Commit a92853b6 authored by Konstantin Khlebnikov's avatar Konstantin Khlebnikov Committed by Linus Torvalds
Browse files

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 5a9d929d ("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: default avatarKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 80c1fe90

fs/direct-io.c

+0 −21
Original line number Diff line number Diff line
@@ -220,27 +220,6 @@ static inline struct page *dio_get_page(struct dio *dio, 
	return dio->pages[sdio->head];

}



/*

 * Warn about a page cache invalidation failure during a direct io 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);

	}

}



/*

 * dio_complete() - called when all DIO BIO I/O has been completed

 *

include/linux/fs.h

+5 −1
Original line number Diff line number Diff line
@@ -3149,7 +3149,6 @@ enum { 
};



void dio_end_io(struct bio *bio);

void dio_warn_stale_pagecache(struct file *filp);



ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,

			     struct block_device *bdev, struct iov_iter *iter,
@@ -3194,6 +3193,11 @@ static inline void inode_dio_end(struct inode *inode) 
		wake_up_bit(&inode->i_state, __I_DIO_WAKEUP);

}



/*

 * Warn about a page cache invalidation failure diring a direct I/O write.

 */

void dio_warn_stale_pagecache(struct file *filp);



extern void inode_set_flags(struct inode *inode, unsigned int flags,

			    unsigned int mask);

mm/filemap.c

+21 −0
Original line number Diff line number Diff line
@@ -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)

{

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