[PATCH] r/o bind mounts: unlink: monitor i_nlink
When a filesystem decrements i_nlink to zero, it means that a write must be
performed in order to drop the inode from the filesystem.
We're shortly going to have keep filesystems from being remounted r/o between
the time that this i_nlink decrement and that write occurs.
So, add a little helper function to do the decrements. We'll tie into it in a
bit to note when i_nlink hits zero.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/shmem.c b/mm/shmem.c
index b96de69..908dd94 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1772,7 +1772,7 @@
dir->i_size -= BOGO_DIRENT_SIZE;
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
- inode->i_nlink--;
+ drop_nlink(inode);
dput(dentry); /* Undo the count from "create" - this does all the work */
return 0;
}
@@ -1782,8 +1782,8 @@
if (!simple_empty(dentry))
return -ENOTEMPTY;
- dentry->d_inode->i_nlink--;
- dir->i_nlink--;
+ drop_nlink(dentry->d_inode);
+ drop_nlink(dir);
return shmem_unlink(dir, dentry);
}
@@ -1804,9 +1804,9 @@
if (new_dentry->d_inode) {
(void) shmem_unlink(new_dir, new_dentry);
if (they_are_dirs)
- old_dir->i_nlink--;
+ drop_nlink(old_dir);
} else if (they_are_dirs) {
- old_dir->i_nlink--;
+ drop_nlink(old_dir);
new_dir->i_nlink++;
}