Re: nfs MAP_SHARED corruption fix

From: Trond Myklebust (trond.myklebust@fys.uio.no)
Date: Thu May 10 2001 - 05:14:56 EST


>>>>> " " == Marcelo Tosatti <marcelo@conectiva.com.br> writes:

> I suggested the removal of I_DIRTY_PAGES check because the
> current behaviour of munmap seems to be synchronous (1), so I
> guess you _always_ want it to be synchronous.

Revised patch (+ necessary change in ksyms.c) follows.

Cheers,
  Trond

diff -u --recursive --new-file linux-2.4.4/fs/nfs/file.c linux-2.4.4-mmap/fs/nfs/file.c
--- linux-2.4.4/fs/nfs/file.c Fri Feb 9 20:29:44 2001
+++ linux-2.4.4-mmap/fs/nfs/file.c Thu May 10 12:12:38 2001
@@ -39,6 +39,7 @@
 static ssize_t nfs_file_write(struct file *, const char *, size_t, loff_t *);
 static int nfs_file_flush(struct file *);
 static int nfs_fsync(struct file *, struct dentry *dentry, int datasync);
+static void nfs_file_close_vma(struct vm_area_struct *);
 
 struct file_operations nfs_file_operations = {
         read: nfs_file_read,
@@ -57,6 +58,11 @@
         setattr: nfs_notify_change,
 };
 
+static struct vm_operations_struct nfs_file_vm_ops = {
+ nopage: filemap_nopage,
+ close: nfs_file_close_vma,
+};
+
 /* Hack for future NFS swap support */
 #ifndef IS_SWAPFILE
 # define IS_SWAPFILE(inode) (0)
@@ -104,6 +110,19 @@
         return result;
 }
 
+static void nfs_file_close_vma(struct vm_area_struct * vma)
+{
+ struct inode * inode;
+
+ inode = vma->vm_file->f_dentry->d_inode;
+
+ filemap_fdatasync(inode->i_mapping);
+ down(&inode->i_sem);
+ nfs_wb_all(inode);
+ up(&inode->i_sem);
+ filemap_fdatawait(inode->i_mapping);
+}
+
 static int
 nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
 {
@@ -115,8 +134,11 @@
                 dentry->d_parent->d_name.name, dentry->d_name.name);
 
         status = nfs_revalidate_inode(NFS_SERVER(inode), inode);
- if (!status)
+ if (!status) {
                 status = generic_file_mmap(file, vma);
+ if (!status)
+ vma->vm_ops = &nfs_file_vm_ops;
+ }
         return status;
 }
 
@@ -283,9 +305,11 @@
          * Flush all pending writes before doing anything
          * with locks..
          */
- down(&filp->f_dentry->d_inode->i_sem);
+ filemap_fdatasync(inode->i_mapping);
+ down(&inode->i_sem);
         status = nfs_wb_all(inode);
- up(&filp->f_dentry->d_inode->i_sem);
+ up(&inode->i_sem);
+ filemap_fdatawait(inode->i_mapping);
         if (status < 0)
                 return status;
 
@@ -300,10 +324,12 @@
          */
  out_ok:
         if ((cmd == F_SETLK || cmd == F_SETLKW) && fl->fl_type != F_UNLCK) {
- down(&filp->f_dentry->d_inode->i_sem);
+ filemap_fdatasync(inode->i_mapping);
+ down(&inode->i_sem);
                 nfs_wb_all(inode); /* we may have slept */
+ up(&inode->i_sem);
+ filemap_fdatawait(inode->i_mapping);
                 nfs_zap_caches(inode);
- up(&filp->f_dentry->d_inode->i_sem);
         }
         return status;
 }
diff -u --recursive --new-file linux-2.4.4/kernel/ksyms.c linux-2.4.4-mmap/kernel/ksyms.c
--- linux-2.4.4/kernel/ksyms.c Fri Apr 27 23:23:25 2001
+++ linux-2.4.4-mmap/kernel/ksyms.c Wed May 9 18:05:58 2001
@@ -262,6 +262,8 @@
 EXPORT_SYMBOL(dentry_open);
 EXPORT_SYMBOL(filemap_nopage);
 EXPORT_SYMBOL(filemap_sync);
+EXPORT_SYMBOL(filemap_fdatasync);
+EXPORT_SYMBOL(filemap_fdatawait);
 EXPORT_SYMBOL(lock_page);
 
 /* device registration */
-
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This archive was generated by hypermail 2b29 : Tue May 15 2001 - 21:00:22 EST