/*
* Clear an Address/Length List so that it holds no pairs.
*/
void
alenlist_clear(alenlist_t alenlist)
{
alenlist_chunk_t chunk, freechunk;
/*
* If this List is not FIXED_SIZE, free all the
* extra chunks.
*/
if (!(alenlist->al_flags & AL_FIXED_SIZE)) {
/* First, free any extension alenlist chunks */
chunk = alenlist->al_chunk.alc_next;
while (chunk) {
freechunk = chunk;
chunk = chunk->alc_next;
snia_kmem_zone_free(alenlist_chunk_zone, freechunk);
DECR_COUNT(&alenlist_chunk_count);
}
alenlist->al_actual_size = ALEN_CHUNK_SZ;
alenlist->al_chunk.alc_next = NULL;
}
alenlist->al_logical_size = 0;
alenlist->al_last_chunk = &alenlist->al_chunk;
do_cursor_init(alenlist, &alenlist->al_cursor);
}
/*
* Destroy an Address/Length List.
*/
void
alenlist_destroy(alenlist_t alenlist)
{
if (alenlist == NULL)
return;
/*
* Turn off FIXED_SIZE so this List can be
* automatically shrunk.
*/
alenlist->al_flags &= ~AL_FIXED_SIZE;
/* Free extension chunks first */
if (alenlist->al_chunk.alc_next)
alenlist_clear(alenlist);
/* Now, free the alenlist itself */
snia_kmem_zone_free(alenlist_zone, alenlist);
DECR_COUNT(&alenlist_count);
}
/*
* xdirtrunc is called to remove all directory entries under this directory.
* The files themselves are removed elsewhere.
*/
void
xdirtrunc(struct xmemnode *dir)
{
register struct xdirent *xdp;
size_t namelen;
timestruc_t now;
ASSERT(RW_WRITE_HELD(&dir->xn_rwlock));
ASSERT(dir->xn_type == VDIR);
for (xdp = dir->xn_dir; xdp; xdp = dir->xn_dir) {
ASSERT(xdp->xd_next != xdp);
ASSERT(xdp->xd_prev != xdp);
ASSERT(xdp->xd_xmemnode);
ASSERT(xdp->xd_xmemnode->xn_nlink > 0);
dir->xn_dir = xdp->xd_next;
namelen = strlen(xdp->xd_name) + 1;
DECR_COUNT(&xdp->xd_xmemnode->xn_nlink,
&xdp->xd_xmemnode->xn_tlock);
xmemfs_hash_out(xdp);
xmem_memfree(xdp, sizeof (struct xdirent) + namelen);
dir->xn_size -= (sizeof (struct xdirent) + namelen);
dir->xn_dirents--;
}
gethrestime(&now);
dir->xn_mtime = now;
dir->xn_ctime = now;
ASSERT(dir->xn_dir == NULL);
ASSERT(dir->xn_size == 0);
ASSERT(dir->xn_dirents == 0);
}
/*
* Free an Address/Length List cursor.
*/
void
alenlist_cursor_destroy(alenlist_cursor_t cursorp)
{
DECR_COUNT(&alenlist_cursor_count);
snia_kmem_zone_free(alenlist_cursor_zone, cursorp);
}
static int
xdirrename(
struct xmemnode *fromparent, /* parent directory of source */
struct xmemnode *fromxp, /* source xmemnode */
struct xmemnode *toparent, /* parent directory of target */
char *nm, /* entry we are trying to change */
struct xmemnode *to, /* target xmemnode */
struct xdirent *where, /* target xmemnode directory entry */
struct cred *cred) /* credentials */
{
int error = 0;
int doingdirectory;
timestruc_t now;
#if defined(lint)
nm = nm;
#endif
ASSERT(RW_WRITE_HELD(&toparent->xn_rwlock));
rw_enter(&fromxp->xn_rwlock, RW_READER);
rw_enter(&to->xn_rwlock, RW_READER);
/*
* Check that everything is on the same filesystem.
*/
if (to->xn_vnode->v_vfsp != toparent->xn_vnode->v_vfsp ||
to->xn_vnode->v_vfsp != fromxp->xn_vnode->v_vfsp) {
error = EXDEV;
goto out;
}
/*
* Short circuit rename of something to itself.
*/
if (fromxp == to) {
error = ESAME; /* special KLUDGE error code */
goto out;
}
/*
* Must have write permission to rewrite target entry.
*/
if (error = xmem_xaccess(fromparent, VWRITE, cred))
goto out;
/*
* If the parent directory is "sticky", then the user must own
* either the parent directory or the destination of the rename,
* or else must have permission to write the destination.
* Otherwise the destination may not be changed (except by the
* privileged users). This implements append-only directories.
*/
if (error = xmem_sticky_remove_access(toparent, to, cred))
goto out;
/*
* Ensure source and target are compatible (both directories
* or both not directories). If target is a directory it must
* be empty and have no links to it; in addition it must not
* be a mount point, and both the source and target must be
* writable.
*/
doingdirectory = (fromxp->xn_type == VDIR);
if (to->xn_type == VDIR) {
if (!doingdirectory) {
error = EISDIR;
goto out;
}
/*
* vn_vfswlock will prevent mounts from using the directory
* until we are done.
*/
if (vn_vfswlock(XNTOV(to))) {
error = EBUSY;
goto out;
}
if (vn_mountedvfs(XNTOV(to)) != NULL) {
vn_vfsunlock(XNTOV(to));
error = EBUSY;
goto out;
}
mutex_enter(&to->xn_tlock);
if (to->xn_dirents > 2 || to->xn_nlink > 2) {
mutex_exit(&to->xn_tlock);
vn_vfsunlock(XNTOV(to));
error = EEXIST; /* SIGH should be ENOTEMPTY */
/*
* Update atime because checking xn_dirents is
* logically equivalent to reading the directory
*/
gethrestime(&to->xn_atime);
goto out;
}
mutex_exit(&to->xn_tlock);
} else if (doingdirectory) {
error = ENOTDIR;
goto out;
}
where->xd_xmemnode = fromxp;
gethrestime(&now);
toparent->xn_mtime = now;
toparent->xn_ctime = now;
/*
* Upgrade to write lock on "to" (i.e., the target xmemnode).
*/
rw_exit(&to->xn_rwlock);
rw_enter(&to->xn_rwlock, RW_WRITER);
/*
* Decrement the link count of the target xmemnode.
*/
DECR_COUNT(&to->xn_nlink, &to->xn_tlock);
to->xn_ctime = now;
if (doingdirectory) {
/*
* The entry for "to" no longer exists so release the vfslock.
*/
vn_vfsunlock(XNTOV(to));
/*
* Decrement the target link count and delete all entires.
*/
xdirtrunc(to);
ASSERT(to->xn_nlink == 0);
/*
* Renaming a directory with the parent different
* requires that ".." be rewritten. The window is
* still there for ".." to be inconsistent, but this
* is unavoidable, and a lot shorter than when it was
* done in a user process.
*/
if (fromparent != toparent)
xdirfixdotdot(fromxp, fromparent, toparent);
}
out:
rw_exit(&to->xn_rwlock);
rw_exit(&fromxp->xn_rwlock);
return (error);
}
/*
* Delete entry xp of name "nm" from dir.
* Free dir entry space and decrement link count on xmemnode(s).
*
* Return 0 on success.
*/
int
xdirdelete(
struct xmemnode *dir,
struct xmemnode *xp,
char *nm,
enum dr_op op,
struct cred *cred)
{
register struct xdirent *tpdp;
int error;
size_t namelen;
struct xmemnode *xptmp;
timestruc_t now;
ASSERT(RW_WRITE_HELD(&dir->xn_rwlock));
ASSERT(RW_WRITE_HELD(&xp->xn_rwlock));
ASSERT(dir->xn_type == VDIR);
ASSERT(nm[0] != '\0');
/*
* return error when removing . and ..
*/
if (nm[0] == '.') {
if (nm[1] == '\0')
return (EINVAL);
if (nm[1] == '.' && nm[2] == '\0')
return (EEXIST); /* thus in ufs */
}
if (error = xmem_xaccess(dir, VEXEC|VWRITE, cred))
return (error);
/*
* If the parent directory is "sticky", then the user must
* own the parent directory or the file in it, or else must
* have permission to write the file. Otherwise it may not
* be deleted (except by privileged users). Same as ufs_dirremove.
*/
if (error = xmem_sticky_remove_access(dir, xp, cred))
return (error);
if (dir->xn_dir == NULL)
return (ENOENT);
tpdp = xmemfs_hash_lookup(nm, dir, 0, &xptmp);
if (tpdp == NULL) {
/*
* If it is gone, some other thread got here first!
* Return error ENOENT.
*/
return (ENOENT);
}
/*
* If the xmemnode in the xdirent changed, we were probably
* the victim of a concurrent rename operation. The original
* is gone, so return that status (same as UFS).
*/
if (xp != xptmp)
return (ENOENT);
xmemfs_hash_out(tpdp);
/*
* Take tpdp out of the directory list.
*/
ASSERT(tpdp->xd_next != tpdp);
ASSERT(tpdp->xd_prev != tpdp);
if (tpdp->xd_prev) {
tpdp->xd_prev->xd_next = tpdp->xd_next;
}
if (tpdp->xd_next) {
tpdp->xd_next->xd_prev = tpdp->xd_prev;
}
/*
* If the roving slot pointer happens to match tpdp,
* point it at the previous dirent.
*/
if (dir->xn_dir->xd_prev == tpdp) {
dir->xn_dir->xd_prev = tpdp->xd_prev;
}
ASSERT(tpdp->xd_next != tpdp);
ASSERT(tpdp->xd_prev != tpdp);
/*
* tpdp points to the correct directory entry
*/
namelen = strlen(tpdp->xd_name) + 1;
xmem_memfree(tpdp, sizeof (struct xdirent) + namelen);
dir->xn_size -= (sizeof (struct xdirent) + namelen);
dir->xn_dirents--;
gethrestime(&now);
dir->xn_mtime = now;
dir->xn_ctime = now;
xp->xn_ctime = now;
ASSERT(xp->xn_nlink > 0);
DECR_COUNT(&xp->xn_nlink, &xp->xn_tlock);
if (op == DR_RMDIR && xp->xn_type == VDIR) {
xdirtrunc(xp);
ASSERT(xp->xn_nlink == 0);
}
return (0);
}
/*
* Enter a directory entry for 'name' and 'xp' into directory 'dir'
*
* Returns 0 on success.
*/
int
xdirenter(
struct xmount *xm,
struct xmemnode *dir, /* target directory to make entry in */
char *name, /* name of entry */
enum de_op op, /* entry operation */
struct xmemnode *fromparent, /* source directory if rename */
struct xmemnode *xp, /* source xmemnode, if link/rename */
struct vattr *va,
struct xmemnode **xpp, /* return xmemnode, if create/mkdir */
struct cred *cred)
{
struct xdirent *xdp;
struct xmemnode *found = NULL;
int error = 0;
char *s;
/*
* xn_rwlock is held to serialize direnter and dirdeletes
*/
ASSERT(RW_WRITE_HELD(&dir->xn_rwlock));
ASSERT(dir->xn_type == VDIR);
/*
* Don't allow '/' characters in pathname component
* (thus in ufs_direnter()).
*/
for (s = name; *s; s++)
if (*s == '/')
return (EACCES);
ASSERT(name[0] != '\0');
/*
* For link and rename lock the source entry and check the link count
* to see if it has been removed while it was unlocked.
*/
if (op == DE_LINK || op == DE_RENAME) {
mutex_enter(&xp->xn_tlock);
if (xp->xn_nlink == 0) {
mutex_exit(&xp->xn_tlock);
return (ENOENT);
}
if (xp->xn_nlink == MAXLINK) {
mutex_exit(&xp->xn_tlock);
return (EMLINK);
}
xp->xn_nlink++;
mutex_exit(&xp->xn_tlock);
gethrestime(&xp->xn_ctime);
}
/*
* This might be a "dangling detached directory".
* it could have been removed, but a reference
* to it kept in u_cwd. don't bother searching
* it, and with any luck the user will get tired
* of dealing with us and cd to some absolute
* pathway. *sigh*, thus in ufs, too.
*/
if (dir->xn_nlink == 0) {
error = ENOENT;
goto out;
}
/*
* If this is a rename of a directory and the parent is
* different (".." must be changed), then the source
* directory must not be in the directory hierarchy
* above the target, as this would orphan everything
* below the source directory.
*/
if (op == DE_RENAME) {
if (xp == dir) {
error = EINVAL;
goto out;
}
if (xp->xn_type == VDIR) {
if ((fromparent != dir) &&
(error = xdircheckpath(xp, dir, cred))) {
goto out;
}
}
}
/*
* Search for the entry. Return "found" if it exists.
*/
xdp = xmemfs_hash_lookup(name, dir, 1, &found);
if (xdp) {
ASSERT(found);
switch (op) {
case DE_CREATE:
case DE_MKDIR:
if (xpp) {
*xpp = found;
error = EEXIST;
} else {
xmemnode_rele(found);
}
break;
case DE_RENAME:
error = xdirrename(fromparent, xp,
dir, name, found, xdp, cred);
xmemnode_rele(found);
break;
case DE_LINK:
/*
* Can't link to an existing file.
*/
error = EEXIST;
xmemnode_rele(found);
break;
}
} else {
/*
* The entry does not exist. Check write permission in
* directory to see if entry can be created.
*/
if (error = xmem_xaccess(dir, VWRITE, cred))
goto out;
if (op == DE_CREATE || op == DE_MKDIR) {
/*
* Make new xmemnode and directory entry as required.
*/
error = xdirmakexnode(dir, xm, va, op, &xp, cred);
if (error)
goto out;
}
if (error = xdiraddentry(dir, xp, name, op, fromparent)) {
if (op == DE_CREATE || op == DE_MKDIR) {
/*
* Unmake the inode we just made.
*/
rw_enter(&xp->xn_rwlock, RW_WRITER);
if ((xp->xn_type) == VDIR) {
ASSERT(xdp == NULL);
/*
* cleanup allocs made by xdirinit()
*/
xdirtrunc(xp);
}
mutex_enter(&xp->xn_tlock);
xp->xn_nlink = 0;
mutex_exit(&xp->xn_tlock);
gethrestime(&xp->xn_ctime);
rw_exit(&xp->xn_rwlock);
xmemnode_rele(xp);
xp = NULL;
}
} else if (xpp) {
*xpp = xp;
} else if (op == DE_CREATE || op == DE_MKDIR) {
xmemnode_rele(xp);
}
}
out:
if (error && (op == DE_LINK || op == DE_RENAME)) {
/*
* Undo bumped link count.
*/
DECR_COUNT(&xp->xn_nlink, &xp->xn_tlock);
gethrestime(&xp->xn_ctime);
}
return (error);
}
