Commit 2af3a815 authored May 10, 2016 by Toshi Kani Committed by Vishal Verma May 17, 2016

block: Add vfs_msg() interface



In preparation of moving DAX capability checks to the block layer
from filesystem code, add a VFS message interface that aligns with
filesystem's message format.

For instance, a vfs_msg() message followed by XFS messages in case
of a dax mount error may look like:

  VFS (pmem0p1): error: unaligned partition for dax
  XFS (pmem0p1): DAX unsupported by block device. Turning off DAX.
  XFS (pmem0p1): Mounting V5 Filesystem
   :

vfs_msg() is largely based on ext4_msg().

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@fb.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Boaz Harrosh <boaz@plexistor.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>

parent 7795bec8

fs/block_dev.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -50,6 +50,18 @@ struct block_device I_BDEV(struct inode inode)
		}
		EXPORT_SYMBOL(I_BDEV);

		void __vfs_msg(struct super_block sb, const char prefix, const char *fmt, ...)
		{
		struct va_format vaf;
		va_list args;

		va_start(args, fmt);
		vaf.fmt = fmt;
		vaf.va = &args;
		printk_ratelimited("%sVFS (%s): %pV\n", prefix, sb->s_id, &vaf);
		va_end(args);
		}

		static void bdev_write_inode(struct block_device *bdev)
		{
		struct inode *inode = bdev->bd_inode;

include/linux/blkdev.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -767,6 +767,17 @@ static inline void rq_flush_dcache_pages(struct request *rq)
		}
		#endif

		#ifdef CONFIG_PRINTK
		#define vfs_msg(sb, level, fmt, ...) \
		__vfs_msg(sb, level, fmt, ##__VA_ARGS__)
		#else
		#define vfs_msg(sb, level, fmt, ...) \
		do { \
		no_printk(fmt, ##__VA_ARGS__); \
		__vfs_msg(sb, "", " "); \
		} while (0)
		#endif

		extern int blk_register_queue(struct gendisk *disk);
		extern void blk_unregister_queue(struct gendisk *disk);
		extern blk_qc_t generic_make_request(struct bio *bio);

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