ocfs2: implement directory read-ahead (aa958874) · Commits · e / devices / android_kernel_xiaomi_markw

fs/ocfs2/buffer_head_io.c

+72 −23

Original line number	Original line	Diff line number	Diff line
	@@ -100,6 +100,9 @@ int ocfs2_read_blocks(struct ocfs2_super *osb, u64 block, int nr,
	mlog_entry("(block=(%llu), nr=(%d), flags=%d, inode=%p)\n",		mlog_entry("(block=(%llu), nr=(%d), flags=%d, inode=%p)\n",
	(unsigned long long)block, nr, flags, inode);		(unsigned long long)block, nr, flags, inode);

			BUG_ON((flags & OCFS2_BH_READAHEAD) &&
			(!inode \|\| !(flags & OCFS2_BH_CACHED)));

	if (osb == NULL \|\| osb->sb == NULL \|\| bhs == NULL) {		if (osb == NULL \|\| osb->sb == NULL \|\| bhs == NULL) {
	status = -EINVAL;		status = -EINVAL;
	mlog_errno(status);		mlog_errno(status);
	@@ -140,6 +143,30 @@ int ocfs2_read_blocks(struct ocfs2_super *osb, u64 block, int nr,
	bh = bhs[i];		bh = bhs[i];
	ignore_cache = 0;		ignore_cache = 0;

			/* There are three read-ahead cases here which we need to
			* be concerned with. All three assume a buffer has
			* previously been submitted with OCFS2_BH_READAHEAD
			* and it hasn't yet completed I/O.
			*
			* 1) The current request is sync to disk. This rarely
			* happens these days, and never when performance
			* matters - the code can just wait on the buffer
			* lock and re-submit.
			*
			* 2) The current request is cached, but not
			* readahead. ocfs2_buffer_uptodate() will return
			* false anyway, so we'll wind up waiting on the
			* buffer lock to do I/O. We re-check the request
			* with after getting the lock to avoid a re-submit.
			*
			* 3) The current request is readahead (and so must
			* also be a caching one). We short circuit if the
			* buffer is locked (under I/O) and if it's in the
			* uptodate cache. The re-check from #2 catches the
			* case that the previous read-ahead completes just
			* before our is-it-in-flight check.
			*/

	if (flags & OCFS2_BH_CACHED &&		if (flags & OCFS2_BH_CACHED &&
	!ocfs2_buffer_uptodate(inode, bh)) {		!ocfs2_buffer_uptodate(inode, bh)) {
	mlog(ML_UPTODATE,		mlog(ML_UPTODATE,
	@@ -169,6 +196,14 @@ int ocfs2_read_blocks(struct ocfs2_super *osb, u64 block, int nr,
	continue;		continue;
	}		}

			/* A read-ahead request was made - if the
			* buffer is already under read-ahead from a
			* previously submitted request than we are
			* done here. */
			if ((flags & OCFS2_BH_READAHEAD)
			&& ocfs2_buffer_read_ahead(inode, bh))
			continue;

	lock_buffer(bh);		lock_buffer(bh);
	if (buffer_jbd(bh)) {		if (buffer_jbd(bh)) {
	#ifdef CATCH_BH_JBD_RACES		#ifdef CATCH_BH_JBD_RACES
	@@ -181,12 +216,21 @@ int ocfs2_read_blocks(struct ocfs2_super *osb, u64 block, int nr,
	continue;		continue;
	#endif		#endif
	}		}

			/* Re-check ocfs2_buffer_uptodate() as a
			* previously read-ahead buffer may have
			* completed I/O while we were waiting for the
			* buffer lock. */
			if ((flags & OCFS2_BH_CACHED)
			&& !(flags & OCFS2_BH_READAHEAD)
			&& ocfs2_buffer_uptodate(inode, bh)) {
			unlock_buffer(bh);
			continue;
			}

	clear_buffer_uptodate(bh);		clear_buffer_uptodate(bh);
	get_bh(bh); /* for end_buffer_read_sync() */		get_bh(bh); /* for end_buffer_read_sync() */
	bh->b_end_io = end_buffer_read_sync;		bh->b_end_io = end_buffer_read_sync;
	if (flags & OCFS2_BH_READAHEAD)
	submit_bh(READA, bh);
	else
	submit_bh(READ, bh);		submit_bh(READ, bh);
	continue;		continue;
	}		}
	@@ -197,6 +241,7 @@ int ocfs2_read_blocks(struct ocfs2_super *osb, u64 block, int nr,
	for (i = (nr - 1); i >= 0; i--) {		for (i = (nr - 1); i >= 0; i--) {
	bh = bhs[i];		bh = bhs[i];

			if (!(flags & OCFS2_BH_READAHEAD)) {
	/* We know this can't have changed as we hold the		/* We know this can't have changed as we hold the
	* inode sem. Avoid doing any work on the bh if the		* inode sem. Avoid doing any work on the bh if the
	* journal has it. */		* journal has it. */
	@@ -215,16 +260,20 @@ int ocfs2_read_blocks(struct ocfs2_super *osb, u64 block, int nr,
	bhs[i] = NULL;		bhs[i] = NULL;
	continue;		continue;
	}		}
			}

			/* Always set the buffer in the cache, even if it was
			* a forced read, or read-ahead which hasn't yet
			* completed. */
	if (inode)		if (inode)
	ocfs2_set_buffer_uptodate(inode, bh);		ocfs2_set_buffer_uptodate(inode, bh);
	}		}
	if (inode)		if (inode)
	mutex_unlock(&OCFS2_I(inode)->ip_io_mutex);		mutex_unlock(&OCFS2_I(inode)->ip_io_mutex);

	mlog(ML_BH_IO, "block=(%llu), nr=(%d), cached=%s\n",		mlog(ML_BH_IO, "block=(%llu), nr=(%d), cached=%s, flags=0x%x\n",
	(unsigned long long)block, nr,		(unsigned long long)block, nr,
	(!(flags & OCFS2_BH_CACHED) \|\| ignore_cache) ? "no" : "yes");		(!(flags & OCFS2_BH_CACHED) \|\| ignore_cache) ? "no" : "yes", flags);

	bail:		bail:

fs/ocfs2/buffer_head_io.h

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -49,7 +49,7 @@ int ocfs2_read_blocks(struct ocfs2_super *osb,


	#define OCFS2_BH_CACHED 1		#define OCFS2_BH_CACHED 1
	#define OCFS2_BH_READAHEAD 8 /* use this to pass READA down to submit_bh */		#define OCFS2_BH_READAHEAD 8

	static inline int ocfs2_read_block(struct ocfs2_super * osb, u64 off,		static inline int ocfs2_read_block(struct ocfs2_super * osb, u64 off,
	struct buffer_head **bh, int flags,		struct buffer_head **bh, int flags,

fs/ocfs2/dir.c

+16 −12

Original line number	Original line	Diff line number	Diff line
	@@ -74,14 +74,14 @@ static int ocfs2_extend_dir(struct ocfs2_super *osb,
	int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir)		int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir)
	{		{
	int error = 0;		int error = 0;
	unsigned long offset, blk;		unsigned long offset, blk, last_ra_blk = 0;
	int i, num, stored;		int i, stored;
	struct buffer_head * bh, * tmp;		struct buffer_head * bh, * tmp;
	struct ocfs2_dir_entry * de;		struct ocfs2_dir_entry * de;
	int err;		int err;
	struct inode *inode = filp->f_dentry->d_inode;		struct inode *inode = filp->f_dentry->d_inode;
	struct super_block * sb = inode->i_sb;		struct super_block * sb = inode->i_sb;
	int have_disk_lock = 0;		unsigned int ra_sectors = 16;

	mlog_entry("dirino=%llu\n",		mlog_entry("dirino=%llu\n",
	(unsigned long long)OCFS2_I(inode)->ip_blkno);		(unsigned long long)OCFS2_I(inode)->ip_blkno);
	@@ -95,9 +95,8 @@ int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir)
	mlog_errno(error);		mlog_errno(error);
	/* we haven't got any yet, so propagate the error. */		/* we haven't got any yet, so propagate the error. */
	stored = error;		stored = error;
	goto bail;		goto bail_nolock;
	}		}
	have_disk_lock = 1;

	offset = filp->f_pos & (sb->s_blocksize - 1);		offset = filp->f_pos & (sb->s_blocksize - 1);

	@@ -113,16 +112,21 @@ int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir)
	continue;		continue;
	}		}

	/*		/* The idea here is to begin with 8k read-ahead and to stay
	* Do the readahead (8k)		* 4k ahead of our current position.
	*/		*
	if (!offset) {		* TODO: Use the pagecache for this. We just need to
	for (i = 16 >> (sb->s_blocksize_bits - 9), num = 0;		* make sure it's cluster-safe... */
			if (!last_ra_blk
			\|\| (((last_ra_blk - blk) << 9) <= (ra_sectors / 2))) {
			for (i = ra_sectors >> (sb->s_blocksize_bits - 9);
	i > 0; i--) {		i > 0; i--) {
	tmp = ocfs2_bread(inode, ++blk, &err, 1);		tmp = ocfs2_bread(inode, ++blk, &err, 1);
	if (tmp)		if (tmp)
	brelse(tmp);		brelse(tmp);
	}		}
			last_ra_blk = blk;
			ra_sectors = 8;
	}		}

	revalidate:		revalidate:
	@@ -194,9 +198,9 @@ revalidate:

	stored = 0;		stored = 0;
	bail:		bail:
	if (have_disk_lock)
	ocfs2_meta_unlock(inode, 0);		ocfs2_meta_unlock(inode, 0);

			bail_nolock:
	mlog_exit(stored);		mlog_exit(stored);

	return stored;		return stored;

fs/ocfs2/inode.c

+0 −4

Original line number	Original line	Diff line number	Diff line
	@@ -1050,12 +1050,8 @@ struct buffer_head ocfs2_bread(struct inode inode,
	u64 p_blkno;		u64 p_blkno;
	int readflags = OCFS2_BH_CACHED;		int readflags = OCFS2_BH_CACHED;

	#if 0
	/* only turn this on if we know we can deal with read_block
	* returning nothing */
	if (reada)		if (reada)
	readflags \|= OCFS2_BH_READAHEAD;		readflags \|= OCFS2_BH_READAHEAD;
	#endif

	if (((u64)block << inode->i_sb->s_blocksize_bits) >=		if (((u64)block << inode->i_sb->s_blocksize_bits) >=
	i_size_read(inode)) {		i_size_read(inode)) {

fs/ocfs2/namei.c

+5 −5

Original line number	Original line	Diff line number	Diff line
	@@ -56,6 +56,7 @@
	#include "journal.h"		#include "journal.h"
	#include "namei.h"		#include "namei.h"
	#include "suballoc.h"		#include "suballoc.h"
			#include "super.h"
	#include "symlink.h"		#include "symlink.h"
	#include "sysfile.h"		#include "sysfile.h"
	#include "uptodate.h"		#include "uptodate.h"
	@@ -1962,13 +1963,8 @@ restart:
	}		}
	num++;		num++;

	/* XXX: questionable readahead stuff here */
	bh = ocfs2_bread(dir, b++, &err, 1);		bh = ocfs2_bread(dir, b++, &err, 1);
	bh_use[ra_max] = bh;		bh_use[ra_max] = bh;
	#if 0 // ???
	if (bh)
	ll_rw_block(READ, 1, &bh);
	#endif
	}		}
	}		}
	if ((bh = bh_use[ra_ptr++]) == NULL)		if ((bh = bh_use[ra_ptr++]) == NULL)
	@@ -1976,6 +1972,10 @@ restart:
	wait_on_buffer(bh);		wait_on_buffer(bh);
	if (!buffer_uptodate(bh)) {		if (!buffer_uptodate(bh)) {
	/* read error, skip block & hope for the best */		/* read error, skip block & hope for the best */
			ocfs2_error(dir->i_sb, "reading directory %llu, "
			"offset %lu\n",
			(unsigned long long)OCFS2_I(dir)->ip_blkno,
			block);
	brelse(bh);		brelse(bh);
	goto next;		goto next;
	}		}