From a92853b6746fe5ffef20a7c30addf6320561e669 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Sat, 30 Nov 2019 17:49:44 -0800 Subject: fs/direct-io.c: keep dio_warn_stale_pagecache() when CONFIG_BLOCK=n This helper prints warning if direct I/O write failed to invalidate cache, and set EIO at inode to warn usersapce about possible data corruption. See also commit 5a9d929d6e13 ("iomap: report collisions between directio and buffered writes to userspace"). Direct I/O is supported by non-disk filesystems, for example NFS. Thus generic code needs this even in kernel without CONFIG_BLOCK. Link: http://lkml.kernel.org/r/157270038074.4812.7980855544557488880.stgit@buzz Signed-off-by: Konstantin Khlebnikov Reviewed-by: Andrew Morton Reviewed-by: Jan Kara Cc: Jens Axboe Cc: Alexander Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/filemap.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'mm/filemap.c') diff --git a/mm/filemap.c b/mm/filemap.c index 288e38199068..189b8f318da2 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3161,6 +3161,27 @@ int pagecache_write_end(struct file *file, struct address_space *mapping, } EXPORT_SYMBOL(pagecache_write_end); +/* + * Warn about a page cache invalidation failure during a direct I/O write. + */ +void dio_warn_stale_pagecache(struct file *filp) +{ + static DEFINE_RATELIMIT_STATE(_rs, 86400 * HZ, DEFAULT_RATELIMIT_BURST); + char pathname[128]; + struct inode *inode = file_inode(filp); + char *path; + + errseq_set(&inode->i_mapping->wb_err, -EIO); + if (__ratelimit(&_rs)) { + path = file_path(filp, pathname, sizeof(pathname)); + if (IS_ERR(path)) + path = "(unknown)"; + pr_crit("Page cache invalidation failure on direct I/O. Possible data corruption due to collision with buffered I/O!\n"); + pr_crit("File: %s PID: %d Comm: %.20s\n", path, current->pid, + current->comm); + } +} + ssize_t generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from) { -- cgit v1.2.3-59-g8ed1b