From 074e427ba7f7398427e4f8e2aec071edcc509673 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Thu, 22 Jan 2015 09:10:33 +1100 Subject: xfs: sanitise sb_bad_features2 handling We currently have to ensure that every time we update sb_features2 that we update sb_bad_features2. Now that we log and format the superblock in it's entirety we actually don't have to care because we can simply update the sb_bad_features2 when we format it into the buffer. This removes the need for anything but the mount and superblock formatting code to care about sb_bad_features2, and hence removes the possibility that we forget to update bad_features2 when necessary in the future. Signed-off-by: Dave Chinner Reviewed-by: Brian Foster Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_format.h | 14 +++++++------- fs/xfs/libxfs/xfs_sb.c | 8 +++++++- 2 files changed, 14 insertions(+), 8 deletions(-) (limited to 'fs/xfs/libxfs') diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h index fbd6da263571..749c86102794 100644 --- a/fs/xfs/libxfs/xfs_format.h +++ b/fs/xfs/libxfs/xfs_format.h @@ -151,10 +151,13 @@ typedef struct xfs_sb { __uint32_t sb_features2; /* additional feature bits */ /* - * bad features2 field as a result of failing to pad the sb - * structure to 64 bits. Some machines will be using this field - * for features2 bits. Easiest just to mark it bad and not use - * it for anything else. + * bad features2 field as a result of failing to pad the sb structure to + * 64 bits. Some machines will be using this field for features2 bits. + * Easiest just to mark it bad and not use it for anything else. + * + * This is not kept up to date in memory; it is always overwritten by + * the value in sb_features2 when formatting the incore superblock to + * the disk buffer. */ __uint32_t sb_bad_features2; @@ -453,13 +456,11 @@ static inline void xfs_sb_version_addattr2(struct xfs_sb *sbp) { sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT; sbp->sb_features2 |= XFS_SB_VERSION2_ATTR2BIT; - sbp->sb_bad_features2 |= XFS_SB_VERSION2_ATTR2BIT; } static inline void xfs_sb_version_removeattr2(struct xfs_sb *sbp) { sbp->sb_features2 &= ~XFS_SB_VERSION2_ATTR2BIT; - sbp->sb_bad_features2 &= ~XFS_SB_VERSION2_ATTR2BIT; if (!sbp->sb_features2) sbp->sb_versionnum &= ~XFS_SB_VERSION_MOREBITSBIT; } @@ -475,7 +476,6 @@ static inline void xfs_sb_version_addprojid32bit(struct xfs_sb *sbp) { sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT; sbp->sb_features2 |= XFS_SB_VERSION2_PROJID32BIT; - sbp->sb_bad_features2 |= XFS_SB_VERSION2_PROJID32BIT; } /* diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c index 63f814872dfb..b0a5fe95a3e2 100644 --- a/fs/xfs/libxfs/xfs_sb.c +++ b/fs/xfs/libxfs/xfs_sb.c @@ -497,7 +497,6 @@ xfs_sb_to_disk( to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks); to->sb_frextents = cpu_to_be64(from->sb_frextents); - to->sb_flags = from->sb_flags; to->sb_shared_vn = from->sb_shared_vn; to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt); @@ -507,6 +506,13 @@ xfs_sb_to_disk( to->sb_logsectlog = from->sb_logsectlog; to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize); to->sb_logsunit = cpu_to_be32(from->sb_logsunit); + + /* + * We need to ensure that bad_features2 always matches features2. + * Hence we enforce that here rather than having to remember to do it + * everywhere else that updates features2. + */ + from->sb_bad_features2 = from->sb_features2; to->sb_features2 = cpu_to_be32(from->sb_features2); to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2); -- cgit v1.2.3-55-g7522