Commit c5574768 authored by Vladimir V. Saveliev's avatar Vladimir V. Saveliev Committed by Linus Torvalds
Browse files

[PATCH] reiserfs: do not add save links for O_DIRECT writes 



We add a save link for O_DIRECT writes to protect the i_size against the
crashes before we actually finish the I/O.  If we hit an -ENOSPC in
aops->prepare_write(), we would do a truncate() to release the blocks which
might have got initialized.  Now the truncate would add another save link
for the same inode causing a reiserfs panic for having multiple save links
for the same inode.

Signed-off-by: default avatarVladimir V. Saveliev <vs@namesys.com>
Signed-off-by: default avatarAmit Arora <amitarora@in.ibm.com>
Signed-off-by: default avatarSuzuki K P <suzuki@in.ibm.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <mason@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 301827ac

fs/reiserfs/file.c

+4 −50
Original line number Diff line number Diff line
@@ -406,6 +406,8 @@ static int reiserfs_allocate_blocks_for_region(struct reiserfs_transaction_handl 
				   we restart it. This will also free the path. */

				if (journal_transaction_should_end

				    (th, th->t_blocks_allocated)) {

					inode->i_size = cpu_key_k_offset(&key) +

						(to_paste << inode->i_blkbits);

					res =

					    restart_transaction(th, inode,

								&path);
@@ -1310,56 +1312,8 @@ static ssize_t reiserfs_file_write(struct file *file, /* the file we are going t 
			count = MAX_NON_LFS - (unsigned long)*ppos;

	}



	if (file->f_flags & O_DIRECT) {	// Direct IO needs treatment

		ssize_t result, after_file_end = 0;

		if ((*ppos + count >= inode->i_size)

		    || (file->f_flags & O_APPEND)) {

			/* If we are appending a file, we need to put this savelink in here.

			   If we will crash while doing direct io, finish_unfinished will

			   cut the garbage from the file end. */

			reiserfs_write_lock(inode->i_sb);

			err =

			    journal_begin(&th, inode->i_sb,

					  JOURNAL_PER_BALANCE_CNT);

			if (err) {

				reiserfs_write_unlock(inode->i_sb);

				return err;

			}

			reiserfs_update_inode_transaction(inode);

			add_save_link(&th, inode, 1 /* Truncate */ );

			after_file_end = 1;

			err =

			    journal_end(&th, inode->i_sb,

					JOURNAL_PER_BALANCE_CNT);

			reiserfs_write_unlock(inode->i_sb);

			if (err)

				return err;

		}

		result = do_sync_write(file, buf, count, ppos);



		if (after_file_end) {	/* Now update i_size and remove the savelink */

			struct reiserfs_transaction_handle th;

			reiserfs_write_lock(inode->i_sb);

			err = journal_begin(&th, inode->i_sb, 1);

			if (err) {

				reiserfs_write_unlock(inode->i_sb);

				return err;

			}

			reiserfs_update_inode_transaction(inode);

			mark_inode_dirty(inode);

			err = journal_end(&th, inode->i_sb, 1);

			if (err) {

				reiserfs_write_unlock(inode->i_sb);

				return err;

			}

			err = remove_save_link(inode, 1 /* truncate */ );

			reiserfs_write_unlock(inode->i_sb);

			if (err)

				return err;

		}



		return result;

	}

	if (file->f_flags & O_DIRECT)

		return do_sync_write(file, buf, count, ppos);



	if (unlikely((ssize_t) count < 0))

		return -EINVAL;