path: root/fs/xfs/xfs_mount.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_sb.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_dir2.h"
#include "xfs_ialloc.h"
#include "xfs_alloc.h"
#include "xfs_rtalloc.h"
#include "xfs_bmap.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_log.h"
#include "xfs_log_priv.h"
#include "xfs_error.h"
#include "xfs_quota.h"
#include "xfs_fsops.h"
#include "xfs_icache.h"
#include "xfs_sysfs.h"
#include "xfs_rmap_btree.h"
#include "xfs_refcount_btree.h"
#include "xfs_reflink.h"
#include "xfs_extent_busy.h"
#include "xfs_health.h"
#include "xfs_trace.h"
#include "xfs_ag.h"
#include "xfs_rtbitmap.h"
#include "xfs_metafile.h"
#include "xfs_rtgroup.h"
#include "xfs_rtrmap_btree.h"
#include "xfs_rtrefcount_btree.h"
#include "scrub/stats.h"
#include "xfs_zone_alloc.h"

static DEFINE_MUTEX(xfs_uuid_table_mutex);
static int xfs_uuid_table_size;
static uuid_t *xfs_uuid_table;

void
xfs_uuid_table_free(void)
{
	if (xfs_uuid_table_size == 0)
		return;
	kfree(xfs_uuid_table);
	xfs_uuid_table = NULL;
	xfs_uuid_table_size = 0;
}

/*
 * 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(
	struct xfs_mount	*mp)
{
	uuid_t			*uuid = &mp->m_sb.sb_uuid;
	int			hole, i;

	/* Publish UUID in struct super_block */
	super_set_uuid(mp->m_super, uuid->b, sizeof(*uuid));

	if (xfs_has_nouuid(mp))
		return 0;

	if (uuid_is_null(uuid)) {
		xfs_warn(mp, "Filesystem has null UUID - can't mount");
		return -EINVAL;
	}

	mutex_lock(&xfs_uuid_table_mutex);
	for (i = 0, hole = -1; i < xfs_uuid_table_size; i++) {
		if (uuid_is_null(&xfs_uuid_table[i])) {
			hole = i;
			continue;
		}
		if (uuid_equal(uuid, &xfs_uuid_table[i]))
			goto out_duplicate;
	}

	if (hole < 0) {
		xfs_uuid_table = krealloc(xfs_uuid_table,
			(xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
			GFP_KERNEL | __GFP_NOFAIL);
		hole = xfs_uuid_table_size++;
	}
	xfs_uuid_table[hole] = *uuid;
	mutex_unlock(&xfs_uuid_table_mutex);

	return 0;

 out_duplicate:
	mutex_unlock(&xfs_uuid_table_mutex);
	xfs_warn(mp, "Filesystem has duplicate UUID %pU - can't mount", uuid);
	return -EINVAL;
}

STATIC void
xfs_uuid_unmount(
	struct xfs_mount	*mp)
{
	uuid_t			*uuid = &mp->m_sb.sb_uuid;
	int			i;

	if (xfs_has_nouuid(mp))
		return;

	mutex_lock(&xfs_uuid_table_mutex);
	for (i = 0; i < xfs_uuid_table_size; i++) {
		if (uuid_is_null(&xfs_uuid_table[i]))
			continue;
		if (!uuid_equal(uuid, &xfs_uuid_table[i]))
			continue;
		memset(&xfs_uuid_table[i], 0, sizeof(uuid_t));
		break;
	}
	ASSERT(i < xfs_uuid_table_size);
	mutex_unlock(&xfs_uuid_table_mutex);
}

/*
 * Check size of device based on the (data/realtime) block count.
 * Note: this check is used by the growfs code as well as mount.
 */
int
xfs_sb_validate_fsb_count(
	xfs_sb_t	*sbp,
	uint64_t	nblocks)
{
	uint64_t		max_bytes;

	ASSERT(sbp->sb_blocklog >= BBSHIFT);

	if (check_shl_overflow(nblocks, sbp->sb_blocklog, &max_bytes))
		return -EFBIG;

	/* Limited by ULONG_MAX of page cache index */
	if (max_bytes >> PAGE_SHIFT > ULONG_MAX)
		return -EFBIG;
	return 0;
}

/*
 * xfs_readsb
 *
 * Does the initial read of the superblock.
 */
int
xfs_readsb(
	struct xfs_mount *mp,
	int		flags)
{
	unsigned int	sector_size;
	struct xfs_buf	*bp;
	struct xfs_sb	*sbp = &mp->m_sb;
	int		error;
	int		loud = !(flags & XFS_MFSI_QUIET);
	const struct xfs_buf_ops *buf_ops;

	ASSERT(mp->m_sb_bp == NULL);
	ASSERT(mp->m_ddev_targp != NULL);

	/*
	 * For the initial read, we must guess at the sector
	 * size based on the block device.  It's enough to
	 * get the sb_sectsize out of the superblock and
	 * then reread with the proper length.
	 * We don't verify it yet, because it may not be complete.
	 */
	sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
	buf_ops = NULL;

	/*
	 * Allocate a (locked) buffer to hold the superblock. This will be kept
	 * around at all times to optimize access to the superblock.
	 */
reread:
	error = xfs_buf_read_uncached(mp->m_ddev_targp, XFS_SB_DADDR,
				      BTOBB(sector_size), &bp, buf_ops);
	if (error) {
		if (loud)
			xfs_warn(mp, "SB validate failed with error %d.", error);
		/* bad CRC means corrupted metadata */
		if (error == -EFSBADCRC)
			error = -EFSCORRUPTED;
		return error;
	}

	/*
	 * Initialize the mount structure from the superblock.
	 */
	xfs_sb_from_disk(sbp, bp->b_addr);

	/*
	 * If we haven't validated the superblock, do so now before we try
	 * to check the sector size and reread the superblock appropriately.
	 */
	if (sbp->sb_magicnum != XFS_SB_MAGIC) {
		if (loud)
			xfs_warn(mp, "Invalid superblock magic number");
		error = -EINVAL;
		goto release_buf;
	}

	/*
	 * We must be able to do sector-sized and sector-aligned IO.
	 */
	if (sector_size > sbp->sb_sectsize) {
		if (loud)
			xfs_warn(mp, "device supports %u byte sectors (not %u)",
				sector_size, sbp->sb_sectsize);
		error = -ENOSYS;
		goto release_buf;
	}

	if (buf_ops == NULL) {
		/*
		 * Re-read the superblock so the buffer is correctly sized,
		 * and properly verified.
		 */
		xfs_buf_relse(bp);
		sector_size = sbp->sb_sectsize;
		buf_ops = loud ? &xfs_sb_buf_ops : &xfs_sb_quiet_buf_ops;
		goto reread;
	}

	mp->m_features |= xfs_sb_version_to_features(sbp);
	xfs_reinit_percpu_counters(mp);

	/*
	 * If logged xattrs are enabled after log recovery finishes, then set
	 * the opstate so that log recovery will work properly.
	 */
	if (xfs_sb_version_haslogxattrs(&mp->m_sb))
		xfs_set_using_logged_xattrs(mp);

	/* no need to be quiet anymore, so reset the buf ops */
	bp->b_ops = &xfs_sb_buf_ops;

	mp->m_sb_bp = bp;
	xfs_buf_unlock(bp);
	return 0;

release_buf:
	xfs_buf_relse(bp);
	return error;
}

/*
 * If the sunit/swidth change would move the precomputed root inode value, we
 * must reject the ondisk change because repair will stumble over that.
 * However, we allow the mount to proceed because we never rejected this
 * combination before.  Returns true to update the sb, false otherwise.
 */
static inline int
xfs_check_new_dalign(
	struct xfs_mount	*mp,
	int			new_dalign,
	bool			*update_sb)
{
	struct xfs_sb		*sbp = &mp->m_sb;
	xfs_ino_t		calc_ino;

	calc_ino = xfs_ialloc_calc_rootino(mp, new_dalign);
	trace_xfs_check_new_dalign(mp, new_dalign, calc_ino);

	if (sbp->sb_rootino == calc_ino) {
		*update_sb = true;
		return 0;
	}

	xfs_warn(mp,
"Cannot change stripe alignment; would require moving root inode.");

	/*
	 * XXX: Next time we add a new incompat feature, this should start
	 * returning -EINVAL to fail the mount.  Until then, spit out a warning
	 * that we're ignoring the administrator's instructions.
	 */
	xfs_warn(mp, "Skipping superblock stripe alignment update.");
	*update_sb = false;
	return 0;
}

/*
 * If we were provided with new sunit/swidth values as mount options, make sure
 * that they pass basic alignment and superblock feature checks, and convert
 * them into the same units (FSB) that everything else expects.  This step
 * /must/ be done before computing the inode geometry.
 */
STATIC int
xfs_validate_new_dalign(
	struct xfs_mount	*mp)
{
	if (mp->m_dalign == 0)
		return 0;

	/*
	 * If stripe unit and stri