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[XFS] superblock endianess annotations
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Creates a new xfs_dsb_t that is __be annotated and keeps xfs_sb_t for the
incore one. xfs_xlatesb is renamed to xfs_sb_to_disk and only handles the
incore -> disk conversion. A new helper xfs_sb_from_disk handles the other
direction and doesn't need the slightly hacky table-driven approach
because we only ever read the full sb from disk.

The handling of shared r/o filesystems has been buggy on little endian
system and fixing this required shuffling around of some code in that
area.

SGI-PV: 968563
SGI-Modid: xfs-linux-melb:xfs-kern:29477a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
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Christoph Hellwig authored and Tim Shimmin committed Oct 15, 2007
1 parent 347d1c0 commit 2bdf7cd
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Showing 6 changed files with 191 additions and 94 deletions.
4 changes: 1 addition & 3 deletions fs/xfs/xfs_fsops.c
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Original file line number Diff line number Diff line change
Expand Up @@ -136,7 +136,6 @@ xfs_growfs_data_private(
xfs_rfsblock_t nfree;
xfs_agnumber_t oagcount;
int pct;
xfs_sb_t *sbp;
xfs_trans_t *tp;

nb = in->newblocks;
Expand Down Expand Up @@ -377,8 +376,7 @@ xfs_growfs_data_private(
error, agno);
break;
}
sbp = XFS_BUF_TO_SBP(bp);
xfs_xlatesb(sbp, &mp->m_sb, -1, XFS_SB_ALL_BITS);
xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, XFS_SB_ALL_BITS);
/*
* If we get an error writing out the alternate superblocks,
* just issue a warning and continue. The real work is
Expand Down
4 changes: 2 additions & 2 deletions fs/xfs/xfs_log_recover.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3846,7 +3846,7 @@ xlog_do_recover(

/* Convert superblock from on-disk format */
sbp = &log->l_mp->m_sb;
xfs_xlatesb(XFS_BUF_TO_SBP(bp), sbp, 1, XFS_SB_ALL_BITS);
xfs_sb_from_disk(sbp, XFS_BUF_TO_SBP(bp));
ASSERT(sbp->sb_magicnum == XFS_SB_MAGIC);
ASSERT(XFS_SB_GOOD_VERSION(sbp));
xfs_buf_relse(bp);
Expand Down Expand Up @@ -4024,7 +4024,7 @@ xlog_recover_check_summary(
sbbp = xfs_getsb(mp, 0);
#ifdef XFS_LOUD_RECOVERY
sbp = &mp->m_sb;
xfs_xlatesb(XFS_BUF_TO_SBP(sbbp), sbp, 1, XFS_SB_ALL_BITS);
xfs_sb_from_disk(sbp, XFS_BUF_TO_SBP(sbbp));
cmn_err(CE_NOTE,
"xlog_recover_check_summary: sb_icount %Lu itotal %Lu",
sbp->sb_icount, itotal);
Expand Down
134 changes: 88 additions & 46 deletions fs/xfs/xfs_mount.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -407,37 +407,79 @@ xfs_initialize_perag(
return index;
}

void
xfs_sb_from_disk(
xfs_sb_t *to,
xfs_dsb_t *from)
{
to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
to->sb_rextents = be64_to_cpu(from->sb_rextents);
memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
to->sb_logstart = be64_to_cpu(from->sb_logstart);
to->sb_rootino = be64_to_cpu(from->sb_rootino);
to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
to->sb_agcount = be32_to_cpu(from->sb_agcount);
to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
to->sb_blocklog = from->sb_blocklog;
to->sb_sectlog = from->sb_sectlog;
to->sb_inodelog = from->sb_inodelog;
to->sb_inopblog = from->sb_inopblog;
to->sb_agblklog = from->sb_agblklog;
to->sb_rextslog = from->sb_rextslog;
to->sb_inprogress = from->sb_inprogress;
to->sb_imax_pct = from->sb_imax_pct;
to->sb_icount = be64_to_cpu(from->sb_icount);
to->sb_ifree = be64_to_cpu(from->sb_ifree);
to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
to->sb_frextents = be64_to_cpu(from->sb_frextents);
to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
to->sb_qflags = be16_to_cpu(from->sb_qflags);
to->sb_flags = from->sb_flags;
to->sb_shared_vn = from->sb_shared_vn;
to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
to->sb_unit = be32_to_cpu(from->sb_unit);
to->sb_width = be32_to_cpu(from->sb_width);
to->sb_dirblklog = from->sb_dirblklog;
to->sb_logsectlog = from->sb_logsectlog;
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);
}

/*
* xfs_xlatesb
* Copy in core superblock to ondisk one.
*
* data - on disk version of sb
* sb - a superblock
* dir - conversion direction: <0 - convert sb to buf
* >0 - convert buf to sb
* fields - which fields to copy (bitmask)
* The fields argument is mask of superblock fields to copy.
*/
void
xfs_xlatesb(
void *data,
xfs_sb_t *sb,
int dir,
xfs_sb_to_disk(
xfs_dsb_t *to,
xfs_sb_t *from,
__int64_t fields)
{
xfs_caddr_t buf_ptr;
xfs_caddr_t mem_ptr;
xfs_caddr_t to_ptr = (xfs_caddr_t)to;
xfs_caddr_t from_ptr = (xfs_caddr_t)from;
xfs_sb_field_t f;
int first;
int size;

ASSERT(dir);
ASSERT(fields);

if (!fields)
return;

buf_ptr = (xfs_caddr_t)data;
mem_ptr = (xfs_caddr_t)sb;

while (fields) {
f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
first = xfs_sb_info[f].offset;
Expand All @@ -446,26 +488,20 @@ xfs_xlatesb(
ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1);

if (size == 1 || xfs_sb_info[f].type == 1) {
if (dir > 0) {
memcpy(mem_ptr + first, buf_ptr + first, size);
} else {
memcpy(buf_ptr + first, mem_ptr + first, size);
}
memcpy(to_ptr + first, from_ptr + first, size);
} else {
switch (size) {
case 2:
INT_XLATE(*(__uint16_t*)(buf_ptr+first),
*(__uint16_t*)(mem_ptr+first),
dir, ARCH_CONVERT);
*(__be16 *)(to_ptr + first) =
cpu_to_be16(*(__u16 *)(from_ptr + first));
break;
case 4:
INT_XLATE(*(__uint32_t*)(buf_ptr+first),
*(__uint32_t*)(mem_ptr+first),
dir, ARCH_CONVERT);
*(__be32 *)(to_ptr + first) =
cpu_to_be32(*(__u32 *)(from_ptr + first));
break;
case 8:
INT_XLATE(*(__uint64_t*)(buf_ptr+first),
*(__uint64_t*)(mem_ptr+first), dir, ARCH_CONVERT);
*(__be64 *)(to_ptr + first) =
cpu_to_be64(*(__u64 *)(from_ptr + first));
break;
default:
ASSERT(0);
Expand All @@ -487,7 +523,6 @@ xfs_readsb(xfs_mount_t *mp, int flags)
unsigned int sector_size;
unsigned int extra_flags;
xfs_buf_t *bp;
xfs_sb_t *sbp;
int error;

ASSERT(mp->m_sb_bp == NULL);
Expand Down Expand Up @@ -515,8 +550,7 @@ xfs_readsb(xfs_mount_t *mp, int flags)
* Initialize the mount structure from the superblock.
* But first do some basic consistency checking.
*/
sbp = XFS_BUF_TO_SBP(bp);
xfs_xlatesb(XFS_BUF_PTR(bp), &(mp->m_sb), 1, XFS_SB_ALL_BITS);
xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp));

error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags);
if (error) {
Expand Down Expand Up @@ -1335,11 +1369,28 @@ xfs_log_sbcount(
return 0;
}

STATIC void
xfs_mark_shared_ro(
xfs_mount_t *mp,
xfs_buf_t *bp)
{
xfs_dsb_t *sb = XFS_BUF_TO_SBP(bp);
__uint16_t version;

if (!(sb->sb_flags & XFS_SBF_READONLY))
sb->sb_flags |= XFS_SBF_READONLY;

version = be16_to_cpu(sb->sb_versionnum);
if ((version & XFS_SB_VERSION_NUMBITS) != XFS_SB_VERSION_4 ||
!(version & XFS_SB_VERSION_SHAREDBIT))
version |= XFS_SB_VERSION_SHAREDBIT;
sb->sb_versionnum = cpu_to_be16(version);
}

int
xfs_unmountfs_writesb(xfs_mount_t *mp)
{
xfs_buf_t *sbp;
xfs_sb_t *sb;
int error = 0;

/*
Expand All @@ -1350,19 +1401,12 @@ xfs_unmountfs_writesb(xfs_mount_t *mp)
XFS_FORCED_SHUTDOWN(mp))) {

sbp = xfs_getsb(mp, 0);
sb = XFS_BUF_TO_SBP(sbp);

/*
* mark shared-readonly if desired
*/
if (mp->m_mk_sharedro) {
if (!(sb->sb_flags & XFS_SBF_READONLY))
sb->sb_flags |= XFS_SBF_READONLY;
if (!XFS_SB_VERSION_HASSHARED(sb))
XFS_SB_VERSION_ADDSHARED(sb);
xfs_fs_cmn_err(CE_NOTE, mp,
"Unmounting, marking shared read-only");
}
if (mp->m_mk_sharedro)
xfs_mark_shared_ro(mp, sbp);

XFS_BUF_UNDONE(sbp);
XFS_BUF_UNREAD(sbp);
Expand Down Expand Up @@ -1397,21 +1441,19 @@ xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
int first;
int last;
xfs_mount_t *mp;
xfs_sb_t *sbp;
xfs_sb_field_t f;

ASSERT(fields);
if (!fields)
return;
mp = tp->t_mountp;
bp = xfs_trans_getsb(tp, mp, 0);
sbp = XFS_BUF_TO_SBP(bp);
first = sizeof(xfs_sb_t);
last = 0;

/* translate/copy */

xfs_xlatesb(XFS_BUF_PTR(bp), &(mp->m_sb), -1, fields);
xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, fields);

/* find modified range */

Expand Down
3 changes: 2 additions & 1 deletion fs/xfs/xfs_mount.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -630,7 +630,8 @@ extern int xfs_syncsub(xfs_mount_t *, int, int *);
extern int xfs_sync_inodes(xfs_mount_t *, int, int *);
extern xfs_agnumber_t xfs_initialize_perag(struct bhv_vfs *, xfs_mount_t *,
xfs_agnumber_t);
extern void xfs_xlatesb(void *, struct xfs_sb *, int, __int64_t);
extern void xfs_sb_from_disk(struct xfs_sb *, struct xfs_dsb *);
extern void xfs_sb_to_disk(struct xfs_dsb *, struct xfs_sb *, __int64_t);
extern int xfs_sb_validate_fsb_count(struct xfs_sb *, __uint64_t);

extern struct xfs_dmops xfs_dmcore_stub;
Expand Down
68 changes: 65 additions & 3 deletions fs/xfs/xfs_sb.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -87,8 +87,10 @@ struct xfs_mount;
(XFS_SB_VERSION2_OKREALFBITS | \
XFS_SB_VERSION2_OKSASHFBITS )

typedef struct xfs_sb
{
/*
* Superblock - in core version. Must match the ondisk version below.
*/
typedef struct xfs_sb {
__uint32_t sb_magicnum; /* magic number == XFS_SB_MAGIC */
__uint32_t sb_blocksize; /* logical block size, bytes */
xfs_drfsbno_t sb_dblocks; /* number of data blocks */
Expand Down Expand Up @@ -145,6 +147,66 @@ typedef struct xfs_sb
__uint32_t sb_features2; /* additional feature bits */
} xfs_sb_t;

/*
* Superblock - on disk version. Must match the in core version below.
*/
typedef struct xfs_dsb {
__be32 sb_magicnum; /* magic number == XFS_SB_MAGIC */
__be32 sb_blocksize; /* logical block size, bytes */
__be64 sb_dblocks; /* number of data blocks */
__be64 sb_rblocks; /* number of realtime blocks */
__be64 sb_rextents; /* number of realtime extents */
uuid_t sb_uuid; /* file system unique id */
__be64 sb_logstart; /* starting block of log if internal */
__be64 sb_rootino; /* root inode number */
__be64 sb_rbmino; /* bitmap inode for realtime extents */
__be64 sb_rsumino; /* summary inode for rt bitmap */
__be32 sb_rextsize; /* realtime extent size, blocks */
__be32 sb_agblocks; /* size of an allocation group */
__be32 sb_agcount; /* number of allocation groups */
__be32 sb_rbmblocks; /* number of rt bitmap blocks */
__be32 sb_logblocks; /* number of log blocks */
__be16 sb_versionnum; /* header version == XFS_SB_VERSION */
__be16 sb_sectsize; /* volume sector size, bytes */
__be16 sb_inodesize; /* inode size, bytes */
__be16 sb_inopblock; /* inodes per block */
char sb_fname[12]; /* file system name */
__u8 sb_blocklog; /* log2 of sb_blocksize */
__u8 sb_sectlog; /* log2 of sb_sectsize */
__u8 sb_inodelog; /* log2 of sb_inodesize */
__u8 sb_inopblog; /* log2 of sb_inopblock */
__u8 sb_agblklog; /* log2 of sb_agblocks (rounded up) */
__u8 sb_rextslog; /* log2 of sb_rextents */
__u8 sb_inprogress; /* mkfs is in progress, don't mount */
__u8 sb_imax_pct; /* max % of fs for inode space */
/* statistics */
/*
* These fields must remain contiguous. If you really
* want to change their layout, make sure you fix the
* code in xfs_trans_apply_sb_deltas().
*/
__be64 sb_icount; /* allocated inodes */
__be64 sb_ifree; /* free inodes */
__be64 sb_fdblocks; /* free data blocks */
__be64 sb_frextents; /* free realtime extents */
/*
* End contiguous fields.
*/
__be64 sb_uquotino; /* user quota inode */
__be64 sb_gquotino; /* group quota inode */
__be16 sb_qflags; /* quota flags */
__u8 sb_flags; /* misc. flags */
__u8 sb_shared_vn; /* shared version number */
__be32 sb_inoalignmt; /* inode chunk alignment, fsblocks */
__be32 sb_unit; /* stripe or raid unit */
__be32 sb_width; /* stripe or raid width */
__u8 sb_dirblklog; /* log2 of dir block size (fsbs) */
__u8 sb_logsectlog; /* log2 of the log sector size */
__be16 sb_logsectsize; /* sector size for the log, bytes */
__be32 sb_logsunit; /* stripe unit size for the log */
__be32 sb_features2; /* additional feature bits */
} xfs_dsb_t;

/*
* Sequence number values for the fields.
*/
Expand Down Expand Up @@ -446,7 +508,7 @@ static inline void xfs_sb_version_addattr2(xfs_sb_t *sbp)

#define XFS_SB_DADDR ((xfs_daddr_t)0) /* daddr in filesystem/ag */
#define XFS_SB_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_SB_DADDR)
#define XFS_BUF_TO_SBP(bp) ((xfs_sb_t *)XFS_BUF_PTR(bp))
#define XFS_BUF_TO_SBP(bp) ((xfs_dsb_t *)XFS_BUF_PTR(bp))

#define XFS_HDR_BLOCK(mp,d) ((xfs_agblock_t)XFS_BB_TO_FSBT(mp,d))
#define XFS_DADDR_TO_FSB(mp,d) XFS_AGB_TO_FSB(mp, \
Expand Down
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