/*
- * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
const unsigned char *to_nameptr;
char from_iname[32];
char to_iname[32];
- u_int32_t tempflag;
+ uint32_t to_flag_special;
+ uint32_t from_flag_special;
cnid_t from_parid;
cnid_t to_parid;
int lockflags;
to_cp = VTOC(to_vp);
hfsmp = VTOHFS(from_vp);
- /* Only normal files can be exchanged. */
- if (!vnode_isreg(from_vp) || !vnode_isreg(to_vp) ||
- VNODE_IS_RSRC(from_vp) || VNODE_IS_RSRC(to_vp)) {
+ /* Resource forks cannot be exchanged. */
+ if (VNODE_IS_RSRC(from_vp) || VNODE_IS_RSRC(to_vp)) {
error = EINVAL;
goto exit;
}
/* Save a copy of from attributes before swapping. */
bcopy(&from_cp->c_desc, &tempdesc, sizeof(struct cat_desc));
bcopy(&from_cp->c_attr, &tempattr, sizeof(struct cat_attr));
- tempflag = from_cp->c_flag & (C_HARDLINK | C_HASXATTRS);
+
+ /* Save whether or not each cnode is a hardlink or has EAs */
+ from_flag_special = from_cp->c_flag & (C_HARDLINK | C_HASXATTRS);
+ to_flag_special = to_cp->c_flag & (C_HARDLINK | C_HASXATTRS);
+
+ /* Drop the special bits from each cnode */
+ from_cp->c_flag &= ~(C_HARDLINK | C_HASXATTRS);
+ to_cp->c_flag &= ~(C_HARDLINK | C_HASXATTRS);
/*
* Swap the descriptors and all non-fork related attributes.
bcopy(&to_cp->c_desc, &from_cp->c_desc, sizeof(struct cat_desc));
from_cp->c_hint = 0;
- from_cp->c_fileid = from_cp->c_cnid;
+ /*
+ * If 'to' was a hardlink, then we copied over its link ID/CNID/(namespace ID)
+ * when we bcopy'd the descriptor above. However, we need to be careful
+ * when setting up the fileID below, because we cannot assume that the
+ * file ID is the same as the CNID if either one was a hardlink.
+ * The file ID is stored in the c_attr as the ca_fileid. So it needs
+ * to be pulled explicitly; we cannot just use the CNID.
+ */
+ from_cp->c_fileid = to_cp->c_attr.ca_fileid;
+
from_cp->c_itime = to_cp->c_itime;
from_cp->c_btime = to_cp->c_btime;
from_cp->c_atime = to_cp->c_atime;
from_cp->c_bsdflags = to_cp->c_bsdflags;
from_cp->c_mode = to_cp->c_mode;
from_cp->c_linkcount = to_cp->c_linkcount;
- from_cp->c_flag = to_cp->c_flag & (C_HARDLINK | C_HASXATTRS);
+ from_cp->c_attr.ca_linkref = to_cp->c_attr.ca_linkref;
+ from_cp->c_attr.ca_firstlink = to_cp->c_attr.ca_firstlink;
+
+ /*
+ * The cnode flags need to stay with the cnode and not get transferred
+ * over along with everything else because they describe the content; they are
+ * not attributes that reflect changes specific to the file ID. In general,
+ * fields that are tied to the file ID are the ones that will move.
+ *
+ * This reflects the fact that the file may have borrowed blocks, dirty metadata,
+ * or other extents, which may not yet have been written to the catalog. If
+ * they were, they would have been transferred above in the ExchangeFileIDs call above...
+ *
+ * The flags that are special are:
+ * C_HARDLINK, C_HASXATTRS
+ *
+ * These flags move with the item and file ID in the namespace since their
+ * state is tied to that of the file ID.
+ *
+ * So to transfer the flags, we have to take the following steps
+ * 1) Store in a localvar whether or not the special bits are set.
+ * 2) Drop the special bits from the current flags
+ * 3) swap the special flag bits to their destination
+ */
+ from_cp->c_flag |= to_flag_special;
+
from_cp->c_attr.ca_recflags = to_cp->c_attr.ca_recflags;
bcopy(to_cp->c_finderinfo, from_cp->c_finderinfo, 32);
bcopy(&tempdesc, &to_cp->c_desc, sizeof(struct cat_desc));
to_cp->c_hint = 0;
- to_cp->c_fileid = to_cp->c_cnid;
+ /*
+ * Pull the file ID from the tempattr we copied above. We can't assume
+ * it is the same as the CNID.
+ */
+ to_cp->c_fileid = tempattr.ca_fileid;
to_cp->c_itime = tempattr.ca_itime;
to_cp->c_btime = tempattr.ca_btime;
to_cp->c_atime = tempattr.ca_atime;
to_cp->c_bsdflags = tempattr.ca_flags;
to_cp->c_mode = tempattr.ca_mode;
to_cp->c_linkcount = tempattr.ca_linkcount;
- to_cp->c_flag = tempflag;
+ to_cp->c_attr.ca_linkref = tempattr.ca_linkref;
+ to_cp->c_attr.ca_firstlink = tempattr.ca_firstlink;
+
+ /*
+ * Only OR in the "from" flags into our cnode flags below.
+ * Leave the rest of the flags alone.
+ */
+ to_cp->c_flag |= from_flag_special;
+
to_cp->c_attr.ca_recflags = tempattr.ca_recflags;
bcopy(tempattr.ca_finderinfo, to_cp->c_finderinfo, 32);
tdcp->c_flag |= C_FORCEUPDATE; // XXXdbg - force it out!
(void) hfs_update(tdvp, 0);
+
+ /* Update the vnode's name now that the rename has completed. */
+ vnode_update_identity(fvp, tdvp, tcnp->cn_nameptr, tcnp->cn_namelen,
+ tcnp->cn_hash, (VNODE_UPDATE_PARENT | VNODE_UPDATE_NAME));
+
+ /*
+ * At this point, we may have a resource fork vnode attached to the
+ * 'from' vnode. If it exists, we will want to update its name, because
+ * it contains the old name + _PATH_RSRCFORKSPEC. ("/..namedfork/rsrc").
+ *
+ * Note that the only thing we need to update here is the name attached to
+ * the vnode, since a resource fork vnode does not have a separate resource
+ * cnode -- it's still 'fcp'.
+ */
+ if (fcp->c_rsrc_vp) {
+ char* rsrc_path = NULL;
+ int len;
+
+ /* Create a new temporary buffer that's going to hold the new name */
+ MALLOC_ZONE (rsrc_path, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
+ len = snprintf (rsrc_path, MAXPATHLEN, "%s%s", tcnp->cn_nameptr, _PATH_RSRCFORKSPEC);
+ len = MIN(len, MAXPATHLEN);
+
+ /*
+ * vnode_update_identity will do the following for us:
+ * 1) release reference on the existing rsrc vnode's name.
+ * 2) copy/insert new name into the name cache
+ * 3) attach the new name to the resource vnode
+ * 4) update the vnode's vid
+ */
+ vnode_update_identity (fcp->c_rsrc_vp, fvp, rsrc_path, len, 0, (VNODE_UPDATE_NAME | VNODE_UPDATE_CACHE));
+
+ /* Free the memory associated with the resource fork's name */
+ FREE_ZONE (rsrc_path, MAXPATHLEN, M_NAMEI);
+ }
out:
if (got_cookie) {
cat_postflight(hfsmp, &cookie, p);
lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_SHARED_LOCK);
- /* Get resource fork data */
- error = cat_lookup(hfsmp, descptr, 1, (struct cat_desc *)0,
- (struct cat_attr *)0, &rsrcfork, NULL);
+ /*
+ * Get resource fork data
+ *
+ * We call cat_idlookup (instead of cat_lookup) below because we can't
+ * trust the descriptor in the provided cnode for lookups at this point.
+ * Between the time of the original lookup of this vnode and now, the
+ * descriptor could have gotten swapped or replaced. If this occurred,
+ * the parent/name combo originally desired may not necessarily be provided
+ * if we use the descriptor. Even worse, if the vnode represents
+ * a hardlink, we could have removed one of the links from the namespace
+ * but left the descriptor alone, since hfs_unlink does not invalidate
+ * the descriptor in the cnode if other links still point to the inode.
+ *
+ * Consider the following (slightly contrived) scenario:
+ * /tmp/a <--> /tmp/b (hardlinks).
+ * 1. Thread A: open rsrc fork on /tmp/b.
+ * 1a. Thread A: does lookup, goes out to lunch right before calling getnamedstream.
+ * 2. Thread B does 'mv /foo/b /tmp/b'
+ * 2. Thread B succeeds.
+ * 3. Thread A comes back and wants rsrc fork info for /tmp/b.
+ *
+ * Even though the hardlink backing /tmp/b is now eliminated, the descriptor
+ * is not removed/updated during the unlink process. So, if you were to
+ * do a lookup on /tmp/b, you'd acquire an entirely different record's resource
+ * fork.
+ *
+ * As a result, we use the fileid, which should be invariant for the lifetime
+ * of the cnode (possibly barring calls to exchangedata).
+ *
+ * Addendum: We can't do the above for HFS standard since we aren't guaranteed to
+ * have thread records for files. They were only required for directories. So
+ * we need to do the lookup with the catalog name. This is OK since hardlinks were
+ * never allowed on HFS standard.
+ */
+
+ if (hfsmp->hfs_flags & HFS_STANDARD) {
+ /*
+ * HFS standard only:
+ *
+ * Get the resource fork for this item via catalog lookup
+ * since HFS standard was case-insensitive only. We don't want the
+ * descriptor; just the fork data here.
+ */
+ error = cat_lookup (hfsmp, descptr, 1, (struct cat_desc*)NULL,
+ (struct cat_attr*)NULL, &rsrcfork, NULL);
+ }
+ else {
+ error = cat_idlookup (hfsmp, cp->c_fileid, 0, 1, NULL, NULL, &rsrcfork);
+ }
hfs_systemfile_unlock(hfsmp, lockflags);
if (error) {
return (error);
}
+
/*
* Supply hfs_getnewvnode with a component name.
*/
projects / apple / xnu.git / blobdiff