xfs_mount.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 1,582 行 · 第 1/3 页

			  sizeof(xfs_perag_busy_t) * XFS_PAGB_NUM_SLOTS);
	kmem_free(mp->m_perag, sbp->sb_agcount * sizeof(xfs_perag_t));
	mp->m_perag = NULL;
	/* FALLTHROUGH */
 error1:
	if (uuid_mounted)
		xfs_uuid_unmount(mp);
	xfs_freesb(mp);
	return error;
}

/*
 * xfs_unmountfs
 *
 * This flushes out the inodes,dquots and the superblock, unmounts the
 * log and makes sure that incore structures are freed.
 */
int
xfs_unmountfs(xfs_mount_t *mp, struct cred *cr)
{
	struct vfs	*vfsp = XFS_MTOVFS(mp);
#if defined(DEBUG) || defined(INDUCE_IO_ERROR)
	int64_t		fsid;
#endif

	xfs_iflush_all(mp, XFS_FLUSH_ALL);

	XFS_QM_DQPURGEALL(mp,
		XFS_QMOPT_UQUOTA | XFS_QMOPT_GQUOTA | XFS_QMOPT_UMOUNTING);

	/*
	 * Flush out the log synchronously so that we know for sure
	 * that nothing is pinned.  This is important because bflush()
	 * will skip pinned buffers.
	 */
	xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE | XFS_LOG_SYNC);

	xfs_binval(mp->m_ddev_targp);
	if (mp->m_rtdev_targp) {
		xfs_binval(mp->m_rtdev_targp);
	}

	xfs_unmountfs_writesb(mp);

	xfs_log_unmount(mp);			/* Done! No more fs ops. */

	xfs_freesb(mp);

	/*
	 * All inodes from this mount point should be freed.
	 */
	ASSERT(mp->m_inodes == NULL);

	/*
	 * We may have bufs that are in the process of getting written still.
	 * We must wait for the I/O completion of those. The sync flag here
	 * does a two pass iteration thru the bufcache.
	 */
	if (XFS_FORCED_SHUTDOWN(mp)) {
		xfs_incore_relse(mp->m_ddev_targp, 0, 1); /* synchronous */
	}

	xfs_unmountfs_close(mp, cr);
	if ((mp->m_flags & XFS_MOUNT_NOUUID) == 0)
		xfs_uuid_unmount(mp);

#if defined(DEBUG) || defined(INDUCE_IO_ERROR)
	/*
	 * clear all error tags on this filesystem
	 */
	memcpy(&fsid, &vfsp->vfs_fsid, sizeof(int64_t));
	xfs_errortag_clearall_umount(fsid, mp->m_fsname, 0);
#endif
	XFS_IODONE(vfsp);
	xfs_mount_free(mp, 1);
	return 0;
}

void
xfs_unmountfs_close(xfs_mount_t *mp, struct cred *cr)
{
	if (mp->m_logdev_targp != mp->m_ddev_targp)
		xfs_free_buftarg(mp->m_logdev_targp, 1);
	if (mp->m_rtdev_targp)
		xfs_free_buftarg(mp->m_rtdev_targp, 1);
	xfs_free_buftarg(mp->m_ddev_targp, 0);
}

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

	/*
	 * skip superblock write if fs is read-only, or
	 * if we are doing a forced umount.
	 */
	sbp = xfs_getsb(mp, 0);
	if (!(XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY ||
		XFS_FORCED_SHUTDOWN(mp))) {
		/*
		 * mark shared-readonly if desired
		 */
		sb = XFS_BUF_TO_SBP(sbp);
		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");
		}
		XFS_BUF_UNDONE(sbp);
		XFS_BUF_UNREAD(sbp);
		XFS_BUF_UNDELAYWRITE(sbp);
		XFS_BUF_WRITE(sbp);
		XFS_BUF_UNASYNC(sbp);
		ASSERT(XFS_BUF_TARGET(sbp) == mp->m_ddev_targp);
		xfsbdstrat(mp, sbp);
		/* Nevermind errors we might get here. */
		error = xfs_iowait(sbp);
		if (error)
			xfs_ioerror_alert("xfs_unmountfs_writesb",
					  mp, sbp, XFS_BUF_ADDR(sbp));
		if (error && mp->m_mk_sharedro)
			xfs_fs_cmn_err(CE_ALERT, mp, "Superblock write error detected while unmounting.  Filesystem may not be marked shared readonly");
	}
	xfs_buf_relse(sbp);
	return (error);
}

/*
 * xfs_mod_sb() can be used to copy arbitrary changes to the
 * in-core superblock into the superblock buffer to be logged.
 * It does not provide the higher level of locking that is
 * needed to protect the in-core superblock from concurrent
 * access.
 */
void
xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
{
	xfs_buf_t	*bp;
	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, ARCH_CONVERT, fields);

	/* find modified range */

	f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
	ASSERT((1LL << f) & XFS_SB_MOD_BITS);
	first = xfs_sb_info[f].offset;

	f = (xfs_sb_field_t)xfs_highbit64((__uint64_t)fields);
	ASSERT((1LL << f) & XFS_SB_MOD_BITS);
	last = xfs_sb_info[f + 1].offset - 1;

	xfs_trans_log_buf(tp, bp, first, last);
}

/*
 * xfs_mod_incore_sb_unlocked() is a utility routine common used to apply
 * a delta to a specified field in the in-core superblock.  Simply
 * switch on the field indicated and apply the delta to that field.
 * Fields are not allowed to dip below zero, so if the delta would
 * do this do not apply it and return EINVAL.
 *
 * The SB_LOCK must be held when this routine is called.
 */
STATIC int
xfs_mod_incore_sb_unlocked(xfs_mount_t *mp, xfs_sb_field_t field,
			int delta, int rsvd)
{
	int		scounter;	/* short counter for 32 bit fields */
	long long	lcounter;	/* long counter for 64 bit fields */
	long long	res_used, rem;

	/*
	 * With the in-core superblock spin lock held, switch
	 * on the indicated field.  Apply the delta to the
	 * proper field.  If the fields value would dip below
	 * 0, then do not apply the delta and return EINVAL.
	 */
	switch (field) {
	case XFS_SBS_ICOUNT:
		lcounter = (long long)mp->m_sb.sb_icount;
		lcounter += delta;
		if (lcounter < 0) {
			ASSERT(0);
			return (XFS_ERROR(EINVAL));
		}
		mp->m_sb.sb_icount = lcounter;
		return (0);
	case XFS_SBS_IFREE:
		lcounter = (long long)mp->m_sb.sb_ifree;
		lcounter += delta;
		if (lcounter < 0) {
			ASSERT(0);
			return (XFS_ERROR(EINVAL));
		}
		mp->m_sb.sb_ifree = lcounter;
		return (0);
	case XFS_SBS_FDBLOCKS:

		lcounter = (long long)mp->m_sb.sb_fdblocks;
		res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);

		if (delta > 0) {		/* Putting blocks back */
			if (res_used > delta) {
				mp->m_resblks_avail += delta;
			} else {
				rem = delta - res_used;
				mp->m_resblks_avail = mp->m_resblks;
				lcounter += rem;
			}
		} else {				/* Taking blocks away */

			lcounter += delta;

		/*
		 * If were out of blocks, use any available reserved blocks if
		 * were allowed to.
		 */

			if (lcounter < 0) {
				if (rsvd) {
					lcounter = (long long)mp->m_resblks_avail + delta;
					if (lcounter < 0) {
						return (XFS_ERROR(ENOSPC));
					}
					mp->m_resblks_avail = lcounter;
					return (0);
				} else {	/* not reserved */
					return (XFS_ERROR(ENOSPC));
				}
			}
		}

		mp->m_sb.sb_fdblocks = lcounter;
		return (0);
	case XFS_SBS_FREXTENTS:
		lcounter = (long long)mp->m_sb.sb_frextents;
		lcounter += delta;
		if (lcounter < 0) {
			return (XFS_ERROR(ENOSPC));
		}
		mp->m_sb.sb_frextents = lcounter;
		return (0);
	case XFS_SBS_DBLOCKS:
		lcounter = (long long)mp->m_sb.sb_dblocks;
		lcounter += delta;
		if (lcounter < 0) {
			ASSERT(0);
			return (XFS_ERROR(EINVAL));
		}
		mp->m_sb.sb_dblocks = lcounter;
		return (0);
	case XFS_SBS_AGCOUNT:
		scounter = mp->m_sb.sb_agcount;
		scounter += delta;
		if (scounter < 0) {
			ASSERT(0);
			return (XFS_ERROR(EINVAL));
		}
		mp->m_sb.sb_agcount = scounter;
		return (0);
	case XFS_SBS_IMAX_PCT:
		scounter = mp->m_sb.sb_imax_pct;
		scounter += delta;
		if (scounter < 0) {
			ASSERT(0);
			return (XFS_ERROR(EINVAL));
		}
		mp->m_sb.sb_imax_pct = scounter;
		return (0);
	case XFS_SBS_REXTSIZE:
		scounter = mp->m_sb.sb_rextsize;
		scounter += delta;
		if (scounter < 0) {
			ASSERT(0);
			return (XFS_ERROR(EINVAL));
		}
		mp->m_sb.sb_rextsize = scounter;
		return (0);
	case XFS_SBS_RBMBLOCKS:
		scounter = mp->m_sb.sb_rbmblocks;
		scounter += delta;
		if (scounter < 0) {
			ASSERT(0);
			return (XFS_ERROR(EINVAL));
		}
		mp->m_sb.sb_rbmblocks = scounter;
		return (0);
	case XFS_SBS_RBLOCKS:
		lcounter = (long long)mp->m_sb.sb_rblocks;
		lcounter += delta;
		if (lcounter < 0) {
			ASSERT(0);
			return (XFS_ERROR(EINVAL));
		}
		mp->m_sb.sb_rblocks = lcounter;
		return (0);
	case XFS_SBS_REXTENTS:
		lcounter = (long long)mp->m_sb.sb_rextents;
		lcounter += delta;
		if (lcounter < 0) {
			ASSERT(0);
			return (XFS_ERROR(EINVAL));
		}
		mp->m_sb.sb_rextents = lcounter;
		return (0);
	case XFS_SBS_REXTSLOG:
		scounter = mp->m_sb.sb_rextslog;
		scounter += delta;
		if (scounter < 0) {
			ASSERT(0);
			return (XFS_ERROR(EINVAL));
		}
		mp->m_sb.sb_rextslog = scounter;
		return (0);
	default:
		ASSERT(0);
		return (XFS_ERROR(EINVAL));
	}
}

/*
 * xfs_mod_incore_sb() is used to change a field in the in-core
 * superblock structure by the specified delta.  This modification
 * is protected by the SB_LOCK.  Just use the xfs_mod_incore_sb_unlocked()
 * routine to do the work.
 */
int
xfs_mod_incore_sb(xfs_mount_t *mp, xfs_sb_field_t field, int delta, int rsvd)
{
	unsigned long	s;
	int	status;

	s = XFS_SB_LOCK(mp);
	status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
	XFS_SB_UNLOCK(mp, s);
	return (status);
}

/*
 * xfs_mod_incore_sb_batch() is used to change more than one field
 * in the in-core superblock structure at a time.  This modification
 * is protected by a lock internal to this module.  The fields and
 * changes to those fields are specified in the array of xfs_mod_sb
 * structures passed in.
 *
 * Either all of the specified deltas will be applied or none of
 * them will.  If any modified field dips below 0, then all modifications
 * will be backed out and EINVAL will be returned.
 */
int
xfs_mod_incore_sb_batch(xfs_mount_t *mp, xfs_mod_sb_t *msb, uint nmsb, int rsvd)
{
	unsigned long	s;
	int		status=0;
	xfs_mod_sb_t	*msbp;

	/*
	 * Loop through the array of mod structures and apply each
	 * individually.  If any fail, then back out all those
	 * which have already been applied.  Do all of this within
	 * the scope of the SB_LOCK so that all of the changes will
	 * be atomic.
	 */
	s = XFS_SB_LOCK(mp);
	msbp = &msb[0];
	for (msbp = &msbp[0]; msbp < (msb + nmsb); msbp++) {
		/*
		 * Apply the delta at index n.  If it fails, break
		 * from the loop so we'll fall into the undo loop
		 * below.
		 */
		status = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
						    msbp->msb_delta, rsvd);
		if (status != 0) {
			break;
		}
	}

	/*
	 * If we didn't complete the loop above, then back out
	 * any changes made to the superblock.  If you add code
	 * between the loop above and here, make sure that you
	 * preserve the value of status. Loop back until
	 * we step below the beginning of the array.  Make sure
	 * we don't touch anything back there.
	 */
	if (status != 0) {
		msbp--;
		while (msbp >= msb) {
			status = xfs_mod_incore_sb_unlocked(mp,
				    msbp->msb_field, -(msbp->msb_delta), rsvd);
			ASSERT(status == 0);
			msbp--;
		}
	}
	XFS_SB_UNLOCK(mp, s);
	return (status);
}

/*
 * xfs_getsb() is called to obtain the buffer for the superblock.
 * The buffer is returned locked and read in from disk.
 * The buffer should be released with a call to xfs_brelse().
 *
 * If the flags parameter is BUF_TRYLOCK, then we'll only return
 * the superblock buffer if it can be locked without sleeping.
 * If it can't then we'll return NULL.
 */
xfs_buf_t *
xfs_getsb(
	xfs_mount_t	*mp,
	int		flags)
{
	xfs_buf_t	*bp;

	ASSERT(mp->m_sb_bp != NULL);
	bp = mp->m_sb_bp;
	if (flags & XFS_BUF_TRYLOCK) {
		if (!XFS_BUF_CPSEMA(bp)) {
			return NULL;
		}
	} else {
		XFS_BUF_PSEMA(bp, PRIBIO);
	}
	XFS_BUF_HOLD(bp);
	ASSERT(XFS_BUF_ISDONE(bp));
	return (bp);
}

/*
 * Used to free the superblock along various error paths.
 */
void
xfs_freesb(
	xfs_mount_t	*mp)
{
	xfs_buf_t	*bp;

	/*
	 * Use xfs_getsb() so that the buffer will be locked
	 * when we call xfs_buf_relse().
	 */
	bp = xfs_getsb(mp, 0);
	XFS_BUF_UNMANAGE(bp);
	xfs_buf_relse(bp);
	mp->m_sb_bp = NULL;
}

/*
 * See if the UUID is unique among mounted XFS filesystems.
 * Mount fails if UUID is nil or a FS with the same UUID is already mounted.
 */
STATIC int
xfs_uuid_mount(
	xfs_mount_t	*mp)
{
	if (uuid_is_nil(&mp->m_sb.sb_uuid)) {
		cmn_err(CE_WARN,
			"XFS: Filesystem %s has nil UUID - can't mount",
			mp->m_fsname);
		return -1;
	}
	if (!uuid_table_insert(&mp->m_sb.sb_uuid)) {
		cmn_err(CE_WARN,
			"XFS: Filesystem %s has duplicate UUID - can't mount",
			mp->m_fsname);
		return -1;
	}
	return 0;
}

/*
 * Remove filesystem from the UUID table.
 */
STATIC void
xfs_uuid_unmount(
	xfs_mount_t	*mp)
{
	uuid_table_remove(&mp->m_sb.sb_uuid);
}

/*
 * 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.
 */
STATIC void
xfs_mount_log_sbunit(
	xfs_mount_t	*mp,
	__int64_t	fields)
{
	xfs_trans_t	*tp;

	ASSERT(fields & (XFS_SB_UNIT|XFS_SB_WIDTH|XFS_SB_UUID));

	tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
	if (xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
				XFS_DEFAULT_LOG_COUNT)) {
		xfs_trans_cancel(tp, 0);
		return;
	}
	xfs_mod_sb(tp, fields);
	xfs_trans_commit(tp, 0, NULL);
}