Commit 970e4936 authored by Joel Becker's avatar Joel Becker Committed by Mark Fasheh
Browse files

ocfs2: Validate metadata only when it's read from disk. 



Add an optional validation hook to ocfs2_read_blocks().  Now the
validation function is only called when a block was actually read off of
disk.  It is not called when the buffer was in cache.

We add a buffer state bit BH_NeedsValidate to flag these buffers.  It
must always be one higher than the last JBD2 buffer state bit.

The dinode, dirblock, extent_block, and xattr_block validators are
lifted to this scheme directly.  The group_descriptor validator needs to
be split into two pieces.  The first part only needs the gd buffer and
is passed to ocfs2_read_block().  The second part requires the dinode as
well, and is called every time.  It's only 3 compares, so it's tiny.
This also allows us to clean up the non-fatal gd check used by resize.c.
It now has no magic argument.

Signed-off-by: default avatarJoel Becker <joel.becker@oracle.com>
Signed-off-by: default avatarMark Fasheh <mfasheh@suse.com>
parent 4ae1d69b

fs/ocfs2/alloc.c

+6 −11
Original line number Diff line number Diff line
@@ -684,6 +684,9 @@ static int ocfs2_validate_extent_block(struct super_block *sb, 
	struct ocfs2_extent_block *eb =

		(struct ocfs2_extent_block *)bh->b_data;



	mlog(0, "Validating extent block %llu\n",

	     (unsigned long long)bh->b_blocknr);



	if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {

		ocfs2_error(sb,

			    "Extent block #%llu has bad signature %.*s",
@@ -719,21 +722,13 @@ int ocfs2_read_extent_block(struct inode *inode, u64 eb_blkno, 
	int rc;

	struct buffer_head *tmp = *bh;



	rc = ocfs2_read_block(inode, eb_blkno, &tmp);

	if (rc)

		goto out;



	rc = ocfs2_validate_extent_block(inode->i_sb, tmp);

	if (rc) {

		brelse(tmp);

		goto out;

	}

	rc = ocfs2_read_block(inode, eb_blkno, &tmp,

			      ocfs2_validate_extent_block);



	/* If ocfs2_read_block() got us a new bh, pass it up. */

	if (!*bh)

	if (!rc && !*bh)

		*bh = tmp;



out:

	return rc;

}

fs/ocfs2/buffer_head_io.c

+32 −1
Original line number Diff line number Diff line
@@ -39,6 +39,19 @@ 


#include "buffer_head_io.h"



/*

 * Bits on bh->b_state used by ocfs2.

 *

 * These MUST be after the JBD2 bits.  Currently BH_Unshadow is the last

 * JBD2 bit.

 */

enum ocfs2_state_bits {

	BH_NeedsValidate = BH_Unshadow + 1,

};



/* Expand the magic b_state functions */

BUFFER_FNS(NeedsValidate, needs_validate);



int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,

		      struct inode *inode)

{
@@ -166,7 +179,9 @@ bail: 
}



int ocfs2_read_blocks(struct inode *inode, u64 block, int nr,

		      struct buffer_head *bhs[], int flags)

		      struct buffer_head *bhs[], int flags,

		      int (*validate)(struct super_block *sb,

				      struct buffer_head *bh))

{

	int status = 0;

	int i, ignore_cache = 0;
@@ -298,6 +313,8 @@ int ocfs2_read_blocks(struct inode *inode, u64 block, int nr, 


			clear_buffer_uptodate(bh);

			get_bh(bh); /* for end_buffer_read_sync() */

			if (validate)

				set_buffer_needs_validate(bh);

			bh->b_end_io = end_buffer_read_sync;

			submit_bh(READ, bh);

			continue;
@@ -328,6 +345,20 @@ int ocfs2_read_blocks(struct inode *inode, u64 block, int nr, 
				bhs[i] = NULL;

				continue;

			}



			if (buffer_needs_validate(bh)) {

				/* We never set NeedsValidate if the

				 * buffer was held by the journal, so

				 * that better not have changed */

				BUG_ON(buffer_jbd(bh));

				clear_buffer_needs_validate(bh);

				status = validate(inode->i_sb, bh);

				if (status) {

					put_bh(bh);

					bhs[i] = NULL;

					continue;

				}

			}

		}



		/* Always set the buffer in the cache, even if it was

fs/ocfs2/buffer_head_io.h

+16 −11
Original line number Diff line number Diff line
@@ -31,21 +31,24 @@ 
void ocfs2_end_buffer_io_sync(struct buffer_head *bh,

			     int uptodate);



static inline int ocfs2_read_block(struct inode	       *inode,

				   u64                  off,

				   struct buffer_head **bh);



int ocfs2_write_block(struct ocfs2_super          *osb,

		      struct buffer_head  *bh,

		      struct inode        *inode);

int ocfs2_read_blocks(struct inode	  *inode,

		      u64                  block,

		      int                  nr,

		      struct buffer_head  *bhs[],

		      int                  flags);

int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,

			   unsigned int nr, struct buffer_head *bhs[]);



/*

 * If not NULL, validate() will be called on a buffer that is freshly

 * read from disk.  It will not be called if the buffer was in cache.

 * Note that if validate() is being used for this buffer, it needs to

 * be set even for a READAHEAD call, as it marks the buffer for later

 * validation.

 */

int ocfs2_read_blocks(struct inode *inode, u64 block, int nr,

		      struct buffer_head *bhs[], int flags,

		      int (*validate)(struct super_block *sb,

				      struct buffer_head *bh));



int ocfs2_write_super_or_backup(struct ocfs2_super *osb,

				struct buffer_head *bh);
@@ -53,7 +56,9 @@ int ocfs2_write_super_or_backup(struct ocfs2_super *osb, 
#define OCFS2_BH_READAHEAD         8



static inline int ocfs2_read_block(struct inode *inode, u64 off,

				   struct buffer_head **bh)

				   struct buffer_head **bh,

				   int (*validate)(struct super_block *sb,

						   struct buffer_head *bh))

{

	int status = 0;
@@ -63,7 +68,7 @@ static inline int ocfs2_read_block(struct inode *inode, u64 off, 
		goto bail;

	}



	status = ocfs2_read_blocks(inode, off, 1, bh, 0);

	status = ocfs2_read_blocks(inode, off, 1, bh, 0, validate);



bail:

	return status;

fs/ocfs2/dir.c

+4 −9
Original line number Diff line number Diff line
@@ -214,6 +214,8 @@ static int ocfs2_validate_dir_block(struct super_block *sb, 
	 * Nothing yet.  We don't validate dirents here, that's handled

	 * in-place when the code walks them.

	 */

	mlog(0, "Validating dirblock %llu\n",

	     (unsigned long long)bh->b_blocknr);



	return 0;

}
@@ -255,20 +257,13 @@ static int ocfs2_read_dir_block(struct inode *inode, u64 v_block, 
		goto out;

	}



	rc = ocfs2_read_blocks(inode, p_blkno, 1, &tmp, flags);

	rc = ocfs2_read_blocks(inode, p_blkno, 1, &tmp, flags,

			       ocfs2_validate_dir_block);

	if (rc) {

		mlog_errno(rc);

		goto out;

	}



	if (!(flags & OCFS2_BH_READAHEAD)) {

		rc = ocfs2_validate_dir_block(inode->i_sb, tmp);

		if (rc) {

			brelse(tmp);

			goto out;

		}

	}



	/* If ocfs2_read_blocks() got us a new bh, pass it up.  */

	if (!*bh)

		*bh = tmp;

fs/ocfs2/inode.c

+5 −13
Original line number Diff line number Diff line
@@ -1255,6 +1255,9 @@ int ocfs2_validate_inode_block(struct super_block *sb, 
	int rc = -EINVAL;

	struct ocfs2_dinode *di = (struct ocfs2_dinode *)bh->b_data;



	mlog(0, "Validating dinode %llu\n",

	     (unsigned long long)bh->b_blocknr);



	BUG_ON(!buffer_uptodate(bh));



	if (!OCFS2_IS_VALID_DINODE(di)) {
@@ -1300,23 +1303,12 @@ int ocfs2_read_inode_block_full(struct inode *inode, struct buffer_head **bh, 
	struct buffer_head *tmp = *bh;



	rc = ocfs2_read_blocks(inode, OCFS2_I(inode)->ip_blkno, 1, &tmp,

			       flags);

	if (rc)

		goto out;



	if (!(flags & OCFS2_BH_READAHEAD)) {

		rc = ocfs2_validate_inode_block(inode->i_sb, tmp);

		if (rc) {

			brelse(tmp);

			goto out;

		}

	}

			       flags, ocfs2_validate_inode_block);



	/* If ocfs2_read_blocks() got us a new bh, pass it up. */

	if (!*bh)

	if (!rc && !*bh)

		*bh = tmp;



out:

	return rc;

}

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