From 60263d5889e6dc5987dc51b801be4955ff2e4aa7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 23 Jul 2020 22:45:59 -0700 Subject: iomap: fall back to buffered writes for invalidation failures Failing to invalid the page cache means data in incoherent, which is a very bad state for the system. Always fall back to buffered I/O through the page cache if we can't invalidate mappings. Signed-off-by: Christoph Hellwig Acked-by: Dave Chinner Reviewed-by: Goldwyn Rodrigues Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Acked-by: Bob Peterson Acked-by: Damien Le Moal Reviewed-by: Theodore Ts'o # for ext4 Reviewed-by: Andreas Gruenbacher # for gfs2 Reviewed-by: Ritesh Harjani --- fs/iomap/direct-io.c | 16 +++++++++++----- fs/iomap/trace.h | 1 + 2 files changed, 12 insertions(+), 5 deletions(-) (limited to 'fs/iomap') diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 190967e87b69..c1aafb2ab990 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -10,6 +10,7 @@ #include #include #include +#include "trace.h" #include "../internal.h" @@ -401,6 +402,9 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length, * can be mapped into multiple disjoint IOs and only a subset of the IOs issued * may be pure data writes. In that case, we still need to do a full data sync * completion. + * + * Returns -ENOTBLK In case of a page invalidation invalidation failure for + * writes. The callers needs to fall back to buffered I/O in this case. */ ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, @@ -478,13 +482,15 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (iov_iter_rw(iter) == WRITE) { /* * Try to invalidate cache pages for the range we are writing. - * If this invalidation fails, tough, the write will still work, - * but racing two incompatible write paths is a pretty crazy - * thing to do, so we don't support it 100%. + * If this invalidation fails, let the caller fall back to + * buffered I/O. */ if (invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT, - end >> PAGE_SHIFT)) - dio_warn_stale_pagecache(iocb->ki_filp); + end >> PAGE_SHIFT)) { + trace_iomap_dio_invalidate_fail(inode, pos, count); + ret = -ENOTBLK; + goto out_free_dio; + } if (!wait_for_completion && !inode->i_sb->s_dio_done_wq) { ret = sb_init_dio_done_wq(inode->i_sb); diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h index 5693a39d52fb..fdc7ae388476 100644 --- a/fs/iomap/trace.h +++ b/fs/iomap/trace.h @@ -74,6 +74,7 @@ DEFINE_EVENT(iomap_range_class, name, \ DEFINE_RANGE_EVENT(iomap_writepage); DEFINE_RANGE_EVENT(iomap_releasepage); DEFINE_RANGE_EVENT(iomap_invalidatepage); +DEFINE_RANGE_EVENT(iomap_dio_invalidate_fail); #define IOMAP_TYPE_STRINGS \ { IOMAP_HOLE, "HOLE" }, \ -- cgit v1.2.3