Changeset 77443 in vbox for trunk/src

Timestamp:

Feb 22, 2019 9:47:06 PM (6 years ago)

Author:

vboxsync

Message:

linux/vboxsf,FsPerf: RTFileWrite vs mmap coherency test and fixes. bugref:9172

File:

• trunk/src/VBox/Additions/linux/sharedfolders/regops.c (modified) (11 diffs)

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

@@ -474 +474 @@
         struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
         struct sf_reg_info *sf_r = file->private_data;
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 2)
-        struct address_space *mapping = file->f_mapping;
-#else
         struct address_space *mapping = inode->i_mapping;
-#endif
 
         TRACE();
@@ -531 +527 @@
         }
 
-# if 0 /* Turns out this is slightly slower than locking the pages even for 4KB reads (4.19/amd64). */
+#if 0 /* Turns out this is slightly slower than locking the pages even for 4KB reads (4.19/amd64). */
         /*
          * For medium sized requests try use a bounce buffer.
@@ -559 +555 @@
                 }
         }
+#endif
+
+        return sf_reg_read_fallback(file, buf, size, off, sf_g, sf_r);
+}
+
+
+/**
+ * Wrapper around invalidate_mapping_pages() for page cache invalidation so that
+ * the changes written via sf_reg_write are made visible to mmap users.
+ */
+DECLINLINE(void) sf_reg_write_invalidate_mapping_range(struct address_space *mapping, loff_t offStart, loff_t offEnd)
+{
+        /*
+         * Only bother with this if the mapping has any pages in it.
+         *
+         * Note! According to the docs, the last parameter, end, is inclusive (we
+         *       would have named it 'last' to indicate this).
+         *
+         * Note! The pre-2.6.12 function might not do enough to sure consistency
+         *       when any of the pages in the range is already mapped.
+         */
+# if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 12)
+        if (mapping)
+                invalidate_inode_pages2_range(mapping, offStart >> PAGE_SHIFT, (offEnd - 1) >> PAGE_SHIFT);
+# elif LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 60)
+        if (mapping && mapping->nrpages > 0)
+                invalidate_mapping_pages(mapping, offStart >> PAGE_SHIFT, (offEnd - 1) >> PAGE_SHIFT);
+# else
+        /** @todo ... */
+        RT_NOREF(mapping, offStart, offEnd);
 # endif
-
-        return sf_reg_read_fallback(file, buf, size, off, sf_g, sf_r);
 }
 
@@ -640 +664 @@
                                 if (offFile > i_size_read(inode))
                                         i_size_write(inode, offFile);
+                                sf_reg_write_invalidate_mapping_range(inode->i_mapping, offFile - cbActual, offFile);
 
                                 /*
@@ -689 +714 @@
                             loff_t * off)
 {
-        loff_t pos;
-        struct inode *inode = GET_F_DENTRY(file)->d_inode;
+        struct inode         *inode = GET_F_DENTRY(file)->d_inode;
         struct sf_inode_info *sf_i = GET_INODE_INFO(inode);
-        struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
-        struct sf_reg_info *sf_r = file->private_data;
+        struct sf_glob_info  *sf_g = GET_GLOB_INFO(inode->i_sb);
+        struct sf_reg_info   *sf_r = file->private_data;
+        struct address_space *mapping = inode->i_mapping;
+        loff_t                pos;
 
         TRACE();
@@ -717 +743 @@
                         *off = pos;
                 return 0;
+        }
+
+        /*
+         * If there are active writable mappings, coordinate with any
+         * pending writes via those.
+         */
+        if (   mapping
+            && mapping->nrpages > 0
+            && mapping_writably_mapped(mapping)) {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 32)
+                int err = filemap_fdatawait_range(mapping, pos, pos + size - 1);
+                if (err)
+                        return err;
+#else
+                /** @todo ...   */
+#endif
         }
 
@@ -738 +780 @@
                                         if (pos > i_size_read(inode))
                                                 i_size_write(inode, pos);
+                                        sf_reg_write_invalidate_mapping_range(mapping, pos - cbRet, pos);
                                 } else
                                         cbRet = -EPROTO;
@@ -751 +794 @@
         }
 
-# if 0 /* Turns out this is slightly slower than locking the pages even for 4KB reads (4.19/amd64). */
+#if 0 /* Turns out this is slightly slower than locking the pages even for 4KB reads (4.19/amd64). */
         /*
          * For medium sized requests try use a bounce buffer.
@@ -771 +814 @@
                                                 if (pos > i_size_read(inode))
                                                         i_size_write(inode, pos);
+                                                sf_reg_write_invalidate_mapping_range(mapping, pos - cbRet, pos);
                                         } else
                                                 cbRet = -EPROTO;
@@ -785 +829 @@
                 }
         }
-# endif
+#endif
 
         return sf_reg_write_fallback(file, buf, size, off, pos, inode, sf_i, sf_g, sf_r);
@@ -1216 +1260 @@
 {
         TRACE();
+#if 0
+        printk("sf_write_begin: pos=%#llx len=%#x flags=%#x\n", pos, len, flags);
+        RTLogBackdoorPrintf("sf_write_begin: pos=%#llx len=%#x flags=%#x\n", pos, len, flags);
+#endif
 /** @todo rig up a FsPerf testcase for this code! */