ZIL: Call brt_pending_add() replaying TX_CLONE_RANGE

[zfs.git] / module / os / linux / zfs / zpl_super.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or https://opensource.org/licenses/CDDL-1.0.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2011, Lawrence Livermore National Security, LLC.
 * Copyright (c) 2023, Datto Inc. All rights reserved.
 */


#include <sys/zfs_znode.h>
#include <sys/zfs_vfsops.h>
#include <sys/zfs_vnops.h>
#include <sys/zfs_ctldir.h>
#include <sys/zpl.h>


static struct inode *
zpl_inode_alloc(struct super_block *sb)
{
        struct inode *ip;

        VERIFY3S(zfs_inode_alloc(sb, &ip), ==, 0);
        inode_set_iversion(ip, 1);

        return (ip);
}

static void
zpl_inode_destroy(struct inode *ip)
{
        ASSERT(atomic_read(&ip->i_count) == 0);
        zfs_inode_destroy(ip);
}

/*
 * Called from __mark_inode_dirty() to reflect that something in the
 * inode has changed.  We use it to ensure the znode system attributes
 * are always strictly update to date with respect to the inode.
 */
#ifdef HAVE_DIRTY_INODE_WITH_FLAGS
static void
zpl_dirty_inode(struct inode *ip, int flags)
{
        fstrans_cookie_t cookie;

        cookie = spl_fstrans_mark();
        zfs_dirty_inode(ip, flags);
        spl_fstrans_unmark(cookie);
}
#else
static void
zpl_dirty_inode(struct inode *ip)
{
        fstrans_cookie_t cookie;

        cookie = spl_fstrans_mark();
        zfs_dirty_inode(ip, 0);
        spl_fstrans_unmark(cookie);
}
#endif /* HAVE_DIRTY_INODE_WITH_FLAGS */

/*
 * When ->drop_inode() is called its return value indicates if the
 * inode should be evicted from the inode cache.  If the inode is
 * unhashed and has no links the default policy is to evict it
 * immediately.
 *
 * The ->evict_inode() callback must minimally truncate the inode pages,
 * and call clear_inode().  For 2.6.35 and later kernels this will
 * simply update the inode state, with the sync occurring before the
 * truncate in evict().  For earlier kernels clear_inode() maps to
 * end_writeback() which is responsible for completing all outstanding
 * write back.  In either case, once this is done it is safe to cleanup
 * any remaining inode specific data via zfs_inactive().
 * remaining filesystem specific data.
 */
static void
zpl_evict_inode(struct inode *ip)
{
        fstrans_cookie_t cookie;

        cookie = spl_fstrans_mark();
        truncate_setsize(ip, 0);
        clear_inode(ip);
        zfs_inactive(ip);
        spl_fstrans_unmark(cookie);
}

static void
zpl_put_super(struct super_block *sb)
{
        fstrans_cookie_t cookie;
        int error;

        cookie = spl_fstrans_mark();
        error = -zfs_umount(sb);
        spl_fstrans_unmark(cookie);
        ASSERT3S(error, <=, 0);
}

static int
zpl_sync_fs(struct super_block *sb, int wait)
{
        fstrans_cookie_t cookie;
        cred_t *cr = CRED();
        int error;

        crhold(cr);
        cookie = spl_fstrans_mark();
        error = -zfs_sync(sb, wait, cr);
        spl_fstrans_unmark(cookie);
        crfree(cr);
        ASSERT3S(error, <=, 0);

        return (error);
}

static int
zpl_statfs(struct dentry *dentry, struct kstatfs *statp)
{
        fstrans_cookie_t cookie;
        int error;

        cookie = spl_fstrans_mark();
        error = -zfs_statvfs(dentry->d_inode, statp);
        spl_fstrans_unmark(cookie);
        ASSERT3S(error, <=, 0);

        /*
         * If required by a 32-bit system call, dynamically scale the
         * block size up to 16MiB and decrease the block counts.  This
         * allows for a maximum size of 64EiB to be reported.  The file
         * counts must be artificially capped at 2^32-1.
         */
        if (unlikely(zpl_is_32bit_api())) {
                while (statp->f_blocks > UINT32_MAX &&
                    statp->f_bsize < SPA_MAXBLOCKSIZE) {
                        statp->f_frsize <<= 1;
                        statp->f_bsize <<= 1;

                        statp->f_blocks >>= 1;
                        statp->f_bfree >>= 1;
                        statp->f_bavail >>= 1;
                }

                uint64_t usedobjs = statp->f_files - statp->f_ffree;
                statp->f_ffree = MIN(statp->f_ffree, UINT32_MAX - usedobjs);
                statp->f_files = statp->f_ffree + usedobjs;
        }

        return (error);
}

static int
zpl_remount_fs(struct super_block *sb, int *flags, char *data)
{
        zfs_mnt_t zm = { .mnt_osname = NULL, .mnt_data = data };
        fstrans_cookie_t cookie;
        int error;

        cookie = spl_fstrans_mark();
        error = -zfs_remount(sb, flags, &zm);
        spl_fstrans_unmark(cookie);
        ASSERT3S(error, <=, 0);

        return (error);
}

static int
__zpl_show_devname(struct seq_file *seq, zfsvfs_t *zfsvfs)
{
        int error;
        if ((error = zpl_enter(zfsvfs, FTAG)) != 0)
                return (error);

        char *fsname = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
        dmu_objset_name(zfsvfs->z_os, fsname);

        for (int i = 0; fsname[i] != 0; i++) {
                /*
                 * Spaces in the dataset name must be converted to their
                 * octal escape sequence for getmntent(3) to correctly
                 * parse then fsname portion of /proc/self/mounts.
                 */
                if (fsname[i] == ' ') {
                        seq_puts(seq, "\\040");
                } else {
                        seq_putc(seq, fsname[i]);
                }
        }

        kmem_free(fsname, ZFS_MAX_DATASET_NAME_LEN);

        zpl_exit(zfsvfs, FTAG);

        return (0);
}

static int
zpl_show_devname(struct seq_file *seq, struct dentry *root)
{
        return (__zpl_show_devname(seq, root->d_sb->s_fs_info));
}

static int
__zpl_show_options(struct seq_file *seq, zfsvfs_t *zfsvfs)
{
        seq_printf(seq, ",%s",
            zfsvfs->z_flags & ZSB_XATTR ? "xattr" : "noxattr");

#ifdef CONFIG_FS_POSIX_ACL
        switch (zfsvfs->z_acl_type) {
        case ZFS_ACLTYPE_POSIX:
                seq_puts(seq, ",posixacl");
                break;
        default:
                seq_puts(seq, ",noacl");
                break;
        }
#endif /* CONFIG_FS_POSIX_ACL */

        switch (zfsvfs->z_case) {
        case ZFS_CASE_SENSITIVE:
                seq_puts(seq, ",casesensitive");
                break;
        case ZFS_CASE_INSENSITIVE:
                seq_puts(seq, ",caseinsensitive");
                break;
        default:
                seq_puts(seq, ",casemixed");
                break;
        }

        return (0);
}

static int
zpl_show_options(struct seq_file *seq, struct dentry *root)
{
        return (__zpl_show_options(seq, root->d_sb->s_fs_info));
}

static int
zpl_fill_super(struct super_block *sb, void *data, int silent)
{
        zfs_mnt_t *zm = (zfs_mnt_t *)data;
        fstrans_cookie_t cookie;
        int error;

        cookie = spl_fstrans_mark();
        error = -zfs_domount(sb, zm, silent);
        spl_fstrans_unmark(cookie);
        ASSERT3S(error, <=, 0);

        return (error);
}

static int
zpl_test_super(struct super_block *s, void *data)
{
        zfsvfs_t *zfsvfs = s->s_fs_info;
        objset_t *os = data;
        /*
         * If the os doesn't match the z_os in the super_block, assume it is
         * not a match. Matching would imply a multimount of a dataset. It is
         * possible that during a multimount, there is a simultaneous operation
         * that changes the z_os, e.g., rollback, where the match will be
         * missed, but in that case the user will get an EBUSY.
         */
        return (zfsvfs != NULL && os == zfsvfs->z_os);
}

static struct super_block *
zpl_mount_impl(struct file_system_type *fs_type, int flags, zfs_mnt_t *zm)
{
        struct super_block *s;
        objset_t *os;
        int err;

        err = dmu_objset_hold(zm->mnt_osname, FTAG, &os);
        if (err)
                return (ERR_PTR(-err));

        /*
         * The dsl pool lock must be released prior to calling sget().
         * It is possible sget() may block on the lock in grab_super()
         * while deactivate_super() holds that same lock and waits for
         * a txg sync.  If the dsl_pool lock is held over sget()
         * this can prevent the pool sync and cause a deadlock.
         */
        dsl_dataset_long_hold(dmu_objset_ds(os), FTAG);
        dsl_pool_rele(dmu_objset_pool(os), FTAG);

        s = sget(fs_type, zpl_test_super, set_anon_super, flags, os);

        /*
         * Recheck with the lock held to prevent mounting the wrong dataset
         * since z_os can be stale when the teardown lock is held.
         *
         * We can't do this in zpl_test_super in since it's under spinlock and
         * also s_umount lock is not held there so it would race with
         * zfs_umount and zfsvfs can be freed.
         */
        if (!IS_ERR(s) && s->s_fs_info != NULL) {
                zfsvfs_t *zfsvfs = s->s_fs_info;
                if (zpl_enter(zfsvfs, FTAG) == 0) {
                        if (os != zfsvfs->z_os)
                                err = -SET_ERROR(EBUSY);
                        zpl_exit(zfsvfs, FTAG);
                } else {
                        err = -SET_ERROR(EBUSY);
                }
        }
        dsl_dataset_long_rele(dmu_objset_ds(os), FTAG);
        dsl_dataset_rele(dmu_objset_ds(os), FTAG);

        if (IS_ERR(s))
                return (ERR_CAST(s));

        if (err) {
                deactivate_locked_super(s);
                return (ERR_PTR(err));
        }

        if (s->s_root == NULL) {
                err = zpl_fill_super(s, zm, flags & SB_SILENT ? 1 : 0);
                if (err) {
                        deactivate_locked_super(s);
                        return (ERR_PTR(err));
                }
                s->s_flags |= SB_ACTIVE;
        } else if ((flags ^ s->s_flags) & SB_RDONLY) {
                deactivate_locked_super(s);
                return (ERR_PTR(-EBUSY));
        }

        return (s);
}

static struct dentry *
zpl_mount(struct file_system_type *fs_type, int flags,
    const char *osname, void *data)
{
        zfs_mnt_t zm = { .mnt_osname = osname, .mnt_data = data };

        struct super_block *sb = zpl_mount_impl(fs_type, flags, &zm);
        if (IS_ERR(sb))
                return (ERR_CAST(sb));

        return (dget(sb->s_root));
}

static void
zpl_kill_sb(struct super_block *sb)
{
        zfs_preumount(sb);
        kill_anon_super(sb);
}

void
zpl_prune_sb(uint64_t nr_to_scan, void *arg)
{
        struct super_block *sb = (struct super_block *)arg;
        int objects = 0;

        (void) -zfs_prune(sb, nr_to_scan, &objects);
}

const struct super_operations zpl_super_operations = {
        .alloc_inode            = zpl_inode_alloc,
        .destroy_inode          = zpl_inode_destroy,
        .dirty_inode            = zpl_dirty_inode,
        .write_inode            = NULL,
        .evict_inode            = zpl_evict_inode,
        .put_super              = zpl_put_super,
        .sync_fs                = zpl_sync_fs,
        .statfs                 = zpl_statfs,
        .remount_fs             = zpl_remount_fs,
        .show_devname           = zpl_show_devname,
        .show_options           = zpl_show_options,
        .show_stats             = NULL,
};

struct file_system_type zpl_fs_type = {
        .owner                  = THIS_MODULE,
        .name                   = ZFS_DRIVER,
#if defined(HAVE_IDMAP_MNT_API)
        .fs_flags               = FS_USERNS_MOUNT | FS_ALLOW_IDMAP,
#else
        .fs_flags               = FS_USERNS_MOUNT,
#endif
        .mount                  = zpl_mount,
        .kill_sb                = zpl_kill_sb,
};