Re: [PATCH 026/119] xfs: add owner field to extent allocation and freeing
From: Dave Chinner <david@fromorbit.com>
Date: 2016-07-06 04:02:30
Also in:
linux-fsdevel
On Thu, Jun 16, 2016 at 06:20:39PM -0700, Darrick J. Wong wrote:
For the rmap btree to work, we have to feed the extent owner information to the the allocation and freeing functions. This information is what will end up in the rmap btree that tracks allocated extents. While we technically don't need the owner information when freeing extents, passing it allows us to validate that the extent we are removing from the rmap btree actually belonged to the owner we expected it to belong to.
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quoted hunk ↗ jump to hunk
--- a/fs/xfs/libxfs/xfs_format.h +++ b/fs/xfs/libxfs/xfs_format.h@@ -1318,6 +1318,71 @@ typedef __be32 xfs_inobt_ptr_t; */ #define XFS_RMAP_CRC_MAGIC 0x524d4233 /* 'RMB3' */ +/* + * Ownership info for an extent. This is used to create reverse-mapping + * entries. + */ +#define XFS_OWNER_INFO_ATTR_FORK (1 << 0) +#define XFS_OWNER_INFO_BMBT_BLOCK (1 << 1) +struct xfs_owner_info { + uint64_t oi_owner; + xfs_fileoff_t oi_offset; + unsigned int oi_flags; +}; + +static inline void +xfs_rmap_ag_owner( + struct xfs_owner_info *oi, + uint64_t owner) +{ + oi->oi_owner = owner; + oi->oi_offset = 0; + oi->oi_flags = 0; +} + +static inline void +xfs_rmap_ino_bmbt_owner( + struct xfs_owner_info *oi, + xfs_ino_t ino, + int whichfork) +{ + oi->oi_owner = ino; + oi->oi_offset = 0; + oi->oi_flags = XFS_OWNER_INFO_BMBT_BLOCK; + if (whichfork == XFS_ATTR_FORK) + oi->oi_flags |= XFS_OWNER_INFO_ATTR_FORK; +} + +static inline void +xfs_rmap_ino_owner( + struct xfs_owner_info *oi, + xfs_ino_t ino, + int whichfork, + xfs_fileoff_t offset) +{ + oi->oi_owner = ino; + oi->oi_offset = offset; + oi->oi_flags = 0; + if (whichfork == XFS_ATTR_FORK) + oi->oi_flags |= XFS_OWNER_INFO_ATTR_FORK; +}
One of the things we've avaoided doing so far is putting functions like this into xfs_format.h. xfs_format.h is really just for the on disk format definitions, not the code to access/pack/unpack it. Hence I think think these sorts of functions need to be moved to xfs_rmap.h.... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs