Commit b3f03bac authored by Dave Chinner's avatar Dave Chinner Committed by Ben Myers
Browse files

xfs: xfs_dir2_block_to_sf temp buffer allocation fails 



If we are using a large directory block size, and memory becomes
fragmented, we can get memory allocation failures trying to
kmem_alloc(64k) for a temporary buffer. However, there is not need
for a directory buffer sized allocation, as the end result ends up
in the inode literal area. This is, at most, slightly less than 2k
of space, and hence we don't need an allocation larger than that
fora temporary buffer.

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarBen Myers <bpm@sgi.com>
Signed-off-by: default avatarBen Myers <bpm@sgi.com>
parent df8052e7

fs/xfs/xfs_dir2_sf.c

+34 −24
Original line number Original line Diff line number Diff line
@@ -170,6 +170,7 @@ xfs_dir2_block_to_sf( 
	char			*ptr;		/* current data pointer */

	char			*ptr;		/* current data pointer */

	xfs_dir2_sf_entry_t	*sfep;		/* shortform entry */

	xfs_dir2_sf_entry_t	*sfep;		/* shortform entry */

	xfs_dir2_sf_hdr_t	*sfp;		/* shortform directory header */

	xfs_dir2_sf_hdr_t	*sfp;		/* shortform directory header */

	xfs_dir2_sf_hdr_t	*dst;		/* temporary data buffer */





	trace_xfs_dir2_block_to_sf(args);

	trace_xfs_dir2_block_to_sf(args);
@@ -177,35 +178,20 @@ xfs_dir2_block_to_sf( 
	mp = dp->i_mount;

	mp = dp->i_mount;





	/*

	/*

	 * Make a copy of the block data, so we can shrink the inode

	 * allocate a temporary destination buffer the size of the inode

	 * and add local data.

	 * to format the data into. Once we have formatted the data, we

	 * can free the block and copy the formatted data into the inode literal

	 * area.

	 */

	 */

	hdr = kmem_alloc(mp->m_dirblksize, KM_SLEEP);

	dst = kmem_alloc(mp->m_sb.sb_inodesize, KM_SLEEP);

	memcpy(hdr, bp->b_addr, mp->m_dirblksize);

	hdr = bp->b_addr;

	logflags = XFS_ILOG_CORE;

	if ((error = xfs_dir2_shrink_inode(args, mp->m_dirdatablk, bp))) {

		ASSERT(error != ENOSPC);

		goto out;

	}





	/*

	 * The buffer is now unconditionally gone, whether

	 * xfs_dir2_shrink_inode worked or not.

	 *

	 * Convert the inode to local format.

	 */

	dp->i_df.if_flags &= ~XFS_IFEXTENTS;

	dp->i_df.if_flags |= XFS_IFINLINE;

	dp->i_d.di_format = XFS_DINODE_FMT_LOCAL;

	ASSERT(dp->i_df.if_bytes == 0);

	xfs_idata_realloc(dp, size, XFS_DATA_FORK);

	logflags |= XFS_ILOG_DDATA;

	/*

	/*

	 * Copy the header into the newly allocate local space.

	 * Copy the header into the newly allocate local space.

	 */

	 */

	sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;

	sfp = (xfs_dir2_sf_hdr_t *)dst;

	memcpy(sfp, sfhp, xfs_dir2_sf_hdr_size(sfhp->i8count));

	memcpy(sfp, sfhp, xfs_dir2_sf_hdr_size(sfhp->i8count));

	dp->i_d.di_size = size;



	/*

	/*

	 * Set up to loop over the block's entries.

	 * Set up to loop over the block's entries.

	 */

	 */
@@ -258,10 +244,34 @@ xfs_dir2_block_to_sf( 
		ptr += dp->d_ops->data_entsize(dep->namelen);

		ptr += dp->d_ops->data_entsize(dep->namelen);

	}

	}

	ASSERT((char *)sfep - (char *)sfp == size);

	ASSERT((char *)sfep - (char *)sfp == size);



	/* now we are done with the block, we can shrink the inode */

	logflags = XFS_ILOG_CORE;

	error = xfs_dir2_shrink_inode(args, mp->m_dirdatablk, bp);

	if (error) {

		ASSERT(error != ENOSPC);

		goto out;

	}



	/*

	 * The buffer is now unconditionally gone, whether

	 * xfs_dir2_shrink_inode worked or not.

	 *

	 * Convert the inode to local format and copy the data in.

	 */

	dp->i_df.if_flags &= ~XFS_IFEXTENTS;

	dp->i_df.if_flags |= XFS_IFINLINE;

	dp->i_d.di_format = XFS_DINODE_FMT_LOCAL;

	ASSERT(dp->i_df.if_bytes == 0);

	xfs_idata_realloc(dp, size, XFS_DATA_FORK);



	logflags |= XFS_ILOG_DDATA;

	memcpy(dp->i_df.if_u1.if_data, dst, size);

	dp->i_d.di_size = size;

	xfs_dir2_sf_check(args);

	xfs_dir2_sf_check(args);

out:

out:

	xfs_trans_log_inode(args->trans, dp, logflags);

	xfs_trans_log_inode(args->trans, dp, logflags);

	kmem_free(hdr);

	kmem_free(dst);

	return error;

	return error;

}

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE