Commit 877f962c authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

buffer: add BH_Prio and BH_Meta flags 



Add buffer_head flags so that buffer cache writebacks can be marked
with the the appropriate request flags, so that metadata blocks can be
marked appropriately in blktrace.

Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 9f203507

fs/buffer.c

+5 −0
Original line number Diff line number Diff line
@@ -2988,6 +2988,11 @@ int submit_bh(int rw, struct buffer_head * bh) 
	/* Take care of bh's that straddle the end of the device */

	guard_bh_eod(rw, bio, bh);



	if (buffer_meta(bh))

		rw |= REQ_META;

	if (buffer_prio(bh))

		rw |= REQ_PRIO;



	bio_get(bio);

	submit_bio(rw, bio);

include/linux/buffer_head.h

+4 −0
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ enum bh_state_bits { 
	BH_Write_EIO,	/* I/O error on write */

	BH_Unwritten,	/* Buffer is allocated on disk but not written */

	BH_Quiet,	/* Buffer Error Prinks to be quiet */

	BH_Meta,	/* Buffer contains metadata */

	BH_Prio,	/* Buffer should be submitted with REQ_PRIO */



	BH_PrivateStart,/* not a state bit, but the first bit available

			 * for private allocation by other entities
@@ -124,6 +126,8 @@ BUFFER_FNS(Delay, delay) 
BUFFER_FNS(Boundary, boundary)

BUFFER_FNS(Write_EIO, write_io_error)

BUFFER_FNS(Unwritten, unwritten)

BUFFER_FNS(Meta, meta)

BUFFER_FNS(Prio, prio)



#define bh_offset(bh)		((unsigned long)(bh)->b_data & ~PAGE_MASK)