combined features2 fixup patches (updating/rewriting what was sent in other threads)
PATCH 1/1 combined features2 fixup patches (updating/rewriting what was sent in other threads)
Ensure "both" features2 slots are consistent, and set mp attr2 flag.
Since older kernels may look in the sb_bad_features2 slot for flags, rather than zeroing it out on fixup, we should make it equal to the sb_features2 value.
Also, if the ATTR2 flag was not found prior to features2 fixup, it was not set in the mount flags, so re-check after the fixup so that the current session will use the feature.
Also fix up the comments to reflect these changes.
Signed-off-by Eric Sandeen <[email protected]>
---
fs/xfs/xfs_mount.c +23 -12
@@ -967,22 +967,26 @@ xfs_mountfs(xfs_mount_common (mp, sbp);/* -* Check for a bad features2 field alignment. This happened on -* some platforms due to xfs_sb_t not being 64bit size aligned -* when sb_features was added and hence the compiler put it in -* the wrong place. +* Check for a mismatched features2 values. Older kernels +* read & wrote into the wrong sb offset for sb_features2 +* on some platforms due to xfs_sb_t not being 64bit size aligned +* when sb_features2 was added, which made older superblock +* reading/writing routines swap it as a 64-bit value. * -* If we detect a bad field, we or the set bits into the existing -* features2 field in case it has already been modified and we -* don't want to lose any features. Zero the bad one and mark -* the two fields as needing updates once the transaction subsystem -* is online. +* For backwards compatibility, we make both slots equal. +* +* If we detect a mismatched field, we OR the set bits into the +* existing features2 field in case it has already been modified; we +* don't want to lose any features. We then update the bad location +* with the ORed value so that older kernels will see any features2 +* flags, and mark the two fields as needing updates once the +* transaction subsystem is online. */ -if (xfs_sb_has_bad_features2 (sbp)) { +if (xfs_sb_has_mismatched_features2 (sbp)) {cmn_err (CE_WARN ,"XFS: correcting sb_features alignment problem" ); sbp->sb_features2 |= sbp->sb_bad_features2; - sbp->sb_bad_features2 =0 ; + sbp->sb_bad_features2 = sbp->sb_features2; update_flags |=XFS_SB_FEATURES2 |XFS_SB_BAD_FEATURES2 ; }
@@ -1181,6 +1185,12 @@ xfs_mountfs(xfs_mount_log_sb (mp, update_flags);/* +* Re-check for ATTR2 in case it was found in bad_features2 slot. +*/ +if (xfs_sb_version_hasattr2 (&mp->m_sb)) + mp->m_flags |=XFS_MOUNT_ATTR2 ; + +/* * Initialise the XFS quota management subsystem for this mount */ error =XFS_QM_INIT (mp, "amount, "aflags);
@@ -1890,7 +1900,8 @@ xfs_uuid_unmount(/* * Used to log changes to the superblock unit and width fields which could -* be altered by the mount options. Only the first superblock is updated. +* be altered by the mount options, as well as any potential sb_features2 +* fixup. Only the first superblock is updated. */ STATIC void xfs_mount_log_sb(
fs/xfs/xfs_sb.h +4 -3
@@ -320,11 +320,12 @@ static inline int xfs_sb_good_version(xf#endif /* __KERNEL__ */ /* -* Detect a bad features2 field +* Detect a mismatched features2 field. Older kernels read/wrote +* this into the wrong slot, so to be safe we keep them in sync. */ -static inline int xfs_sb_has_bad_features2 (xfs_sb_t *sbp) +static inline int xfs_sb_has_mismatched_features2 (xfs_sb_t *sbp) { -return (sbp->sb_bad_features2 !=0 ); +return (sbp->sb_bad_features2 != sbp->sb_features2); }static inline unsigned xfs_sb_version_tonew (unsigned v)
Quoted 45 lines · Eric Sandeen
Ensure "both" features2 slots are consistent, and set mp attr2 flag.
Since older kernels may look in the
sb_bad_features2slot for flags, rather than zeroing it out on fixup, we should make it equal to thesb_features2value.Also, if the ATTR2 flag was not found prior to features2 fixup, it was not set in the mount flags, so re-check after the fixup so that the current session will use the feature.
Also fix up the comments to reflect these changes.
Signed-off-by Eric Sandeen <[email protected]>---
Index:
linux-2.6-xfs/fs/xfs/xfs_mount.c
===================================================================fs/xfs/xfs_mount.c +12
-9@@ -967,22 +967,26 @@ xfs_mountfs(xfs_mount_common (mp, sbp);/* -* Check for a bad features2 field alignment. This happened on -* some platforms due to xfs_sb_t not being 64bit size aligned -* when sb_features was added and hence the compiler put it in -* the wrong place. +* Check for a mismatched features2 values. Older kernels +* read & wrote into the wrong sb offset for sb_features2 +* on some platforms due to xfs_sb_t not being 64bit size aligned +* when sb_features2 was added, which made older superblock +* reading/writing routines swap it as a 64-bit value. * -* If we detect a bad field, we or the set bits into the existing -* features2 field in case it has already been modified and we -* don't want to lose any features. Zero the bad one and mark -* the two fields as needing updates once the transaction subsystem -* is online. +* For backwards compatibility, we make both slots equal. +* +* If we detect a mismatched field, we OR the set bits into the +* existing features2 field in case it has already been modified; we +* don't want to lose any features. We then update the bad location +* with the ORed value so that older kernels will see any features2 +* flags, and mark the two fields as needing updates once the
fs/xfs/xfs_mount.c xfs_mountfs( · line 990
Quoted 10 lines
fs/xfs/xfs_mount.c +3
-2+* transaction subsystem is online. */ -if (xfs_sb_has_bad_features2 (sbp)) { +if (xfs_sb_has_mismatched_features2 (sbp)) {cmn_err (CE_WARN ,"XFS: correcting sb_features alignment problem" ); sbp->sb_features2 |= sbp->sb_bad_features2; - sbp->sb_bad_features2 =0 ; + sbp->sb_bad_features2 = sbp->sb_features2; update_flags |=XFS_SB_FEATURES2 |XFS_SB_BAD_FEATURES2 ;
Probably should update XFS_MOUNT_ATTR2 here, not later. i.e. before we mount he log and start recovery.
fs/xfs/xfs_mount.c xfs_mountfs( · line 1192
Quoted 9 lines
fs/xfs/xfs_mount.c +5
-0@@ -1181,6 +1185,12 @@ xfs_mountfs(xfs_mount_log_sb (mp, update_flags);/* +* Re-check for ATTR2 in case it was found in bad_features2 slot. +*/ +if (xfs_sb_version_hasattr2 (&mp->m_sb)) + mp->m_flags |=XFS_MOUNT_ATTR2 ; +
Rather than here.
fs/xfs/xfs_mount.c xfs_mountfs(
Quoted 11 lines
fs/xfs/xfs_mount.c +4
-3/* -* Detect a bad features2 field +* Detect a mismatched features2 field. Older kernels read/wrote +* this into the wrong slot, so to be safe we keep them in sync. */ -static inline int xfs_sb_has_bad_features2 (xfs_sb_t *sbp) +static inline int xfs_sb_has_mismatched_features2 (xfs_sb_t *sbp) { -return (sbp->sb_bad_features2 !=0 ); +return (sbp->sb_bad_features2 != sbp->sb_features2); }
Yep, makes sense.
Cheers,
Dave.
Signature · 3 lines
Dave Chinner Principal Engineer SGI Australian Software Group
PATCH v2 1/1 combined features2 fixup patches (updating/rewriting what was sent in other threads)
(Addressing Dave's review point)
Ensure "both" features2 slots are consistent, and set mp attr2 flag.
Since older kernels may look in the sb_bad_features2 slot for flags, rather than zeroing it out on fixup, we should make it equal to the sb_features2 value.
Also, if the ATTR2 flag was not found prior to features2 fixup, it was not set in the mount flags, so re-check after the fixup so that the current session will use the feature.
Also fix up the comments to reflect these changes.
Signed-off-by Eric Sandeen <[email protected]>
---
fs/xfs/xfs_mount.c +22 -12
@@ -967,23 +967,32 @@ xfs_mountfs(xfs_mount_common (mp, sbp);/* -* Check for a bad features2 field alignment. This happened on -* some platforms due to xfs_sb_t not being 64bit size aligned -* when sb_features was added and hence the compiler put it in -* the wrong place. +* Check for a mismatched features2 values. Older kernels +* read & wrote into the wrong sb offset for sb_features2 +* on some platforms due to xfs_sb_t not being 64bit size aligned +* when sb_features2 was added, which made older superblock +* reading/writing routines swap it as a 64-bit value. * -* If we detect a bad field, we or the set bits into the existing -* features2 field in case it has already been modified and we -* don't want to lose any features. Zero the bad one and mark -* the two fields as needing updates once the transaction subsystem -* is online. +* For backwards compatibility, we make both slots equal. +* +* If we detect a mismatched field, we OR the set bits into the +* existing features2 field in case it has already been modified; we +* don't want to lose any features. We then update the bad location +* with the ORed value so that older kernels will see any features2 +* flags, and mark the two fields as needing updates once the +* transaction subsystem is online. */ -if (xfs_sb_has_bad_features2 (sbp)) { +if (xfs_sb_has_mismatched_features2 (sbp)) {cmn_err (CE_WARN ,"XFS: correcting sb_features alignment problem" ); sbp->sb_features2 |= sbp->sb_bad_features2; - sbp->sb_bad_features2 =0 ; + sbp->sb_bad_features2 = sbp->sb_features2; update_flags |=XFS_SB_FEATURES2 |XFS_SB_BAD_FEATURES2 ; +/* +* Re-check for ATTR2 from the bad_features2 slot. +*/ +if (xfs_sb_version_hasattr2 (&mp->m_sb)) + mp->m_flags |=XFS_MOUNT_ATTR2 ; }/*
@@ -1890,7 +1899,8 @@ xfs_uuid_unmount(/* * Used to log changes to the superblock unit and width fields which could -* be altered by the mount options. Only the first superblock is updated. +* be altered by the mount options, as well as any potential sb_features2 +* fixup. Only the first superblock is updated. */ STATIC void xfs_mount_log_sb(
fs/xfs/xfs_sb.h +4 -3
@@ -320,11 +320,12 @@ static inline int xfs_sb_good_version(xf#endif /* __KERNEL__ */ /* -* Detect a bad features2 field +* Detect a mismatched features2 field. Older kernels read/wrote +* this into the wrong slot, so to be safe we keep them in sync. */ -static inline int xfs_sb_has_bad_features2 (xfs_sb_t *sbp) +static inline int xfs_sb_has_mismatched_features2 (xfs_sb_t *sbp) { -return (sbp->sb_bad_features2 !=0 ); +return (sbp->sb_bad_features2 != sbp->sb_features2); }static inline unsigned xfs_sb_version_tonew (unsigned v)