diff --git a/module/os/linux/zfs/zpl_super.c b/module/os/linux/zfs/zpl_super.c index d98d32c1f9fb..0a82b8858eb8 100644 --- a/module/os/linux/zfs/zpl_super.c +++ b/module/os/linux/zfs/zpl_super.c @@ -1,411 +1,417 @@ /* * 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 #include #include #include #include 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; + boolean_t issnap = B_FALSE; 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); + issnap = zfsvfs->z_issnap; 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) { + } else if (!issnap && ((flags ^ s->s_flags) & SB_RDONLY)) { + /* + * Skip ro check for snap since snap is always ro regardless + * ro flag is passed by mount or not. + */ 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, };