Commit 0b3171b6 authored Jul 08, 2020 by Jan Kara Committed by Theodore Ts'o Aug 06, 2020

ext4: do not block RWF_NOWAIT dio write on unallocated space



Since commit 378f32ba ("ext4: introduce direct I/O write using iomap
infrastructure") we don't properly bail out of RWF_NOWAIT direct IO
write if underlying blocks are not allocated. Also
ext4_dio_write_checks() does not honor RWF_NOWAIT when re-acquiring
i_rwsem. Fix both issues.

Fixes: 378f32ba ("ext4: introduce direct I/O write using iomap infrastructure")
Cc: stable@kernel.org
Reported-by: Filipe Manana <fdmanana@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/20200708153516.9507-1-jack@suse.cz


Signed-off-by: Theodore Ts'o <tytso@mit.edu>

parent e65bf6e4

fs/ext4/file.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -427,6 +427,10 @@ restart:
		*/
		if (ilock_shared && (!IS_NOSEC(inode) \|\| extend \|\|
		!ext4_overwrite_io(inode, offset, count))) {
		if (iocb->ki_flags & IOCB_NOWAIT) {
		ret = -EAGAIN;
		goto out;
		}
		inode_unlock_shared(inode);
		*ilock_shared = false;
		inode_lock(inode);

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