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Commit 70456600 authored by Michael Halcrow's avatar Michael Halcrow Committed by Linus Torvalds
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[PATCH] eCryptfs: convert f_op->write() to vfs_write() 



sys_write() takes a local copy of f_pos and writes that back
into the struct file. It does this so that two concurrent write()
callers don't make a mess of f_pos, and of the file contents.

ecryptfs should be calling vfs_write().  That way we also get the fsnotify
notifications, which ecryptfs presently appears to have subverted.

Convert direct calls to f_op->write() into calls to vfs_write().

Signed-off-by: default avatarMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e77a56dd

fs/ecryptfs/crypto.c

+22 −5
Original line number Diff line number Diff line
@@ -1344,24 +1344,41 @@ static int ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt 
	mm_segment_t oldfs;

	int current_header_page;

	int header_pages;

	ssize_t size;

	int rc = 0;



	lower_file->f_pos = 0;

	oldfs = get_fs();

	set_fs(get_ds());

	lower_file->f_op->write(lower_file, (char __user *)page_virt,

				PAGE_CACHE_SIZE, &lower_file->f_pos);

	size = vfs_write(lower_file, (char __user *)page_virt, PAGE_CACHE_SIZE,

			 &lower_file->f_pos);

	if (size < 0) {

		rc = (int)size;

		printk(KERN_ERR "Error attempting to write lower page; "

		       "rc = [%d]\n", rc);

		set_fs(oldfs);

		goto out;

	}

	header_pages = ((crypt_stat->header_extent_size

			 * crypt_stat->num_header_extents_at_front)

			/ PAGE_CACHE_SIZE);

	memset(page_virt, 0, PAGE_CACHE_SIZE);

	current_header_page = 1;

	while (current_header_page < header_pages) {

		lower_file->f_op->write(lower_file, (char __user *)page_virt,

		size = vfs_write(lower_file, (char __user *)page_virt,

				 PAGE_CACHE_SIZE, &lower_file->f_pos);

		if (size < 0) {

			rc = (int)size;

			printk(KERN_ERR "Error attempting to write lower page; "

			       "rc = [%d]\n", rc);

			set_fs(oldfs);

			goto out;

		}

		current_header_page++;

	}

	set_fs(oldfs);

	return 0;

out:

	return rc;

}



static int ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry,

fs/ecryptfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -201,7 +201,7 @@ static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry) 
			lower_dentry->d_name.name);

	inode = ecryptfs_dentry->d_inode;

	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;

	lower_flags = ((O_CREAT | O_WRONLY | O_TRUNC) & O_ACCMODE) | O_RDWR;

	lower_flags = ((O_CREAT | O_TRUNC) & O_ACCMODE) | O_RDWR;

#if BITS_PER_LONG != 32

	lower_flags |= O_LARGEFILE;

#endif