Changeset 77559 in vbox for trunk/src/VBox/Additions/linux/sharedfolders

Timestamp:

Mar 4, 2019 4:19:23 PM (6 years ago)

Author:

vboxsync

Message:

linux/vboxsf: Reviewing revalidate and d_revalidate locking. bugref:9172

Location:

trunk/src/VBox/Additions/linux/sharedfolders

Files:

• dirops.c (modified) (1 diff)
• regops.c (modified) (2 diffs)
• utils.c (modified) (12 diffs)
• vfsmod.h (modified) (2 diffs)

trunk/src/VBox/Additions/linux/sharedfolders/dirops.c

@@ -1115 +1115 @@
     .unlink = vbsf_inode_unlink,
     .rename = vbsf_inode_rename,
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0)
-    .revalidate = vbsf_inode_revalidate
-#else
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 18)
     .getattr = vbsf_inode_getattr,
     .setattr = vbsf_inode_setattr,
+#else
+    .revalidate = vbsf_inode_revalidate
+#endif
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0)
     .symlink = vbsf_ino_symlink
 #endif

trunk/src/VBox/Additions/linux/sharedfolders/regops.c

@@ -1258 +1258 @@
         case SEEK_END: {
             struct vbsf_reg_info *sf_r = file->private_data;
-            int rc = vbsf_inode_revalidate_with_handle(VBSF_GET_F_DENTRY(file), sf_r->Handle.hHost, true /*fForce*/,
-                                 false /*fInodeLocked*/);
+            int rc = vbsf_inode_revalidate_with_handle(VBSF_GET_F_DENTRY(file), sf_r->Handle.hHost,
+                                                       true /*fForce*/, false /*fInodeLocked*/);
             if (rc == 0)
                 break;
@@ -1359 +1359 @@
 
 struct inode_operations vbsf_reg_iops = {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0)
-    .revalidate = vbsf_inode_revalidate
-#else
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 18)
     .getattr = vbsf_inode_getattr,
     .setattr = vbsf_inode_setattr
+#else
+    .revalidate = vbsf_inode_revalidate
 #endif
 };

trunk/src/VBox/Additions/linux/sharedfolders/utils.c

@@ -244 +244 @@
  * Update the inode with new object info from the host.
  *
- * Called by sf_inode_revalidate() and sf_inode_revalidate_with_handle(), the
- * inode is probably locked...
- *
- * @todo sort out the inode locking situation.
+ * Called by sf_inode_revalidate() and sf_inode_revalidate_with_handle().
  */
 void vbsf_update_inode(struct inode *pInode, struct vbsf_inode_info *pInodeInfo, PSHFLFSOBJINFO pObjInfo,
@@ -370 +367 @@
  * @sa sf_inode_revalidate()
  */
-int vbsf_inode_revalidate_worker(struct dentry *dentry, bool fForced)
+int vbsf_inode_revalidate_worker(struct dentry *dentry, bool fForced, bool fInodeLocked)
 {
     int rc;
@@ -403 +400 @@
                          * Reset the TTL and copy the info over into the inode structure.
                          */
-                        vbsf_update_inode(pInode, sf_i, &pReq->ObjInfo, sf_g, true /*fInodeLocked??*/);
+                        vbsf_update_inode(pInode, sf_i, &pReq->ObjInfo, sf_g, fInodeLocked);
                     } else if (rc == VERR_INVALID_HANDLE) {
                         rc = -ENOENT; /* Restore.*/
@@ -431 +428 @@
                              * Reset the TTL and copy the info over into the inode structure.
                              */
-                            vbsf_update_inode(pInode, sf_i, &pReq->CreateParms.Info, sf_g, true /*fInodeLocked??*/);
+                            vbsf_update_inode(pInode, sf_i, &pReq->CreateParms.Info, sf_g, fInodeLocked);
                             rc = 0;
                         } else {
@@ -456 +453 @@
 
 
-/**
- * Revalidate an inode.
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 5, 18)
+/**
+ * Revalidate an inode for 2.4.
  *
- * This is called directly as inode-op on 2.4, indirectly as dir-op
- * vbsf_dentry_revalidate() on 2.4/2.6.  The job is to find out whether
- * dentry/inode is still valid.  The test fails if @a dentry does not have an
- * inode or vbsf_stat() is unsuccessful, otherwise we return success and update
- * inode attributes.
+ * This is called in the stat(), lstat() and readlink() code paths.  In the stat
+ * cases the caller will use the result afterwards to produce the stat data.
+ *
+ * @note 2.4.x has a getattr() inode operation too, but it is not used.
  */
 int vbsf_inode_revalidate(struct dentry *dentry)
 {
-    return vbsf_inode_revalidate_worker(dentry, false /*fForced*/);
-}
+    /*
+     * We pretend the inode is locked here, as 2.4.x does not have inode level locking.
+     */
+    return vbsf_inode_revalidate_worker(dentry, false /*fForced*/, true /*fInodeLocked*/);
+}
+#endif /* < 2.5.18 */
 
 
@@ -525 +526 @@
    has inode at all) from these new attributes we derive [kstat] via
    [generic_fillattr] */
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 18)
 
 # if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
@@ -551 +552 @@
     switch (flags & AT_STATX_SYNC_TYPE) {
         default:
-            rc = vbsf_inode_revalidate_worker(dentry, false /*fForced*/);
+            rc = vbsf_inode_revalidate_worker(dentry, false /*fForced*/, false /*fInodeLocked*/);
             break;
 
         case AT_STATX_FORCE_SYNC:
-            rc = vbsf_inode_revalidate_worker(dentry, true /*fForced*/);
+            rc = vbsf_inode_revalidate_worker(dentry, true /*fForced*/, false /*fInodeLocked*/);
             break;
 
@@ -563 +564 @@
     }
 # else
-    rc = vbsf_inode_revalidate_worker(dentry, false /*fForced*/);
+    rc = vbsf_inode_revalidate_worker(dentry, false /*fForced*/, false /*fInodeLocked*/);
 # endif
     if (rc == 0) {
@@ -717 +718 @@
      * dentry and all its parent entries are valid and could touch their timestamps
      * extending their TTL (CIFS does that). */
-    return vbsf_inode_revalidate_worker(dentry, true /*fForced*/);
+    return vbsf_inode_revalidate_worker(dentry, true /*fForced*/, true /*fInodeLocked*/);
 
  fail1:
@@ -729 +730 @@
 }
 
-#endif /* >= 2.6.0 */
+#endif /* >= 2.5.18 */
 
 static int vbsf_make_path(const char *caller, struct vbsf_inode_info *sf_i,
@@ -869 +870 @@
  * cache is still valid.  The actual validation is job is handled by
  * vbsf_inode_revalidate_worker().
+ *
+ * @note Caller holds no relevant locks, just a dentry reference.
  */
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 6, 0)
@@ -922 +925 @@
                 SFLOGFLOW(("vbsf_dentry_revalidate: age: %lu vs. TTL %lu -> 1\n", cJiffiesAge, sf_g->ttl));
                 rc = 1;
-            } else if (!vbsf_inode_revalidate_worker(dentry, true /*fForced*/)) {
+            } else if (!vbsf_inode_revalidate_worker(dentry, true /*fForced*/, false /*fInodeLocked*/)) {
                 vbsf_dentry_set_update_jiffies(dentry, jiffies); /** @todo get jiffies from inode. */
                 SFLOGFLOW(("vbsf_dentry_revalidate: age: %lu vs. TTL %lu -> reval -> 1\n", cJiffiesAge, sf_g->ttl));

trunk/src/VBox/Additions/linux/sharedfolders/vfsmod.h

@@ -213 +213 @@
 extern void vbsf_update_inode(struct inode *pInode, struct vbsf_inode_info *pInodeInfo, PSHFLFSOBJINFO pObjInfo,
                               struct vbsf_super_info *sf_g, bool fInodeLocked);
-extern int  vbsf_inode_revalidate(struct dentry *dentry);
-extern int  vbsf_inode_revalidate_worker(struct dentry *dentry, bool fForced);
+extern int  vbsf_inode_revalidate_worker(struct dentry *dentry, bool fForced, bool fInodeLocked);
 extern int  vbsf_inode_revalidate_with_handle(struct dentry *dentry, SHFLHANDLE hHostFile, bool fForced, bool fInodeLocked);
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 18)
 # if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
 extern int  vbsf_inode_getattr(const struct path *path, struct kstat *kstat, u32 request_mask, unsigned int query_flags);
@@ -223 +222 @@
 # endif
 extern int  vbsf_inode_setattr(struct dentry *dentry, struct iattr *iattr);
-#endif
+#else  /* < 2.5.44 */
+extern int  vbsf_inode_revalidate(struct dentry *dentry);
+#endif /* < 2.5.44 */