufmax, len;
KASSERT(uio->uio_rw == UIO_READ);
bufmax = uio->uio_resid+1;
if (bufmax > PATH_MAX) {
bufmax = PATH_MAX;
}
buf = kmalloc(bufmax);
if (buf == NULL) {
return ENOMEM;
}
reserve_buffers(SFS_BLOCKSIZE);
bufpos = bufmax;
VOP_INCREF(&sv->sv_absvn);
while (1) {
lock_acquire(sv->sv_lock);
/* not allowed to lock child since we're going up the tree */
result = sfs_lookonce(sv, "..", &parent, NULL);
lock_release(sv->sv_lock);
if (result) {
VOP_DECREF(&sv->sv_absvn);
kfree(buf);
unreserve_buffers(SFS_BLOCKSIZE);
return result;
}
if (parent == sv) {
/* .. was equal to . - must be root, so we're done */
VOP_DECREF(&parent->sv_absvn);
VOP_DECREF(&sv->sv_absvn);
break;
}
lock_acquire(parent->sv_lock);
result = sfs_getonename(parent, sv->sv_ino, buf, &bufpos);
lock_release(parent->sv_lock);
if (result) {
VOP_DECREF(&parent->sv_absvn);
VOP_DECREF(&sv->sv_absvn);
kfree(buf);
unreserve_buffers(SFS_BLOCKSIZE);
return result;
}
VOP_DECREF(&sv->sv_absvn);
sv = parent;
parent = NULL;
}
/* Done looking, now send back the string */
if (bufmax == bufpos) {
/* root directory; do nothing (send back empty string) */
result = 0;
}
else {
len = bufmax - bufpos;
len--; /* skip the trailing slash */
KASSERT(len <= uio->uio_resid);
result = uiomove(buf+bufpos, len, uio);
}
kfree(buf);
unreserve_buffers(SFS_BLOCKSIZE);
return result;
}
/*
* Rename a file.
*
* Locking:
* Locks sfs_renamelock.
* Calls check_parent, which locks various directories one at a
* time.
* Locks the target vnodes and their parents in a complex fashion
* (described in detail below) which is carefully arranged so
* it won't deadlock with rmdir. Or at least I hope so.
* Then unlocks everything.
*
* The rationale for all this is complex. See the comments below.
*
* Requires up to 7 buffers.
*/
static
int
sfs_rename(struct vnode *absdir1, const char *name1,
struct vnode *absdir2, const char *name2)
{
struct sfs_fs *sfs = absdir1->vn_fs->fs_data;
struct sfs_vnode *dir1 = absdir1->vn_data;
struct sfs_vnode *dir2 = absdir2->vn_data;
struct sfs_vnode *obj1=NULL, *obj2=NULL;
struct sfs_dinode *dir1_inodeptr, *dir2_inodeptr;
struct sfs_dinode *obj1_inodeptr, *obj2_inodeptr;
int slot1=-1, slot2=-1;
int result, result2;
struct sfs_direntry sd;
int found_dir1;
/* make gcc happy */
obj2_inodeptr = NULL;
/* The VFS layer is supposed to enforce this */
KASSERT(absdir1->vn_fs == absdir2->vn_fs);
if (!strcmp(name1, ".") || !strcmp(name2, ".") ||
!strcmp(name1, "..") || !strcmp(name2, "..")) {
return EINVAL;
}
if (strlen(name2)+1 > sizeof(sd.sfd_name)) {
return ENAMETOOLONG;
}
/*
* We only allow one rename to occur at a time. This appears
* to be necessary to preserve the consistency of the
* filesystem: once you do the parent check (that n1 is not an
* ancestor of d2/n2) nothing may be allowed to happen that
* might invalidate that result until all of the
* rearrangements are complete. If other renames are allowed
* to proceed, we'd need to lock every descendent of n1 to
* make sure that some ancestor of d2/n2 doesn't get inserted
* at some point deep down. This is impractical, so we use one
* global lock.
*
* To prevent certain deadlocks while locking the vnodes we
* need, the rename lock goes outside all the vnode locks.
*/
reserve_buffers(SFS_BLOCKSIZE);
lock_acquire(sfs->sfs_renamelock);
/*
* Get the objects we're moving.
*
* Lock each directory temporarily. We'll check again later to
* make sure they haven't disappeared and to find slots.
*/
lock_acquire(dir1->sv_lock);
result = sfs_lookonce(dir1, name1, &obj1, NULL);
lock_release(dir1->sv_lock);
if (result) {
goto out0;
}
lock_acquire(dir2->sv_lock);
result = sfs_lookonce(dir2, name2, &obj2, NULL);
lock_release(dir2->sv_lock);
if (result && result != ENOENT) {
goto out0;
}
if (result==ENOENT) {
/*
* sfs_lookonce returns a null vnode with ENOENT in
* order to make our life easier.
*/
KASSERT(obj2==NULL);
}
/*
* Prohibit the case where obj1 is a directory and it's a direct
* ancestor in the tree of dir2 (or is the same as dir2). If
* that were to be permitted, it'd create a detached chunk of
* the directory tree, and we don't like that.
*
* If we see dir1 while checking up the tree, found_dir1 is
* set to true. We use this info to choose the correct ordering
* for locking dir1 and dir2.
*
* To prevent deadlocks, the parent check must be done without
* holding locks on any other directories.
*/
result = check_parent(dir1, obj1, dir2, &found_dir1);
if (result) {
goto out0;
}
/*
* Now check for cases where some of the four vnodes we have
* are the same.
*
* These cases are, in the order they are handled below:
*
* dir1 == obj1 Already checked.
* dir2 == obj2 Already checked.
* dir2 == obj1 Already checked.
* dir1 == obj2 Checked below.
* dir1 == dir2 Legal.
* obj1 == obj2 Legal, special handling.
*/
/*
* A directory should have no entries for itself other than '.'.
* Thus, since we explicitly reject '.' above, the names
* within the directories should not refer to the directories
* themselves.
*/
KASSERT(dir1 != obj1);
KASSERT(dir2 != obj2);
/*
* The parent check should have caught this case.
*/
KASSERT(dir2 != obj1);
/*
* Check for dir1 == obj2.
*
* This is not necessarily wrong if obj1 is the last entry in
* dir1 (this is essentially "mv ./foo/bar ./foo") but our
* implementation doesn't tolerate it. Because we need to
* unlink g2 before linking g1 in the new place, it will
* always fail complaining that g2 (sv1) isn't empty. We could
* just charge ahead and let this happen, but we'll get into
* trouble with our locks if we do, so detect this as a
* special case and return ENOTEMPTY.
*/
if (obj2==dir1) {
result = ENOTEMPTY;
goto out0;
}
/*
* Now we can begin acquiring locks for real.
*
* If we saw dir1 while doing the parent check, it means
* dir1 is higher in the tree than dir2. Thus, we should
* lock dir1 before dir2.
*
* If on the other hand we didn't see dir1, either dir2 is
* higher in the tree than dir1, in which case we should lock
* dir2 first, or dir1 and dir2 are on disjoint branches of
* the tree, in which case (because there's a single rename
* lock for the whole fs) it doesn't matter what order we lock
* in.
*
* If we lock dir1 first, we don't need to lock obj1 before
* dir2, since (due to the parent check) obj1 cannot be an
* ancestor of dir2.
*
* However, if we lock dir2 first, obj2 must be locked before
* dir1, in case obj2 is an ancestor of dir1. (In this case we
* will find that obj2 is not empty and cannot be removed, but
* we must lock it before we can check that.)
*
* Thus we lock in this order:
*
* dir1 (if found_dir1)
* dir2
* obj2 (if non-NULL)
* dir1 (if !found_dir1)
* obj1
*
* Also, look out for the case where both dirs are the same.
* (If this is true, found_dir1 will be set.)
*/
if (dir1==dir2) {
/* This locks "both" dirs */
lock_acquire(dir1->sv_lock);
KASSERT(found_dir1);
}
else {
if (found_dir1) {
lock_acquire(dir1->sv_lock);
}
lock_acquire(dir2->sv_lock);
}
/*
* Now lock obj2.
*
* Note that we must redo the lookup and get a new obj2, as it
* may have changed under us. Since we hold the rename lock
* for the whole fs, the fs structure cannot have changed, so
* we don't need to redo the parent check or any of the checks
* for vnode aliasing with dir1 or dir2 above. Note however
* that obj1 and obj2 may now be the same even if they weren't
* before.
*/
KASSERT(lock_do_i_hold(dir2->sv_lock));
if (obj2) {
VOP_DECREF(&obj2->sv_absvn);
obj2 = NULL;
}
result = sfs_lookonce(dir2, name2, &obj2, &slot2);
if (result==0) {
KASSERT(obj2 != NULL);
lock_acquire(obj2->sv_lock);
result = sfs_dinode_load(obj2);
if (result) {
/* ENOENT would confuse us below; but it can't be */
KASSERT(result != ENOENT);
lock_release(obj2->sv_lock);
VOP_DECREF(&obj2->sv_absvn);
/* continue to check below */
}
else {
obj2_inodeptr = sfs_dinode_map(obj2);
}
}
else if (result==ENOENT) {
/*
* sfs_lookonce returns a null vnode and an empty slot
* with ENOENT in order to make our life easier.
*/
KASSERT(obj2==NULL);
KASSERT(slot2>=0);
}
if (!found_dir1) {
lock_acquire(dir1->sv_lock);
}
/* Postpone this check to simplify the error cleanup. */
if (result != 0 && result != ENOENT) {
goto out1;
}
/*
* Now reload obj1.
*/
KASSERT(lock_do_i_hold(dir1->sv_lock));
VOP_DECREF(&obj1->sv_absvn);
obj1 = NULL;
result = sfs_lookonce(dir1, name1, &obj1, &slot1);
if (result) {
goto out1;
}
/*
* POSIX mandates that if obj1==obj2, we succeed and nothing
* happens. This is somewhat stupid if obj1==obj2 and dir1 != dir2,
* but we'll go with POSIX anyway.
*/
if (obj1==obj2) {
result = 0;
VOP_DECREF(&obj1->sv_absvn);
obj1 = NULL;
goto out1;
}
lock_acquire(obj1->sv_lock);
result = sfs_dinode_load(obj1);
if (result) {
lock_release(obj1->sv_lock);
VOP_DECREF(&obj1->sv_absvn);
obj1 = NULL;
goto out1;
}
obj1_inodeptr = sfs_dinode_map(obj1);
result = sfs_dinode_load(dir2);
if (result) {
goto out2;
}
dir2_inodeptr = sfs_dinode_map(dir2);
result = sfs_dinode_load(dir1);
if (result) {
goto out3;
}
dir1_inodeptr = sfs_dinode_map(dir1);
/*
* One final piece of paranoia: make sure dir2 hasn't been rmdir'd.
* (If dir1 was, the obj1 lookup above would have failed.)
*/
if (dir2_inodeptr->sfi_linkcount==0) {
result = ENOENT;
goto out4;
}
/*
* Now we have all the locks we need and we can proceed with
* the operation.
*/
/* At this point we should have valid slots in both dirs. */
KASSERT(slot1>=0);
KASSERT(slot2>=0);
if (obj2 != NULL) {
/*
* Target already exists.
* Must be the same type (file or directory) as the source,
* and if a directory, must be empty. Then unlink it.
*/
if (obj1_inodeptr->sfi_type == SFS_TYPE_DIR) {
if (obj2_inodeptr->sfi_type != SFS_TYPE_DIR) {
result = ENOTDIR;
goto out4;
}
result = sfs_dir_checkempty(obj2);
if (result) {
goto out4;
}
/* Remove the name */
result = sfs_dir_unlink(dir2, slot2);
if (result) {
goto out4;
}
/* Dispose of the directory */
KASSERT(dir2_inodeptr->sfi_linkcount > 1);
KASSERT(obj2_inodeptr->sfi_linkcount == 2);
dir2_inodeptr->sfi_linkcount--;
obj2_inodeptr->sfi_linkcount -= 2;
sfs_dinode_mark_dirty(dir2);
sfs_dinode_mark_dirty(obj2);
/* ignore errors on this */
sfs_itrunc(obj2, 0);
}
else {
KASSERT(obj1->sv_type == SFS_TYPE_FILE);
if (obj2->sv_type != SFS_TYPE_FILE) {
result = EISDIR;
goto out4;
}
/* Remove the name */
result = sfs_dir_unlink(dir2, slot2);
if (result) {
goto out4;
}
/* Dispose of the file */
KASSERT(obj2_inodeptr->sfi_linkcount > 0);
obj2_inodeptr->sfi_linkcount--;
sfs_dinode_mark_dirty(obj2);
}
sfs_dinode_unload(obj2);
lock_release(obj2->sv_lock);
VOP_DECREF(&obj2->sv_absvn);
obj2 = NULL;
}
/*
* At this point the target should be nonexistent and we have
* a slot in the target directory we can use. Create a link
* there. Do it by hand instead of using sfs_dir_link to avoid
* duplication of effort.
*/
KASSERT(obj2==NULL);
bzero(&sd, sizeof(sd));
sd.sfd_ino = obj1->sv_ino;
strcpy(sd.sfd_name, name2);
result = sfs_writedir(dir2, slot2, &sd);
if (result) {
goto out4;
}
obj1_inodeptr->sfi_linkcount++;
sfs_dinode_mark_dirty(obj1);
if (obj1->sv_type == SFS_TYPE_DIR && dir1 != dir2) {
/* Directory: reparent it */
result = sfs_readdir(obj1, DOTDOTSLOT, &sd);
if (result) {
goto recover1;
}
if (strcmp(sd.sfd_name, "..")) {
panic("sfs: %s: rename: moving dir: .. is not "
"in slot %d\n", sfs->sfs_sb.sb_volname,
DOTDOTSLOT);
}
if (sd.sfd_ino != dir1->sv_ino) {
panic("sfs: %s: rename: moving dir: .. is i%u "
"and not i%u\n", sfs->sfs_sb.sb_volname,
sd.sfd_ino, dir1->sv_ino);
}
sd.sfd_ino = dir2->sv_ino;
result = sfs_writedir(obj1, DOTDOTSLOT, &sd);
if (result) {
goto recover1;
}
dir1_inodeptr->sfi_linkcount--;
sfs_dinode_mark_dirty(dir1);
dir2_inodeptr->sfi_linkcount++;
sfs_dinode_mark_dirty(dir2);
}
result = sfs_dir_unlink(dir1, slot1);
if (result) {
goto recover2;
}
obj1_inodeptr->sfi_linkcount--;
sfs_dinode_mark_dirty(obj1);
KASSERT(result==0);
if (0) {
/* Only reached on error */
recover2:
if (obj1->sv_type == SFS_TYPE_DIR) {
sd.sfd_ino = dir1->sv_ino;
result2 = sfs_writedir(obj1, DOTDOTSLOT, &sd);
if (result2) {
recovermsg(sfs->sfs_sb.sb_volname,
result, result2);
}
dir1_inodeptr->sfi_linkcount++;
sfs_dinode_mark_dirty(dir1);
dir2_inodeptr->sfi_linkcount--;
sfs_dinode_mark_dirty(dir2);
}
recover1:
result2 = sfs_dir_unlink(dir2, slot2);
if (result2) {
recovermsg(sfs->sfs_sb.sb_volname,
result, result2);
}
obj1_inodeptr->sfi_linkcount--;
sfs_dinode_mark_dirty(obj1);
}
out4:
sfs_dinode_unload(dir1);
out3:
sfs_dinode_unload(dir2);
out2:
sfs_dinode_unload(obj1);
lock_release(obj1->sv_lock);
out1:
if (obj2) {
sfs_dinode_unload(obj2);
lock_release(obj2->sv_lock);
}
lock_release(dir1->sv_lock);
if (dir1 != dir2) {
lock_release(dir2->sv_lock);
}
out0:
if (obj2 != NULL) {
VOP_DECREF(&obj2->sv_absvn);
}
if (obj1 != NULL) {
VOP_DECREF(&obj1->sv_absvn);
}
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sfs->sfs_renamelock);
return result;
}