linux-fh-based-cache-20090511

LICENSE IPL10
FIXES 123620

rework previous fh-based cache support. now allows use of
arbitrarily large file handles, and build correctly for UKERNEL.

we now just use this if there's no iget, instead of providing a configure
switch.

because this relies on the somewhat invasive patch from 124184 it is not
currently pulled up to 1.4.x

diff --git a/acinclude.m4 b/acinclude.m4
index fed8e0f..1d12f45 100644 (file)
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -189,12 +189,6 @@ AC_ARG_ENABLE([pthreaded-ubik],
          disabled)])],
     ,
     [enable_pthreaded_ubik="no"])
-AC_ARG_ENABLE([linux-fh],
-    [AS_HELP_STRING([--enable-linux-fh],
-        [enable opening cache files by file hande instead of inode numbers
-         with linux (defaults to disabled)])],
-    ,
-    [enable_linux_fh="no"])
 
 dnl Kernel module build options.
 AC_ARG_WITH([dux-kernel-headers],
@@ -927,6 +921,9 @@ case $AFS_SYSNAME in *_linux* | *_umlinux*)
                 LINUX_REGISTER_SYSCTL_TABLE_NOFLAG
                 LINUX_SYSCTL_TABLE_CHECKING
                 LINUX_HAVE_IGET
+                if test "x$ac_cv_linux_have_iget" = "xno"; then
+                  AC_DEFINE([LINUX_USE_FH], 1, [define to use linux file handles for cache files])
+                fi
                 LINUX_HAVE_I_SIZE_READ
                 LINUX_HAVE_D_ALLOC_ANON
                 if test "x$ac_cv_linux_d_alloc_anon" = "xno"; then
@@ -1194,9 +1191,6 @@ case $AFS_SYSNAME in *_linux* | *_umlinux*)
                 if test "x$ac_cv_linux_have_kmem_cache_t" = "xyes" ; then
                  AC_DEFINE(KMEM_CACHE_TAKES_DTOR, 1, [define if kmem_cache_create takes a destructor argument])
                 fi
-                if test "$enable_linux_fh" = "yes"; then
-                 AC_DEFINE(LINUX_USE_FH, 1, [define if you want to open cache files by file handle instead of inode numbers])
-                fi
                 if test "x$ac_cv_linux_kernel_page_follow_link" = "xyes" -o "x$ac_cv_linux_func_i_put_link_takes_cookie" = "xyes"; then
                  AC_DEFINE(USABLE_KERNEL_PAGE_SYMLINK_CACHE, 1, [define if your kernel has a usable symlink cache API])
                 else

diff --git a/src/afs/LINUX/osi_file.c b/src/afs/LINUX/osi_file.c
index e217065..479b519 100644 (file)
--- a/src/afs/LINUX/osi_file.c
+++ b/src/afs/LINUX/osi_file.c
@@ -23,8 +23,10 @@ RCSID
 #if defined(AFS_LINUX26_ENV)
 #include "h/namei.h"
 #endif
-#if !defined(HAVE_IGET)
+#if defined(LINUX_USE_FH)
 #include "h/exportfs.h"
+int cache_fh_type = -1;
+int cache_fh_len = -1;
 #endif
 
 afs_lock_t afs_xosi;           /* lock is for tvattr */
@@ -43,9 +45,7 @@ osi_UFSOpen(afs_dcache_id_t *ainode)
     struct inode *tip = NULL;
     struct dentry *dp = NULL;
     struct file *filp = NULL;
-#if !defined(HAVE_IGET) || defined(LINUX_USE_FH)
-    struct fid fid;
-#endif
+
     AFS_STATCNT(osi_UFSOpen);
     if (cacheDiskType != AFS_FCACHE_TYPE_UFS) {
        osi_Panic("UFSOpen called for non-UFS cache\n");
@@ -63,20 +63,14 @@ osi_UFSOpen(afs_dcache_id_t *ainode)
                  (int)sizeof(struct osi_file));
     }
     memset(afile, 0, sizeof(struct osi_file));
-#if defined(HAVE_IGET)
+#if !defined(LINUX_USE_FH)
     tip = iget(afs_cacheSBp, ainode->ufs);
     if (!tip)
        osi_Panic("Can't get inode %d\n", ainode->ufs);
 
     dp = d_alloc_anon(tip);
 #else
-# if defined(LINUX_USE_FH)
-    dp = afs_cacheSBp->s_export_op->fh_to_dentry(afs_cacheSBp, &ainode->ufs.fh, sizeof(struct fid), ainode->ufs.fh_type);
-# else
-    fid.i32.ino = ainode->ufs;
-    fid.i32.gen = 0;
-    dp = afs_cacheSBp->s_export_op->fh_to_dentry(afs_cacheSBp, &fid, sizeof(fid), FILEID_INO32_GEN);
-# endif
+    dp = afs_cacheSBp->s_export_op->fh_to_dentry(afs_cacheSBp, &ainode->ufs.fh, cache_fh_len, cache_fh_type);
     if (!dp) 
            osi_Panic("Can't get dentry\n");          
     tip = dp->d_inode;
@@ -99,11 +93,7 @@ osi_UFSOpen(afs_dcache_id_t *ainode)
     AFS_GLOCK();
     afile->offset = 0;
     afile->proc = (int (*)())0;
-#if defined(LINUX_USE_FH)
     afile->inum = tip->i_ino;  /* for hint validity checking */
-#else
-    afile->inum = ainode->ufs; /* for hint validity checking */
-#endif
     return (void *)afile;
 }
 #else
@@ -160,15 +150,41 @@ osi_UFSOpen(afs_dcache_id_t *ainode)
 #endif
 
 #if defined(LINUX_USE_FH)
+/*
+ * Given a dentry, return the file handle as encoded by the filesystem.
+ * We can't assume anything about the length (words, not bytes).
+ * The cache has to live on a single filesystem with uniform file 
+ * handles, otherwise we panic.
+ */
 void osi_get_fh(struct dentry *dp, afs_ufs_dcache_id_t *ainode) {
-    int max_len = sizeof(struct fid);
+    int max_len;
+    int type;
 
+    if (cache_fh_len > 0)
+       max_len = cache_fh_len;
+    else
+       max_len = MAX_FH_LEN;
     if (dp->d_sb->s_export_op->encode_fh) {
-       ainode->fh_type = dp->d_sb->s_export_op->encode_fh(dp, (__u32 *)&ainode->fh, &max_len, 0);
+        type = dp->d_sb->s_export_op->encode_fh(dp, &ainode->raw[0], &max_len, 0);
+        if (type == 255) {
+           osi_Panic("File handle encoding failed\n");
+        }
+        if (cache_fh_type < 0)
+            cache_fh_type = type;
+        if (cache_fh_len < 0) {
+            cache_fh_len = max_len;
+        }
+        if (type != cache_fh_type || max_len != cache_fh_len) {
+           osi_Panic("Inconsistent file handles within cache\n");
+        }
     } else {
-       ainode->fh_type = FILEID_INO32_GEN;
-       ainode->fh.i32.ino = dp->d_inode->i_ino;
-       ainode->fh.i32.gen = dp->d_inode->i_generation;
+         /* If fs doesn't provide an encode_fh method, assume the default INO32 type */
+       if (cache_fh_type < 0)
+           cache_fh_type = FILEID_INO32_GEN;
+       if (cache_fh_len < 0)
+           cache_fh_len = sizeof(struct fid)/4;
+        ainode->fh.i32.ino = dp->d_inode->i_ino;
+        ainode->fh.i32.gen = dp->d_inode->i_generation;
     }
 }
 #else

diff --git a/src/afs/afs.h b/src/afs/afs.h
index b9b35ad..e81d10e 100644 (file)
--- a/src/afs/afs.h
+++ b/src/afs/afs.h
@@ -1029,10 +1029,13 @@ typedef afs_int32 afs_ufs_dcache_id_t;
  */
 typedef ino64_t afs_ufs_dcache_id_t;
 #elif defined(LINUX_USE_FH)
-typedef struct {
+#define MAX_FH_LEN 10
+typedef union {
      struct fid fh;
-     int fh_type;
+     __u32 raw[MAX_FH_LEN];
 } afs_ufs_dcache_id_t;
+extern int cache_fh_type;
+extern int cache_fh_len;
 #elif defined(AFS_LINUX_64BIT_KERNEL) && !defined(AFS_S390X_LINUX24_ENV)
 typedef long afs_ufs_dcache_id_t;
 #elif defined(AFS_AIX51_ENV) || defined(AFS_HPUX1123_ENV)