xnu-2050.48.11.tar.gz

[apple/xnu.git] / bsd / nfs / nfs_node.c

diff --git a/bsd/nfs/nfs_node.c b/bsd/nfs/nfs_node.c
index 7fc9ddaef8c8eed4132aa73247b0fae0666a2170..9563cc5de1b4aad486ae4617d4b3673521f09937 100644 (file)
--- 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@
  * 
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 


@@ -72,6 +72,7 @@
 #include <sys/proc.h>
 #include <sys/kauth.h>
 #include <sys/mount_internal.h>
 #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>
 #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);
 }
 
        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!!
 /*
  * 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);
                } 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);
                        *npp = np;
                }
                FSDBG_BOT(263, dnp, *npp, 0xcace0000, error);