// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
 * All Rights Reserved.
 */

#include "xfs_platform.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_sb.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_bmap.h"
#include "xfs_alloc.h"
#include "xfs_fsops.h"
#include "xfs_trans.h"
#include "xfs_buf_item.h"
#include "xfs_log.h"
#include "xfs_log_priv.h"
#include "xfs_dir2.h"
#include "xfs_extfree_item.h"
#include "xfs_mru_cache.h"
#include "xfs_inode_item.h"
#include "xfs_icache.h"
#include "xfs_trace.h"
#include "xfs_icreate_item.h"
#include "xfs_filestream.h"
#include "xfs_quota.h"
#include "xfs_sysfs.h"
#include "xfs_ondisk.h"
#include "xfs_rmap_item.h"
#include "xfs_refcount_item.h"
#include "xfs_bmap_item.h"
#include "xfs_reflink.h"
#include "xfs_pwork.h"
#include "xfs_ag.h"
#include "xfs_defer.h"
#include "xfs_attr_item.h"
#include "xfs_xattr.h"
#include "xfs_error.h"
#include "xfs_errortag.h"
#include "xfs_iunlink_item.h"
#include "xfs_dahash_test.h"
#include "xfs_rtbitmap.h"
#include "xfs_exchmaps_item.h"
#include "xfs_parent.h"
#include "xfs_rtalloc.h"
#include "xfs_zone_alloc.h"
#include "xfs_healthmon.h"
#include "scrub/stats.h"
#include "scrub/rcbag_btree.h"

#include <linux/magic.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/fserror.h>

static const struct super_operations xfs_super_operations;

static struct dentry *xfs_debugfs;      /* top-level xfs debugfs dir */
static struct kset *xfs_kset;           /* top-level xfs sysfs dir */
#ifdef DEBUG
static struct xfs_kobj xfs_dbg_kobj;    /* global debug sysfs attrs */
#endif

enum xfs_dax_mode {
        XFS_DAX_INODE = 0,
        XFS_DAX_ALWAYS = 1,
        XFS_DAX_NEVER = 2,
};

/* Were quota mount options provided?  Must use the upper 16 bits of qflags. */
#define XFS_QFLAGS_MNTOPTS      (1U << 31)

static void
xfs_mount_set_dax_mode(
        struct xfs_mount        *mp,
        enum xfs_dax_mode       mode)
{
        switch (mode) {
        case XFS_DAX_INODE:
                mp->m_features &= ~(XFS_FEAT_DAX_ALWAYS | XFS_FEAT_DAX_NEVER);
                break;
        case XFS_DAX_ALWAYS:
                mp->m_features |= XFS_FEAT_DAX_ALWAYS;
                mp->m_features &= ~XFS_FEAT_DAX_NEVER;
                break;
        case XFS_DAX_NEVER:
                mp->m_features |= XFS_FEAT_DAX_NEVER;
                mp->m_features &= ~XFS_FEAT_DAX_ALWAYS;
                break;
        }
}

static const struct constant_table dax_param_enums[] = {
        {"inode",       XFS_DAX_INODE },
        {"always",      XFS_DAX_ALWAYS },
        {"never",       XFS_DAX_NEVER },
        {}
};

/*
 * Table driven mount option parser.
 */
enum {
        Op_deprecated, Opt_logbufs, Opt_logbsize, Opt_logdev, Opt_rtdev,
        Opt_wsync, Opt_noalign, Opt_swalloc, Opt_sunit, Opt_swidth, Opt_nouuid,
        Opt_grpid, Opt_nogrpid, Opt_bsdgroups, Opt_sysvgroups,
        Opt_allocsize, Opt_norecovery, Opt_inode64, Opt_inode32,
        Opt_largeio, Opt_nolargeio,
        Opt_filestreams, Opt_quota, Opt_noquota, Opt_usrquota, Opt_grpquota,
        Opt_prjquota, Opt_uquota, Opt_gquota, Opt_pquota,
        Opt_uqnoenforce, Opt_gqnoenforce, Opt_pqnoenforce, Opt_qnoenforce,
        Opt_discard, Opt_nodiscard, Opt_dax, Opt_dax_enum, Opt_max_open_zones,
        Opt_lifetime, Opt_nolifetime, Opt_max_atomic_write, Opt_errortag,
};

#define fsparam_dead(NAME) \
        __fsparam(NULL, (NAME), Op_deprecated, fs_param_deprecated, NULL)

static const struct fs_parameter_spec xfs_fs_parameters[] = {
        /*
         * These mount options were supposed to be deprecated in September 2025
         * but the deprecation warning was buggy, so not all users were
         * notified.  The deprecation is now obnoxiously loud and postponed to
         * September 2030.
         */
        fsparam_dead("attr2"),
        fsparam_dead("noattr2"),
        fsparam_dead("ikeep"),
        fsparam_dead("noikeep"),

        fsparam_u32("logbufs",          Opt_logbufs),
        fsparam_string("logbsize",      Opt_logbsize),
        fsparam_string("logdev",        Opt_logdev),
        fsparam_string("rtdev",         Opt_rtdev),
        fsparam_flag("wsync",           Opt_wsync),
        fsparam_flag("noalign",         Opt_noalign),
        fsparam_flag("swalloc",         Opt_swalloc),
        fsparam_u32("sunit",            Opt_sunit),
        fsparam_u32("swidth",           Opt_swidth),
        fsparam_flag("nouuid",          Opt_nouuid),
        fsparam_flag("grpid",           Opt_grpid),
        fsparam_flag("nogrpid",         Opt_nogrpid),
        fsparam_flag("bsdgroups",       Opt_bsdgroups),
        fsparam_flag("sysvgroups",      Opt_sysvgroups),
        fsparam_string("allocsize",     Opt_allocsize),
        fsparam_flag("norecovery",      Opt_norecovery),
        fsparam_flag("inode64",         Opt_inode64),
        fsparam_flag("inode32",         Opt_inode32),
        fsparam_flag("largeio",         Opt_largeio),
        fsparam_flag("nolargeio",       Opt_nolargeio),
        fsparam_flag("filestreams",     Opt_filestreams),
        fsparam_flag("quota",           Opt_quota),
        fsparam_flag("noquota",         Opt_noquota),
        fsparam_flag("usrquota",        Opt_usrquota),
        fsparam_flag("grpquota",        Opt_grpquota),
        fsparam_flag("prjquota",        Opt_prjquota),
        fsparam_flag("uquota",          Opt_uquota),
        fsparam_flag("gquota",          Opt_gquota),
        fsparam_flag("pquota",          Opt_pquota),
        fsparam_flag("uqnoenforce",     Opt_uqnoenforce),
        fsparam_flag("gqnoenforce",     Opt_gqnoenforce),
        fsparam_flag("pqnoenforce",     Opt_pqnoenforce),
        fsparam_flag("qnoenforce",      Opt_qnoenforce),
        fsparam_flag("discard",         Opt_discard),
        fsparam_flag("nodiscard",       Opt_nodiscard),
        fsparam_flag("dax",             Opt_dax),
        fsparam_enum("dax",             Opt_dax_enum, dax_param_enums),
        fsparam_u32("max_open_zones",   Opt_max_open_zones),
        fsparam_flag("lifetime",        Opt_lifetime),
        fsparam_flag("nolifetime",      Opt_nolifetime),
        fsparam_string("max_atomic_write",      Opt_max_atomic_write),
        fsparam_string("errortag",      Opt_errortag),
        {}
};

struct proc_xfs_info {
        uint64_t        flag;
        char            *str;
};

static int
xfs_fs_show_options(
        struct seq_file         *m,
        struct dentry           *root)
{
        static struct proc_xfs_info xfs_info_set[] = {
                /* the few simple ones we can get from the mount struct */
                { XFS_FEAT_WSYNC,               ",wsync" },
                { XFS_FEAT_NOALIGN,             ",noalign" },
                { XFS_FEAT_SWALLOC,             ",swalloc" },
                { XFS_FEAT_NOUUID,              ",nouuid" },
                { XFS_FEAT_NORECOVERY,          ",norecovery" },
                { XFS_FEAT_FILESTREAMS,         ",filestreams" },
                { XFS_FEAT_GRPID,               ",grpid" },
                { XFS_FEAT_DISCARD,             ",discard" },
                { XFS_FEAT_LARGE_IOSIZE,        ",largeio" },
                { XFS_FEAT_DAX_ALWAYS,          ",dax=always" },
                { XFS_FEAT_DAX_NEVER,           ",dax=never" },
                { XFS_FEAT_NOLIFETIME,          ",nolifetime" },
                { 0, NULL }
        };
        struct xfs_mount        *mp = XFS_M(root->d_sb);
        struct proc_xfs_info    *xfs_infop;

        for (xfs_infop = xfs_info_set; xfs_infop->flag; xfs_infop++) {
                if (mp->m_features & xfs_infop->flag)
                        seq_puts(m, xfs_infop->str);
        }

        seq_printf(m, ",inode%d", xfs_has_small_inums(mp) ? 32 : 64);

        if (xfs_has_allocsize(mp))
                seq_printf(m, ",allocsize=%dk",
                           (1 << mp->m_allocsize_log) >> 10);

        if (mp->m_logbufs > 0)
                seq_printf(m, ",logbufs=%d", mp->m_logbufs);
        if (mp->m_logbsize > 0)
                seq_printf(m, ",logbsize=%dk", mp->m_logbsize >> 10);

        if (mp->m_logname)
                seq_show_option(m, "logdev", mp->m_logname);
        if (mp->m_rtname)
                seq_show_option(m, "rtdev", mp->m_rtname);

        if (mp->m_dalign > 0)
                seq_printf(m, ",sunit=%d",
                                (int)XFS_FSB_TO_BB(mp, mp->m_dalign));
        if (mp->m_swidth > 0)
                seq_printf(m, ",swidth=%d",
                                (int)XFS_FSB_TO_BB(mp, mp->m_swidth));

        if (mp->m_qflags & XFS_UQUOTA_ENFD)
                seq_puts(m, ",usrquota");
        else if (mp->m_qflags & XFS_UQUOTA_ACCT)
                seq_puts(m, ",uqnoenforce");

        if (mp->m_qflags & XFS_PQUOTA_ENFD)
                seq_puts(m, ",prjquota");
        else if (mp->m_qflags & XFS_PQUOTA_ACCT)
                seq_puts(m, ",pqnoenforce");

        if (mp->m_qflags & XFS_GQUOTA_ENFD)
                seq_puts(m, ",grpquota");
        else if (mp->m_qflags & XFS_GQUOTA_ACCT)
                seq_puts(m, ",gqnoenforce");

        if (!(mp->m_qflags & XFS_ALL_QUOTA_ACCT))
                seq_puts(m, ",noquota");

        if (mp->m_max_open_zones)
                seq_printf(m, ",max_open_zones=%u", mp->m_max_open_zones);
        if (mp->m_awu_max_bytes)
                seq_printf(m, ",max_atomic_write=%lluk",
                                mp->m_awu_max_bytes >> 10);

        return 0;
}

static bool
xfs_set_inode_alloc_perag(
        struct xfs_perag        *pag,
        xfs_ino_t               ino,
        xfs_agnumber_t          max_metadata)
{
        if (!xfs_is_inode32(pag_mount(pag))) {
                set_bit(XFS_AGSTATE_ALLOWS_INODES, &pag->pag_opstate);
                clear_bit(XFS_AGSTATE_PREFERS_METADATA, &pag->pag_opstate);
                return false;
        }

        if (ino > XFS_MAXINUMBER_32) {
                clear_bit(XFS_AGSTATE_ALLOWS_INODES, &pag->pag_opstate);
                clear_bit(XFS_AGSTATE_PREFERS_METADATA, &pag->pag_opstate);
                return false;
        }

        set_bit(XFS_AGSTATE_ALLOWS_INODES, &pag->pag_opstate);
        if (pag_agno(pag) < max_metadata)
                set_bit(XFS_AGSTATE_PREFERS_METADATA, &pag->pag_opstate);
        else
                clear_bit(XFS_AGSTATE_PREFERS_METADATA, &pag->pag_opstate);
        return true;
}

/*
 * Set parameters for inode allocation heuristics, taking into account
 * filesystem size and inode32/inode64 mount options; i.e. specifically
 * whether or not XFS_FEAT_SMALL_INUMS is set.
 *
 * Inode allocation patterns are altered only if inode32 is requested
 * (XFS_FEAT_SMALL_INUMS), and the filesystem is sufficiently large.
 * If altered, XFS_OPSTATE_INODE32 is set as well.
 *
 * An agcount independent of that in the mount structure is provided
 * because in the growfs case, mp->m_sb.sb_agcount is not yet updated
 * to the potentially higher ag count.
 *
 * Returns the maximum AG index which may contain inodes.
 */
xfs_agnumber_t
xfs_set_inode_alloc(
        struct xfs_mount *mp,
        xfs_agnumber_t  agcount)
{
        xfs_agnumber_t  index;
        xfs_agnumber_t  maxagi = 0;
        xfs_sb_t        *sbp = &mp->m_sb;
        xfs_agnumber_t  max_metadata;
        xfs_agino_t     agino;
        xfs_ino_t       ino;

        /*
         * Calculate how much should be reserved for inodes to meet
         * the max inode percentage.  Used only for inode32.
         */
        if (M_IGEO(mp)->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;
        }

        /* Get the last possible inode in the filesystem */
        agino = XFS_AGB_TO_AGINO(mp, sbp->sb_agblocks - 1);
        ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);

        /*
         * If user asked for no more than 32-bit inodes, and the fs is
         * sufficiently large, set XFS_OPSTATE_INODE32 if we must alter
         * the allocator to accommodate the request.
         */
        if (xfs_has_small_inums(mp) && ino > XFS_MAXINUMBER_32)
                xfs_set_inode32(mp);
        else
                xfs_clear_inode32(mp);

        for (index = 0; index < agcount; index++) {
                struct xfs_perag        *pag;

                ino = XFS_AGINO_TO_INO(mp, index, agino);

                pag = xfs_perag_get(mp, index);
                if (xfs_set_inode_alloc_perag(pag, ino, max_metadata))
                        maxagi++;
                xfs_perag_put(pag);
        }

        return xfs_is_inode32(mp) ? maxagi : agcount;
}

static int
xfs_setup_dax_always(
        struct xfs_mount        *mp)
{
        if (!mp->m_ddev_targp->bt_daxdev &&
            (!mp->m_rtdev_targp || !mp->m_rtdev_targp->bt_daxdev)) {
                xfs_alert(mp,
                        "DAX unsupported by block device. Turning off DAX.");
                goto disable_dax;
        }

        if (mp->m_super->s_blocksize != PAGE_SIZE) {
                xfs_alert(mp,
                        "DAX not supported for blocksize. Turning off DAX.");
                goto disable_dax;
        }

        if (xfs_has_reflink(mp) &&
            bdev_is_partition(mp->m_ddev_targp->bt_bdev)) {
                xfs_alert(mp,
                        "DAX and reflink cannot work with multi-partitions!");
                return -EINVAL;
        }

        return 0;

disable_dax:
        xfs_mount_set_dax_mode(mp, XFS_DAX_NEVER);
        return 0;
}

STATIC int
xfs_blkdev_get(
        xfs_mount_t             *mp,
        const char              *name,
        struct file             **bdev_filep)
{
        int                     error = 0;
        blk_mode_t              mode;

        mode = sb_open_mode(mp->m_super->s_flags);
        *bdev_filep = bdev_file_open_by_path(name, mode,
                        mp->m_super, &fs_holder_ops);
        if (IS_ERR(*bdev_filep)) {
                error = PTR_ERR(*bdev_filep);
                *bdev_filep = NULL;
                xfs_warn(mp, "Invalid device [%s], error=%d", name, error);
        }

        return error;
}

STATIC void
xfs_shutdown_devices(
        struct xfs_mount        *mp)
{
        /*
         * Udev is triggered whenever anyone closes a block device or unmounts
         * a file systemm on a block device.
         * The default udev rules invoke blkid to read the fs super and create
         * symlinks to the bdev under /dev/disk.  For this, it uses buffered
         * reads through the page cache.
         *
         * xfs_db also uses buffered reads to examine metadata.  There is no
         * coordination between xfs_db and udev, which means that they can run
         * concurrently.  Note there is no coordination between the kernel and
         * blkid either.
         *
         * On a system with 64k pages, the page cache can cache the superblock
         * and the root inode (and hence the root directory) with the same 64k
         * page.  If udev spawns blkid after the mkfs and the system is busy
         * enough that it is still running when xfs_db starts up, they'll both
         * read from the same page in the pagecache.
         *
         * The unmount writes updated inode metadata to disk directly.  The XFS
         * buffer cache does not use the bdev pagecache, so it needs to
         * invalidate that pagecache on unmount.  If the above scenario occurs,
         * the pagecache no longer reflects what's on disk, xfs_db reads the
         * stale metadata, and fails to find /a.  Most of the time this succeeds
         * because closing a bdev invalidates the page cache, but when processes
         * race, everyone loses.
         */
        if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
                blkdev_issue_flush(mp->m_logdev_targp->bt_bdev);
                invalidate_bdev(mp->m_logdev_targp->bt_bdev);
        }
        if (mp->m_rtdev_targp) {
                blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
                invalidate_bdev(mp->m_rtdev_targp->bt_bdev);
        }
        blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
        invalidate_bdev(mp->m_ddev_targp->bt_bdev);
}

/*
 * The file system configurations are:
 *      (1) device (partition) with data and internal log
 *      (2) logical volume with data and log subvolumes.
 *      (3) logical volume with data, log, and realtime subvolumes.
 *
 * We only have to handle opening the log and realtime volumes here if
 * they are present.  The data subvolume has already been opened by
 * get_sb_bdev() and is stored in sb->s_bdev.
 */
STATIC int
xfs_open_devices(
        struct xfs_mount        *mp)
{
        struct super_block      *sb = mp->m_super;
        struct block_device     *ddev = sb->s_bdev;
        struct file             *logdev_file = NULL, *rtdev_file = NULL;
        int                     error;

        /*
         * Open real time and log devices - order is important.
         */
        if (mp->m_logname) {
                error = xfs_blkdev_get(mp, mp->m_logname, &logdev_file);
                if (error)
                        return error;
        }

        if (mp->m_rtname) {
                error = xfs_blkdev_get(mp, mp->m_rtname, &rtdev_file);
                if (error)
                        goto out_close_logdev;

                if (file_bdev(rtdev_file) == ddev ||
                    (logdev_file &&
                     file_bdev(rtdev_file) == file_bdev(logdev_file))) {
                        xfs_warn(mp,
        "Cannot mount filesystem with identical rtdev and ddev/logdev.");
                        error = -EINVAL;
                        goto out_close_rtdev;
                }
        }

        /*
         * Setup xfs_mount buffer target pointers
         */
        mp->m_ddev_targp = xfs_alloc_buftarg(mp, sb->s_bdev_file);
        if (IS_ERR(mp->m_ddev_targp)) {
                error = PTR_ERR(mp->m_ddev_targp);
                mp->m_ddev_targp = NULL;
                goto out_close_rtdev;
        }

        if (rtdev_file) {
                mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev_file);
                if (IS_ERR(mp->m_rtdev_targp)) {
                        error = PTR_ERR(mp->m_rtdev_targp);
                        mp->m_rtdev_targp = NULL;
                        goto out_free_ddev_targ;
                }
        }

        if (logdev_file && file_bdev(logdev_file) != ddev) {
                mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev_file);
                if (IS_ERR(mp->m_logdev_targp)) {
                        error = PTR_ERR(mp->m_logdev_targp);
                        mp->m_logdev_targp = NULL;
                        goto out_free_rtdev_targ;
                }
        } else {
                mp->m_logdev_targp = mp->m_ddev_targp;
                /* Handle won't be used, drop it */
                if (logdev_file)
                        bdev_fput(logdev_file);
        }

        return 0;

 out_free_rtdev_targ:
        if (mp->m_rtdev_targp)
                xfs_free_buftarg(mp->m_rtdev_targp);
 out_free_ddev_targ:
        xfs_free_buftarg(mp->m_ddev_targp);
 out_close_rtdev:
         if (rtdev_file)
                bdev_fput(rtdev_file);
 out_close_logdev:
        if (logdev_file)
                bdev_fput(logdev_file);
        return error;
}

/*
 * Setup xfs_mount buffer target pointers based on superblock
 */
STATIC int
xfs_setup_devices(
        struct xfs_mount        *mp)
{
        int                     error;

        error = xfs_configure_buftarg(mp->m_ddev_targp, mp->m_sb.sb_sectsize,
                        mp->m_sb.sb_dblocks);
        if (error)
                return error;

        if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
                unsigned int    log_sector_size = BBSIZE;

                if (xfs_has_sector(mp))
                        log_sector_size = mp->m_sb.sb_logsectsize;
                error = xfs_configure_buftarg(mp->m_logdev_targp,
                                log_sector_size, mp->m_sb.sb_logblocks);
                if (error)
                        return error;
        }

        if (mp->m_sb.sb_rtstart) {
                if (mp->m_rtdev_targp) {
                        xfs_warn(mp,
                "can't use internal and external rtdev at the same time");
                        return -EINVAL;
                }
                mp->m_rtdev_targp = mp->m_ddev_targp;
        } else if (mp->m_rtname) {
                error = xfs_configure_buftarg(mp->m_rtdev_targp,
                                mp->m_sb.sb_sectsize, mp->m_sb.sb_rblocks);
                if (error)
                        return error;
        }

        return 0;
}

STATIC int
xfs_init_mount_workqueues(
        struct xfs_mount        *mp)
{
        mp->m_buf_workqueue = alloc_workqueue("xfs-buf/%s",
                        XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_PERCPU),
                        1, mp->m_super->s_id);
        if (!mp->m_buf_workqueue)
                goto out;

        mp->m_unwritten_workqueue = alloc_workqueue("xfs-conv/%s",
                        XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_PERCPU),
                        0, mp->m_super->s_id);
        if (!mp->m_unwritten_workqueue)
                goto out_destroy_buf;

        mp->m_reclaim_workqueue = alloc_workqueue("xfs-reclaim/%s",
                        XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_PERCPU),
                        0, mp->m_super->s_id);
        if (!mp->m_reclaim_workqueue)
                goto out_destroy_unwritten;

        mp->m_blockgc_wq = alloc_workqueue("xfs-blockgc/%s",
                        XFS_WQFLAGS(WQ_UNBOUND | WQ_FREEZABLE | WQ_MEM_RECLAIM),
                        0, mp->m_super->s_id);
        if (!mp->m_blockgc_wq)
                goto out_destroy_reclaim;

        mp->m_inodegc_wq = alloc_workqueue("xfs-inodegc/%s",
                        XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_PERCPU),
                        1, mp->m_super->s_id);
        if (!mp->m_inodegc_wq)
                goto out_destroy_blockgc;

        mp->m_sync_workqueue = alloc_workqueue("xfs-sync/%s",
                        XFS_WQFLAGS(WQ_FREEZABLE | WQ_PERCPU), 0,
                        mp->m_super->s_id);
        if (!mp->m_sync_workqueue)
                goto out_destroy_inodegc;

        return 0;

out_destroy_inodegc:
        destroy_workqueue(mp->m_inodegc_wq);
out_destroy_blockgc:
        destroy_workqueue(mp->m_blockgc_wq);
out_destroy_reclaim:
        destroy_workqueue(mp->m_reclaim_workqueue);
out_destroy_unwritten:
        destroy_workqueue(mp->m_unwritten_workqueue);
out_destroy_buf:
        destroy_workqueue(mp->m_buf_workqueue);
out:
        return -ENOMEM;
}

STATIC void
xfs_destroy_mount_workqueues(
        struct xfs_mount        *mp)
{
        destroy_workqueue(mp->m_sync_workqueue);
        destroy_workqueue(mp->m_blockgc_wq);
        destroy_workqueue(mp->m_inodegc_wq);
        destroy_workqueue(mp->m_reclaim_workqueue);
        destroy_workqueue(mp->m_unwritten_workqueue);
        destroy_workqueue(mp->m_buf_workqueue);
}

static void
xfs_flush_inodes_worker(
        struct work_struct      *work)
{
        struct xfs_mount        *mp = container_of(work, struct xfs_mount,
                                                   m_flush_inodes_work);
        struct super_block      *sb = mp->m_super;

        if (down_read_trylock(&sb->s_umount)) {
                sync_inodes_sb(sb);
                up_read(&sb->s_umount);
        }
}

/*
 * Flush all dirty data to disk. Must not be called while holding an XFS_ILOCK
 * or a page lock. We use sync_inodes_sb() here to ensure we block while waiting
 * for IO to complete so that we effectively throttle multiple callers to the
 * rate at which IO is completing.
 */
void
xfs_flush_inodes(
        struct xfs_mount        *mp)
{
        /*
         * If flush_work() returns true then that means we waited for a flush
         * which was already in progress.  Don't bother running another scan.
         */
        if (flush_work(&mp->m_flush_inodes_work))
                return;

        queue_work(mp->m_sync_workqueue, &mp->m_flush_inodes_work);
        flush_work(&mp->m_flush_inodes_work);
}

/* Catch misguided souls that try to use this interface on XFS */
STATIC struct inode *
xfs_fs_alloc_inode(
        struct super_block      *sb)
{
        BUG();
        return NULL;
}

/*
 * Now that the generic code is guaranteed not to be accessing
 * the linux inode, we can inactivate and reclaim the inode.
 */
STATIC void
xfs_fs_destroy_inode(
        struct inode            *inode)
{
        struct xfs_inode        *ip = XFS_I(inode);

        trace_xfs_destroy_inode(ip);

        ASSERT(!rwsem_is_locked(&inode->i_rwsem));
        XFS_STATS_INC(ip->i_mount, xs_inode_destroy);
        XFS_STATS_INC(ip->i_mount, xs_inode_destroy2);
        xfs_inode_mark_reclaimable(ip);
}

/*
 * Slab object creation initialisation for the XFS inode.
 * This covers only the idempotent fields in the XFS inode;
 * all other fields need to be initialised on allocation
 * from the slab. This avoids the need to repeatedly initialise
 * fields in the xfs inode that left in the initialise state
 * when freeing the inode.
 */
STATIC void
xfs_fs_inode_init_once(
        void                    *inode)
{
        struct xfs_inode        *ip = inode;

        memset(ip, 0, sizeof(struct xfs_inode));

        /* vfs inode */
        inode_init_once(VFS_I(ip));

        /* xfs inode */
        atomic_set(&ip->i_pincount, 0);
        spin_lock_init(&ip->i_flags_lock);
        init_rwsem(&ip->i_lock);
}

/*
 * We do an unlocked check for XFS_IDONTCACHE here because we are already
 * serialised against cache hits here via the inode->i_lock and igrab() in
 * xfs_iget_cache_hit(). Hence a lookup that might clear this flag will not be
 * racing with us, and it avoids needing to grab a spinlock here for every inode
 * we drop the final reference on.
 */
STATIC int
xfs_fs_drop_inode(
        struct inode            *inode)
{
        struct xfs_inode        *ip = XFS_I(inode);

        /*
         * If this unlinked inode is in the middle of recovery, don't
         * drop the inode just yet; log recovery will take care of
         * that.  See the comment for this inode flag.
         */
        if (ip->i_flags & XFS_IRECOVERY) {
                ASSERT(xlog_recovery_needed(ip->i_mount->m_log));
                return 0;
        }

        return inode_generic_drop(inode);
}

STATIC void
xfs_fs_evict_inode(
        struct inode            *inode)
{
        if (IS_DAX(inode))
                dax_break_layout_final(inode);

        truncate_inode_pages_final(&inode->i_data);
        clear_inode(inode);

        if (IS_ENABLED(CONFIG_XFS_RT) &&
            S_ISREG(inode->i_mode) && inode->i_private) {
                xfs_open_zone_put(inode->i_private);
                inode->i_private = NULL;
        }
}

static void
xfs_mount_free(
        struct xfs_mount        *mp)
{
        if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp)
                xfs_free_buftarg(mp->m_logdev_targp);
        if (mp->m_rtdev_targp && mp->m_rtdev_targp != mp->m_ddev_targp)
                xfs_free_buftarg(mp->m_rtdev_targp);
        if (mp->m_ddev_targp)
                xfs_free_buftarg(mp->m_ddev_targp);

        debugfs_remove(mp->m_debugfs);
        kfree(mp->m_rtname);
        kfree(mp->m_logname);
#ifdef DEBUG
        kfree(mp->m_errortag);
#endif
        kfree(mp);
}

STATIC int
xfs_fs_sync_fs(
        struct super_block      *sb,
        int                     wait)
{
        struct xfs_mount        *mp = XFS_M(sb);
        int                     error;

        trace_xfs_fs_sync_fs(mp, __return_address);

        /*
         * Doing anything during the async pass would be counterproductive.
         */
        if (!wait)
                return 0;

        error = xfs_log_force(mp, XFS_LOG_SYNC);
        if (error)
                return error;

        /*
         * If we are called with page faults frozen out, it means we are about
         * to freeze the transaction subsystem. Take the opportunity to shut
         * down inodegc because once SB_FREEZE_FS is set it's too late to
         * prevent inactivation races with freeze. The fs doesn't get called
         * again by the freezing process until after SB_FREEZE_FS has been set,
         * so it's now or never.  Same logic applies to speculative allocation
         * garbage collection.
         *
         * We don't care if this is a normal syncfs call that does this or
         * freeze that does this - we can run this multiple times without issue
         * and we won't race with a restart because a restart can only occur
         * when the state is either SB_FREEZE_FS or SB_FREEZE_COMPLETE.
         */
        if (sb->s_writers.frozen == SB_FREEZE_PAGEFAULT) {
                xfs_inodegc_stop(mp);
                xfs_blockgc_stop(mp);
                xfs_zone_gc_stop(mp);
        }

        return 0;
}

static xfs_extlen_t
xfs_internal_log_size(
        struct xfs_mount        *mp)
{
        if (!mp->m_sb.sb_logstart)
                return 0;
        return mp->m_sb.sb_logblocks;
}

static void
xfs_statfs_data(
        struct xfs_mount        *mp,
        struct kstatfs          *st)
{
        int64_t                 fdblocks =
                xfs_sum_freecounter(mp, XC_FREE_BLOCKS);

        /* make sure st->f_bfree does not underflow */
        st->f_bfree = max(0LL,
                fdblocks - xfs_freecounter_unavailable(mp, XC_FREE_BLOCKS));

        /*
         * sb_dblocks can change during growfs, but nothing cares about reporting
         * the old or new value during growfs.
         */
        st->f_blocks = mp->m_sb.sb_dblocks - xfs_internal_log_size(mp);
}

/*
 * When stat(v)fs is called on a file with the realtime bit set or a directory
 * with the rtinherit bit, report freespace information for the RT device
 * instead of the main data device.
 */
static void
xfs_statfs_rt(
        struct xfs_mount        *mp,
        struct kstatfs          *st)
{
        st->f_bfree = xfs_rtbxlen_to_blen(mp,
                        xfs_sum_freecounter(mp, XC_FREE_RTEXTENTS));
        st->f_blocks = mp->m_sb.sb_rblocks - xfs_rtbxlen_to_blen(mp,
                        mp->m_free[XC_FREE_RTEXTENTS].res_total);
}

static void
xfs_statfs_inodes(
        struct xfs_mount        *mp,
        struct kstatfs          *st)
{
        uint64_t                icount = percpu_counter_sum(&mp->m_icount);
        uint64_t                ifree = percpu_counter_sum(&mp->m_ifree);
        uint64_t                fakeinos = XFS_FSB_TO_INO(mp, st->f_bfree);

        st->f_files = min(icount + fakeinos, (uint64_t)XFS_MAXINUMBER);
        if (M_IGEO(mp)->maxicount)
                st->f_files = min_t(typeof(st->f_files), st->f_files,
                                        M_IGEO(mp)->maxicount);

        /* If sb_icount overshot maxicount, report actual allocation */
        st->f_files = max_t(typeof(st->f_files), st->f_files,
                        mp->m_sb.sb_icount);

        /* Make sure st->f_ffree does not underflow */
        st->f_ffree = max_t(int64_t, 0, st->f_files - (icount - ifree));
}

STATIC int
xfs_fs_statfs(
        struct dentry           *dentry,
        struct kstatfs          *st)
{
        struct xfs_mount        *mp = XFS_M(dentry->d_sb);
        struct xfs_inode        *ip = XFS_I(d_inode(dentry));

        /*
         * Expedite background inodegc but don't wait. We do not want to block
         * here waiting hours for a billion extent file to be truncated.
         */
        xfs_inodegc_push(mp);

        st->f_type = XFS_SUPER_MAGIC;
        st->f_namelen = MAXNAMELEN - 1;
        st->f_bsize = mp->m_sb.sb_blocksize;
        st->f_fsid = u64_to_fsid(huge_encode_dev(mp->m_ddev_targp->bt_dev));

        xfs_statfs_data(mp, st);
        xfs_statfs_inodes(mp, st);

        if (XFS_IS_REALTIME_MOUNT(mp) &&
            (ip->i_diflags & (XFS_DIFLAG_RTINHERIT | XFS_DIFLAG_REALTIME)))
                xfs_statfs_rt(mp, st);

        if ((ip->i_diflags & XFS_DIFLAG_PROJINHERIT) &&
            ((mp->m_qflags & (XFS_PQUOTA_ACCT|XFS_PQUOTA_ENFD))) ==
                              (XFS_PQUOTA_ACCT|XFS_PQUOTA_ENFD))
                xfs_qm_statvfs(ip, st);

        /*
         * XFS does not distinguish between blocks available to privileged and
         * unprivileged users.
         */
        st->f_bavail = st->f_bfree;
        return 0;
}

STATIC void
xfs_save_resvblks(
        struct xfs_mount        *mp)
{
        enum xfs_free_counter   i;

        for (i = 0; i < XC_FREE_NR; i++) {
                mp->m_free[i].res_saved = mp->m_free[i].res_total;
                xfs_reserve_blocks(mp, i, 0);
        }
}

STATIC void
xfs_restore_resvblks(
        struct xfs_mount        *mp)
{
        uint64_t                resblks;
        enum xfs_free_counter   i;

        for (i = 0; i < XC_FREE_NR; i++) {
                if (mp->m_free[i].res_saved) {
                        resblks = mp->m_free[i].res_saved;
                        mp->m_free[i].res_saved = 0;
                } else
                        resblks = xfs_default_resblks(mp, i);
                xfs_reserve_blocks(mp, i, resblks);
        }
}

/*
 * Second stage of a freeze. The data is already frozen so we only
 * need to take care of the metadata. Once that's done sync the superblock
 * to the log to dirty it in case of a crash while frozen. This ensures that we
 * will recover the unlinked inode lists on the next mount.
 */
STATIC int
xfs_fs_freeze(
        struct super_block      *sb)
{
        struct xfs_mount        *mp = XFS_M(sb);
        unsigned int            flags;
        int                     ret;

        /*
         * The filesystem is now frozen far enough that memory reclaim
         * cannot safely operate on the filesystem. Hence we need to
         * set a GFP_NOFS context here to avoid recursion deadlocks.
         */
        flags = memalloc_nofs_save();
        xfs_save_resvblks(mp);
        ret = xfs_log_quiesce(mp);
        memalloc_nofs_restore(flags);

        /*
         * For read-write filesystems, we need to restart the inodegc on error
         * because we stopped it at SB_FREEZE_PAGEFAULT level and a thaw is not
         * going to be run to restart it now.  We are at SB_FREEZE_FS level
         * here, so we can restart safely without racing with a stop in
         * xfs_fs_sync_fs().
         */
        if (ret && !xfs_is_readonly(mp)) {
                xfs_blockgc_start(mp);
                xfs_inodegc_start(mp);
                xfs_zone_gc_start(mp);
        }

        return ret;
}

STATIC int
xfs_fs_unfreeze(
        struct super_block      *sb)
{
        struct xfs_mount        *mp = XFS_M(sb);

        xfs_restore_resvblks(mp);
        xfs_log_work_queue(mp);

        /*
         * Don't reactivate the inodegc worker on a readonly filesystem because
         * inodes are sent directly to reclaim.  Don't reactivate the blockgc
         * worker because there are no speculative preallocations on a readonly
         * filesystem.
         */
        if (!xfs_is_readonly(mp)) {
                xfs_zone_gc_start(mp);
                xfs_blockgc_start(mp);
                xfs_inodegc_start(mp);
        }

        return 0;
}

/*
 * This function fills in xfs_mount_t fields based on mount args.
 * Note: the superblock _has_ now been read in.
 */
STATIC int
xfs_finish_flags(
        struct xfs_mount        *mp)
{
        /* Fail a mount where the logbuf is smaller than the log stripe */
        if (xfs_has_logv2(mp)) {
                if (mp->m_logbsize <= 0 &&
                    mp->m_sb.sb_logsunit > XLOG_BIG_RECORD_BSIZE) {
                        mp->m_logbsize = mp->m_sb.sb_logsunit;
                } else if (mp->m_logbsize > 0 &&
                           mp->m_logbsize < mp->m_sb.sb_logsunit) {
                        xfs_warn(mp,
                "logbuf size must be greater than or equal to log stripe size");
                        return -EINVAL;
                }
        } else {
                /* Fail a mount if the logbuf is larger than 32K */
                if (mp->m_logbsize > XLOG_BIG_RECORD_BSIZE) {
                        xfs_warn(mp,
                "logbuf size for version 1 logs must be 16K or 32K");
                        return -EINVAL;
                }
        }

        /*
         * prohibit r/w mounts of read-only filesystems
         */
        if ((mp->m_sb.sb_flags & XFS_SBF_READONLY) && !xfs_is_readonly(mp)) {
                xfs_warn(mp,
                        "cannot mount a read-only filesystem as read-write");
                return -EROFS;
        }

        if ((mp->m_qflags & XFS_GQUOTA_ACCT) &&
            (mp->m_qflags & XFS_PQUOTA_ACCT) &&
            !xfs_has_pquotino(mp)) {
                xfs_warn(mp,
                  "Super block does not support project and group quota together");
                return -EINVAL;
        }

        if (!xfs_has_zoned(mp)) {
                if (mp->m_max_open_zones) {
                        xfs_warn(mp,
"max_open_zones mount option only supported on zoned file systems.");
                        return -EINVAL;
                }
                if (mp->m_features & XFS_FEAT_NOLIFETIME) {
                        xfs_warn(mp,
"nolifetime mount option only supported on zoned file systems.");
                        return -EINVAL;
                }
        }

        return 0;
}

static int
xfs_init_percpu_counters(
        struct xfs_mount        *mp)
{
        int                     error;
        int                     i;

        error = percpu_counter_init(&mp->m_icount, 0, GFP_KERNEL);
        if (error)
                return -ENOMEM;

        error = percpu_counter_init(&mp->m_ifree, 0, GFP_KERNEL);
        if (error)
                goto free_icount;

        error = percpu_counter_init(&mp->m_delalloc_blks, 0, GFP_KERNEL);
        if (error)
                goto free_ifree;

        error = percpu_counter_init(&mp->m_delalloc_rtextents, 0, GFP_KERNEL);
        if (error)
                goto free_delalloc;

        for (i = 0; i < XC_FREE_NR; i++) {
                error = percpu_counter_init(&mp->m_free[i].count, 0,
                                GFP_KERNEL);
                if (error)
                        goto free_freecounters;
        }

        return 0;

free_freecounters:
        while (--i >= 0)
                percpu_counter_destroy(&mp->m_free[i].count);
        percpu_counter_destroy(&mp->m_delalloc_rtextents);
free_delalloc:
        percpu_counter_destroy(&mp->m_delalloc_blks);
free_ifree:
        percpu_counter_destroy(&mp->m_ifree);
free_icount:
        percpu_counter_destroy(&mp->m_icount);
        return -ENOMEM;
}

void
xfs_reinit_percpu_counters(
        struct xfs_mount        *mp)
{
        percpu_counter_set(&mp->m_icount, mp->m_sb.sb_icount);
        percpu_counter_set(&mp->m_ifree, mp->m_sb.sb_ifree);
        xfs_set_freecounter(mp, XC_FREE_BLOCKS, mp->m_sb.sb_fdblocks);
        if (!xfs_has_zoned(mp))
                xfs_set_freecounter(mp, XC_FREE_RTEXTENTS,
                                mp->m_sb.sb_frextents);
}

static void
xfs_destroy_percpu_counters(
        struct xfs_mount        *mp)
{
        enum xfs_free_counter   i;

        for (i = 0; i < XC_FREE_NR; i++)
                percpu_counter_destroy(&mp->m_free[i].count);
        percpu_counter_destroy(&mp->m_icount);
        percpu_counter_destroy(&mp->m_ifree);
        ASSERT(xfs_is_shutdown(mp) ||
               percpu_counter_sum(&mp->m_delalloc_rtextents) == 0);
        percpu_counter_destroy(&mp->m_delalloc_rtextents);
        ASSERT(xfs_is_shutdown(mp) ||
               percpu_counter_sum(&mp->m_delalloc_blks) == 0);
        percpu_counter_destroy(&mp->m_delalloc_blks);
}

static int
xfs_inodegc_init_percpu(
        struct xfs_mount        *mp)
{
        struct xfs_inodegc      *gc;
        int                     cpu;

        mp->m_inodegc = alloc_percpu(struct xfs_inodegc);
        if (!mp->m_inodegc)
                return -ENOMEM;

        for_each_possible_cpu(cpu) {
                gc = per_cpu_ptr(mp->m_inodegc, cpu);
                gc->cpu = cpu;
                gc->mp = mp;
                init_llist_head(&gc->list);
                gc->items = 0;
                gc->error = 0;
                INIT_DELAYED_WORK(&gc->work, xfs_inodegc_worker);
        }
        return 0;
}

static void
xfs_inodegc_free_percpu(
        struct xfs_mount        *mp)
{
        if (!mp->m_inodegc)
                return;
        free_percpu(mp->m_inodegc);
}

static void
xfs_fs_put_super(
        struct super_block      *sb)
{
        struct xfs_mount        *mp = XFS_M(sb);

        xfs_notice(mp, "Unmounting Filesystem %pU", &mp->m_sb.sb_uuid);
        xfs_filestream_unmount(mp);
        xfs_unmountfs(mp);

        xfs_rtmount_freesb(mp);
        xfs_freesb(mp);
        xchk_mount_stats_free(mp);
        free_percpu(mp->m_stats.xs_stats);
        xfs_inodegc_free_percpu(mp);
        xfs_destroy_percpu_counters(mp);
        xfs_destroy_mount_workqueues(mp);
        xfs_shutdown_devices(mp);
}

static long
xfs_fs_nr_cached_objects(
        struct super_block      *sb,
        struct shrink_control   *sc)
{
        /* Paranoia: catch incorrect calls during mount setup or teardown */
        if (WARN_ON_ONCE(!sb->s_fs_info))
                return 0;
        return xfs_reclaim_inodes_count(XFS_M(sb));
}

static long
xfs_fs_free_cached_objects(
        struct super_block      *sb,
        struct shrink_control   *sc)
{
        return xfs_reclaim_inodes_nr(XFS_M(sb), sc->nr_to_scan);
}

static void
xfs_fs_shutdown(
        struct super_block      *sb)
{
        xfs_force_shutdown(XFS_M(sb), SHUTDOWN_DEVICE_REMOVED);
}

static int
xfs_fs_show_stats(
        struct seq_file         *m,
        struct dentry           *root)
{
        struct xfs_mount        *mp = XFS_M(root->d_sb);

        if (xfs_has_zoned(mp) && IS_ENABLED(CONFIG_XFS_RT))
                xfs_zoned_show_stats(m, mp);
        return 0;
}

static void
xfs_fs_report_error(
        const struct fserror_event      *event)
{
        /* healthmon already knows about non-inode and metadata errors */
        if (event->inode && event->type != FSERR_METADATA)
                xfs_healthmon_report_file_ioerror(XFS_I(event->inode), event);
}

static const struct super_operations xfs_super_operations = {
        .alloc_inode            = xfs_fs_alloc_inode,
        .destroy_inode          = xfs_fs_destroy_inode,
        .drop_inode             = xfs_fs_drop_inode,
        .evict_inode            = xfs_fs_evict_inode,
        .put_super              = xfs_fs_put_super,
        .sync_fs                = xfs_fs_sync_fs,
        .freeze_fs              = xfs_fs_freeze,
        .unfreeze_fs            = xfs_fs_unfreeze,
        .statfs                 = xfs_fs_statfs,
        .show_options           = xfs_fs_show_options,
        .nr_cached_objects      = xfs_fs_nr_cached_objects,
        .free_cached_objects    = xfs_fs_free_cached_objects,
        .shutdown               = xfs_fs_shutdown,
        .show_stats             = xfs_fs_show_stats,
        .report_error           = xfs_fs_report_error,
};

static int
suffix_kstrtoint(
        const char      *s,
        unsigned int    base,
        int             *res)
{
        int             last, shift_left_factor = 0, _res;
        char            *value;
        int             ret = 0;

        value = kstrdup(s, GFP_KERNEL);
        if (!value)
                return -ENOMEM;

        last = strlen(value) - 1;
        if (value[last] == 'K' || value[last] == 'k') {
                shift_left_factor = 10;
                value[last] = '\0';
        }
        if (value[last] == 'M' || value[last] == 'm') {
                shift_left_factor = 20;
                value[last] = '\0';
        }
        if (value[last] == 'G' || value[last] == 'g') {
                shift_left_factor = 30;
                value[last] = '\0';
        }

        if (kstrtoint(value, base, &_res))
                ret = -EINVAL;
        kfree(value);
        *res = _res << shift_left_factor;
        return ret;
}

static int
suffix_kstrtoull(
        const char              *s,
        unsigned int            base,
        unsigned long long      *res)
{
        int                     last, shift_left_factor = 0;
        unsigned long long      _res;
        char                    *value;
        int                     ret = 0;

        value = kstrdup(s, GFP_KERNEL);
        if (!value)
                return -ENOMEM;

        last = strlen(value) - 1;
        if (value[last] == 'K' || value[last] == 'k') {
                shift_left_factor = 10;
                value[last] = '\0';
        }
        if (value[last] == 'M' || value[last] == 'm') {
                shift_left_factor = 20;
                value[last] = '\0';
        }
        if (value[last] == 'G' || value[last] == 'g') {
                shift_left_factor = 30;
                value[last] = '\0';
        }

        if (kstrtoull(value, base, &_res))
                ret = -EINVAL;
        kfree(value);
        *res = _res << shift_left_factor;
        return ret;
}

static inline void
xfs_fs_warn_deprecated(
        struct fs_context       *fc,
        struct fs_parameter     *param)
{
        /*
         * Always warn about someone passing in a deprecated mount option.
         * Previously we wouldn't print the warning if we were reconfiguring
         * and current mount point already had the flag set, but that was not
         * the right thing to do.
         *
         * Many distributions mount the root filesystem with no options in the
         * initramfs and rely on mount -a to remount the root fs with the
         * options in fstab.  However, the old behavior meant that there would
         * never be a warning about deprecated mount options for the root fs in
         * /etc/fstab.  On a single-fs system, that means no warning at all.
         *
         * Compounding this problem are distribution scripts that copy
         * /proc/mounts to fstab, which means that we can't remove mount
         * options unless we're 100% sure they have only ever been advertised
         * in /proc/mounts in response to explicitly provided mount options.
         */
        xfs_warn(fc->s_fs_info, "%s mount option is deprecated.", param->key);
}

/*
 * Set mount state from a mount option.
 *
 * NOTE: mp->m_super is NULL here!
 */
static int
xfs_fs_parse_param(
        struct fs_context       *fc,
        struct fs_parameter     *param)
{
        struct xfs_mount        *parsing_mp = fc->s_fs_info;
        struct fs_parse_result  result;
        int                     size = 0;
        int                     opt;

        BUILD_BUG_ON(XFS_QFLAGS_MNTOPTS & XFS_MOUNT_QUOTA_ALL);

        opt = fs_parse(fc, xfs_fs_parameters, param, &result);
        if (opt < 0)
                return opt;

        switch (opt) {
        case Op_deprecated:
                xfs_fs_warn_deprecated(fc, param);
                return 0;
        case Opt_logbufs:
                parsing_mp->m_logbufs = result.uint_32;
                return 0;
        case Opt_logbsize:
                if (suffix_kstrtoint(param->string, 10, &parsing_mp->m_logbsize))
                        return -EINVAL;
                return 0;
        case Opt_logdev:
                kfree(parsing_mp->m_logname);
                parsing_mp->m_logname = kstrdup(param->string, GFP_KERNEL);
                if (!parsing_mp->m_logname)
                        return -ENOMEM;
                return 0;
        case Opt_rtdev:
                kfree(parsing_mp->m_rtname);
                parsing_mp->m_rtname = kstrdup(param->string, GFP_KERNEL);
                if (!parsing_mp->m_rtname)
                        return -ENOMEM;
                return 0;
        case Opt_allocsize:
                if (suffix_kstrtoint(param->string, 10, &size))
                        return -EINVAL;
                parsing_mp->m_allocsize_log = ffs(size) - 1;
                parsing_mp->m_features |= XFS_FEAT_ALLOCSIZE;
                return 0;
        case Opt_grpid:
        case Opt_bsdgroups:
                parsing_mp->m_features |= XFS_FEAT_GRPID;
                return 0;
        case Opt_nogrpid:
        case Opt_sysvgroups:
                parsing_mp->m_features &= ~XFS_FEAT_GRPID;
                return 0;
        case Opt_wsync:
                parsing_mp->m_features |= XFS_FEAT_WSYNC;
                return 0;
        case Opt_norecovery:
                parsing_mp->m_features |= XFS_FEAT_NORECOVERY;
                return 0;
        case Opt_noalign:
                parsing_mp->m_features |= XFS_FEAT_NOALIGN;
                return 0;
        case Opt_swalloc:
                parsing_mp->m_features |= XFS_FEAT_SWALLOC;
                return 0;
        case Opt_sunit:
                parsing_mp->m_dalign = result.uint_32;
                return 0;
        case Opt_swidth:
                parsing_mp->m_swidth = result.uint_32;
                return 0;
        case Opt_inode32:
                parsing_mp->m_features |= XFS_FEAT_SMALL_INUMS;
                return 0;
        case Opt_inode64:
                parsing_mp->m_features &= ~XFS_FEAT_SMALL_INUMS;
                return 0;
        case Opt_nouuid:
                parsing_mp->m_features |= XFS_FEAT_NOUUID;
                return 0;
        case Opt_largeio:
                parsing_mp->m_features |= XFS_FEAT_LARGE_IOSIZE;
                return 0;
        case Opt_nolargeio:
                parsing_mp->m_features &= ~XFS_FEAT_LARGE_IOSIZE;
                return 0;
        case Opt_filestreams:
                parsing_mp->m_features |= XFS_FEAT_FILESTREAMS;
                return 0;
        case Opt_noquota:
                parsing_mp->m_qflags &= ~XFS_ALL_QUOTA_ACCT;
                parsing_mp->m_qflags &= ~XFS_ALL_QUOTA_ENFD;
                parsing_mp->m_qflags |= XFS_QFLAGS_MNTOPTS;
                return 0;
        case Opt_quota:
        case Opt_uquota:
        case Opt_usrquota:
                parsing_mp->m_qflags |= (XFS_UQUOTA_ACCT | XFS_UQUOTA_ENFD);
                parsing_mp->m_qflags |= XFS_QFLAGS_MNTOPTS;
                return 0;
        case Opt_qnoenforce:
        case Opt_uqnoenforce:
                parsing_mp->m_qflags |= XFS_UQUOTA_ACCT;
                parsing_mp->m_qflags &= ~XFS_UQUOTA_ENFD;
                parsing_mp->m_qflags |= XFS_QFLAGS_MNTOPTS;
                return 0;
        case Opt_pquota:
        case Opt_prjquota:
                parsing_mp->m_qflags |= (XFS_PQUOTA_ACCT | XFS_PQUOTA_ENFD);
                parsing_mp->m_qflags |= XFS_QFLAGS_MNTOPTS;
                return 0;
        case Opt_pqnoenforce:
                parsing_mp->m_qflags |= XFS_PQUOTA_ACCT;
                parsing_mp->m_qflags &= ~XFS_PQUOTA_ENFD;
                parsing_mp->m_qflags |= XFS_QFLAGS_MNTOPTS;
                return 0;
        case Opt_gquota:
        case Opt_grpquota:
                parsing_mp->m_qflags |= (XFS_GQUOTA_ACCT | XFS_GQUOTA_ENFD);
                parsing_mp->m_qflags |= XFS_QFLAGS_MNTOPTS;
                return 0;
        case Opt_gqnoenforce:
                parsing_mp->m_qflags |= XFS_GQUOTA_ACCT;
                parsing_mp->m_qflags &= ~XFS_GQUOTA_ENFD;
                parsing_mp->m_qflags |= XFS_QFLAGS_MNTOPTS;
                return 0;
        case Opt_discard:
                parsing_mp->m_features |= XFS_FEAT_DISCARD;
                return 0;
        case Opt_nodiscard:
                parsing_mp->m_features &= ~XFS_FEAT_DISCARD;
                return 0;
#ifdef CONFIG_FS_DAX
        case Opt_dax:
                xfs_mount_set_dax_mode(parsing_mp, XFS_DAX_ALWAYS);
                return 0;
        case Opt_dax_enum:
                xfs_mount_set_dax_mode(parsing_mp, result.uint_32);
                return 0;
#endif
        case Opt_max_open_zones:
                parsing_mp->m_max_open_zones = result.uint_32;
                return 0;
        case Opt_lifetime:
                parsing_mp->m_features &= ~XFS_FEAT_NOLIFETIME;
                return 0;
        case Opt_nolifetime:
                parsing_mp->m_features |= XFS_FEAT_NOLIFETIME;
                return 0;
        case Opt_max_atomic_write:
                if (suffix_kstrtoull(param->string, 10,
                                     &parsing_mp->m_awu_max_bytes)) {
                        xfs_warn(parsing_mp,
 "max atomic write size must be positive integer");
                        return -EINVAL;
                }
                return 0;
        case Opt_errortag:
                return xfs_errortag_add_name(parsing_mp, param->string);
        default:
                xfs_warn(parsing_mp, "unknown mount option [%s].", param->key);
                return -EINVAL;
        }

        return 0;
}

static int
xfs_fs_validate_params(
        struct xfs_mount        *mp)
{
        /* No recovery flag requires a read-only mount */
        if (xfs_has_norecovery(mp) && !xfs_is_readonly(mp)) {
                xfs_warn(mp, "no-recovery mounts must be read-only.");
                return -EINVAL;
        }

        if (xfs_has_noalign(mp) && (mp->m_dalign || mp->m_swidth)) {
                xfs_warn(mp,
        "sunit and swidth options incompatible with the noalign option");
                return -EINVAL;
        }

        if (!IS_ENABLED(CONFIG_XFS_QUOTA) &&
            (mp->m_qflags & ~XFS_QFLAGS_MNTOPTS)) {
                xfs_warn(mp, "quota support not available in this kernel.");
                return -EINVAL;
        }

        if ((mp->m_dalign && !mp->m_swidth) ||
            (!mp->m_dalign && mp->m_swidth)) {
                xfs_warn(mp, "sunit and swidth must be specified together");
                return -EINVAL;
        }

        if (mp->m_dalign && (mp->m_swidth % mp->m_dalign != 0)) {
                xfs_warn(mp,
        "stripe width (%d) must be a multiple of the stripe unit (%d)",
                        mp->m_swidth, mp->m_dalign);
                return -EINVAL;
        }

        if (mp->m_logbufs != -1 &&
            mp->m_logbufs != 0 &&
            (mp->m_logbufs < XLOG_MIN_ICLOGS ||
             mp->m_logbufs > XLOG_MAX_ICLOGS)) {
                xfs_warn(mp, "invalid logbufs value: %d [not %d-%d]",
                        mp->m_logbufs, XLOG_MIN_ICLOGS, XLOG_MAX_ICLOGS);
                return -EINVAL;
        }

        if (mp->m_logbsize != -1 &&
            mp->m_logbsize !=  0 &&
            (mp->m_logbsize < XLOG_MIN_RECORD_BSIZE ||
             mp->m_logbsize > XLOG_MAX_RECORD_BSIZE ||
             !is_power_of_2(mp->m_logbsize))) {
                xfs_warn(mp,
                        "invalid logbufsize: %d [not 16k,32k,64k,128k or 256k]",
                        mp->m_logbsize);
                return -EINVAL;
        }

        if (xfs_has_allocsize(mp) &&
            (mp->m_allocsize_log > XFS_MAX_IO_LOG ||
             mp->m_allocsize_log < XFS_MIN_IO_LOG)) {
                xfs_warn(mp, "invalid log iosize: %d [not %d-%d]",
                        mp->m_allocsize_log, XFS_MIN_IO_LOG, XFS_MAX_IO_LOG);
                return -EINVAL;
        }

        return 0;
}

struct dentry *
xfs_debugfs_mkdir(
        const char      *name,
        struct dentry   *parent)
{
        struct dentry   *child;

        /* Apparently we're expected to ignore error returns?? */
        child = debugfs_create_dir(name, parent);
        if (IS_ERR(child))
                return NULL;

        return child;
}

static int
xfs_fs_fill_super(
        struct super_block      *sb,
        struct fs_context       *fc)
{
        struct xfs_mount        *mp = sb->s_fs_info;
        struct inode            *root;
        int                     flags = 0, error;

        mp->m_super = sb;

        /*
         * Copy VFS mount flags from the context now that all parameter parsing
         * is guaranteed to have been completed by either the old mount API or
         * the newer fsopen/fsconfig API.
         */
        if (fc->sb_flags & SB_RDONLY)
                xfs_set_readonly(mp);
        if (fc->sb_flags & SB_DIRSYNC)
                mp->m_features |= XFS_FEAT_DIRSYNC;
        if (fc->sb_flags & SB_SYNCHRONOUS)
                mp->m_features |= XFS_FEAT_WSYNC;

        error = xfs_fs_validate_params(mp);
        if (error)
                return error;

        if (!sb_min_blocksize(sb, BBSIZE)) {
                xfs_err(mp, "unable to set blocksize");
                return -EINVAL;
        }
        sb->s_xattr = xfs_xattr_handlers;
        sb->s_export_op = &xfs_export_operations;
#ifdef CONFIG_XFS_QUOTA
        sb->s_qcop = &xfs_quotactl_operations;
        sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
#endif
        sb->s_op = &xfs_super_operations;

        /*
         * Delay mount work if the debug hook is set. This is debug
         * instrumention to coordinate simulation of xfs mount failures with
         * VFS superblock operations
         */
        if (xfs_globals.mount_delay) {
                xfs_notice(mp, "Delaying mount for %d seconds.",
                        xfs_globals.mount_delay);
                msleep(xfs_globals.mount_delay * 1000);
        }

        if (fc->sb_flags & SB_SILENT)
                flags |= XFS_MFSI_QUIET;

        error = xfs_open_devices(mp);
        if (error)
                return error;

        if (xfs_debugfs) {
                mp->m_debugfs = xfs_debugfs_mkdir(mp->m_super->s_id,
                                                  xfs_debugfs);
        } else {
                mp->m_debugfs = NULL;
        }

        error = xfs_init_mount_workqueues(mp);
        if (error)
                goto out_shutdown_devices;

        error = xfs_init_percpu_counters(mp);
        if (error)
                goto out_destroy_workqueues;

        error = xfs_inodegc_init_percpu(mp);
        if (error)
                goto out_destroy_counters;

        /* Allocate stats memory before we do operations that might use it */
        mp->m_stats.xs_stats = alloc_percpu(struct xfsstats);
        if (!mp->m_stats.xs_stats) {
                error = -ENOMEM;
                goto out_destroy_inodegc;
        }

        error = xchk_mount_stats_alloc(mp);
        if (error)
                goto out_free_stats;

        error = xfs_readsb(mp, flags);
        if (error)
                goto out_free_scrub_stats;

        error = xfs_finish_flags(mp);
        if (error)
                goto out_free_sb;

        error = xfs_setup_devices(mp);
        if (error)
                goto out_free_sb;

        /*
         * V4 support is undergoing deprecation.
         *
         * Note: this has to use an open coded m_features check as xfs_has_crc
         * always returns false for !CONFIG_XFS_SUPPORT_V4.
         */
        if (!(mp->m_features & XFS_FEAT_CRC)) {
                if (!IS_ENABLED(CONFIG_XFS_SUPPORT_V4)) {
                        xfs_warn(mp,
        "Deprecated V4 format (crc=0) not supported by kernel.");
                        error = -EINVAL;
                        goto out_free_sb;
                }
                xfs_warn_once(mp,
        "Deprecated V4 format (crc=0) will not be supported after September 2030.");
        }

        /* ASCII case insensitivity is undergoing deprecation. */
        if (xfs_has_asciici(mp)) {
#ifdef CONFIG_XFS_SUPPORT_ASCII_CI
                xfs_warn_once(mp,
        "Deprecated ASCII case-insensitivity feature (ascii-ci=1) will not be supported after September 2030.");
#else
                xfs_warn(mp,
        "Deprecated ASCII case-insensitivity feature (ascii-ci=1) not supported by kernel.");
                error = -EINVAL;
                goto out_free_sb;
#endif
        }

        /*
         * Filesystem claims it needs repair, so refuse the mount unless
         * norecovery is also specified, in which case the filesystem can
         * be mounted with no risk of further damage.
         */
        if (xfs_has_needsrepair(mp) && !xfs_has_norecovery(mp)) {
                xfs_warn(mp, "Filesystem needs repair.  Please run xfs_repair.");
                error = -EFSCORRUPTED;
                goto out_free_sb;
        }

        /*
         * Don't touch the filesystem if a user tool thinks it owns the primary
         * superblock.  mkfs doesn't clear the flag from secondary supers, so
         * we don't check them at all.
         */
        if (mp->m_sb.sb_inprogress) {
                xfs_warn(mp, "Offline file system operation in progress!");
                error = -EFSCORRUPTED;
                goto out_free_sb;
        }

        if (mp->m_sb.sb_blocksize > PAGE_SIZE) {
                size_t max_folio_size = mapping_max_folio_size_supported();

                if (!xfs_has_crc(mp)) {
                        xfs_warn(mp,
"V4 Filesystem with blocksize %d bytes. Only pagesize (%ld) or less is supported.",
                                mp->m_sb.sb_blocksize, PAGE_SIZE);
                        error = -ENOSYS;
                        goto out_free_sb;
                }

                if (mp->m_sb.sb_blocksize > max_folio_size) {
                        xfs_warn(mp,
"block size (%u bytes) not supported; Only block size (%zu) or less is supported",
                                mp->m_sb.sb_blocksize, max_folio_size);
                        error = -ENOSYS;
                        goto out_free_sb;
                }
        }

        /* Ensure this filesystem fits in the page cache limits */
        if (xfs_sb_validate_fsb_count(&mp->m_sb, mp->m_sb.sb_dblocks) ||
            xfs_sb_validate_fsb_count(&mp->m_sb, mp->m_sb.sb_rblocks)) {
                xfs_warn(mp,
                "file system too large to be mounted on this system.");
                error = -EFBIG;
                goto out_free_sb;
        }

        /*
         * XFS block mappings use 54 bits to store the logical block offset.
         * This should suffice to handle the maximum file size that the VFS
         * supports (currently 2^63 bytes on 64-bit and ULONG_MAX << PAGE_SHIFT
         * bytes on 32-bit), but as XFS and VFS have gotten the s_maxbytes
         * calculation wrong on 32-bit kernels in the past, we'll add a WARN_ON
         * to check this assertion.
         *
         * Avoid integer overflow by comparing the maximum bmbt offset to the
         * maximum pagecache offset in units of fs blocks.
         */
        if (!xfs_verify_fileoff(mp, XFS_B_TO_FSBT(mp, MAX_LFS_FILESIZE))) {
                xfs_warn(mp,
"MAX_LFS_FILESIZE block offset (%llu) exceeds extent map maximum (%llu)!",
                         XFS_B_TO_FSBT(mp, MAX_LFS_FILESIZE),
                         XFS_MAX_FILEOFF);
                error = -EINVAL;
                goto out_free_sb;
        }

        error = xfs_rtmount_readsb(mp);
        if (error)
                goto out_free_sb;

        error = xfs_filestream_mount(mp);
        if (error)
                goto out_free_rtsb;

        /*
         * we must configure the block size in the superblock before we run the
         * full mount process as the mount process can lookup and cache inodes.
         */
        sb->s_magic = XFS_SUPER_MAGIC;
        sb->s_blocksize = mp->m_sb.sb_blocksize;
        sb->s_blocksize_bits = ffs(sb->s_blocksize) - 1;
        sb->s_maxbytes = MAX_LFS_FILESIZE;
        sb->s_max_links = XFS_MAXLINK;
        sb->s_time_gran = 1;
        if (xfs_has_bigtime(mp)) {
                sb->s_time_min = xfs_bigtime_to_unix(XFS_BIGTIME_TIME_MIN);
                sb->s_time_max = xfs_bigtime_to_unix(XFS_BIGTIME_TIME_MAX);
        } else {
                sb->s_time_min = XFS_LEGACY_TIME_MIN;
                sb->s_time_max = XFS_LEGACY_TIME_MAX;
        }
        trace_xfs_inode_timestamp_range(mp, sb->s_time_min, sb->s_time_max);
        sb->s_iflags |= SB_I_CGROUPWB | SB_I_ALLOW_HSM;

        set_posix_acl_flag(sb);

        /* version 5 superblocks support inode version counters. */
        if (xfs_has_crc(mp))
                sb->s_flags |= SB_I_VERSION;

        if (xfs_has_dax_always(mp)) {
                error = xfs_setup_dax_always(mp);
                if (error)
                        goto out_filestream_unmount;
        }

        if (xfs_has_discard(mp) && !bdev_max_discard_sectors(sb->s_bdev)) {
                xfs_warn(mp,
        "mounting with \"discard\" option, but the device does not support discard");
                mp->m_features &= ~XFS_FEAT_DISCARD;
        }

        if (xfs_has_zoned(mp)) {
                if (!xfs_has_metadir(mp)) {
                        xfs_alert(mp,
                "metadir feature required for zoned realtime devices.");
                        error = -EINVAL;
                        goto out_filestream_unmount;
                }
                xfs_warn_experimental(mp, XFS_EXPERIMENTAL_ZONED);
        }

        if (xfs_has_reflink(mp)) {
                if (xfs_has_realtime(mp) &&
                    !xfs_reflink_supports_rextsize(mp, mp->m_sb.sb_rextsize)) {
                        xfs_alert(mp,
        "reflink not compatible with realtime extent size %u!",
                                        mp->m_sb.sb_rextsize);
                        error = -EINVAL;
                        goto out_filestream_unmount;
                }

                if (xfs_has_zoned(mp)) {
                        xfs_alert(mp,
        "reflink not compatible with zoned RT device!");
                        error = -EINVAL;
                        goto out_filestream_unmount;
                }

                if (xfs_globals.always_cow) {
                        xfs_info(mp, "using DEBUG-only always_cow mode.");
                        mp->m_always_cow = true;
                }
        }

        /*
         * If no quota mount options were provided, maybe we'll try to pick
         * up the quota accounting and enforcement flags from the ondisk sb.
         */
        if (!(mp->m_qflags & XFS_QFLAGS_MNTOPTS))
                xfs_set_resuming_quotaon(mp);
        mp->m_qflags &= ~XFS_QFLAGS_MNTOPTS;

        error = xfs_mountfs(mp);
        if (error)
                goto out_filestream_unmount;

        root = igrab(VFS_I(mp->m_rootip));
        if (!root) {
                error = -ENOENT;
                goto out_unmount;
        }
        sb->s_root = d_make_root(root);
        if (!sb->s_root) {
                error = -ENOMEM;
                goto out_unmount;
        }

        return 0;

 out_filestream_unmount:
        xfs_filestream_unmount(mp);
 out_free_rtsb:
        xfs_rtmount_freesb(mp);
 out_free_sb:
        xfs_freesb(mp);
 out_free_scrub_stats:
        xchk_mount_stats_free(mp);
 out_free_stats:
        free_percpu(mp->m_stats.xs_stats);
 out_destroy_inodegc:
        xfs_inodegc_free_percpu(mp);
 out_destroy_counters:
        xfs_destroy_percpu_counters(mp);
 out_destroy_workqueues:
        xfs_destroy_mount_workqueues(mp);
 out_shutdown_devices:
        xfs_shutdown_devices(mp);
        return error;

 out_unmount:
        xfs_filestream_unmount(mp);
        xfs_unmountfs(mp);
        goto out_free_rtsb;
}

static int
xfs_fs_get_tree(
        struct fs_context       *fc)
{
        return get_tree_bdev(fc, xfs_fs_fill_super);
}

static int
xfs_remount_rw(
        struct xfs_mount        *mp)
{
        struct xfs_sb           *sbp = &mp->m_sb;
        int error;

        if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp &&
            xfs_readonly_buftarg(mp->m_logdev_targp)) {
                xfs_warn(mp,
                        "ro->rw transition prohibited by read-only logdev");
                return -EACCES;
        }

        if (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp)) {
                xfs_warn(mp,
                        "ro->rw transition prohibited by read-only rtdev");
                return -EACCES;
        }

        if (xfs_has_norecovery(mp)) {
                xfs_warn(mp,
                        "ro->rw transition prohibited on norecovery mount");
                return -EINVAL;
        }

        if (xfs_sb_is_v5(sbp) &&
            xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
                xfs_warn(mp,
        "ro->rw transition prohibited on unknown (0x%x) ro-compat filesystem",
                        (sbp->sb_features_ro_compat &
                                XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
                return -EINVAL;
        }

        xfs_clear_readonly(mp);

        /*
         * If this is the first remount to writeable state we might have some
         * superblock changes to update.
         */
        if (mp->m_update_sb) {
                error = xfs_sync_sb(mp, false);
                if (error) {
                        xfs_warn(mp, "failed to write sb changes");
                        return error;
                }
                mp->m_update_sb = false;
        }

        /*
         * Fill out the reserve pool if it is empty. Use the stashed value if
         * it is non-zero, otherwise go with the default.
         */
        xfs_restore_resvblks(mp);
        xfs_log_work_queue(mp);
        xfs_blockgc_start(mp);

        /* Create the per-AG metadata reservation pool .*/
        error = xfs_fs_reserve_ag_blocks(mp);
        if (error && error != -ENOSPC)
                return error;

        /* Re-enable the background inode inactivation worker. */
        xfs_inodegc_start(mp);

        /* Restart zone reclaim */
        xfs_zone_gc_start(mp);

        return 0;
}

static int
xfs_remount_ro(
        struct xfs_mount        *mp)
{
        struct xfs_icwalk       icw = {
                .icw_flags      = XFS_ICWALK_FLAG_SYNC,
        };
        int                     error;

        /* Flush all the dirty data to disk. */
        error = sync_filesystem(mp->m_super);
        if (error)
                return error;

        /*
         * Cancel background eofb scanning so it cannot race with the final
         * log force+buftarg wait and deadlock the remount.
         */
        xfs_blockgc_stop(mp);

        /*
         * Clear out all remaining COW staging extents and speculative post-EOF
         * preallocations so that we don't leave inodes requiring inactivation
         * cleanups during reclaim on a read-only mount.  We must process every
         * cached inode, so this requires a synchronous cache scan.
         */
        error = xfs_blockgc_free_space(mp, &icw);
        if (error) {
                xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
                return error;
        }

        /*
         * Stop the inodegc background worker.  xfs_fs_reconfigure already
         * flushed all pending inodegc work when it sync'd the filesystem.
         * The VFS holds s_umount, so we know that inodes cannot enter
         * xfs_fs_destroy_inode during a remount operation.  In readonly mode
         * we send inodes straight to reclaim, so no inodes will be queued.
         */
        xfs_inodegc_stop(mp);

        /* Stop zone reclaim */
        xfs_zone_gc_stop(mp);

        /* Free the per-AG metadata reservation pool. */
        xfs_fs_unreserve_ag_blocks(mp);

        /*
         * Before we sync the metadata, we need to free up the reserve block
         * pool so that the used block count in the superblock on disk is
         * correct at the end of the remount. Stash the current* reserve pool
         * size so that if we get remounted rw, we can return it to the same
         * size.
         */
        xfs_save_resvblks(mp);

        xfs_log_clean(mp);
        xfs_set_readonly(mp);

        return 0;
}

/*
 * Logically we would return an error here to prevent users from believing
 * they might have changed mount options using remount which can't be changed.
 *
 * But unfortunately mount(8) adds all options from mtab and fstab to the mount
 * arguments in some cases so we can't blindly reject options, but have to
 * check for each specified option if it actually differs from the currently
 * set option and only reject it if that's the case.
 *
 * Until that is implemented we return success for every remount request, and
 * silently ignore all options that we can't actually change.
 */
static int
xfs_fs_reconfigure(
        struct fs_context *fc)
{
        struct xfs_mount        *mp = XFS_M(fc->root->d_sb);
        struct xfs_mount        *new_mp = fc->s_fs_info;
        int                     flags = fc->sb_flags;
        int                     error;

        new_mp->m_qflags &= ~XFS_QFLAGS_MNTOPTS;

        /* version 5 superblocks always support version counters. */
        if (xfs_has_crc(mp))
                fc->sb_flags |= SB_I_VERSION;

        error = xfs_fs_validate_params(new_mp);
        if (error)
                return error;

        xfs_errortag_copy(mp, new_mp);

        /* Validate new max_atomic_write option before making other changes */
        if (mp->m_awu_max_bytes != new_mp->m_awu_max_bytes) {
                error = xfs_set_max_atomic_write_opt(mp,
                                new_mp->m_awu_max_bytes);
                if (error)
                        return error;
        }

        /* inode32 -> inode64 */
        if (xfs_has_small_inums(mp) && !xfs_has_small_inums(new_mp)) {
                mp->m_features &= ~XFS_FEAT_SMALL_INUMS;
                mp->m_maxagi = xfs_set_inode_alloc(mp, mp->m_sb.sb_agcount);
        }

        /* inode64 -> inode32 */
        if (!xfs_has_small_inums(mp) && xfs_has_small_inums(new_mp)) {
                mp->m_features |= XFS_FEAT_SMALL_INUMS;
                mp->m_maxagi = xfs_set_inode_alloc(mp, mp->m_sb.sb_agcount);
        }

        /*
         * Now that mp has been modified according to the remount options, we
         * do a final option validation with xfs_finish_flags() just like it is
         * just like it is done during mount. We cannot use
         * done during mount. We cannot use xfs_finish_flags() on new_mp as it
         * contains only the user given options.
         */
        error = xfs_finish_flags(mp);
        if (error)
                return error;

        /* ro -> rw */
        if (xfs_is_readonly(mp) && !(flags & SB_RDONLY)) {
                error = xfs_remount_rw(mp);
                if (error)
                        return error;
        }

        /* rw -> ro */
        if (!xfs_is_readonly(mp) && (flags & SB_RDONLY)) {
                error = xfs_remount_ro(mp);
                if (error)
                        return error;
        }

        return 0;
}

static void
xfs_fs_free(
        struct fs_context       *fc)
{
        struct xfs_mount        *mp = fc->s_fs_info;

        /*
         * mp is stored in the fs_context when it is initialized.
         * mp is transferred to the superblock on a successful mount,
         * but if an error occurs before the transfer we have to free
         * it here.
         */
        if (mp)
                xfs_mount_free(mp);
}

static const struct fs_context_operations xfs_context_ops = {
        .parse_param = xfs_fs_parse_param,
        .get_tree    = xfs_fs_get_tree,
        .reconfigure = xfs_fs_reconfigure,
        .free        = xfs_fs_free,
};

/*
 * WARNING: do not initialise any parameters in this function that depend on
 * mount option parsing having already been performed as this can be called from
 * fsopen() before any parameters have been set.
 */
static int
xfs_init_fs_context(
        struct fs_context       *fc)
{
        struct xfs_mount        *mp;
        int                     i;

        mp = kzalloc_obj(struct xfs_mount);
        if (!mp)
                return -ENOMEM;
#ifdef DEBUG
        mp->m_errortag = kzalloc_objs(*mp->m_errortag, XFS_ERRTAG_MAX);
        if (!mp->m_errortag) {
                kfree(mp);
                return -ENOMEM;
        }
#endif

        spin_lock_init(&mp->m_sb_lock);
        for (i = 0; i < XG_TYPE_MAX; i++)
                xa_init(&mp->m_groups[i].xa);
        mutex_init(&mp->m_growlock);
        mutex_init(&mp->m_metafile_resv_lock);
        INIT_WORK(&mp->m_flush_inodes_work, xfs_flush_inodes_worker);
        INIT_DELAYED_WORK(&mp->m_reclaim_work, xfs_reclaim_worker);
        mp->m_kobj.kobject.kset = xfs_kset;
        /*
         * We don't create the finobt per-ag space reservation until after log
         * recovery, so we must set this to true so that an ifree transaction
         * started during log recovery will not depend on space reservations
         * for finobt expansion.
         */
        mp->m_finobt_nores = true;

        /*
         * These can be overridden by the mount option parsing.
         */
        mp->m_logbufs = -1;
        mp->m_logbsize = -1;
        mp->m_allocsize_log = 16; /* 64k */

        xfs_hooks_init(&mp->m_dir_update_hooks);

        fc->s_fs_info = mp;
        fc->ops = &xfs_context_ops;

        return 0;
}

static void
xfs_kill_sb(
        struct super_block              *sb)
{
        kill_block_super(sb);
        xfs_mount_free(XFS_M(sb));
}

static struct file_system_type xfs_fs_type = {
        .owner                  = THIS_MODULE,
        .name                   = "xfs",
        .init_fs_context        = xfs_init_fs_context,
        .parameters             = xfs_fs_parameters,
        .kill_sb                = xfs_kill_sb,
        .fs_flags               = FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME |
                                  FS_LBS,
};
MODULE_ALIAS_FS("xfs");

STATIC int __init
xfs_init_caches(void)
{
        int             error;

        xfs_buf_cache = kmem_cache_create("xfs_buf", sizeof(struct xfs_buf), 0,
                                         SLAB_HWCACHE_ALIGN |
                                         SLAB_RECLAIM_ACCOUNT,
                                         NULL);
        if (!xfs_buf_cache)
                goto out;

        xfs_log_ticket_cache = kmem_cache_create("xfs_log_ticket",
                                                sizeof(struct xlog_ticket),
                                                0, 0, NULL);
        if (!xfs_log_ticket_cache)
                goto out_destroy_buf_cache;

        error = xfs_btree_init_cur_caches();
        if (error)
                goto out_destroy_log_ticket_cache;

        error = rcbagbt_init_cur_cache();
        if (error)
                goto out_destroy_btree_cur_cache;

        error = xfs_defer_init_item_caches();
        if (error)
                goto out_destroy_rcbagbt_cur_cache;

        xfs_da_state_cache = kmem_cache_create("xfs_da_state",
                                              sizeof(struct xfs_da_state),
                                              0, 0, NULL);
        if (!xfs_da_state_cache)
                goto out_destroy_defer_item_cache;

        xfs_ifork_cache = kmem_cache_create("xfs_ifork",
                                           sizeof(struct xfs_ifork),
                                           0, 0, NULL);
        if (!xfs_ifork_cache)
                goto out_destroy_da_state_cache;

        xfs_trans_cache = kmem_cache_create("xfs_trans",
                                           sizeof(struct xfs_trans),
                                           0, 0, NULL);
        if (!xfs_trans_cache)
                goto out_destroy_ifork_cache;


        /*
         * The size of the cache-allocated buf log item is the maximum
         * size possible under XFS.  This wastes a little bit of memory,
         * but it is much faster.
         */
        xfs_buf_item_cache = kmem_cache_create("xfs_buf_item",
                                              sizeof(struct xfs_buf_log_item),
                                              0, 0, NULL);
        if (!xfs_buf_item_cache)
                goto out_destroy_trans_cache;

        xfs_efd_cache = kmem_cache_create("xfs_efd_item",
                        xfs_efd_log_item_sizeof(XFS_EFD_MAX_FAST_EXTENTS),
                        0, 0, NULL);
        if (!xfs_efd_cache)
                goto out_destroy_buf_item_cache;

        xfs_efi_cache = kmem_cache_create("xfs_efi_item",
                        xfs_efi_log_item_sizeof(XFS_EFI_MAX_FAST_EXTENTS),
                        0, 0, NULL);
        if (!xfs_efi_cache)
                goto out_destroy_efd_cache;

        xfs_inode_cache = kmem_cache_create("xfs_inode",
                                           sizeof(struct xfs_inode), 0,
                                           (SLAB_HWCACHE_ALIGN |
                                            SLAB_RECLAIM_ACCOUNT |
                                            SLAB_ACCOUNT),
                                           xfs_fs_inode_init_once);
        if (!xfs_inode_cache)
                goto out_destroy_efi_cache;

        xfs_ili_cache = kmem_cache_create("xfs_ili",
                                         sizeof(struct xfs_inode_log_item), 0,
                                         SLAB_RECLAIM_ACCOUNT,
                                         NULL);
        if (!xfs_ili_cache)
                goto out_destroy_inode_cache;

        xfs_icreate_cache = kmem_cache_create("xfs_icr",
                                             sizeof(struct xfs_icreate_item),
                                             0, 0, NULL);
        if (!xfs_icreate_cache)
                goto out_destroy_ili_cache;

        xfs_rud_cache = kmem_cache_create("xfs_rud_item",
                                         sizeof(struct xfs_rud_log_item),
                                         0, 0, NULL);
        if (!xfs_rud_cache)
                goto out_destroy_icreate_cache;

        xfs_rui_cache = kmem_cache_create("xfs_rui_item",
                        xfs_rui_log_item_sizeof(XFS_RUI_MAX_FAST_EXTENTS),
                        0, 0, NULL);
        if (!xfs_rui_cache)
                goto out_destroy_rud_cache;

        xfs_cud_cache = kmem_cache_create("xfs_cud_item",
                                         sizeof(struct xfs_cud_log_item),
                                         0, 0, NULL);
        if (!xfs_cud_cache)
                goto out_destroy_rui_cache;

        xfs_cui_cache = kmem_cache_create("xfs_cui_item",
                        xfs_cui_log_item_sizeof(XFS_CUI_MAX_FAST_EXTENTS),
                        0, 0, NULL);
        if (!xfs_cui_cache)
                goto out_destroy_cud_cache;

        xfs_bud_cache = kmem_cache_create("xfs_bud_item",
                                         sizeof(struct xfs_bud_log_item),
                                         0, 0, NULL);
        if (!xfs_bud_cache)
                goto out_destroy_cui_cache;

        xfs_bui_cache = kmem_cache_create("xfs_bui_item",
                        xfs_bui_log_item_sizeof(XFS_BUI_MAX_FAST_EXTENTS),
                        0, 0, NULL);
        if (!xfs_bui_cache)
                goto out_destroy_bud_cache;

        xfs_attrd_cache = kmem_cache_create("xfs_attrd_item",
                                            sizeof(struct xfs_attrd_log_item),
                                            0, 0, NULL);
        if (!xfs_attrd_cache)
                goto out_destroy_bui_cache;

        xfs_attri_cache = kmem_cache_create("xfs_attri_item",
                                            sizeof(struct xfs_attri_log_item),
                                            0, 0, NULL);
        if (!xfs_attri_cache)
                goto out_destroy_attrd_cache;

        xfs_iunlink_cache = kmem_cache_create("xfs_iul_item",
                                             sizeof(struct xfs_iunlink_item),
                                             0, 0, NULL);
        if (!xfs_iunlink_cache)
                goto out_destroy_attri_cache;

        xfs_xmd_cache = kmem_cache_create("xfs_xmd_item",
                                         sizeof(struct xfs_xmd_log_item),
                                         0, 0, NULL);
        if (!xfs_xmd_cache)
                goto out_destroy_iul_cache;

        xfs_xmi_cache = kmem_cache_create("xfs_xmi_item",
                                         sizeof(struct xfs_xmi_log_item),
                                         0, 0, NULL);
        if (!xfs_xmi_cache)
                goto out_destroy_xmd_cache;

        xfs_parent_args_cache = kmem_cache_create("xfs_parent_args",
                                             sizeof(struct xfs_parent_args),
                                             0, 0, NULL);
        if (!xfs_parent_args_cache)
                goto out_destroy_xmi_cache;

        return 0;

 out_destroy_xmi_cache:
        kmem_cache_destroy(xfs_xmi_cache);
 out_destroy_xmd_cache:
        kmem_cache_destroy(xfs_xmd_cache);
 out_destroy_iul_cache:
        kmem_cache_destroy(xfs_iunlink_cache);
 out_destroy_attri_cache:
        kmem_cache_destroy(xfs_attri_cache);
 out_destroy_attrd_cache:
        kmem_cache_destroy(xfs_attrd_cache);
 out_destroy_bui_cache:
        kmem_cache_destroy(xfs_bui_cache);
 out_destroy_bud_cache:
        kmem_cache_destroy(xfs_bud_cache);
 out_destroy_cui_cache:
        kmem_cache_destroy(xfs_cui_cache);
 out_destroy_cud_cache:
        kmem_cache_destroy(xfs_cud_cache);
 out_destroy_rui_cache:
        kmem_cache_destroy(xfs_rui_cache);
 out_destroy_rud_cache:
        kmem_cache_destroy(xfs_rud_cache);
 out_destroy_icreate_cache:
        kmem_cache_destroy(xfs_icreate_cache);
 out_destroy_ili_cache:
        kmem_cache_destroy(xfs_ili_cache);
 out_destroy_inode_cache:
        kmem_cache_destroy(xfs_inode_cache);
 out_destroy_efi_cache:
        kmem_cache_destroy(xfs_efi_cache);
 out_destroy_efd_cache:
        kmem_cache_destroy(xfs_efd_cache);
 out_destroy_buf_item_cache:
        kmem_cache_destroy(xfs_buf_item_cache);
 out_destroy_trans_cache:
        kmem_cache_destroy(xfs_trans_cache);
 out_destroy_ifork_cache:
        kmem_cache_destroy(xfs_ifork_cache);
 out_destroy_da_state_cache:
        kmem_cache_destroy(xfs_da_state_cache);
 out_destroy_defer_item_cache:
        xfs_defer_destroy_item_caches();
 out_destroy_rcbagbt_cur_cache:
        rcbagbt_destroy_cur_cache();
 out_destroy_btree_cur_cache:
        xfs_btree_destroy_cur_caches();
 out_destroy_log_ticket_cache:
        kmem_cache_destroy(xfs_log_ticket_cache);
 out_destroy_buf_cache:
        kmem_cache_destroy(xfs_buf_cache);
 out:
        return -ENOMEM;
}

STATIC void
xfs_destroy_caches(void)
{
        /*
         * Make sure all delayed rcu free are flushed before we
         * destroy caches.
         */
        rcu_barrier();
        kmem_cache_destroy(xfs_parent_args_cache);
        kmem_cache_destroy(xfs_xmd_cache);
        kmem_cache_destroy(xfs_xmi_cache);
        kmem_cache_destroy(xfs_iunlink_cache);
        kmem_cache_destroy(xfs_attri_cache);
        kmem_cache_destroy(xfs_attrd_cache);
        kmem_cache_destroy(xfs_bui_cache);
        kmem_cache_destroy(xfs_bud_cache);
        kmem_cache_destroy(xfs_cui_cache);
        kmem_cache_destroy(xfs_cud_cache);
        kmem_cache_destroy(xfs_rui_cache);
        kmem_cache_destroy(xfs_rud_cache);
        kmem_cache_destroy(xfs_icreate_cache);
        kmem_cache_destroy(xfs_ili_cache);
        kmem_cache_destroy(xfs_inode_cache);
        kmem_cache_destroy(xfs_efi_cache);
        kmem_cache_destroy(xfs_efd_cache);
        kmem_cache_destroy(xfs_buf_item_cache);
        kmem_cache_destroy(xfs_trans_cache);
        kmem_cache_destroy(xfs_ifork_cache);
        kmem_cache_destroy(xfs_da_state_cache);
        xfs_defer_destroy_item_caches();
        rcbagbt_destroy_cur_cache();
        xfs_btree_destroy_cur_caches();
        kmem_cache_destroy(xfs_log_ticket_cache);
        kmem_cache_destroy(xfs_buf_cache);
}

STATIC int __init
xfs_init_workqueues(void)
{
        /*
         * The allocation workqueue can be used in memory reclaim situations
         * (writepage path), and parallelism is only limited by the number of
         * AGs in all the filesystems mounted. Hence use the default large
         * max_active value for this workqueue.
         */
        xfs_alloc_wq = alloc_workqueue("xfsalloc", XFS_WQFLAGS(WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_PERCPU),
                        0);
        if (!xfs_alloc_wq)
                return -ENOMEM;

        xfs_discard_wq = alloc_workqueue("xfsdiscard", XFS_WQFLAGS(WQ_UNBOUND),
                        0);
        if (!xfs_discard_wq)
                goto out_free_alloc_wq;

        return 0;
out_free_alloc_wq:
        destroy_workqueue(xfs_alloc_wq);
        return -ENOMEM;
}

STATIC void
xfs_destroy_workqueues(void)
{
        destroy_workqueue(xfs_discard_wq);
        destroy_workqueue(xfs_alloc_wq);
}

STATIC int __init
init_xfs_fs(void)
{
        int                     error;

        xfs_check_ondisk_structs();

        error = xfs_dahash_test();
        if (error)
                return error;

        printk(KERN_INFO XFS_VERSION_STRING " with "
                         XFS_BUILD_OPTIONS " enabled\n");

        xfs_dir_startup();

        error = xfs_init_caches();
        if (error)
                goto out;

        error = xfs_init_workqueues();
        if (error)
                goto out_destroy_caches;

        error = xfs_mru_cache_init();
        if (error)
                goto out_destroy_wq;

        error = xfs_init_procfs();
        if (error)
                goto out_mru_cache_uninit;

        error = xfs_sysctl_register();
        if (error)
                goto out_cleanup_procfs;

        xfs_debugfs = xfs_debugfs_mkdir("xfs", NULL);

        xfs_kset = kset_create_and_add("xfs", NULL, fs_kobj);
        if (!xfs_kset) {
                error = -ENOMEM;
                goto out_debugfs_unregister;
        }

        xfsstats.xs_kobj.kobject.kset = xfs_kset;

        xfsstats.xs_stats = alloc_percpu(struct xfsstats);
        if (!xfsstats.xs_stats) {
                error = -ENOMEM;
                goto out_kset_unregister;
        }

        error = xfs_sysfs_init(&xfsstats.xs_kobj, &xfs_stats_ktype, NULL,
                               "stats");
        if (error)
                goto out_free_stats;

        error = xchk_global_stats_setup(xfs_debugfs);
        if (error)
                goto out_remove_stats_kobj;

#ifdef DEBUG
        xfs_dbg_kobj.kobject.kset = xfs_kset;
        error = xfs_sysfs_init(&xfs_dbg_kobj, &xfs_dbg_ktype, NULL, "debug");
        if (error)
                goto out_remove_scrub_stats;
#endif

        error = xfs_qm_init();
        if (error)
                goto out_remove_dbg_kobj;

        error = register_filesystem(&xfs_fs_type);
        if (error)
                goto out_qm_exit;
        return 0;

 out_qm_exit:
        xfs_qm_exit();
 out_remove_dbg_kobj:
#ifdef DEBUG
        xfs_sysfs_del(&xfs_dbg_kobj);
 out_remove_scrub_stats:
#endif
        xchk_global_stats_teardown();
 out_remove_stats_kobj:
        xfs_sysfs_del(&xfsstats.xs_kobj);
 out_free_stats:
        free_percpu(xfsstats.xs_stats);
 out_kset_unregister:
        kset_unregister(xfs_kset);
 out_debugfs_unregister:
        debugfs_remove(xfs_debugfs);
        xfs_sysctl_unregister();
 out_cleanup_procfs:
        xfs_cleanup_procfs();
 out_mru_cache_uninit:
        xfs_mru_cache_uninit();
 out_destroy_wq:
        xfs_destroy_workqueues();
 out_destroy_caches:
        xfs_destroy_caches();
 out:
        return error;
}

STATIC void __exit
exit_xfs_fs(void)
{
        xfs_qm_exit();
        unregister_filesystem(&xfs_fs_type);
#ifdef DEBUG
        xfs_sysfs_del(&xfs_dbg_kobj);
#endif
        xchk_global_stats_teardown();
        xfs_sysfs_del(&xfsstats.xs_kobj);
        free_percpu(xfsstats.xs_stats);
        kset_unregister(xfs_kset);
        debugfs_remove(xfs_debugfs);
        xfs_sysctl_unregister();
        xfs_cleanup_procfs();
        xfs_mru_cache_uninit();
        xfs_destroy_workqueues();
        xfs_destroy_caches();
        xfs_uuid_table_free();
}

module_init(init_xfs_fs);
module_exit(exit_xfs_fs);

MODULE_AUTHOR("Silicon Graphics, Inc.");
MODULE_DESCRIPTION(XFS_VERSION_STRING " with " XFS_BUILD_OPTIONS " enabled");
MODULE_LICENSE("GPL");