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LU-9558 llite: generic_readlink is no longer exported
[fs/lustre-release.git] / lustre / llite / symlink.c
index 7a446dd..7095955 100644 (file)
@@ -1,6 +1,4 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * GPL HEADER START
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * You should have received a copy of the GNU General Public License
  * version 2 along with this program; If not, see
- * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
- *
- * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
+ * http://www.gnu.org/licenses/gpl-2.0.html
  *
  * GPL HEADER END
  */
 /*
- * Copyright  2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2014, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/stat.h>
-#include <linux/smp_lock.h>
 #include <linux/version.h>
 #define DEBUG_SUBSYSTEM S_LLITE
 
-#include <lustre_lite.h>
 #include "llite_internal.h"
 
 static int ll_readlink_internal(struct inode *inode,
@@ -51,38 +45,53 @@ static int ll_readlink_internal(struct inode *inode,
         struct ll_sb_info *sbi = ll_i2sbi(inode);
         int rc, symlen = i_size_read(inode) + 1;
         struct mdt_body *body;
-        struct obd_capa *oc;
+        struct md_op_data *op_data;
         ENTRY;
 
         *request = NULL;
 
-        if (lli->lli_symlink_name) {
-                *symname = lli->lli_symlink_name;
-                CDEBUG(D_INODE, "using cached symlink %s\n", *symname);
-                RETURN(0);
-        }
-
-        oc = ll_mdscapa_get(inode);
-        rc = md_getattr(sbi->ll_md_exp, ll_inode2fid(inode), oc,
-                        OBD_MD_LINKNAME, symlen, request);
-        capa_put(oc);
+       if (lli->lli_symlink_name) {
+               int print_limit = min_t(int, PAGE_SIZE - 128, symlen);
+
+               *symname = lli->lli_symlink_name;
+               /* If the total CDEBUG() size is larger than a page, it
+                * will print a warning to the console, avoid this by
+                * printing just the last part of the symlink. */
+               CDEBUG(D_INODE, "using cached symlink %s%.*s, len = %d\n",
+                      print_limit < symlen ? "..." : "", print_limit,
+                      (*symname) + symlen - print_limit, symlen);
+               RETURN(0);
+       }
+
+        op_data = ll_prep_md_op_data(NULL, inode, NULL, NULL, 0, symlen,
+                                     LUSTRE_OPC_ANY, NULL);
+        if (IS_ERR(op_data))
+                RETURN(PTR_ERR(op_data));
+
+        op_data->op_valid = OBD_MD_LINKNAME;
+        rc = md_getattr(sbi->ll_md_exp, op_data, request);
+        ll_finish_md_op_data(op_data);
         if (rc) {
                 if (rc != -ENOENT)
-                        CERROR("inode %lu: rc = %d\n", inode->i_ino, rc);
+                       CERROR("%s: inode "DFID": rc = %d\n",
+                              ll_get_fsname(inode->i_sb, NULL, 0),
+                              PFID(ll_inode2fid(inode)), rc);
                 GOTO (failed, rc);
         }
 
         body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
         LASSERT(body != NULL);
-        if ((body->valid & OBD_MD_LINKNAME) == 0) {
-                CERROR("OBD_MD_LINKNAME not set on reply\n");
-                GOTO(failed, rc = -EPROTO);
-        }
-
-        LASSERT(symlen != 0);
-        if (body->eadatasize != symlen) {
-                CERROR("inode %lu: symlink length %d not expected %d\n",
-                        inode->i_ino, body->eadatasize - 1, symlen - 1);
+       if ((body->mbo_valid & OBD_MD_LINKNAME) == 0) {
+               CERROR("OBD_MD_LINKNAME not set on reply\n");
+               GOTO(failed, rc = -EPROTO);
+       }
+
+       LASSERT(symlen != 0);
+       if (body->mbo_eadatasize != symlen) {
+               CERROR("%s: inode "DFID": symlink length %d not expected %d\n",
+                      ll_get_fsname(inode->i_sb, NULL, 0),
+                      PFID(ll_inode2fid(inode)), body->mbo_eadatasize - 1,
+                      symlen - 1);
                 GOTO(failed, rc = -EPROTO);
         }
 
@@ -90,8 +99,9 @@ static int ll_readlink_internal(struct inode *inode,
         if (*symname == NULL ||
             strnlen(*symname, symlen) != symlen - 1) {
                 /* not full/NULL terminated */
-                CERROR("inode %lu: symlink not NULL terminated string"
-                        "of length %d\n", inode->i_ino, symlen - 1);
+               CERROR("%s: inode "DFID": symlink not NULL terminated string"
+                      "of length %d\n", ll_get_fsname(inode->i_sb, NULL, 0),
+                      PFID(ll_inode2fid(inode)), symlen - 1);
                 GOTO(failed, rc = -EPROTO);
         }
 
@@ -107,56 +117,28 @@ failed:
         RETURN (rc);
 }
 
-static int ll_readlink(struct dentry *dentry, char *buffer, int buflen)
-{
-        struct inode *inode = dentry->d_inode;
-        struct ptlrpc_request *request;
-        char *symname;
-        int rc;
-        ENTRY;
-
-        CDEBUG(D_VFSTRACE, "VFS Op\n");
-        /* on symlinks lli_open_sem protects lli_symlink_name allocation/data */
-        ll_inode_size_lock(inode, 0);
-        rc = ll_readlink_internal(inode, &request, &symname);
-        if (rc)
-                GOTO(out, rc);
-
-        rc = vfs_readlink(dentry, buffer, buflen, symname);
- out:
-        ptlrpc_req_finished(request);
-        ll_inode_size_unlock(inode, 0);
-        RETURN(rc);
-}
-
-#ifdef HAVE_COOKIE_FOLLOW_LINK
-# define LL_FOLLOW_LINK_RETURN_TYPE void *
+#ifdef HAVE_SYMLINK_OPS_USE_NAMEIDATA
+static void ll_put_link(struct dentry *dentry,
+                       struct nameidata *nd, void *cookie)
 #else
-# define LL_FOLLOW_LINK_RETURN_TYPE int
+# ifdef HAVE_IOP_GET_LINK
+static void ll_put_link(void *cookie)
+# else
+static void ll_put_link(struct inode *unused, void *cookie)
+# endif
 #endif
-
-static LL_FOLLOW_LINK_RETURN_TYPE ll_follow_link(struct dentry *dentry,
-                                                 struct nameidata *nd)
 {
-        struct inode *inode = dentry->d_inode;
-#ifdef HAVE_VFS_INTENT_PATCHES
-        struct lookup_intent *it = ll_nd2it(nd);
-#endif
-        struct ptlrpc_request *request = NULL;
-        int rc;
-        char *symname;
-        ENTRY;
-
-#ifdef HAVE_VFS_INTENT_PATCHES
-        if (it != NULL) {
-                int op = it->it_op;
-                int mode = it->it_create_mode;
+       ptlrpc_req_finished(cookie);
+}
 
-                ll_intent_release(it);
-                it->it_op = op;
-                it->it_create_mode = mode;
-        }
-#endif
+#ifdef HAVE_SYMLINK_OPS_USE_NAMEIDATA
+static void *ll_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+       struct inode *inode = dentry->d_inode;
+       struct ptlrpc_request *request = NULL;
+       int rc;
+       char *symname = NULL;
+       ENTRY;
 
         CDEBUG(D_VFSTRACE, "VFS Op\n");
         /* Limit the recursive symlink depth to 5 instead of default
@@ -167,65 +149,92 @@ static LL_FOLLOW_LINK_RETURN_TYPE ll_follow_link(struct dentry *dentry,
         } else if (THREAD_SIZE == 8192 && current->link_count >= 8) {
                 rc = -ELOOP;
         } else {
-                ll_inode_size_lock(inode, 0);
-                rc = ll_readlink_internal(inode, &request, &symname);
-                ll_inode_size_unlock(inode, 0);
-        }
-        if (rc) {
-                path_release(nd); /* Kernel assumes that ->follow_link()
-                                     releases nameidata on error */
-                GOTO(out, rc);
-        }
-
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,8))
-        rc = vfs_follow_link(nd, symname);
-#else
-#ifdef HAVE_COOKIE_FOLLOW_LINK
-        nd_set_link(nd, symname);
-        /* @symname may contain a pointer to the request message buffer,
-           we delay request releasing until ll_put_link then. */
-        RETURN(request);
-#else
-        if (lli->lli_symlink_name == NULL) {
-                /* falling back to recursive follow link if the request
-                 * needs to be cleaned up still. */
-                rc = vfs_follow_link(nd, symname);
-                GOTO(out, rc);
+               ll_inode_size_lock(inode);
+               rc = ll_readlink_internal(inode, &request, &symname);
+               ll_inode_size_unlock(inode);
         }
-        nd_set_link(nd, symname);
-        RETURN(0);
-#endif
-#endif
-out:
-        ptlrpc_req_finished(request);
-#ifdef HAVE_COOKIE_FOLLOW_LINK
-        RETURN(ERR_PTR(rc));
+       if (rc) {
+               ptlrpc_req_finished(request);
+               request = NULL;
+               symname = ERR_PTR(rc);
+       }
+
+       nd_set_link(nd, symname);
+       /* symname may contain a pointer to the request message buffer,
+        * we delay request releasing until ll_put_link then.
+        */
+       RETURN(request);
+}
 #else
-        RETURN(rc);
-#endif
+# ifdef HAVE_IOP_GET_LINK
+static const char *ll_get_link(struct dentry *dentry,
+                              struct inode *inode,
+                              struct delayed_call *done)
+{
+       struct ptlrpc_request *request;
+       char *symname = NULL;
+       int rc;
+
+       ENTRY;
+       CDEBUG(D_VFSTRACE, "VFS Op\n");
+       if (!dentry)
+               RETURN(ERR_PTR(-ECHILD));
+       ll_inode_size_lock(inode);
+       rc = ll_readlink_internal(inode, &request, &symname);
+       ll_inode_size_unlock(inode);
+       if (rc < 0) {
+               ptlrpc_req_finished(request);
+               return ERR_PTR(rc);
+       }
+
+       /* symname may contain a pointer to the request message buffer,
+        * we delay request releasing then.
+        */
+       set_delayed_call(done, ll_put_link, request);
+       RETURN(symname);
 }
-
-#ifdef HAVE_COOKIE_FOLLOW_LINK
-static void ll_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
+# else
+static const char *ll_follow_link(struct dentry *dentry, void **cookie)
 {
-        ptlrpc_req_finished(cookie);
+       struct inode *inode = d_inode(dentry);
+       struct ptlrpc_request *request;
+       char *symname = NULL;
+       int rc;
+       ENTRY;
+
+       CDEBUG(D_VFSTRACE, "VFS Op\n");
+       ll_inode_size_lock(inode);
+       rc = ll_readlink_internal(inode, &request, &symname);
+       ll_inode_size_unlock(inode);
+       if (rc < 0) {
+               ptlrpc_req_finished(request);
+               return ERR_PTR(rc);
+       }
+
+       /* symname may contain a pointer to the request message buffer,
+        * we delay request releasing until ll_put_link then.
+        */
+       *cookie = request;
+       RETURN(symname);
 }
-#endif
+# endif /* HAVE_IOP_GET_LINK */
+#endif /* HAVE_SYMLINK_OPS_USE_NAMEIDATA */
 
 struct inode_operations ll_fast_symlink_inode_operations = {
-        .readlink       = ll_readlink,
-        .setattr        = ll_setattr,
-#ifdef HAVE_VFS_INTENT_PATCHES
-        .setattr_raw    = ll_setattr_raw,
+#ifdef HAVE_IOP_GENERIC_READLINK
+       .readlink       = generic_readlink,
 #endif
-        .follow_link    = ll_follow_link,
-#ifdef HAVE_COOKIE_FOLLOW_LINK
-        .put_link       = ll_put_link,
+       .setattr        = ll_setattr,
+#ifdef HAVE_IOP_GET_LINK
+       .get_link       = ll_get_link,
+#else
+       .follow_link    = ll_follow_link,
+       .put_link       = ll_put_link,
 #endif
-        .getattr        = ll_getattr,
-        .permission     = ll_inode_permission,
-        .setxattr       = ll_setxattr,
-        .getxattr       = ll_getxattr,
-        .listxattr      = ll_listxattr,
-        .removexattr    = ll_removexattr,
+       .getattr        = ll_getattr,
+       .permission     = ll_inode_permission,
+       .setxattr       = ll_setxattr,
+       .getxattr       = ll_getxattr,
+       .listxattr      = ll_listxattr,
+       .removexattr    = ll_removexattr,
 };