From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Fri, 15 Feb 2008 23:40:12 -0800 (PST) Received: from larry.melbourne.sgi.com (larry.melbourne.sgi.com [134.14.52.130]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with SMTP id m1G7e2mm004769 for ; Fri, 15 Feb 2008 23:40:06 -0800 Date: Sat, 16 Feb 2008 18:40:19 +1100 From: David Chinner Subject: Re: Differences in mkfs.xfs and xfs_info output. Message-ID: <20080216074019.GV155407@sgi.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Jan Derfinak Cc: xfs@oss.sgi.com On Sat, Feb 16, 2008 at 02:34:08AM +0100, Jan Derfinak wrote: > Hello. > > I found following problem with xfs_info (xfs_grows -p xfs_info) command: > > # mkfs.xfs -f /dev/loop0 > meta-data=/dev/loop0 isize=256 agcount=4, agsize=32000 blks > = sectsz=512 attr=2 > data = bsize=4096 blocks=128000, imaxpct=25 > = sunit=0 swidth=0 blks > naming =version 2 bsize=4096 > log =internal log bsize=4096 blocks=1200, version=2 > = sectsz=512 sunit=0 blks, lazy-count=1 > realtime =none extsz=4096 blocks=0, rtextents=0 > # mount /dev/loop0 /mnt/usb > # xfs_info /mnt/usb > meta-data=/dev/loop0 isize=256 agcount=4, agsize=32000 blks > = sectsz=512 attr=0 > data = bsize=4096 blocks=128000, imaxpct=25 > = sunit=0 swidth=0 blks > naming =version 2 bsize=4096 > log =internal bsize=4096 blocks=1200, version=2 > = sectsz=512 sunit=0 blks, lazy-count=0 > realtime =none extsz=4096 blocks=0, rtextents=0 > > Can somebody explain the difference in attr and lazy-count parameters? > Which output is the right one? ..... > # xfs_db -r /dev/loop0 > xfs_db> sb > xfs_db> print .... > features2 = 0 That's why. I've been meaning to push out a patch to fix this - just haven't had time. The patch below should fix the problem - mkfs.xfs is writing the features2 field to the wrong location in the superblock, and this patch detects and corrects it. You'll probably see the output: XFS: correcting sb_features alignment problem in dmesg when you first mount the filesystem with the patched kernel, and then it won't appear again (unless you mkfs it again). Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group --- fs/xfs/xfs_mount.c | 34 ++++++++++++++++++++++++++++------ fs/xfs/xfs_sb.h | 37 ++++++++++++++++++++++++++++++++++--- 2 files changed, 62 insertions(+), 9 deletions(-) Index: 2.6.x-xfs-new/fs/xfs/xfs_mount.c =================================================================== --- 2.6.x-xfs-new.orig/fs/xfs/xfs_mount.c 2007-11-22 10:25:25.590278381 +1100 +++ 2.6.x-xfs-new/fs/xfs/xfs_mount.c 2007-11-22 10:31:27.891999961 +1100 @@ -44,7 +44,7 @@ #include "xfs_quota.h" #include "xfs_fsops.h" -STATIC void xfs_mount_log_sbunit(xfs_mount_t *, __int64_t); +STATIC void xfs_mount_log_sb(xfs_mount_t *, __int64_t); STATIC int xfs_uuid_mount(xfs_mount_t *); STATIC void xfs_uuid_unmount(xfs_mount_t *mp); STATIC void xfs_unmountfs_wait(xfs_mount_t *); @@ -119,6 +119,7 @@ static const struct { { offsetof(xfs_sb_t, sb_logsectsize),0 }, { offsetof(xfs_sb_t, sb_logsunit), 0 }, { offsetof(xfs_sb_t, sb_features2), 0 }, + { offsetof(xfs_sb_t, sb_bad_features2), 0 }, { sizeof(xfs_sb_t), 0 } }; @@ -455,6 +456,7 @@ xfs_sb_from_disk( to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize); to->sb_logsunit = be32_to_cpu(from->sb_logsunit); to->sb_features2 = be32_to_cpu(from->sb_features2); + to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2); } /* @@ -976,6 +978,26 @@ 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. + * + * 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. + */ + if (xfs_sb_has_bad_features2(sbp)) { + cmn_err(CE_WARN, + "XFS: correcting sb_features alignment problem"); + sbp->sb_features2 |= sbp->sb_bad_features2; + sbp->sb_bad_features2 = 0; + update_flags |= XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2; + } + + /* * Check if sb_agblocks is aligned at stripe boundary * If sb_agblocks is NOT aligned turn off m_dalign since * allocator alignment is within an ag, therefore ag has @@ -1165,11 +1187,10 @@ xfs_mountfs( } /* - * If fs is not mounted readonly, then update the superblock - * unit and width changes. + * If fs is not mounted readonly, then update the superblock changes. */ if (update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) - xfs_mount_log_sbunit(mp, update_flags); + xfs_mount_log_sb(mp, update_flags); /* * Initialise the XFS quota management subsystem for this mount @@ -1884,13 +1905,14 @@ xfs_uuid_unmount( * be altered by the mount options. Only the first superblock is updated. */ STATIC void -xfs_mount_log_sbunit( +xfs_mount_log_sb( xfs_mount_t *mp, __int64_t fields) { xfs_trans_t *tp; - ASSERT(fields & (XFS_SB_UNIT|XFS_SB_WIDTH|XFS_SB_UUID)); + ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID | + XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2)); tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT); if (xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0, Index: 2.6.x-xfs-new/fs/xfs/xfs_sb.h =================================================================== --- 2.6.x-xfs-new.orig/fs/xfs/xfs_sb.h 2007-11-22 10:25:25.598277360 +1100 +++ 2.6.x-xfs-new/fs/xfs/xfs_sb.h 2007-11-22 10:31:27.891999961 +1100 @@ -89,6 +89,7 @@ struct xfs_mount; /* * Superblock - in core version. Must match the ondisk version below. + * Must be padded to 64 bit alignment. */ typedef struct xfs_sb { __uint32_t sb_magicnum; /* magic number == XFS_SB_MAGIC */ @@ -145,10 +146,21 @@ typedef struct xfs_sb { __uint16_t sb_logsectsize; /* sector size for the log, bytes */ __uint32_t sb_logsunit; /* stripe unit size for the log */ __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. + */ + __uint32_t sb_bad_features2; + + /* must be padded to 64 bit alignment */ } xfs_sb_t; /* - * Superblock - on disk version. Must match the in core version below. + * Superblock - on disk version. Must match the in core version above. + * Must be padded to 64 bit alignment. */ typedef struct xfs_dsb { __be32 sb_magicnum; /* magic number == XFS_SB_MAGIC */ @@ -205,6 +217,15 @@ typedef struct xfs_dsb { __be16 sb_logsectsize; /* sector size for the log, bytes */ __be32 sb_logsunit; /* stripe unit size for the log */ __be32 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. + */ + __be32 sb_bad_features2; + + /* must be padded to 64 bit alignment */ } xfs_dsb_t; /* @@ -223,7 +244,7 @@ typedef enum { XFS_SBS_GQUOTINO, XFS_SBS_QFLAGS, XFS_SBS_FLAGS, XFS_SBS_SHARED_VN, XFS_SBS_INOALIGNMT, XFS_SBS_UNIT, XFS_SBS_WIDTH, XFS_SBS_DIRBLKLOG, XFS_SBS_LOGSECTLOG, XFS_SBS_LOGSECTSIZE, XFS_SBS_LOGSUNIT, - XFS_SBS_FEATURES2, + XFS_SBS_FEATURES2, XFS_SBS_BAD_FEATURES2, XFS_SBS_FIELDCOUNT } xfs_sb_field_t; @@ -248,13 +269,15 @@ typedef enum { #define XFS_SB_IFREE XFS_SB_MVAL(IFREE) #define XFS_SB_FDBLOCKS XFS_SB_MVAL(FDBLOCKS) #define XFS_SB_FEATURES2 XFS_SB_MVAL(FEATURES2) +#define XFS_SB_BAD_FEATURES2 XFS_SB_MVAL(BAD_FEATURES2) #define XFS_SB_NUM_BITS ((int)XFS_SBS_FIELDCOUNT) #define XFS_SB_ALL_BITS ((1LL << XFS_SB_NUM_BITS) - 1) #define XFS_SB_MOD_BITS \ (XFS_SB_UUID | XFS_SB_ROOTINO | XFS_SB_RBMINO | XFS_SB_RSUMINO | \ XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO | XFS_SB_GQUOTINO | \ XFS_SB_QFLAGS | XFS_SB_SHARED_VN | XFS_SB_UNIT | XFS_SB_WIDTH | \ - XFS_SB_ICOUNT | XFS_SB_IFREE | XFS_SB_FDBLOCKS | XFS_SB_FEATURES2) + XFS_SB_ICOUNT | XFS_SB_IFREE | XFS_SB_FDBLOCKS | XFS_SB_FEATURES2 | \ + XFS_SB_BAD_FEATURES2) /* @@ -297,6 +320,14 @@ static inline int xfs_sb_good_version(xf } #endif /* __KERNEL__ */ +/* + * Detect a bad features2 field + */ +static inline int xfs_sb_has_bad_features2(xfs_sb_t *sbp) +{ + return (sbp->sb_bad_features2 != 0); +} + #define XFS_SB_VERSION_TONEW(v) xfs_sb_version_tonew(v) static inline unsigned xfs_sb_version_tonew(unsigned v) {