v4.19.13 snapshot.
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
new file mode 100644
index 0000000..02d1509
--- /dev/null
+++ b/fs/xfs/xfs_mount.c
@@ -0,0 +1,1442 @@
+// 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_defer.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.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_error.h"
+#include "xfs_quota.h"
+#include "xfs_fsops.h"
+#include "xfs_trace.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"
+
+
+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;
+ kmem_free(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 */
+ uuid_copy(&mp->m_super->s_uuid, uuid);
+
+ if (mp->m_flags & XFS_MOUNT_NOUUID)
+ 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 = kmem_realloc(xfs_uuid_table,
+ (xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
+ KM_SLEEP);
+ 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 (mp->m_flags & XFS_MOUNT_NOUUID)
+ 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);
+}
+
+
+STATIC void
+__xfs_free_perag(
+ struct rcu_head *head)
+{
+ struct xfs_perag *pag = container_of(head, struct xfs_perag, rcu_head);
+
+ ASSERT(atomic_read(&pag->pag_ref) == 0);
+ kmem_free(pag);
+}
+
+/*
+ * Free up the per-ag resources associated with the mount structure.
+ */
+STATIC void
+xfs_free_perag(
+ xfs_mount_t *mp)
+{
+ xfs_agnumber_t agno;
+ struct xfs_perag *pag;
+
+ for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
+ spin_lock(&mp->m_perag_lock);
+ pag = radix_tree_delete(&mp->m_perag_tree, agno);
+ spin_unlock(&mp->m_perag_lock);
+ ASSERT(pag);
+ ASSERT(atomic_read(&pag->pag_ref) == 0);
+ xfs_buf_hash_destroy(pag);
+ mutex_destroy(&pag->pag_ici_reclaim_lock);
+ call_rcu(&pag->rcu_head, __xfs_free_perag);
+ }
+}
+
+/*
+ * 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)
+{
+ ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
+ ASSERT(sbp->sb_blocklog >= BBSHIFT);
+
+ /* Limited by ULONG_MAX of page cache index */
+ if (nblocks >> (PAGE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
+ return -EFBIG;
+ return 0;
+}
+
+int
+xfs_initialize_perag(
+ xfs_mount_t *mp,
+ xfs_agnumber_t agcount,
+ xfs_agnumber_t *maxagi)
+{
+ xfs_agnumber_t index;
+ xfs_agnumber_t first_initialised = NULLAGNUMBER;
+ xfs_perag_t *pag;
+ int error = -ENOMEM;
+
+ /*
+ * Walk the current per-ag tree so we don't try to initialise AGs
+ * that already exist (growfs case). Allocate and insert all the
+ * AGs we don't find ready for initialisation.
+ */
+ for (index = 0; index < agcount; index++) {
+ pag = xfs_perag_get(mp, index);
+ if (pag) {
+ xfs_perag_put(pag);
+ continue;
+ }
+
+ pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
+ if (!pag)
+ goto out_unwind_new_pags;
+ pag->pag_agno = index;
+ pag->pag_mount = mp;
+ spin_lock_init(&pag->pag_ici_lock);
+ mutex_init(&pag->pag_ici_reclaim_lock);
+ INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC);
+ if (xfs_buf_hash_init(pag))
+ goto out_free_pag;
+ init_waitqueue_head(&pag->pagb_wait);
+ spin_lock_init(&pag->pagb_lock);
+ pag->pagb_count = 0;
+ pag->pagb_tree = RB_ROOT;
+
+ if (radix_tree_preload(GFP_NOFS))
+ goto out_hash_destroy;
+
+ spin_lock(&mp->m_perag_lock);
+ if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
+ BUG();
+ spin_unlock(&mp->m_perag_lock);
+ radix_tree_preload_end();
+ error = -EEXIST;
+ goto out_hash_destroy;
+ }
+ spin_unlock(&mp->m_perag_lock);
+ radix_tree_preload_end();
+ /* first new pag is fully initialized */
+ if (first_initialised == NULLAGNUMBER)
+ first_initialised = index;
+ }
+
+ index = xfs_set_inode_alloc(mp, agcount);
+
+ if (maxagi)
+ *maxagi = index;
+
+ mp->m_ag_prealloc_blocks = xfs_prealloc_blocks(mp);
+ return 0;
+
+out_hash_destroy:
+ xfs_buf_hash_destroy(pag);
+out_free_pag:
+ mutex_destroy(&pag->pag_ici_reclaim_lock);
+ kmem_free(pag);
+out_unwind_new_pags:
+ /* unwind any prior newly initialized pags */
+ for (index = first_initialised; index < agcount; index++) {
+ pag = radix_tree_delete(&mp->m_perag_tree, index);
+ if (!pag)
+ break;
+ xfs_buf_hash_destroy(pag);
+ mutex_destroy(&pag->pag_ici_reclaim_lock);
+ kmem_free(pag);
+ }
+ return error;
+}
+
+/*
+ * 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. Therefore,
+ * set XBF_NO_IOACCT to make sure it doesn't hold the buftarg count
+ * elevated.
+ */
+reread:
+ error = xfs_buf_read_uncached(mp->m_ddev_targp, XFS_SB_DADDR,
+ BTOBB(sector_size), XBF_NO_IOACCT, &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, XFS_BUF_TO_SBP(bp));
+
+ /*
+ * 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;
+ }
+
+ xfs_reinit_percpu_counters(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;
+}
+
+/*
+ * Update alignment values based on mount options and sb values
+ */
+STATIC int
+xfs_update_alignment(xfs_mount_t *mp)
+{
+ xfs_sb_t *sbp = &(mp->m_sb);
+
+ if (mp->m_dalign) {
+ /*
+ * If stripe unit and stripe width are not multiples
+ * of the fs blocksize turn off alignment.
+ */
+ if ((BBTOB(mp->m_dalign) & mp->m_blockmask) ||
+ (BBTOB(mp->m_swidth) & mp->m_blockmask)) {
+ xfs_warn(mp,
+ "alignment check failed: sunit/swidth vs. blocksize(%d)",
+ sbp->sb_blocksize);
+ return -EINVAL;
+ } else {
+ /*
+ * Convert the stripe unit and width to FSBs.
+ */
+ mp->m_dalign = XFS_BB_TO_FSBT(mp, mp->m_dalign);
+ if (mp->m_dalign && (sbp->sb_agblocks % mp->m_dalign)) {
+ xfs_warn(mp,
+ "alignment check failed: sunit/swidth vs. agsize(%d)",
+ sbp->sb_agblocks);
+ return -EINVAL;
+ } else if (mp->m_dalign) {
+ mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth);
+ } else {
+ xfs_warn(mp,
+ "alignment check failed: sunit(%d) less than bsize(%d)",
+ mp->m_dalign, sbp->sb_blocksize);
+ return -EINVAL;
+ }
+ }
+
+ /*
+ * Update superblock with new values
+ * and log changes
+ */
+ if (xfs_sb_version_hasdalign(sbp)) {
+ if (sbp->sb_unit != mp->m_dalign) {
+ sbp->sb_unit = mp->m_dalign;
+ mp->m_update_sb = true;
+ }
+ if (sbp->sb_width != mp->m_swidth) {
+ sbp->sb_width = mp->m_swidth;
+ mp->m_update_sb = true;
+ }
+ } else {
+ xfs_warn(mp,
+ "cannot change alignment: superblock does not support data alignment");
+ return -EINVAL;
+ }
+ } else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN &&
+ xfs_sb_version_hasdalign(&mp->m_sb)) {
+ mp->m_dalign = sbp->sb_unit;
+ mp->m_swidth = sbp->sb_width;
+ }
+
+ return 0;
+}
+
+/*
+ * Set the maximum inode count for this filesystem
+ */
+STATIC void
+xfs_set_maxicount(xfs_mount_t *mp)
+{
+ xfs_sb_t *sbp = &(mp->m_sb);
+ uint64_t icount;
+
+ if (sbp->sb_imax_pct) {
+ /*
+ * Make sure the maximum inode count is a multiple
+ * of the units we allocate inodes in.
+ */
+ icount = sbp->sb_dblocks * sbp->sb_imax_pct;
+ do_div(icount, 100);
+ do_div(icount, mp->m_ialloc_blks);
+ mp->m_maxicount = (icount * mp->m_ialloc_blks) <<
+ sbp->sb_inopblog;
+ } else {
+ mp->m_maxicount = 0;
+ }
+}
+
+/*
+ * Set the default minimum read and write sizes unless
+ * already specified in a mount option.
+ * We use smaller I/O sizes when the file system
+ * is being used for NFS service (wsync mount option).
+ */
+STATIC void
+xfs_set_rw_sizes(xfs_mount_t *mp)
+{
+ xfs_sb_t *sbp = &(mp->m_sb);
+ int readio_log, writeio_log;
+
+ if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
+ if (mp->m_flags & XFS_MOUNT_WSYNC) {
+ readio_log = XFS_WSYNC_READIO_LOG;
+ writeio_log = XFS_WSYNC_WRITEIO_LOG;
+ } else {
+ readio_log = XFS_READIO_LOG_LARGE;
+ writeio_log = XFS_WRITEIO_LOG_LARGE;
+ }
+ } else {
+ readio_log = mp->m_readio_log;
+ writeio_log = mp->m_writeio_log;
+ }
+
+ if (sbp->sb_blocklog > readio_log) {
+ mp->m_readio_log = sbp->sb_blocklog;
+ } else {
+ mp->m_readio_log = readio_log;
+ }
+ mp->m_readio_blocks = 1 << (mp->m_readio_log - sbp->sb_blocklog);
+ if (sbp->sb_blocklog > writeio_log) {
+ mp->m_writeio_log = sbp->sb_blocklog;
+ } else {
+ mp->m_writeio_log = writeio_log;
+ }
+ mp->m_writeio_blocks = 1 << (mp->m_writeio_log - sbp->sb_blocklog);
+}
+
+/*
+ * precalculate the low space thresholds for dynamic speculative preallocation.
+ */
+void
+xfs_set_low_space_thresholds(
+ struct xfs_mount *mp)
+{
+ int i;
+
+ for (i = 0; i < XFS_LOWSP_MAX; i++) {
+ uint64_t space = mp->m_sb.sb_dblocks;
+
+ do_div(space, 100);
+ mp->m_low_space[i] = space * (i + 1);
+ }
+}
+
+
+/*
+ * Set whether we're using inode alignment.
+ */
+STATIC void
+xfs_set_inoalignment(xfs_mount_t *mp)
+{
+ if (xfs_sb_version_hasalign(&mp->m_sb) &&
+ mp->m_sb.sb_inoalignmt >= xfs_icluster_size_fsb(mp))
+ mp->m_inoalign_mask = mp->m_sb.sb_inoalignmt - 1;
+ else
+ mp->m_inoalign_mask = 0;
+ /*
+ * If we are using stripe alignment, check whether
+ * the stripe unit is a multiple of the inode alignment
+ */
+ if (mp->m_dalign && mp->m_inoalign_mask &&
+ !(mp->m_dalign & mp->m_inoalign_mask))
+ mp->m_sinoalign = mp->m_dalign;
+ else
+ mp->m_sinoalign = 0;
+}
+
+/*
+ * Check that the data (and log if separate) is an ok size.
+ */
+STATIC int
+xfs_check_sizes(
+ struct xfs_mount *mp)
+{
+ struct xfs_buf *bp;
+ xfs_daddr_t d;
+ int error;
+
+ d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
+ if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) {
+ xfs_warn(mp, "filesystem size mismatch detected");
+ return -EFBIG;
+ }
+ error = xfs_buf_read_uncached(mp->m_ddev_targp,
+ d - XFS_FSS_TO_BB(mp, 1),
+ XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL);
+ if (error) {
+ xfs_warn(mp, "last sector read failed");
+ return error;
+ }
+ xfs_buf_relse(bp);
+
+ if (mp->m_logdev_targp == mp->m_ddev_targp)
+ return 0;
+
+ d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
+ if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) {
+ xfs_warn(mp, "log size mismatch detected");
+ return -EFBIG;
+ }
+ error = xfs_buf_read_uncached(mp->m_logdev_targp,
+ d - XFS_FSB_TO_BB(mp, 1),
+ XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
+ if (error) {
+ xfs_warn(mp, "log device read failed");
+ return error;
+ }
+ xfs_buf_relse(bp);
+ return 0;
+}
+
+/*
+ * Clear the quotaflags in memory and in the superblock.
+ */
+int
+xfs_mount_reset_sbqflags(
+ struct xfs_mount *mp)
+{
+ mp->m_qflags = 0;
+
+ /* It is OK to look at sb_qflags in the mount path without m_sb_lock. */
+ if (mp->m_sb.sb_qflags == 0)
+ return 0;
+ spin_lock(&mp->m_sb_lock);
+ mp->m_sb.sb_qflags = 0;
+ spin_unlock(&mp->m_sb_lock);
+
+ if (!xfs_fs_writable(mp, SB_FREEZE_WRITE))
+ return 0;
+
+ return xfs_sync_sb(mp, false);
+}
+
+uint64_t
+xfs_default_resblks(xfs_mount_t *mp)
+{
+ uint64_t resblks;
+
+ /*
+ * We default to 5% or 8192 fsbs of space reserved, whichever is
+ * smaller. This is intended to cover concurrent allocation
+ * transactions when we initially hit enospc. These each require a 4
+ * block reservation. Hence by default we cover roughly 2000 concurrent
+ * allocation reservations.
+ */
+ resblks = mp->m_sb.sb_dblocks;
+ do_div(resblks, 20);
+ resblks = min_t(uint64_t, resblks, 8192);
+ return resblks;
+}
+
+/* Ensure the summary counts are correct. */
+STATIC int
+xfs_check_summary_counts(
+ struct xfs_mount *mp)
+{
+ /*
+ * The AG0 superblock verifier rejects in-progress filesystems,
+ * so we should never see the flag set this far into mounting.
+ */
+ if (mp->m_sb.sb_inprogress) {
+ xfs_err(mp, "sb_inprogress set after log recovery??");
+ WARN_ON(1);
+ return -EFSCORRUPTED;
+ }
+
+ /*
+ * Now the log is mounted, we know if it was an unclean shutdown or
+ * not. If it was, with the first phase of recovery has completed, we
+ * have consistent AG blocks on disk. We have not recovered EFIs yet,
+ * but they are recovered transactionally in the second recovery phase
+ * later.
+ *
+ * If the log was clean when we mounted, we can check the summary
+ * counters. If any of them are obviously incorrect, we can recompute
+ * them from the AGF headers in the next step.
+ */
+ if (XFS_LAST_UNMOUNT_WAS_CLEAN(mp) &&
+ (mp->m_sb.sb_fdblocks > mp->m_sb.sb_dblocks ||
+ !xfs_verify_icount(mp, mp->m_sb.sb_icount) ||
+ mp->m_sb.sb_ifree > mp->m_sb.sb_icount))
+ mp->m_flags |= XFS_MOUNT_BAD_SUMMARY;
+
+ /*
+ * We can safely re-initialise incore superblock counters from the
+ * per-ag data. These may not be correct if the filesystem was not
+ * cleanly unmounted, so we waited for recovery to finish before doing
+ * this.
+ *
+ * If the filesystem was cleanly unmounted or the previous check did
+ * not flag anything weird, then we can trust the values in the
+ * superblock to be correct and we don't need to do anything here.
+ * Otherwise, recalculate the summary counters.
+ */
+ if ((!xfs_sb_version_haslazysbcount(&mp->m_sb) ||
+ XFS_LAST_UNMOUNT_WAS_CLEAN(mp)) &&
+ !(mp->m_flags & XFS_MOUNT_BAD_SUMMARY))
+ return 0;
+
+ return xfs_initialize_perag_data(mp, mp->m_sb.sb_agcount);
+}
+
+/*
+ * This function does the following on an initial mount of a file system:
+ * - reads the superblock from disk and init the mount struct
+ * - if we're a 32-bit kernel, do a size check on the superblock
+ * so we don't mount terabyte filesystems
+ * - init mount struct realtime fields
+ * - allocate inode hash table for fs
+ * - init directory manager
+ * - perform recovery and init the log manager
+ */
+int
+xfs_mountfs(
+ struct xfs_mount *mp)
+{
+ struct xfs_sb *sbp = &(mp->m_sb);
+ struct xfs_inode *rip;
+ uint64_t resblks;
+ uint quotamount = 0;
+ uint quotaflags = 0;
+ int error = 0;
+
+ xfs_sb_mount_common(mp, sbp);
+
+ /*
+ * 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.
+ *
+ * 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. The
+ * superblock writeback code ensures the new sb_features2 is copied to
+ * sb_bad_features2 before it is logged or written to disk.
+ */
+ if (xfs_sb_has_mismatched_features2(sbp)) {
+ xfs_warn(mp, "correcting sb_features alignment problem");
+ sbp->sb_features2 |= sbp->sb_bad_features2;
+ mp->m_update_sb = true;
+
+ /*
+ * 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_NOATTR2))
+ mp->m_flags |= XFS_MOUNT_ATTR2;
+ }
+
+ if (xfs_sb_version_hasattr2(&mp->m_sb) &&
+ (mp->m_flags & XFS_MOUNT_NOATTR2)) {
+ xfs_sb_version_removeattr2(&mp->m_sb);
+ mp->m_update_sb = true;
+
+ /* update sb_versionnum for the clearing of the morebits */
+ if (!sbp->sb_features2)
+ mp->m_update_sb = true;
+ }
+
+ /* always use v2 inodes by default now */
+ if (!(mp->m_sb.sb_versionnum & XFS_SB_VERSION_NLINKBIT)) {
+ mp->m_sb.sb_versionnum |= XFS_SB_VERSION_NLINKBIT;
+ mp->m_update_sb = true;
+ }
+
+ /*
+ * 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
+ * to be aligned at stripe boundary.
+ */
+ error = xfs_update_alignment(mp);
+ if (error)
+ goto out;
+
+ xfs_alloc_compute_maxlevels(mp);
+ xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK);
+ xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK);
+ xfs_ialloc_compute_maxlevels(mp);
+ xfs_rmapbt_compute_maxlevels(mp);
+ xfs_refcountbt_compute_maxlevels(mp);
+
+ xfs_set_maxicount(mp);
+
+ /* enable fail_at_unmount as default */
+ mp->m_fail_unmount = true;
+
+ error = xfs_sysfs_init(&mp->m_kobj, &xfs_mp_ktype, NULL, mp->m_fsname);
+ if (error)
+ goto out;
+
+ error = xfs_sysfs_init(&mp->m_stats.xs_kobj, &xfs_stats_ktype,
+ &mp->m_kobj, "stats");
+ if (error)
+ goto out_remove_sysfs;
+
+ error = xfs_error_sysfs_init(mp);
+ if (error)
+ goto out_del_stats;
+
+ error = xfs_errortag_init(mp);
+ if (error)
+ goto out_remove_error_sysfs;
+
+ error = xfs_uuid_mount(mp);
+ if (error)
+ goto out_remove_errortag;
+
+ /*
+ * Set the minimum read and write sizes
+ */
+ xfs_set_rw_sizes(mp);
+
+ /* set the low space thresholds for dynamic preallocation */
+ xfs_set_low_space_thresholds(mp);
+
+ /*
+ * Set the inode cluster size.
+ * This may still be overridden by the file system
+ * block size if it is larger than the chosen cluster size.
+ *
+ * For v5 filesystems, scale the cluster size with the inode size to
+ * keep a constant ratio of inode per cluster buffer, but only if mkfs
+ * has set the inode alignment value appropriately for larger cluster
+ * sizes.
+ */
+ mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE;
+ if (xfs_sb_version_hascrc(&mp->m_sb)) {
+ int new_size = mp->m_inode_cluster_size;
+
+ new_size *= mp->m_sb.sb_inodesize / XFS_DINODE_MIN_SIZE;
+ if (mp->m_sb.sb_inoalignmt >= XFS_B_TO_FSBT(mp, new_size))
+ mp->m_inode_cluster_size = new_size;
+ }
+
+ /*
+ * If enabled, sparse inode chunk alignment is expected to match the
+ * cluster size. Full inode chunk alignment must match the chunk size,
+ * but that is checked on sb read verification...
+ */
+ if (xfs_sb_version_hassparseinodes(&mp->m_sb) &&
+ mp->m_sb.sb_spino_align !=
+ XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size)) {
+ xfs_warn(mp,
+ "Sparse inode block alignment (%u) must match cluster size (%llu).",
+ mp->m_sb.sb_spino_align,
+ XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size));
+ error = -EINVAL;
+ goto out_remove_uuid;
+ }
+
+ /*
+ * Set inode alignment fields
+ */
+ xfs_set_inoalignment(mp);
+
+ /*
+ * Check that the data (and log if separate) is an ok size.
+ */
+ error = xfs_check_sizes(mp);
+ if (error)
+ goto out_remove_uuid;
+
+ /*
+ * Initialize realtime fields in the mount structure
+ */
+ error = xfs_rtmount_init(mp);
+ if (error) {
+ xfs_warn(mp, "RT mount failed");
+ goto out_remove_uuid;
+ }
+
+ /*
+ * Copies the low order bits of the timestamp and the randomly
+ * set "sequence" number out of a UUID.
+ */
+ mp->m_fixedfsid[0] =
+ (get_unaligned_be16(&sbp->sb_uuid.b[8]) << 16) |
+ get_unaligned_be16(&sbp->sb_uuid.b[4]);
+ mp->m_fixedfsid[1] = get_unaligned_be32(&sbp->sb_uuid.b[0]);
+
+ error = xfs_da_mount(mp);
+ if (error) {
+ xfs_warn(mp, "Failed dir/attr init: %d", error);
+ goto out_remove_uuid;
+ }
+
+ /*
+ * Initialize the precomputed transaction reservations values.
+ */
+ xfs_trans_init(mp);
+
+ /*
+ * Allocate and initialize the per-ag data.
+ */
+ error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
+ if (error) {
+ xfs_warn(mp, "Failed per-ag init: %d", error);
+ goto out_free_dir;
+ }
+
+ if (!sbp->sb_logblocks) {
+ xfs_warn(mp, "no log defined");
+ XFS_ERROR_REPORT("xfs_mountfs", XFS_ERRLEVEL_LOW, mp);
+ error = -EFSCORRUPTED;
+ goto out_free_perag;
+ }
+
+ /*
+ * Log's mount-time initialization. The first part of recovery can place
+ * some items on the AIL, to be handled when recovery is finished or
+ * cancelled.
+ */
+ error = xfs_log_mount(mp, mp->m_logdev_targp,
+ XFS_FSB_TO_DADDR(mp, sbp->sb_logstart),
+ XFS_FSB_TO_BB(mp, sbp->sb_logblocks));
+ if (error) {
+ xfs_warn(mp, "log mount failed");
+ goto out_fail_wait;
+ }
+
+ /* Make sure the summary counts are ok. */
+ error = xfs_check_summary_counts(mp);
+ if (error)
+ goto out_log_dealloc;
+
+ /*
+ * Get and sanity-check the root inode.
+ * Save the pointer to it in the mount structure.
+ */
+ error = xfs_iget(mp, NULL, sbp->sb_rootino, XFS_IGET_UNTRUSTED,
+ XFS_ILOCK_EXCL, &rip);
+ if (error) {
+ xfs_warn(mp,
+ "Failed to read root inode 0x%llx, error %d",
+ sbp->sb_rootino, -error);
+ goto out_log_dealloc;
+ }
+
+ ASSERT(rip != NULL);
+
+ if (unlikely(!S_ISDIR(VFS_I(rip)->i_mode))) {
+ xfs_warn(mp, "corrupted root inode %llu: not a directory",
+ (unsigned long long)rip->i_ino);
+ xfs_iunlock(rip, XFS_ILOCK_EXCL);
+ XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW,
+ mp);
+ error = -EFSCORRUPTED;
+ goto out_rele_rip;
+ }
+ mp->m_rootip = rip; /* save it */
+
+ xfs_iunlock(rip, XFS_ILOCK_EXCL);
+
+ /*
+ * Initialize realtime inode pointers in the mount structure
+ */
+ error = xfs_rtmount_inodes(mp);
+ if (error) {
+ /*
+ * Free up the root inode.
+ */
+ xfs_warn(mp, "failed to read RT inodes");
+ goto out_rele_rip;
+ }
+
+ /*
+ * If this is a read-only mount defer the superblock updates until
+ * the next remount into writeable mode. Otherwise we would never
+ * perform the update e.g. for the root filesystem.
+ */
+ if (mp->m_update_sb && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
+ error = xfs_sync_sb(mp, false);
+ if (error) {
+ xfs_warn(mp, "failed to write sb changes");
+ goto out_rtunmount;
+ }
+ }
+
+ /*
+ * Initialise the XFS quota management subsystem for this mount
+ */
+ if (XFS_IS_QUOTA_RUNNING(mp)) {
+ error = xfs_qm_newmount(mp, "amount, "aflags);
+ if (error)
+ goto out_rtunmount;
+ } else {
+ ASSERT(!XFS_IS_QUOTA_ON(mp));
+
+ /*
+ * If a file system had quotas running earlier, but decided to
+ * mount without -o uquota/pquota/gquota options, revoke the
+ * quotachecked license.
+ */
+ if (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT) {
+ xfs_notice(mp, "resetting quota flags");
+ error = xfs_mount_reset_sbqflags(mp);
+ if (error)
+ goto out_rtunmount;
+ }
+ }
+
+ /*
+ * Finish recovering the file system. This part needed to be delayed
+ * until after the root and real-time bitmap inodes were consistently
+ * read in.
+ */
+ error = xfs_log_mount_finish(mp);
+ if (error) {
+ xfs_warn(mp, "log mount finish failed");
+ goto out_rtunmount;
+ }
+
+ /*
+ * Now the log is fully replayed, we can transition to full read-only
+ * mode for read-only mounts. This will sync all the metadata and clean
+ * the log so that the recovery we just performed does not have to be
+ * replayed again on the next mount.
+ *
+ * We use the same quiesce mechanism as the rw->ro remount, as they are
+ * semantically identical operations.
+ */
+ if ((mp->m_flags & (XFS_MOUNT_RDONLY|XFS_MOUNT_NORECOVERY)) ==
+ XFS_MOUNT_RDONLY) {
+ xfs_quiesce_attr(mp);
+ }
+
+ /*
+ * Complete the quota initialisation, post-log-replay component.
+ */
+ if (quotamount) {
+ ASSERT(mp->m_qflags == 0);
+ mp->m_qflags = quotaflags;
+
+ xfs_qm_mount_quotas(mp);
+ }
+
+ /*
+ * Now we are mounted, reserve a small amount of unused space for
+ * privileged transactions. This is needed so that transaction
+ * space required for critical operations can dip into this pool
+ * when at ENOSPC. This is needed for operations like create with
+ * attr, unwritten extent conversion at ENOSPC, etc. Data allocations
+ * are not allowed to use this reserved space.
+ *
+ * This may drive us straight to ENOSPC on mount, but that implies
+ * we were already there on the last unmount. Warn if this occurs.
+ */
+ if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
+ resblks = xfs_default_resblks(mp);
+ error = xfs_reserve_blocks(mp, &resblks, NULL);
+ if (error)
+ xfs_warn(mp,
+ "Unable to allocate reserve blocks. Continuing without reserve pool.");
+
+ /* Recover any CoW blocks that never got remapped. */
+ error = xfs_reflink_recover_cow(mp);
+ if (error) {
+ xfs_err(mp,
+ "Error %d recovering leftover CoW allocations.", error);
+ xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+ goto out_quota;
+ }
+
+ /* Reserve AG blocks for future btree expansion. */
+ error = xfs_fs_reserve_ag_blocks(mp);
+ if (error && error != -ENOSPC)
+ goto out_agresv;
+ }
+
+ return 0;
+
+ out_agresv:
+ xfs_fs_unreserve_ag_blocks(mp);
+ out_quota:
+ xfs_qm_unmount_quotas(mp);
+ out_rtunmount:
+ xfs_rtunmount_inodes(mp);
+ out_rele_rip:
+ xfs_irele(rip);
+ /* Clean out dquots that might be in memory after quotacheck. */
+ xfs_qm_unmount(mp);
+ /*
+ * Cancel all delayed reclaim work and reclaim the inodes directly.
+ * We have to do this /after/ rtunmount and qm_unmount because those
+ * two will have scheduled delayed reclaim for the rt/quota inodes.
+ *
+ * This is slightly different from the unmountfs call sequence
+ * because we could be tearing down a partially set up mount. In
+ * particular, if log_mount_finish fails we bail out without calling
+ * qm_unmount_quotas and therefore rely on qm_unmount to release the
+ * quota inodes.
+ */
+ cancel_delayed_work_sync(&mp->m_reclaim_work);
+ xfs_reclaim_inodes(mp, SYNC_WAIT);
+ out_log_dealloc:
+ mp->m_flags |= XFS_MOUNT_UNMOUNTING;
+ xfs_log_mount_cancel(mp);
+ out_fail_wait:
+ if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp)
+ xfs_wait_buftarg(mp->m_logdev_targp);
+ xfs_wait_buftarg(mp->m_ddev_targp);
+ out_free_perag:
+ xfs_free_perag(mp);
+ out_free_dir:
+ xfs_da_unmount(mp);
+ out_remove_uuid:
+ xfs_uuid_unmount(mp);
+ out_remove_errortag:
+ xfs_errortag_del(mp);
+ out_remove_error_sysfs:
+ xfs_error_sysfs_del(mp);
+ out_del_stats:
+ xfs_sysfs_del(&mp->m_stats.xs_kobj);
+ out_remove_sysfs:
+ xfs_sysfs_del(&mp->m_kobj);
+ out:
+ return error;
+}
+
+/*
+ * This flushes out the inodes,dquots and the superblock, unmounts the
+ * log and makes sure that incore structures are freed.
+ */
+void
+xfs_unmountfs(
+ struct xfs_mount *mp)
+{
+ uint64_t resblks;
+ int error;
+
+ xfs_icache_disable_reclaim(mp);
+ xfs_fs_unreserve_ag_blocks(mp);
+ xfs_qm_unmount_quotas(mp);
+ xfs_rtunmount_inodes(mp);
+ xfs_irele(mp->m_rootip);
+
+ /*
+ * We can potentially deadlock here if we have an inode cluster
+ * that has been freed has its buffer still pinned in memory because
+ * the transaction is still sitting in a iclog. The stale inodes
+ * on that buffer will have their flush locks held until the
+ * transaction hits the disk and the callbacks run. the inode
+ * flush takes the flush lock unconditionally and with nothing to
+ * push out the iclog we will never get that unlocked. hence we
+ * need to force the log first.
+ */
+ xfs_log_force(mp, XFS_LOG_SYNC);
+
+ /*
+ * Wait for all busy extents to be freed, including completion of
+ * any discard operation.
+ */
+ xfs_extent_busy_wait_all(mp);
+ flush_workqueue(xfs_discard_wq);
+
+ /*
+ * We now need to tell the world we are unmounting. This will allow
+ * us to detect that the filesystem is going away and we should error
+ * out anything that we have been retrying in the background. This will
+ * prevent neverending retries in AIL pushing from hanging the unmount.
+ */
+ mp->m_flags |= XFS_MOUNT_UNMOUNTING;
+
+ /*
+ * Flush all pending changes from the AIL.
+ */
+ xfs_ail_push_all_sync(mp->m_ail);
+
+ /*
+ * And reclaim all inodes. At this point there should be no dirty
+ * inodes and none should be pinned or locked, but use synchronous
+ * reclaim just to be sure. We can stop background inode reclaim
+ * here as well if it is still running.
+ */
+ cancel_delayed_work_sync(&mp->m_reclaim_work);
+ xfs_reclaim_inodes(mp, SYNC_WAIT);
+
+ xfs_qm_unmount(mp);
+
+ /*
+ * Unreserve any blocks we have so that when we unmount we don't account
+ * the reserved free space as used. This is really only necessary for
+ * lazy superblock counting because it trusts the incore superblock
+ * counters to be absolutely correct on clean unmount.
+ *
+ * We don't bother correcting this elsewhere for lazy superblock
+ * counting because on mount of an unclean filesystem we reconstruct the
+ * correct counter value and this is irrelevant.
+ *
+ * For non-lazy counter filesystems, this doesn't matter at all because
+ * we only every apply deltas to the superblock and hence the incore
+ * value does not matter....
+ */
+ resblks = 0;
+ error = xfs_reserve_blocks(mp, &resblks, NULL);
+ if (error)
+ xfs_warn(mp, "Unable to free reserved block pool. "
+ "Freespace may not be correct on next mount.");
+
+ error = xfs_log_sbcount(mp);
+ if (error)
+ xfs_warn(mp, "Unable to update superblock counters. "
+ "Freespace may not be correct on next mount.");
+
+
+ xfs_log_unmount(mp);
+ xfs_da_unmount(mp);
+ xfs_uuid_unmount(mp);
+
+#if defined(DEBUG)
+ xfs_errortag_clearall(mp);
+#endif
+ xfs_free_perag(mp);
+
+ xfs_errortag_del(mp);
+ xfs_error_sysfs_del(mp);
+ xfs_sysfs_del(&mp->m_stats.xs_kobj);
+ xfs_sysfs_del(&mp->m_kobj);
+}
+
+/*
+ * Determine whether modifications can proceed. The caller specifies the minimum
+ * freeze level for which modifications should not be allowed. This allows
+ * certain operations to proceed while the freeze sequence is in progress, if
+ * necessary.
+ */
+bool
+xfs_fs_writable(
+ struct xfs_mount *mp,
+ int level)
+{
+ ASSERT(level > SB_UNFROZEN);
+ if ((mp->m_super->s_writers.frozen >= level) ||
+ XFS_FORCED_SHUTDOWN(mp) || (mp->m_flags & XFS_MOUNT_RDONLY))
+ return false;
+
+ return true;
+}
+
+/*
+ * xfs_log_sbcount
+ *
+ * Sync the superblock counters to disk.
+ *
+ * Note this code can be called during the process of freezing, so we use the
+ * transaction allocator that does not block when the transaction subsystem is
+ * in its frozen state.
+ */
+int
+xfs_log_sbcount(xfs_mount_t *mp)
+{
+ /* allow this to proceed during the freeze sequence... */
+ if (!xfs_fs_writable(mp, SB_FREEZE_COMPLETE))
+ return 0;
+
+ /*
+ * we don't need to do this if we are updating the superblock
+ * counters on every modification.
+ */
+ if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
+ return 0;
+
+ return xfs_sync_sb(mp, true);
+}
+
+/*
+ * Deltas for the inode count are +/-64, hence we use a large batch size
+ * of 128 so we don't need to take the counter lock on every update.
+ */
+#define XFS_ICOUNT_BATCH 128
+int
+xfs_mod_icount(
+ struct xfs_mount *mp,
+ int64_t delta)
+{
+ percpu_counter_add_batch(&mp->m_icount, delta, XFS_ICOUNT_BATCH);
+ if (__percpu_counter_compare(&mp->m_icount, 0, XFS_ICOUNT_BATCH) < 0) {
+ ASSERT(0);
+ percpu_counter_add(&mp->m_icount, -delta);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+int
+xfs_mod_ifree(
+ struct xfs_mount *mp,
+ int64_t delta)
+{
+ percpu_counter_add(&mp->m_ifree, delta);
+ if (percpu_counter_compare(&mp->m_ifree, 0) < 0) {
+ ASSERT(0);
+ percpu_counter_add(&mp->m_ifree, -delta);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/*
+ * Deltas for the block count can vary from 1 to very large, but lock contention
+ * only occurs on frequent small block count updates such as in the delayed
+ * allocation path for buffered writes (page a time updates). Hence we set
+ * a large batch count (1024) to minimise global counter updates except when
+ * we get near to ENOSPC and we have to be very accurate with our updates.
+ */
+#define XFS_FDBLOCKS_BATCH 1024
+int
+xfs_mod_fdblocks(
+ struct xfs_mount *mp,
+ int64_t delta,
+ bool rsvd)
+{
+ int64_t lcounter;
+ long long res_used;
+ s32 batch;
+
+ if (delta > 0) {
+ /*
+ * If the reserve pool is depleted, put blocks back into it
+ * first. Most of the time the pool is full.
+ */
+ if (likely(mp->m_resblks == mp->m_resblks_avail)) {
+ percpu_counter_add(&mp->m_fdblocks, delta);
+ return 0;
+ }
+
+ spin_lock(&mp->m_sb_lock);
+ res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
+
+ if (res_used > delta) {
+ mp->m_resblks_avail += delta;
+ } else {
+ delta -= res_used;
+ mp->m_resblks_avail = mp->m_resblks;
+ percpu_counter_add(&mp->m_fdblocks, delta);
+ }
+ spin_unlock(&mp->m_sb_lock);
+ return 0;
+ }
+
+ /*
+ * Taking blocks away, need to be more accurate the closer we
+ * are to zero.
+ *
+ * If the counter has a value of less than 2 * max batch size,
+ * then make everything serialise as we are real close to
+ * ENOSPC.
+ */
+ if (__percpu_counter_compare(&mp->m_fdblocks, 2 * XFS_FDBLOCKS_BATCH,
+ XFS_FDBLOCKS_BATCH) < 0)
+ batch = 1;
+ else
+ batch = XFS_FDBLOCKS_BATCH;
+
+ percpu_counter_add_batch(&mp->m_fdblocks, delta, batch);
+ if (__percpu_counter_compare(&mp->m_fdblocks, mp->m_alloc_set_aside,
+ XFS_FDBLOCKS_BATCH) >= 0) {
+ /* we had space! */
+ return 0;
+ }
+
+ /*
+ * lock up the sb for dipping into reserves before releasing the space
+ * that took us to ENOSPC.
+ */
+ spin_lock(&mp->m_sb_lock);
+ percpu_counter_add(&mp->m_fdblocks, -delta);
+ if (!rsvd)
+ goto fdblocks_enospc;
+
+ lcounter = (long long)mp->m_resblks_avail + delta;
+ if (lcounter >= 0) {
+ mp->m_resblks_avail = lcounter;
+ spin_unlock(&mp->m_sb_lock);
+ return 0;
+ }
+ printk_once(KERN_WARNING
+ "Filesystem \"%s\": reserve blocks depleted! "
+ "Consider increasing reserve pool size.",
+ mp->m_fsname);
+fdblocks_enospc:
+ spin_unlock(&mp->m_sb_lock);
+ return -ENOSPC;
+}
+
+int
+xfs_mod_frextents(
+ struct xfs_mount *mp,
+ int64_t delta)
+{
+ int64_t lcounter;
+ int ret = 0;
+
+ spin_lock(&mp->m_sb_lock);
+ lcounter = mp->m_sb.sb_frextents + delta;
+ if (lcounter < 0)
+ ret = -ENOSPC;
+ else
+ mp->m_sb.sb_frextents = lcounter;
+ spin_unlock(&mp->m_sb_lock);
+ return ret;
+}
+
+/*
+ * 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.
+ */
+struct xfs_buf *
+xfs_getsb(
+ struct xfs_mount *mp,
+ int flags)
+{
+ struct xfs_buf *bp = mp->m_sb_bp;
+
+ if (!xfs_buf_trylock(bp)) {
+ if (flags & XBF_TRYLOCK)
+ return NULL;
+ xfs_buf_lock(bp);
+ }
+
+ xfs_buf_hold(bp);
+ ASSERT(bp->b_flags & XBF_DONE);
+ return bp;
+}
+
+/*
+ * Used to free the superblock along various error paths.
+ */
+void
+xfs_freesb(
+ struct xfs_mount *mp)
+{
+ struct xfs_buf *bp = mp->m_sb_bp;
+
+ xfs_buf_lock(bp);
+ mp->m_sb_bp = NULL;
+ xfs_buf_relse(bp);
+}
+
+/*
+ * If the underlying (data/log/rt) device is readonly, there are some
+ * operations that cannot proceed.
+ */
+int
+xfs_dev_is_read_only(
+ struct xfs_mount *mp,
+ char *message)
+{
+ if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
+ xfs_readonly_buftarg(mp->m_logdev_targp) ||
+ (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
+ xfs_notice(mp, "%s required on read-only device.", message);
+ xfs_notice(mp, "write access unavailable, cannot proceed.");
+ return -EROFS;
+ }
+ return 0;
+}
+
+/* Force the summary counters to be recalculated at next mount. */
+void
+xfs_force_summary_recalc(
+ struct xfs_mount *mp)
+{
+ if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
+ return;
+
+ spin_lock(&mp->m_sb_lock);
+ mp->m_flags |= XFS_MOUNT_BAD_SUMMARY;
+ spin_unlock(&mp->m_sb_lock);
+}