[PATCH 2.5] Report write errors to applications

From: Oliver Xymoron (oxymoron@waste.org)
Date: Wed Jan 29 2003 - 01:09:16 EST


Andrew, this is a forward-port of the 2.4 write error propagation
patch I just posted, applies against -mm6. Lightly tested on 2.5, but
should be straightforward.

diff -urN -x '.patch*' -x '*.orig' orig/fs/buffer.c patched/fs/buffer.c
--- orig/fs/buffer.c 2003-01-24 13:24:21.000000000 -0600
+++ patched/fs/buffer.c 2003-01-24 13:25:08.000000000 -0600
@@ -165,15 +165,27 @@
  * Default synchronous end-of-IO handler.. Just mark it up-to-date and
  * unlock the buffer. This is what ll_rw_block uses too.
  */
-void end_buffer_io_sync(struct buffer_head *bh, int uptodate)
+void end_buffer_read_sync(struct buffer_head *bh, int uptodate)
 {
         if (uptodate) {
                 set_buffer_uptodate(bh);
         } else {
- /*
- * This happens, due to failed READA attempts.
- * buffer_io_error(bh);
- */
+ /* This happens, due to failed READA attempts. */
+ clear_buffer_uptodate(bh);
+ }
+ unlock_buffer(bh);
+ put_bh(bh);
+}
+
+void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
+{
+ if (uptodate) {
+ set_buffer_uptodate(bh);
+ } else {
+ buffer_io_error(bh);
+ printk(KERN_WARNING "lost page write due to I/O error on %s\n",
+ bdevname(bh->b_bdev));
+ bh->b_page->mapping->error = -EIO;
                 clear_buffer_uptodate(bh);
         }
         unlock_buffer(bh);
@@ -550,6 +562,9 @@
                 set_buffer_uptodate(bh);
         } else {
                 buffer_io_error(bh);
+ printk(KERN_WARNING "lost page write due to I/O error on %s\n",
+ bdevname(bh->b_bdev));
+ bh->b_page->mapping->error = -EIO;
                 clear_buffer_uptodate(bh);
                 SetPageError(page);
         }
@@ -1201,7 +1216,7 @@
                 if (buffer_dirty(bh))
                         buffer_error();
                 get_bh(bh);
- bh->b_end_io = end_buffer_io_sync;
+ bh->b_end_io = end_buffer_read_sync;
                 submit_bh(READ, bh);
                 wait_on_buffer(bh);
                 if (buffer_uptodate(bh))
@@ -2604,13 +2619,14 @@
                         continue;
 
                 get_bh(bh);
- bh->b_end_io = end_buffer_io_sync;
                 if (rw == WRITE) {
+ bh->b_end_io = end_buffer_write_sync;
                         if (test_clear_buffer_dirty(bh)) {
                                 submit_bh(WRITE, bh);
                                 continue;
                         }
                 } else {
+ bh->b_end_io = end_buffer_read_sync;
                         if (!buffer_uptodate(bh)) {
                                 submit_bh(rw, bh);
                                 continue;
diff -urN -x '.patch*' -x '*.orig' orig/fs/inode.c patched/fs/inode.c
--- orig/fs/inode.c 2003-01-24 13:24:21.000000000 -0600
+++ patched/fs/inode.c 2003-01-24 13:24:26.000000000 -0600
@@ -134,6 +134,7 @@
                 mapping->dirtied_when = 0;
                 mapping->assoc_mapping = NULL;
                 mapping->backing_dev_info = &default_backing_dev_info;
+ mapping->error = 0;
                 if (sb->s_bdev)
                         inode->i_data.backing_dev_info = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
                 memset(&inode->u, 0, sizeof(inode->u));
diff -urN -x '.patch*' -x '*.orig' orig/fs/ntfs/compress.c patched/fs/ntfs/compress.c
--- orig/fs/ntfs/compress.c 2003-01-13 23:58:43.000000000 -0600
+++ patched/fs/ntfs/compress.c 2003-01-24 13:24:26.000000000 -0600
@@ -598,7 +598,7 @@
                         continue;
                 }
                 atomic_inc(&tbh->b_count);
- tbh->b_end_io = end_buffer_io_sync;
+ tbh->b_end_io = end_buffer_read_sync;
                 submit_bh(READ, tbh);
         }
 
diff -urN -x '.patch*' -x '*.orig' orig/fs/open.c patched/fs/open.c
--- orig/fs/open.c 2003-01-13 23:58:05.000000000 -0600
+++ patched/fs/open.c 2003-01-24 13:24:26.000000000 -0600
@@ -843,21 +843,41 @@
  */
 int filp_close(struct file *filp, fl_owner_t id)
 {
- int retval;
+ struct address_space *mapping = filp->f_dentry->d_inode->i_mapping;
+ struct inode *inode = mapping->host;
+ int retval = 0, err;
+
+ /* Report and clear outstanding errors */
+ err = filp->f_error;
+ if (err) {
+ filp->f_error = 0;
+ retval = err;
+ }
+
+ down(&inode->i_sem);
+ err = mapping->error;
+ if (err && !retval) {
+ mapping->error = 0;
+ retval = err;
+ }
+ up(&inode->i_sem);
 
         if (!file_count(filp)) {
                 printk(KERN_ERR "VFS: Close: file count is 0\n");
- return 0;
+ return retval;
         }
- retval = 0;
+
         if (filp->f_op && filp->f_op->flush) {
                 lock_kernel();
- retval = filp->f_op->flush(filp);
+ err = filp->f_op->flush(filp);
                 unlock_kernel();
+ if (err && !retval)
+ retval = err;
         }
         dnotify_flush(filp, id);
         locks_remove_posix(filp, id);
         fput(filp);
+
         return retval;
 }
 
diff -urN -x '.patch*' -x '*.orig' orig/include/linux/buffer_head.h patched/include/linux/buffer_head.h
--- orig/include/linux/buffer_head.h 2003-01-24 13:24:21.000000000 -0600
+++ patched/include/linux/buffer_head.h 2003-01-24 13:24:26.000000000 -0600
@@ -136,7 +136,8 @@
 int try_to_free_buffers(struct page *);
 void create_empty_buffers(struct page *, unsigned long,
                         unsigned long b_state);
-void end_buffer_io_sync(struct buffer_head *bh, int uptodate);
+void end_buffer_read_sync(struct buffer_head *bh, int uptodate);
+void end_buffer_write_sync(struct buffer_head *bh, int uptodate);
 
 /* Things to do with buffers at mapping->private_list */
 void buffer_insert_list(spinlock_t *lock,
diff -urN -x '.patch*' -x '*.orig' orig/include/linux/fs.h patched/include/linux/fs.h
--- orig/include/linux/fs.h 2003-01-24 13:24:21.000000000 -0600
+++ patched/include/linux/fs.h 2003-01-24 13:24:26.000000000 -0600
@@ -326,6 +326,7 @@
         spinlock_t private_lock; /* for use by the address_space */
         struct list_head private_list; /* ditto */
         struct address_space *assoc_mapping; /* ditto */
+ int error; /* write error for fsync */
 };
 
 struct char_device {
diff -urN -x '.patch*' -x '*.orig' orig/kernel/ksyms.c patched/kernel/ksyms.c
--- orig/kernel/ksyms.c 2003-01-24 13:24:21.000000000 -0600
+++ patched/kernel/ksyms.c 2003-01-24 13:24:26.000000000 -0600
@@ -176,7 +176,8 @@
 EXPORT_SYMBOL(d_lookup);
 EXPORT_SYMBOL(d_path);
 EXPORT_SYMBOL(mark_buffer_dirty);
-EXPORT_SYMBOL(end_buffer_io_sync);
+EXPORT_SYMBOL(end_buffer_read_sync);
+EXPORT_SYMBOL(end_buffer_write_sync);
 EXPORT_SYMBOL(__mark_inode_dirty);
 EXPORT_SYMBOL(get_empty_filp);
 EXPORT_SYMBOL(init_private_file);
diff -urN -x '.patch*' -x '*.orig' orig/mm/filemap.c patched/mm/filemap.c
--- orig/mm/filemap.c 2003-01-24 13:24:21.000000000 -0600
+++ patched/mm/filemap.c 2003-01-24 13:24:26.000000000 -0600
@@ -185,6 +185,14 @@
                 write_lock(&mapping->page_lock);
         }
         write_unlock(&mapping->page_lock);
+
+ /* Check for outstanding write errors */
+ if (mapping->error)
+ {
+ ret = mapping->error;
+ mapping->error = 0;
+ }
+
         return ret;
 }
 
diff -urN -x '.patch*' -x '*.orig' orig/mm/vmscan.c patched/mm/vmscan.c
--- orig/mm/vmscan.c 2003-01-24 13:24:21.000000000 -0600
+++ patched/mm/vmscan.c 2003-01-24 13:24:26.000000000 -0600
@@ -342,6 +342,9 @@
                                 SetPageReclaim(page);
                                 res = mapping->a_ops->writepage(page, &wbc);
 
+ if (res < 0) {
+ mapping->error = res;
+ }
                                 if (res == WRITEPAGE_ACTIVATE) {
                                         ClearPageReclaim(page);
                                         goto activate_locked;

-- 
 "Love the dolphins," she advised him. "Write by W.A.S.T.E.." 
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This archive was generated by hypermail 2b29 : Fri Jan 31 2003 - 22:00:21 EST