X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/316670eb35587141e969394ae8537d66b9211e80..bd504ef0e0b883cdd7917b73b3574eb9ce669905:/bsd/nfs/nfs_node.c

diff --git a/bsd/nfs/nfs_node.c b/bsd/nfs/nfs_node.c
index 7fc9ddaef..9563cc5de 100644
--- a/bsd/nfs/nfs_node.c
+++ b/bsd/nfs/nfs_node.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2011 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
@@ -72,6 +72,7 @@
 #include <sys/proc.h>
 #include <sys/kauth.h>
 #include <sys/mount_internal.h>
+#include <sys/vnode_internal.h>
 #include <sys/vnode.h>
 #include <sys/ubc.h>
 #include <sys/malloc.h>
@@ -132,6 +133,48 @@ nfs_hash(u_char *fhp, int fhsize)
 	return (fhsum);
 }
 
+	
+int nfs_case_insensitive(mount_t);
+
+int
+nfs_case_insensitive(mount_t mp)
+{
+	struct nfsmount *nmp = VFSTONFS(mp);
+	int answer = 0;
+	int skip = 0;
+	
+	if (nmp == NULL) {
+		return (0);
+	}
+	
+	if (nmp->nm_vers == NFS_VER2) {
+		/* V2 has no way to know */
+		return (0);
+	}
+
+	lck_mtx_lock(&nmp->nm_lock);
+	if (nmp->nm_vers == NFS_VER3) {
+		if (!(nmp->nm_state & NFSSTA_GOTPATHCONF)) {
+			/* We're holding the node lock so we just return 
+			 * with answer as case sensitive. Is very rare
+			 * for file systems not to be homogenous w.r.t. pathconf
+			 */
+			skip = 1;
+		} 
+	} else if (!(nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_HOMOGENEOUS)) {
+		/* no pathconf info cached */
+		skip = 1;
+	}
+
+	if (!skip && NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_CASE_INSENSITIVE))
+		answer = 1;
+
+	lck_mtx_unlock(&nmp->nm_lock);
+
+	return (answer);
+}
+
+	
 /*
  * Look up a vnode/nfsnode by file handle.
  * Callers must check for mount points!!
@@ -234,6 +277,84 @@ loop:
 		} else {
 			if (dnp && cnp && (flags & NG_MAKEENTRY))
 				cache_enter(NFSTOV(dnp), vp, cnp);
+			/*
+			 * Update the vnode if the name/and or the parent has
+			 * changed. We need to do this so that if getattrlist is
+			 * called asking for ATTR_CMN_NAME, that the "most"
+			 * correct name is being returned if we're not making an
+			 * entry. In addition for monitored vnodes we need to
+			 * kick the vnode out of the name cache. We do this so
+			 * that if there are hard links in the same directory
+			 * the link will not be found and a lookup will get us
+			 * here to return the name of the current link. In
+			 * addition by removing the name from the name cache the
+			 * old name will not be found after a rename done on
+			 * another client or the server.  The principle reason
+			 * to do this is because Finder is asking for
+			 * notifications on a directory.  The directory changes,
+			 * Finder gets notified, reads the directory (which we
+			 * have purged) and for each entry returned calls
+			 * getattrlist with the name returned from
+			 * readdir. gettattrlist has to call namei/lookup to
+			 * resolve the name, because its not in the cache we end
+			 * up here. We need to update the name so Finder will
+			 * get the name it called us with.
+			 *
+			 * We had an imperfect solution with respect to case
+			 * sensitivity.  There is a test that is run in
+			 * FileBuster that does renames from some name to
+			 * another name differing only in case. It then reads
+			 * the directory looking for the new name, after it
+			 * finds that new name, it ask gettattrlist to verify
+			 * that the name is the new name.  Usually that works,
+			 * but renames generate fsevents and fseventsd will do a
+			 * lookup on the name via lstat. Since that test renames
+			 * old name to new name back and forth there is a race
+			 * that an fsevent will be behind and will access the
+			 * file by the old name, on a case insensitive file
+			 * system that will work. Problem is if we do a case
+			 * sensitive compare, we're going to change the name,
+			 * which the test's getattrlist verification step is
+			 * going to fail. So we will check the case sensitivity
+			 * of the file system and do the appropriate compare. In
+			 * a rare instance for non homogeneous file systems
+			 * w.r.t. pathconf we will use case sensitive compares.
+			 * That could break if the file system is actually case
+			 * insensitive.
+			 *
+			 * Note that V2 does not know the case, so we just
+			 * assume case sensitivity. 
+			 *
+			 * This is clearly not perfect due to races, but this is
+			 * as good as its going to get. You can defeat the
+			 * handling of hard links simply by doing:
+			 *
+			 *	while :; do ls -l > /dev/null; done
+			 *
+			 * in a terminal window. Even a single ls -l can cause a
+			 * race.
+			 *
+			 * <rant>What we really need is for the caller, that
+			 * knows the name being used is valid since it got it
+			 * from a readdir to use that name and not ask for the
+			 * ATTR_CMN_NAME</rant>
+			 */
+			if (dnp && cnp && (vp != NFSTOV(dnp))) {
+				int update_flags = vnode_ismonitored((NFSTOV(dnp))) ? VNODE_UPDATE_CACHE : 0;
+				int (*cmp)(const char *s1, const char *s2, size_t n);
+
+				cmp = nfs_case_insensitive(mp) ? strncasecmp : strncmp;
+
+				if (vp->v_name && cnp->cn_namelen && (*cmp)(cnp->cn_nameptr, vp->v_name, cnp->cn_namelen))
+					update_flags |= VNODE_UPDATE_NAME;
+				if ((vp->v_name == NULL && cnp->cn_namelen != 0) || (vp->v_name != NULL && cnp->cn_namelen == 0))
+					update_flags |= VNODE_UPDATE_NAME;
+				if (vnode_parent(vp) != NFSTOV(dnp))
+					update_flags |= VNODE_UPDATE_PARENT;
+				if (update_flags)
+					vnode_update_identity(vp, NFSTOV(dnp), cnp->cn_nameptr, cnp->cn_namelen, 0, update_flags);
+			}
+
 			*npp = np;
 		}
 		FSDBG_BOT(263, dnp, *npp, 0xcace0000, error);