zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/fs/xfs/xfs_mount.c b/ap/os/linux/linux-3.4.x/fs/xfs/xfs_mount.c
new file mode 100644
index 0000000..1ffead4
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/xfs/xfs_mount.c
@@ -0,0 +1,2567 @@
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_types.h"
+#include "xfs_bit.h"
+#include "xfs_log.h"
+#include "xfs_inum.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_dir2.h"
+#include "xfs_mount.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_btree.h"
+#include "xfs_ialloc.h"
+#include "xfs_alloc.h"
+#include "xfs_rtalloc.h"
+#include "xfs_bmap.h"
+#include "xfs_error.h"
+#include "xfs_rw.h"
+#include "xfs_quota.h"
+#include "xfs_fsops.h"
+#include "xfs_utils.h"
+#include "xfs_trace.h"
+
+
+#ifdef HAVE_PERCPU_SB
+STATIC void xfs_icsb_balance_counter(xfs_mount_t *, xfs_sb_field_t,
+ int);
+STATIC void xfs_icsb_balance_counter_locked(xfs_mount_t *, xfs_sb_field_t,
+ int);
+STATIC void xfs_icsb_disable_counter(xfs_mount_t *, xfs_sb_field_t);
+#else
+
+#define xfs_icsb_balance_counter(mp, a, b) do { } while (0)
+#define xfs_icsb_balance_counter_locked(mp, a, b) do { } while (0)
+#endif
+
+static const struct {
+ short offset;
+ short type; /* 0 = integer
+ * 1 = binary / string (no translation)
+ */
+} xfs_sb_info[] = {
+ { offsetof(xfs_sb_t, sb_magicnum), 0 },
+ { offsetof(xfs_sb_t, sb_blocksize), 0 },
+ { offsetof(xfs_sb_t, sb_dblocks), 0 },
+ { offsetof(xfs_sb_t, sb_rblocks), 0 },
+ { offsetof(xfs_sb_t, sb_rextents), 0 },
+ { offsetof(xfs_sb_t, sb_uuid), 1 },
+ { offsetof(xfs_sb_t, sb_logstart), 0 },
+ { offsetof(xfs_sb_t, sb_rootino), 0 },
+ { offsetof(xfs_sb_t, sb_rbmino), 0 },
+ { offsetof(xfs_sb_t, sb_rsumino), 0 },
+ { offsetof(xfs_sb_t, sb_rextsize), 0 },
+ { offsetof(xfs_sb_t, sb_agblocks), 0 },
+ { offsetof(xfs_sb_t, sb_agcount), 0 },
+ { offsetof(xfs_sb_t, sb_rbmblocks), 0 },
+ { offsetof(xfs_sb_t, sb_logblocks), 0 },
+ { offsetof(xfs_sb_t, sb_versionnum), 0 },
+ { offsetof(xfs_sb_t, sb_sectsize), 0 },
+ { offsetof(xfs_sb_t, sb_inodesize), 0 },
+ { offsetof(xfs_sb_t, sb_inopblock), 0 },
+ { offsetof(xfs_sb_t, sb_fname[0]), 1 },
+ { offsetof(xfs_sb_t, sb_blocklog), 0 },
+ { offsetof(xfs_sb_t, sb_sectlog), 0 },
+ { offsetof(xfs_sb_t, sb_inodelog), 0 },
+ { offsetof(xfs_sb_t, sb_inopblog), 0 },
+ { offsetof(xfs_sb_t, sb_agblklog), 0 },
+ { offsetof(xfs_sb_t, sb_rextslog), 0 },
+ { offsetof(xfs_sb_t, sb_inprogress), 0 },
+ { offsetof(xfs_sb_t, sb_imax_pct), 0 },
+ { offsetof(xfs_sb_t, sb_icount), 0 },
+ { offsetof(xfs_sb_t, sb_ifree), 0 },
+ { offsetof(xfs_sb_t, sb_fdblocks), 0 },
+ { offsetof(xfs_sb_t, sb_frextents), 0 },
+ { offsetof(xfs_sb_t, sb_uquotino), 0 },
+ { offsetof(xfs_sb_t, sb_gquotino), 0 },
+ { offsetof(xfs_sb_t, sb_qflags), 0 },
+ { offsetof(xfs_sb_t, sb_flags), 0 },
+ { offsetof(xfs_sb_t, sb_shared_vn), 0 },
+ { offsetof(xfs_sb_t, sb_inoalignmt), 0 },
+ { offsetof(xfs_sb_t, sb_unit), 0 },
+ { offsetof(xfs_sb_t, sb_width), 0 },
+ { offsetof(xfs_sb_t, sb_dirblklog), 0 },
+ { offsetof(xfs_sb_t, sb_logsectlog), 0 },
+ { 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 }
+};
+
+static DEFINE_MUTEX(xfs_uuid_table_mutex);
+static int xfs_uuid_table_size;
+static uuid_t *xfs_uuid_table;
+
+/*
+ * 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;
+
+ if (mp->m_flags & XFS_MOUNT_NOUUID)
+ return 0;
+
+ if (uuid_is_nil(uuid)) {
+ xfs_warn(mp, "Filesystem has nil UUID - can't mount");
+ return XFS_ERROR(EINVAL);
+ }
+
+ mutex_lock(&xfs_uuid_table_mutex);
+ for (i = 0, hole = -1; i < xfs_uuid_table_size; i++) {
+ if (uuid_is_nil(&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),
+ xfs_uuid_table_size * 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 XFS_ERROR(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_nil(&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);
+}
+
+
+/*
+ * Reference counting access wrappers to the perag structures.
+ * Because we never free per-ag structures, the only thing we
+ * have to protect against changes is the tree structure itself.
+ */
+struct xfs_perag *
+xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
+{
+ struct xfs_perag *pag;
+ int ref = 0;
+
+ rcu_read_lock();
+ pag = radix_tree_lookup(&mp->m_perag_tree, agno);
+ if (pag) {
+ ASSERT(atomic_read(&pag->pag_ref) >= 0);
+ ref = atomic_inc_return(&pag->pag_ref);
+ }
+ rcu_read_unlock();
+ trace_xfs_perag_get(mp, agno, ref, _RET_IP_);
+ return pag;
+}
+
+/*
+ * search from @first to find the next perag with the given tag set.
+ */
+struct xfs_perag *
+xfs_perag_get_tag(
+ struct xfs_mount *mp,
+ xfs_agnumber_t first,
+ int tag)
+{
+ struct xfs_perag *pag;
+ int found;
+ int ref;
+
+ rcu_read_lock();
+ found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
+ (void **)&pag, first, 1, tag);
+ if (found <= 0) {
+ rcu_read_unlock();
+ return NULL;
+ }
+ ref = atomic_inc_return(&pag->pag_ref);
+ rcu_read_unlock();
+ trace_xfs_perag_get_tag(mp, pag->pag_agno, ref, _RET_IP_);
+ return pag;
+}
+
+void
+xfs_perag_put(struct xfs_perag *pag)
+{
+ int ref;
+
+ ASSERT(atomic_read(&pag->pag_ref) > 0);
+ ref = atomic_dec_return(&pag->pag_ref);
+ trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);
+}
+
+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);
+ 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);
+
+#if XFS_BIG_BLKNOS /* Limited by ULONG_MAX of page cache index */
+ if (nblocks >> (PAGE_CACHE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
+ return EFBIG;
+#else /* Limited by UINT_MAX of sectors */
+ if (nblocks << (sbp->sb_blocklog - BBSHIFT) > UINT_MAX)
+ return EFBIG;
+#endif
+ return 0;
+}
+
+/*
+ * Check the validity of the SB found.
+ */
+STATIC int
+xfs_mount_validate_sb(
+ xfs_mount_t *mp,
+ xfs_sb_t *sbp,
+ int flags)
+{
+ int loud = !(flags & XFS_MFSI_QUIET);
+
+ /*
+ * If the log device and data device have the
+ * same device number, the log is internal.
+ * Consequently, the sb_logstart should be non-zero. If
+ * we have a zero sb_logstart in this case, we may be trying to mount
+ * a volume filesystem in a non-volume manner.
+ */
+ if (sbp->sb_magicnum != XFS_SB_MAGIC) {
+ if (loud)
+ xfs_warn(mp, "bad magic number");
+ return XFS_ERROR(EWRONGFS);
+ }
+
+ if (!xfs_sb_good_version(sbp)) {
+ if (loud)
+ xfs_warn(mp, "bad version");
+ return XFS_ERROR(EWRONGFS);
+ }
+
+ if (unlikely(
+ sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
+ if (loud)
+ xfs_warn(mp,
+ "filesystem is marked as having an external log; "
+ "specify logdev on the mount command line.");
+ return XFS_ERROR(EINVAL);
+ }
+
+ if (unlikely(
+ sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
+ if (loud)
+ xfs_warn(mp,
+ "filesystem is marked as having an internal log; "
+ "do not specify logdev on the mount command line.");
+ return XFS_ERROR(EINVAL);
+ }
+
+ /*
+ * More sanity checking. Most of these were stolen directly from
+ * xfs_repair.
+ */
+ if (unlikely(
+ sbp->sb_agcount <= 0 ||
+ sbp->sb_sectsize < XFS_MIN_SECTORSIZE ||
+ sbp->sb_sectsize > XFS_MAX_SECTORSIZE ||
+ sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG ||
+ sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG ||
+ sbp->sb_sectsize != (1 << sbp->sb_sectlog) ||
+ sbp->sb_blocksize < XFS_MIN_BLOCKSIZE ||
+ sbp->sb_blocksize > XFS_MAX_BLOCKSIZE ||
+ sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG ||
+ sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
+ sbp->sb_blocksize != (1 << sbp->sb_blocklog) ||
+ sbp->sb_inodesize < XFS_DINODE_MIN_SIZE ||
+ sbp->sb_inodesize > XFS_DINODE_MAX_SIZE ||
+ sbp->sb_inodelog < XFS_DINODE_MIN_LOG ||
+ sbp->sb_inodelog > XFS_DINODE_MAX_LOG ||
+ sbp->sb_inodesize != (1 << sbp->sb_inodelog) ||
+ (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog) ||
+ (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE) ||
+ (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) ||
+ (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */) ||
+ sbp->sb_dblocks == 0 ||
+ sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp) ||
+ sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp))) {
+ if (loud)
+ XFS_CORRUPTION_ERROR("SB sanity check failed",
+ XFS_ERRLEVEL_LOW, mp, sbp);
+ return XFS_ERROR(EFSCORRUPTED);
+ }
+
+ /*
+ * Until this is fixed only page-sized or smaller data blocks work.
+ */
+ if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
+ if (loud) {
+ xfs_warn(mp,
+ "File system with blocksize %d bytes. "
+ "Only pagesize (%ld) or less will currently work.",
+ sbp->sb_blocksize, PAGE_SIZE);
+ }
+ return XFS_ERROR(ENOSYS);
+ }
+
+ /*
+ * Currently only very few inode sizes are supported.
+ */
+ switch (sbp->sb_inodesize) {
+ case 256:
+ case 512:
+ case 1024:
+ case 2048:
+ break;
+ default:
+ if (loud)
+ xfs_warn(mp, "inode size of %d bytes not supported",
+ sbp->sb_inodesize);
+ return XFS_ERROR(ENOSYS);
+ }
+
+ if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
+ xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
+ if (loud)
+ xfs_warn(mp,
+ "file system too large to be mounted on this system.");
+ return XFS_ERROR(EFBIG);
+ }
+
+ if (unlikely(sbp->sb_inprogress)) {
+ if (loud)
+ xfs_warn(mp, "file system busy");
+ return XFS_ERROR(EFSCORRUPTED);
+ }
+
+ /*
+ * Version 1 directory format has never worked on Linux.
+ */
+ if (unlikely(!xfs_sb_version_hasdirv2(sbp))) {
+ if (loud)
+ xfs_warn(mp,
+ "file system using version 1 directory format");
+ return XFS_ERROR(ENOSYS);
+ }
+
+ return 0;
+}
+
+int
+xfs_initialize_perag(
+ xfs_mount_t *mp,
+ xfs_agnumber_t agcount,
+ xfs_agnumber_t *maxagi)
+{
+ xfs_agnumber_t index, max_metadata;
+ xfs_agnumber_t first_initialised = 0;
+ xfs_perag_t *pag;
+ xfs_agino_t agino;
+ xfs_ino_t ino;
+ xfs_sb_t *sbp = &mp->m_sb;
+ 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;
+ }
+ if (!first_initialised)
+ first_initialised = index;
+
+ pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
+ if (!pag)
+ goto out_unwind;
+ 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);
+ spin_lock_init(&pag->pag_buf_lock);
+ pag->pag_buf_tree = RB_ROOT;
+
+ if (radix_tree_preload(GFP_NOFS))
+ goto out_unwind;
+
+ 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_unwind;
+ }
+ spin_unlock(&mp->m_perag_lock);
+ radix_tree_preload_end();
+ }
+
+ /*
+ * If we mount with the inode64 option, or no inode overflows
+ * the legacy 32-bit address space clear the inode32 option.
+ */
+ agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
+ ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
+
+ if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && ino > XFS_MAXINUMBER_32)
+ mp->m_flags |= XFS_MOUNT_32BITINODES;
+ else
+ mp->m_flags &= ~XFS_MOUNT_32BITINODES;
+
+ if (mp->m_flags & XFS_MOUNT_32BITINODES) {
+ /*
+ * Calculate how much should be reserved for inodes to meet
+ * the max inode percentage.
+ */
+ if (mp->m_maxicount) {
+ __uint64_t icount;
+
+ icount = sbp->sb_dblocks * sbp->sb_imax_pct;
+ do_div(icount, 100);
+ icount += sbp->sb_agblocks - 1;
+ do_div(icount, sbp->sb_agblocks);
+ max_metadata = icount;
+ } else {
+ max_metadata = agcount;
+ }
+
+ for (index = 0; index < agcount; index++) {
+ ino = XFS_AGINO_TO_INO(mp, index, agino);
+ if (ino > XFS_MAXINUMBER_32) {
+ index++;
+ break;
+ }
+
+ pag = xfs_perag_get(mp, index);
+ pag->pagi_inodeok = 1;
+ if (index < max_metadata)
+ pag->pagf_metadata = 1;
+ xfs_perag_put(pag);
+ }
+ } else {
+ for (index = 0; index < agcount; index++) {
+ pag = xfs_perag_get(mp, index);
+ pag->pagi_inodeok = 1;
+ xfs_perag_put(pag);
+ }
+ }
+
+ if (maxagi)
+ *maxagi = index;
+ return 0;
+
+out_unwind:
+ kmem_free(pag);
+ for (; index > first_initialised; index--) {
+ pag = radix_tree_delete(&mp->m_perag_tree, index);
+ kmem_free(pag);
+ }
+ return error;
+}
+
+void
+xfs_sb_from_disk(
+ struct xfs_mount *mp,
+ xfs_dsb_t *from)
+{
+ struct xfs_sb *to = &mp->m_sb;
+
+ 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);
+ to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
+}
+
+/*
+ * Copy in core superblock to ondisk one.
+ *
+ * The fields argument is mask of superblock fields to copy.
+ */
+void
+xfs_sb_to_disk(
+ xfs_dsb_t *to,
+ xfs_sb_t *from,
+ __int64_t fields)
+{
+ 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(fields);
+ if (!fields)
+ return;
+
+ while (fields) {
+ f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
+ first = xfs_sb_info[f].offset;
+ size = xfs_sb_info[f + 1].offset - first;
+
+ ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1);
+
+ if (size == 1 || xfs_sb_info[f].type == 1) {
+ memcpy(to_ptr + first, from_ptr + first, size);
+ } else {
+ switch (size) {
+ case 2:
+ *(__be16 *)(to_ptr + first) =
+ cpu_to_be16(*(__u16 *)(from_ptr + first));
+ break;
+ case 4:
+ *(__be32 *)(to_ptr + first) =
+ cpu_to_be32(*(__u32 *)(from_ptr + first));
+ break;
+ case 8:
+ *(__be64 *)(to_ptr + first) =
+ cpu_to_be64(*(__u64 *)(from_ptr + first));
+ break;
+ default:
+ ASSERT(0);
+ }
+ }
+
+ fields &= ~(1LL << f);
+ }
+}
+
+/*
+ * xfs_readsb
+ *
+ * Does the initial read of the superblock.
+ */
+int
+xfs_readsb(xfs_mount_t *mp, int flags)
+{
+ unsigned int sector_size;
+ xfs_buf_t *bp;
+ int error;
+ int loud = !(flags & XFS_MFSI_QUIET);
+
+ ASSERT(mp->m_sb_bp == NULL);
+ ASSERT(mp->m_ddev_targp != NULL);
+
+ /*
+ * Allocate a (locked) buffer to hold the superblock.
+ * This will be kept around at all times to optimize
+ * access to the superblock.
+ */
+ sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
+
+reread:
+ bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
+ XFS_SB_DADDR, sector_size, 0);
+ if (!bp) {
+ if (loud)
+ xfs_warn(mp, "SB buffer read failed");
+ return EIO;
+ }
+
+ /*
+ * Initialize the mount structure from the superblock.
+ * But first do some basic consistency checking.
+ */
+ xfs_sb_from_disk(mp, XFS_BUF_TO_SBP(bp));
+ error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags);
+ if (error) {
+ if (loud)
+ xfs_warn(mp, "SB validate failed");
+ goto release_buf;
+ }
+
+ /*
+ * We must be able to do sector-sized and sector-aligned IO.
+ */
+ if (sector_size > mp->m_sb.sb_sectsize) {
+ if (loud)
+ xfs_warn(mp, "device supports %u byte sectors (not %u)",
+ sector_size, mp->m_sb.sb_sectsize);
+ error = ENOSYS;
+ goto release_buf;
+ }
+
+ /*
+ * If device sector size is smaller than the superblock size,
+ * re-read the superblock so the buffer is correctly sized.
+ */
+ if (sector_size < mp->m_sb.sb_sectsize) {
+ xfs_buf_relse(bp);
+ sector_size = mp->m_sb.sb_sectsize;
+ goto reread;
+ }
+
+ /* Initialize per-cpu counters */
+ xfs_icsb_reinit_counters(mp);
+
+ mp->m_sb_bp = bp;
+ xfs_buf_unlock(bp);
+ return 0;
+
+release_buf:
+ xfs_buf_relse(bp);
+ return error;
+}
+
+
+/*
+ * xfs_mount_common
+ *
+ * Mount initialization code establishing various mount
+ * fields from the superblock associated with the given
+ * mount structure
+ */
+STATIC void
+xfs_mount_common(xfs_mount_t *mp, xfs_sb_t *sbp)
+{
+ mp->m_agfrotor = mp->m_agirotor = 0;
+ spin_lock_init(&mp->m_agirotor_lock);
+ mp->m_maxagi = mp->m_sb.sb_agcount;
+ mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
+ mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
+ mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
+ mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
+ mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
+ mp->m_blockmask = sbp->sb_blocksize - 1;
+ mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
+ mp->m_blockwmask = mp->m_blockwsize - 1;
+
+ mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
+ mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
+ mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
+ mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
+
+ mp->m_inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
+ mp->m_inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
+ mp->m_inobt_mnr[0] = mp->m_inobt_mxr[0] / 2;
+ mp->m_inobt_mnr[1] = mp->m_inobt_mxr[1] / 2;
+
+ mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
+ mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
+ mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
+ mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
+
+ mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
+ mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
+ sbp->sb_inopblock);
+ mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
+}
+
+/*
+ * xfs_initialize_perag_data
+ *
+ * Read in each per-ag structure so we can count up the number of
+ * allocated inodes, free inodes and used filesystem blocks as this
+ * information is no longer persistent in the superblock. Once we have
+ * this information, write it into the in-core superblock structure.
+ */
+STATIC int
+xfs_initialize_perag_data(xfs_mount_t *mp, xfs_agnumber_t agcount)
+{
+ xfs_agnumber_t index;
+ xfs_perag_t *pag;
+ xfs_sb_t *sbp = &mp->m_sb;
+ uint64_t ifree = 0;
+ uint64_t ialloc = 0;
+ uint64_t bfree = 0;
+ uint64_t bfreelst = 0;
+ uint64_t btree = 0;
+ int error;
+
+ for (index = 0; index < agcount; index++) {
+ /*
+ * read the agf, then the agi. This gets us
+ * all the information we need and populates the
+ * per-ag structures for us.
+ */
+ error = xfs_alloc_pagf_init(mp, NULL, index, 0);
+ if (error)
+ return error;
+
+ error = xfs_ialloc_pagi_init(mp, NULL, index);
+ if (error)
+ return error;
+ pag = xfs_perag_get(mp, index);
+ ifree += pag->pagi_freecount;
+ ialloc += pag->pagi_count;
+ bfree += pag->pagf_freeblks;
+ bfreelst += pag->pagf_flcount;
+ btree += pag->pagf_btreeblks;
+ xfs_perag_put(pag);
+ }
+ /*
+ * Overwrite incore superblock counters with just-read data
+ */
+ spin_lock(&mp->m_sb_lock);
+ sbp->sb_ifree = ifree;
+ sbp->sb_icount = ialloc;
+ sbp->sb_fdblocks = bfree + bfreelst + btree;
+ spin_unlock(&mp->m_sb_lock);
+
+ /* Fixup the per-cpu counters as well. */
+ xfs_icsb_reinit_counters(mp);
+
+ return 0;
+}
+
+/*
+ * 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)) {
+ if (mp->m_flags & XFS_MOUNT_RETERR) {
+ xfs_warn(mp, "alignment check failed: "
+ "(sunit/swidth vs. blocksize)");
+ return XFS_ERROR(EINVAL);
+ }
+ mp->m_dalign = mp->m_swidth = 0;
+ } 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)) {
+ if (mp->m_flags & XFS_MOUNT_RETERR) {
+ xfs_warn(mp, "alignment check failed: "
+ "(sunit/swidth vs. ag size)");
+ return XFS_ERROR(EINVAL);
+ }
+ xfs_warn(mp,
+ "stripe alignment turned off: sunit(%d)/swidth(%d) "
+ "incompatible with agsize(%d)",
+ mp->m_dalign, mp->m_swidth,
+ sbp->sb_agblocks);
+
+ mp->m_dalign = 0;
+ mp->m_swidth = 0;
+ } else if (mp->m_dalign) {
+ mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth);
+ } else {
+ if (mp->m_flags & XFS_MOUNT_RETERR) {
+ xfs_warn(mp, "alignment check failed: "
+ "sunit(%d) less than bsize(%d)",
+ mp->m_dalign,
+ mp->m_blockmask +1);
+ return XFS_ERROR(EINVAL);
+ }
+ mp->m_swidth = 0;
+ }
+ }
+
+ /*
+ * 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_flags |= XFS_SB_UNIT;
+ }
+ if (sbp->sb_width != mp->m_swidth) {
+ sbp->sb_width = mp->m_swidth;
+ mp->m_update_flags |= XFS_SB_WIDTH;
+ }
+ }
+ } 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_B_TO_FSBT(mp, mp->m_inode_cluster_size))
+ 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) are an ok size.
+ */
+STATIC int
+xfs_check_sizes(xfs_mount_t *mp)
+{
+ xfs_buf_t *bp;
+ xfs_daddr_t d;
+
+ 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 XFS_ERROR(EFBIG);
+ }
+ bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
+ d - XFS_FSS_TO_BB(mp, 1),
+ BBTOB(XFS_FSS_TO_BB(mp, 1)), 0);
+ if (!bp) {
+ xfs_warn(mp, "last sector read failed");
+ return EIO;
+ }
+ xfs_buf_relse(bp);
+
+ if (mp->m_logdev_targp != mp->m_ddev_targp) {
+ 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 XFS_ERROR(EFBIG);
+ }
+ bp = xfs_buf_read_uncached(mp, mp->m_logdev_targp,
+ d - XFS_FSB_TO_BB(mp, 1),
+ XFS_FSB_TO_B(mp, 1), 0);
+ if (!bp) {
+ xfs_warn(mp, "log device read failed");
+ return EIO;
+ }
+ xfs_buf_relse(bp);
+ }
+ return 0;
+}
+
+/*
+ * Clear the quotaflags in memory and in the superblock.
+ */
+int
+xfs_mount_reset_sbqflags(
+ struct xfs_mount *mp)
+{
+ int error;
+ struct xfs_trans *tp;
+
+ mp->m_qflags = 0;
+
+ /*
+ * It is OK to look at sb_qflags here in 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 the fs is readonly, let the incore superblock run
+ * with quotas off but don't flush the update out to disk
+ */
+ if (mp->m_flags & XFS_MOUNT_RDONLY)
+ return 0;
+
+ tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SBCHANGE);
+ error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
+ XFS_DEFAULT_LOG_COUNT);
+ if (error) {
+ xfs_trans_cancel(tp, 0);
+ xfs_alert(mp, "%s: Superblock update failed!", __func__);
+ return error;
+ }
+
+ xfs_mod_sb(tp, XFS_SB_QFLAGS);
+ return xfs_trans_commit(tp, 0);
+}
+
+__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;
+}
+
+/*
+ * 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(
+ xfs_mount_t *mp)
+{
+ xfs_sb_t *sbp = &(mp->m_sb);
+ xfs_inode_t *rip;
+ __uint64_t resblks;
+ uint quotamount = 0;
+ uint quotaflags = 0;
+ int error = 0;
+
+ xfs_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, and mark the two fields as needing updates once the
+ * transaction subsystem is online.
+ */
+ if (xfs_sb_has_mismatched_features2(sbp)) {
+ xfs_warn(mp, "correcting sb_features alignment problem");
+ sbp->sb_features2 |= sbp->sb_bad_features2;
+ sbp->sb_bad_features2 = sbp->sb_features2;
+ mp->m_update_flags |= XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;
+
+ /*
+ * 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_flags |= XFS_SB_FEATURES2;
+
+ /* update sb_versionnum for the clearing of the morebits */
+ if (!sbp->sb_features2)
+ mp->m_update_flags |= XFS_SB_VERSIONNUM;
+ }
+
+ /*
+ * 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_set_maxicount(mp);
+
+ mp->m_maxioffset = xfs_max_file_offset(sbp->sb_blocklog);
+
+ error = xfs_uuid_mount(mp);
+ if (error)
+ goto out;
+
+ /*
+ * 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.
+ */
+ mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE;
+
+ /*
+ * Set inode alignment fields
+ */
+ xfs_set_inoalignment(mp);
+
+ /*
+ * Check that the data (and log if separate) are 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.
+ */
+ uuid_getnodeuniq(&sbp->sb_uuid, mp->m_fixedfsid);
+
+ mp->m_dmevmask = 0; /* not persistent; set after each mount */
+
+ xfs_dir_mount(mp);
+
+ /*
+ * Initialize the attribute manager's entries.
+ */
+ mp->m_attr_magicpct = (mp->m_sb.sb_blocksize * 37) / 100;
+
+ /*
+ * Initialize the precomputed transaction reservations values.
+ */
+ xfs_trans_init(mp);
+
+ /*
+ * Allocate and initialize the per-ag data.
+ */
+ spin_lock_init(&mp->m_perag_lock);
+ INIT_RADIX_TREE(&mp->m_perag_tree, GFP_ATOMIC);
+ error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
+ if (error) {
+ xfs_warn(mp, "Failed per-ag init: %d", error);
+ goto out_remove_uuid;
+ }
+
+ if (!sbp->sb_logblocks) {
+ xfs_warn(mp, "no log defined");
+ XFS_ERROR_REPORT("xfs_mountfs", XFS_ERRLEVEL_LOW, mp);
+ error = XFS_ERROR(EFSCORRUPTED);
+ goto out_free_perag;
+ }
+
+ /*
+ * log's mount-time initialization. Perform 1st part recovery if needed
+ */
+ 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_free_perag;
+ }
+
+ /*
+ * 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.
+ *
+ * Hence 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 need to wait for recovery to finish before
+ * doing this.
+ *
+ * If the filesystem was cleanly unmounted, then we can trust the
+ * values in the superblock to be correct and we don't need to do
+ * anything here.
+ *
+ * If we are currently making the filesystem, the initialisation will
+ * fail as the perag data is in an undefined state.
+ */
+ if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
+ !XFS_LAST_UNMOUNT_WAS_CLEAN(mp) &&
+ !mp->m_sb.sb_inprogress) {
+ error = xfs_initialize_perag_data(mp, sbp->sb_agcount);
+ if (error)
+ goto out_free_perag;
+ }
+
+ /*
+ * Get and sanity-check the root inode.
+ * Save the pointer to it in the mount structure.
+ */
+ error = xfs_iget(mp, NULL, sbp->sb_rootino, 0, XFS_ILOCK_EXCL, &rip);
+ if (error) {
+ xfs_warn(mp, "failed to read root inode");
+ goto out_log_dealloc;
+ }
+
+ ASSERT(rip != NULL);
+
+ if (unlikely(!S_ISDIR(rip->i_d.di_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 = XFS_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_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
+ error = xfs_mount_log_sb(mp, mp->m_update_flags);
+ 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)
+ return error;
+ }
+ }
+
+ /*
+ * 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;
+ }
+
+ /*
+ * 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.");
+ }
+
+ return 0;
+
+ out_rtunmount:
+ xfs_rtunmount_inodes(mp);
+ out_rele_rip:
+ IRELE(rip);
+ out_log_dealloc:
+ xfs_log_unmount(mp);
+ out_free_perag:
+ xfs_free_perag(mp);
+ out_remove_uuid:
+ xfs_uuid_unmount(mp);
+ 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_qm_unmount_quotas(mp);
+ xfs_rtunmount_inodes(mp);
+ 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);
+
+ /*
+ * Do a delwri reclaim pass first so that as many dirty inodes are
+ * queued up for IO as possible. Then flush the buffers before making
+ * a synchronous path to catch all the remaining inodes are reclaimed.
+ * This makes the reclaim process as quick as possible by avoiding
+ * synchronous writeout and blocking on inodes already in the delwri
+ * state as much as possible.
+ */
+ xfs_reclaim_inodes(mp, 0);
+ xfs_flush_buftarg(mp->m_ddev_targp, 1);
+ xfs_reclaim_inodes(mp, SYNC_WAIT);
+
+ xfs_qm_unmount(mp);
+
+ /*
+ * 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_LOG_SYNC);
+
+ /*
+ * 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_unmountfs_writesb(mp);
+
+ /*
+ * Make sure all buffers have been flushed and completed before
+ * unmounting the log.
+ */
+ error = xfs_flush_buftarg(mp->m_ddev_targp, 1);
+ if (error)
+ xfs_warn(mp, "%d busy buffers during unmount.", error);
+ xfs_wait_buftarg(mp->m_ddev_targp);
+
+ xfs_log_unmount_write(mp);
+ xfs_log_unmount(mp);
+ xfs_uuid_unmount(mp);
+
+#if defined(DEBUG)
+ xfs_errortag_clearall(mp, 0);
+#endif
+ xfs_free_perag(mp);
+}
+
+int
+xfs_fs_writable(xfs_mount_t *mp)
+{
+ return !(xfs_test_for_freeze(mp) || XFS_FORCED_SHUTDOWN(mp) ||
+ (mp->m_flags & XFS_MOUNT_RDONLY));
+}
+
+/*
+ * xfs_log_sbcount
+ *
+ * Sync the superblock counters to disk.
+ *
+ * Note this code can be called during the process of freezing, so
+ * we may need to use the transaction allocator which does not
+ * block when the transaction subsystem is in its frozen state.
+ */
+int
+xfs_log_sbcount(xfs_mount_t *mp)
+{
+ xfs_trans_t *tp;
+ int error;
+
+ if (!xfs_fs_writable(mp))
+ return 0;
+
+ xfs_icsb_sync_counters(mp, 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;
+
+ tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP);
+ error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
+ XFS_DEFAULT_LOG_COUNT);
+ if (error) {
+ xfs_trans_cancel(tp, 0);
+ return error;
+ }
+
+ xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS);
+ xfs_trans_set_sync(tp);
+ error = xfs_trans_commit(tp, 0);
+ return error;
+}
+
+int
+xfs_unmountfs_writesb(xfs_mount_t *mp)
+{
+ xfs_buf_t *sbp;
+ int error = 0;
+
+ /*
+ * skip superblock write if fs is read-only, or
+ * if we are doing a forced umount.
+ */
+ if (!((mp->m_flags & XFS_MOUNT_RDONLY) ||
+ XFS_FORCED_SHUTDOWN(mp))) {
+
+ sbp = xfs_getsb(mp, 0);
+
+ XFS_BUF_UNDONE(sbp);
+ XFS_BUF_UNREAD(sbp);
+ xfs_buf_delwri_dequeue(sbp);
+ XFS_BUF_WRITE(sbp);
+ XFS_BUF_UNASYNC(sbp);
+ ASSERT(sbp->b_target == mp->m_ddev_targp);
+ xfsbdstrat(mp, sbp);
+ error = xfs_buf_iowait(sbp);
+ if (error)
+ xfs_buf_ioerror_alert(sbp, __func__);
+ 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_field_t f;
+
+ ASSERT(fields);
+ if (!fields)
+ return;
+ mp = tp->t_mountp;
+ bp = xfs_trans_getsb(tp, mp, 0);
+ first = sizeof(xfs_sb_t);
+ last = 0;
+
+ /* translate/copy */
+
+ xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, fields);
+
+ /* find modified range */
+ 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;
+
+ f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
+ ASSERT((1LL << f) & XFS_SB_MOD_BITS);
+ first = xfs_sb_info[f].offset;
+
+ 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 m_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,
+ int64_t 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 - XFS_ALLOC_SET_ASIDE(mp);
+ 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 (lcounter >= 0) {
+ mp->m_sb.sb_fdblocks = lcounter +
+ XFS_ALLOC_SET_ASIDE(mp);
+ return 0;
+ }
+
+ /*
+ * We are out of blocks, use any available reserved
+ * blocks if were allowed to.
+ */
+ if (!rsvd)
+ return XFS_ERROR(ENOSPC);
+
+ lcounter = (long long)mp->m_resblks_avail + delta;
+ if (lcounter >= 0) {
+ mp->m_resblks_avail = lcounter;
+ return 0;
+ }
+ printk_once(KERN_WARNING
+ "Filesystem \"%s\": reserve blocks depleted! "
+ "Consider increasing reserve pool size.",
+ mp->m_fsname);
+ return XFS_ERROR(ENOSPC);
+ }
+
+ mp->m_sb.sb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
+ 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 m_sb_lock. Just use the xfs_mod_incore_sb_unlocked()
+ * routine to do the work.
+ */
+int
+xfs_mod_incore_sb(
+ struct xfs_mount *mp,
+ xfs_sb_field_t field,
+ int64_t delta,
+ int rsvd)
+{
+ int status;
+
+#ifdef HAVE_PERCPU_SB
+ ASSERT(field < XFS_SBS_ICOUNT || field > XFS_SBS_FDBLOCKS);
+#endif
+ spin_lock(&mp->m_sb_lock);
+ status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
+ spin_unlock(&mp->m_sb_lock);
+
+ return status;
+}
+
+/*
+ * Change more than one field in the in-core superblock structure at a time.
+ *
+ * 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.
+ *
+ * Note that this function may not be used for the superblock values that
+ * are tracked with the in-memory per-cpu counters - a direct call to
+ * xfs_icsb_modify_counters is required for these.
+ */
+int
+xfs_mod_incore_sb_batch(
+ struct xfs_mount *mp,
+ xfs_mod_sb_t *msb,
+ uint nmsb,
+ int rsvd)
+{
+ xfs_mod_sb_t *msbp;
+ int error = 0;
+
+ /*
+ * 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 m_sb_lock so that all of the
+ * changes will be atomic.
+ */
+ spin_lock(&mp->m_sb_lock);
+ for (msbp = msb; msbp < (msb + nmsb); msbp++) {
+ ASSERT(msbp->msb_field < XFS_SBS_ICOUNT ||
+ msbp->msb_field > XFS_SBS_FDBLOCKS);
+
+ error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
+ msbp->msb_delta, rsvd);
+ if (error)
+ goto unwind;
+ }
+ spin_unlock(&mp->m_sb_lock);
+ return 0;
+
+unwind:
+ while (--msbp >= msb) {
+ error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
+ -msbp->msb_delta, rsvd);
+ ASSERT(error == 0);
+ }
+ spin_unlock(&mp->m_sb_lock);
+ return error;
+}
+
+/*
+ * 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(XFS_BUF_ISDONE(bp));
+ 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);
+}
+
+/*
+ * Used to log changes to the superblock unit and width fields which could
+ * be altered by the mount options, as well as any potential sb_features2
+ * fixup. Only the first superblock is updated.
+ */
+int
+xfs_mount_log_sb(
+ xfs_mount_t *mp,
+ __int64_t fields)
+{
+ xfs_trans_t *tp;
+ int error;
+
+ ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID |
+ XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2 |
+ XFS_SB_VERSIONNUM));
+
+ tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
+ error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
+ XFS_DEFAULT_LOG_COUNT);
+ if (error) {
+ xfs_trans_cancel(tp, 0);
+ return error;
+ }
+ xfs_mod_sb(tp, fields);
+ error = xfs_trans_commit(tp, 0);
+ return error;
+}
+
+/*
+ * 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;
+}
+
+#ifdef HAVE_PERCPU_SB
+/*
+ * Per-cpu incore superblock counters
+ *
+ * Simple concept, difficult implementation
+ *
+ * Basically, replace the incore superblock counters with a distributed per cpu
+ * counter for contended fields (e.g. free block count).
+ *
+ * Difficulties arise in that the incore sb is used for ENOSPC checking, and
+ * hence needs to be accurately read when we are running low on space. Hence
+ * there is a method to enable and disable the per-cpu counters based on how
+ * much "stuff" is available in them.
+ *
+ * Basically, a counter is enabled if there is enough free resource to justify
+ * running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local
+ * ENOSPC), then we disable the counters to synchronise all callers and
+ * re-distribute the available resources.
+ *
+ * If, once we redistributed the available resources, we still get a failure,
+ * we disable the per-cpu counter and go through the slow path.
+ *
+ * The slow path is the current xfs_mod_incore_sb() function. This means that
+ * when we disable a per-cpu counter, we need to drain its resources back to
+ * the global superblock. We do this after disabling the counter to prevent
+ * more threads from queueing up on the counter.
+ *
+ * Essentially, this means that we still need a lock in the fast path to enable
+ * synchronisation between the global counters and the per-cpu counters. This
+ * is not a problem because the lock will be local to a CPU almost all the time
+ * and have little contention except when we get to ENOSPC conditions.
+ *
+ * Basically, this lock becomes a barrier that enables us to lock out the fast
+ * path while we do things like enabling and disabling counters and
+ * synchronising the counters.
+ *
+ * Locking rules:
+ *
+ * 1. m_sb_lock before picking up per-cpu locks
+ * 2. per-cpu locks always picked up via for_each_online_cpu() order
+ * 3. accurate counter sync requires m_sb_lock + per cpu locks
+ * 4. modifying per-cpu counters requires holding per-cpu lock
+ * 5. modifying global counters requires holding m_sb_lock
+ * 6. enabling or disabling a counter requires holding the m_sb_lock
+ * and _none_ of the per-cpu locks.
+ *
+ * Disabled counters are only ever re-enabled by a balance operation
+ * that results in more free resources per CPU than a given threshold.
+ * To ensure counters don't remain disabled, they are rebalanced when
+ * the global resource goes above a higher threshold (i.e. some hysteresis
+ * is present to prevent thrashing).
+ */
+
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * hot-plug CPU notifier support.
+ *
+ * We need a notifier per filesystem as we need to be able to identify
+ * the filesystem to balance the counters out. This is achieved by
+ * having a notifier block embedded in the xfs_mount_t and doing pointer
+ * magic to get the mount pointer from the notifier block address.
+ */
+STATIC int
+xfs_icsb_cpu_notify(
+ struct notifier_block *nfb,
+ unsigned long action,
+ void *hcpu)
+{
+ xfs_icsb_cnts_t *cntp;
+ xfs_mount_t *mp;
+
+ mp = (xfs_mount_t *)container_of(nfb, xfs_mount_t, m_icsb_notifier);
+ cntp = (xfs_icsb_cnts_t *)
+ per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
+ switch (action) {
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
+ /* Easy Case - initialize the area and locks, and
+ * then rebalance when online does everything else for us. */
+ memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
+ break;
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ xfs_icsb_lock(mp);
+ xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
+ xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
+ xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
+ xfs_icsb_unlock(mp);
+ break;
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ /* Disable all the counters, then fold the dead cpu's
+ * count into the total on the global superblock and
+ * re-enable the counters. */
+ xfs_icsb_lock(mp);
+ spin_lock(&mp->m_sb_lock);
+ xfs_icsb_disable_counter(mp, XFS_SBS_ICOUNT);
+ xfs_icsb_disable_counter(mp, XFS_SBS_IFREE);
+ xfs_icsb_disable_counter(mp, XFS_SBS_FDBLOCKS);
+
+ mp->m_sb.sb_icount += cntp->icsb_icount;
+ mp->m_sb.sb_ifree += cntp->icsb_ifree;
+ mp->m_sb.sb_fdblocks += cntp->icsb_fdblocks;
+
+ memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
+
+ xfs_icsb_balance_counter_locked(mp, XFS_SBS_ICOUNT, 0);
+ xfs_icsb_balance_counter_locked(mp, XFS_SBS_IFREE, 0);
+ xfs_icsb_balance_counter_locked(mp, XFS_SBS_FDBLOCKS, 0);
+ spin_unlock(&mp->m_sb_lock);
+ xfs_icsb_unlock(mp);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+
+int
+xfs_icsb_init_counters(
+ xfs_mount_t *mp)
+{
+ xfs_icsb_cnts_t *cntp;
+ int i;
+
+ mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t);
+ if (mp->m_sb_cnts == NULL)
+ return -ENOMEM;
+
+#ifdef CONFIG_HOTPLUG_CPU
+ mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
+ mp->m_icsb_notifier.priority = 0;
+ register_hotcpu_notifier(&mp->m_icsb_notifier);
+#endif /* CONFIG_HOTPLUG_CPU */
+
+ for_each_online_cpu(i) {
+ cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
+ memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
+ }
+
+ mutex_init(&mp->m_icsb_mutex);
+
+ /*
+ * start with all counters disabled so that the
+ * initial balance kicks us off correctly
+ */
+ mp->m_icsb_counters = -1;
+ return 0;
+}
+
+void
+xfs_icsb_reinit_counters(
+ xfs_mount_t *mp)
+{
+ xfs_icsb_lock(mp);
+ /*
+ * start with all counters disabled so that the
+ * initial balance kicks us off correctly
+ */
+ mp->m_icsb_counters = -1;
+ xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
+ xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
+ xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
+ xfs_icsb_unlock(mp);
+}
+
+void
+xfs_icsb_destroy_counters(
+ xfs_mount_t *mp)
+{
+ if (mp->m_sb_cnts) {
+ unregister_hotcpu_notifier(&mp->m_icsb_notifier);
+ free_percpu(mp->m_sb_cnts);
+ }
+ mutex_destroy(&mp->m_icsb_mutex);
+}
+
+STATIC void
+xfs_icsb_lock_cntr(
+ xfs_icsb_cnts_t *icsbp)
+{
+ while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
+ ndelay(1000);
+ }
+}
+
+STATIC void
+xfs_icsb_unlock_cntr(
+ xfs_icsb_cnts_t *icsbp)
+{
+ clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
+}
+
+
+STATIC void
+xfs_icsb_lock_all_counters(
+ xfs_mount_t *mp)
+{
+ xfs_icsb_cnts_t *cntp;
+ int i;
+
+ for_each_online_cpu(i) {
+ cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
+ xfs_icsb_lock_cntr(cntp);
+ }
+}
+
+STATIC void
+xfs_icsb_unlock_all_counters(
+ xfs_mount_t *mp)
+{
+ xfs_icsb_cnts_t *cntp;
+ int i;
+
+ for_each_online_cpu(i) {
+ cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
+ xfs_icsb_unlock_cntr(cntp);
+ }
+}
+
+STATIC void
+xfs_icsb_count(
+ xfs_mount_t *mp,
+ xfs_icsb_cnts_t *cnt,
+ int flags)
+{
+ xfs_icsb_cnts_t *cntp;
+ int i;
+
+ memset(cnt, 0, sizeof(xfs_icsb_cnts_t));
+
+ if (!(flags & XFS_ICSB_LAZY_COUNT))
+ xfs_icsb_lock_all_counters(mp);
+
+ for_each_online_cpu(i) {
+ cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
+ cnt->icsb_icount += cntp->icsb_icount;
+ cnt->icsb_ifree += cntp->icsb_ifree;
+ cnt->icsb_fdblocks += cntp->icsb_fdblocks;
+ }
+
+ if (!(flags & XFS_ICSB_LAZY_COUNT))
+ xfs_icsb_unlock_all_counters(mp);
+}
+
+STATIC int
+xfs_icsb_counter_disabled(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field)
+{
+ ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
+ return test_bit(field, &mp->m_icsb_counters);
+}
+
+STATIC void
+xfs_icsb_disable_counter(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field)
+{
+ xfs_icsb_cnts_t cnt;
+
+ ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
+
+ /*
+ * If we are already disabled, then there is nothing to do
+ * here. We check before locking all the counters to avoid
+ * the expensive lock operation when being called in the
+ * slow path and the counter is already disabled. This is
+ * safe because the only time we set or clear this state is under
+ * the m_icsb_mutex.
+ */
+ if (xfs_icsb_counter_disabled(mp, field))
+ return;
+
+ xfs_icsb_lock_all_counters(mp);
+ if (!test_and_set_bit(field, &mp->m_icsb_counters)) {
+ /* drain back to superblock */
+
+ xfs_icsb_count(mp, &cnt, XFS_ICSB_LAZY_COUNT);
+ switch(field) {
+ case XFS_SBS_ICOUNT:
+ mp->m_sb.sb_icount = cnt.icsb_icount;
+ break;
+ case XFS_SBS_IFREE:
+ mp->m_sb.sb_ifree = cnt.icsb_ifree;
+ break;
+ case XFS_SBS_FDBLOCKS:
+ mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
+ break;
+ default:
+ BUG();
+ }
+ }
+
+ xfs_icsb_unlock_all_counters(mp);
+}
+
+STATIC void
+xfs_icsb_enable_counter(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field,
+ uint64_t count,
+ uint64_t resid)
+{
+ xfs_icsb_cnts_t *cntp;
+ int i;
+
+ ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
+
+ xfs_icsb_lock_all_counters(mp);
+ for_each_online_cpu(i) {
+ cntp = per_cpu_ptr(mp->m_sb_cnts, i);
+ switch (field) {
+ case XFS_SBS_ICOUNT:
+ cntp->icsb_icount = count + resid;
+ break;
+ case XFS_SBS_IFREE:
+ cntp->icsb_ifree = count + resid;
+ break;
+ case XFS_SBS_FDBLOCKS:
+ cntp->icsb_fdblocks = count + resid;
+ break;
+ default:
+ BUG();
+ break;
+ }
+ resid = 0;
+ }
+ clear_bit(field, &mp->m_icsb_counters);
+ xfs_icsb_unlock_all_counters(mp);
+}
+
+void
+xfs_icsb_sync_counters_locked(
+ xfs_mount_t *mp,
+ int flags)
+{
+ xfs_icsb_cnts_t cnt;
+
+ xfs_icsb_count(mp, &cnt, flags);
+
+ if (!xfs_icsb_counter_disabled(mp, XFS_SBS_ICOUNT))
+ mp->m_sb.sb_icount = cnt.icsb_icount;
+ if (!xfs_icsb_counter_disabled(mp, XFS_SBS_IFREE))
+ mp->m_sb.sb_ifree = cnt.icsb_ifree;
+ if (!xfs_icsb_counter_disabled(mp, XFS_SBS_FDBLOCKS))
+ mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
+}
+
+/*
+ * Accurate update of per-cpu counters to incore superblock
+ */
+void
+xfs_icsb_sync_counters(
+ xfs_mount_t *mp,
+ int flags)
+{
+ spin_lock(&mp->m_sb_lock);
+ xfs_icsb_sync_counters_locked(mp, flags);
+ spin_unlock(&mp->m_sb_lock);
+}
+
+/*
+ * Balance and enable/disable counters as necessary.
+ *
+ * Thresholds for re-enabling counters are somewhat magic. inode counts are
+ * chosen to be the same number as single on disk allocation chunk per CPU, and
+ * free blocks is something far enough zero that we aren't going thrash when we
+ * get near ENOSPC. We also need to supply a minimum we require per cpu to
+ * prevent looping endlessly when xfs_alloc_space asks for more than will
+ * be distributed to a single CPU but each CPU has enough blocks to be
+ * reenabled.
+ *
+ * Note that we can be called when counters are already disabled.
+ * xfs_icsb_disable_counter() optimises the counter locking in this case to
+ * prevent locking every per-cpu counter needlessly.
+ */
+
+#define XFS_ICSB_INO_CNTR_REENABLE (uint64_t)64
+#define XFS_ICSB_FDBLK_CNTR_REENABLE(mp) \
+ (uint64_t)(512 + XFS_ALLOC_SET_ASIDE(mp))
+STATIC void
+xfs_icsb_balance_counter_locked(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field,
+ int min_per_cpu)
+{
+ uint64_t count, resid;
+ int weight = num_online_cpus();
+ uint64_t min = (uint64_t)min_per_cpu;
+
+ /* disable counter and sync counter */
+ xfs_icsb_disable_counter(mp, field);
+
+ /* update counters - first CPU gets residual*/
+ switch (field) {
+ case XFS_SBS_ICOUNT:
+ count = mp->m_sb.sb_icount;
+ resid = do_div(count, weight);
+ if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
+ return;
+ break;
+ case XFS_SBS_IFREE:
+ count = mp->m_sb.sb_ifree;
+ resid = do_div(count, weight);
+ if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
+ return;
+ break;
+ case XFS_SBS_FDBLOCKS:
+ count = mp->m_sb.sb_fdblocks;
+ resid = do_div(count, weight);
+ if (count < max(min, XFS_ICSB_FDBLK_CNTR_REENABLE(mp)))
+ return;
+ break;
+ default:
+ BUG();
+ count = resid = 0; /* quiet, gcc */
+ break;
+ }
+
+ xfs_icsb_enable_counter(mp, field, count, resid);
+}
+
+STATIC void
+xfs_icsb_balance_counter(
+ xfs_mount_t *mp,
+ xfs_sb_field_t fields,
+ int min_per_cpu)
+{
+ spin_lock(&mp->m_sb_lock);
+ xfs_icsb_balance_counter_locked(mp, fields, min_per_cpu);
+ spin_unlock(&mp->m_sb_lock);
+}
+
+int
+xfs_icsb_modify_counters(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field,
+ int64_t delta,
+ int rsvd)
+{
+ xfs_icsb_cnts_t *icsbp;
+ long long lcounter; /* long counter for 64 bit fields */
+ int ret = 0;
+
+ might_sleep();
+again:
+ preempt_disable();
+ icsbp = this_cpu_ptr(mp->m_sb_cnts);
+
+ /*
+ * if the counter is disabled, go to slow path
+ */
+ if (unlikely(xfs_icsb_counter_disabled(mp, field)))
+ goto slow_path;
+ xfs_icsb_lock_cntr(icsbp);
+ if (unlikely(xfs_icsb_counter_disabled(mp, field))) {
+ xfs_icsb_unlock_cntr(icsbp);
+ goto slow_path;
+ }
+
+ switch (field) {
+ case XFS_SBS_ICOUNT:
+ lcounter = icsbp->icsb_icount;
+ lcounter += delta;
+ if (unlikely(lcounter < 0))
+ goto balance_counter;
+ icsbp->icsb_icount = lcounter;
+ break;
+
+ case XFS_SBS_IFREE:
+ lcounter = icsbp->icsb_ifree;
+ lcounter += delta;
+ if (unlikely(lcounter < 0))
+ goto balance_counter;
+ icsbp->icsb_ifree = lcounter;
+ break;
+
+ case XFS_SBS_FDBLOCKS:
+ BUG_ON((mp->m_resblks - mp->m_resblks_avail) != 0);
+
+ lcounter = icsbp->icsb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
+ lcounter += delta;
+ if (unlikely(lcounter < 0))
+ goto balance_counter;
+ icsbp->icsb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
+ break;
+ default:
+ BUG();
+ break;
+ }
+ xfs_icsb_unlock_cntr(icsbp);
+ preempt_enable();
+ return 0;
+
+slow_path:
+ preempt_enable();
+
+ /*
+ * serialise with a mutex so we don't burn lots of cpu on
+ * the superblock lock. We still need to hold the superblock
+ * lock, however, when we modify the global structures.
+ */
+ xfs_icsb_lock(mp);
+
+ /*
+ * Now running atomically.
+ *
+ * If the counter is enabled, someone has beaten us to rebalancing.
+ * Drop the lock and try again in the fast path....
+ */
+ if (!(xfs_icsb_counter_disabled(mp, field))) {
+ xfs_icsb_unlock(mp);
+ goto again;
+ }
+
+ /*
+ * The counter is currently disabled. Because we are
+ * running atomically here, we know a rebalance cannot
+ * be in progress. Hence we can go straight to operating
+ * on the global superblock. We do not call xfs_mod_incore_sb()
+ * here even though we need to get the m_sb_lock. Doing so
+ * will cause us to re-enter this function and deadlock.
+ * Hence we get the m_sb_lock ourselves and then call
+ * xfs_mod_incore_sb_unlocked() as the unlocked path operates
+ * directly on the global counters.
+ */
+ spin_lock(&mp->m_sb_lock);
+ ret = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
+ spin_unlock(&mp->m_sb_lock);
+
+ /*
+ * Now that we've modified the global superblock, we
+ * may be able to re-enable the distributed counters
+ * (e.g. lots of space just got freed). After that
+ * we are done.
+ */
+ if (ret != ENOSPC)
+ xfs_icsb_balance_counter(mp, field, 0);
+ xfs_icsb_unlock(mp);
+ return ret;
+
+balance_counter:
+ xfs_icsb_unlock_cntr(icsbp);
+ preempt_enable();
+
+ /*
+ * We may have multiple threads here if multiple per-cpu
+ * counters run dry at the same time. This will mean we can
+ * do more balances than strictly necessary but it is not
+ * the common slowpath case.
+ */
+ xfs_icsb_lock(mp);
+
+ /*
+ * running atomically.
+ *
+ * This will leave the counter in the correct state for future
+ * accesses. After the rebalance, we simply try again and our retry
+ * will either succeed through the fast path or slow path without
+ * another balance operation being required.
+ */
+ xfs_icsb_balance_counter(mp, field, delta);
+ xfs_icsb_unlock(mp);
+ goto again;
+}
+
+#endif