| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2007 Oracle. All rights reserved. |
| */ |
| |
| #include <linux/blkdev.h> |
| #include <linux/module.h> |
| #include <linux/fs.h> |
| #include <linux/pagemap.h> |
| #include <linux/highmem.h> |
| #include <linux/time.h> |
| #include <linux/init.h> |
| #include <linux/seq_file.h> |
| #include <linux/string.h> |
| #include <linux/backing-dev.h> |
| #include <linux/mount.h> |
| #include <linux/writeback.h> |
| #include <linux/statfs.h> |
| #include <linux/compat.h> |
| #include <linux/parser.h> |
| #include <linux/ctype.h> |
| #include <linux/namei.h> |
| #include <linux/miscdevice.h> |
| #include <linux/magic.h> |
| #include <linux/slab.h> |
| #include <linux/ratelimit.h> |
| #include <linux/crc32c.h> |
| #include <linux/btrfs.h> |
| #include <linux/security.h> |
| #include <linux/fs_parser.h> |
| #include <linux/swap.h> |
| #include "messages.h" |
| #include "delayed-inode.h" |
| #include "ctree.h" |
| #include "disk-io.h" |
| #include "transaction.h" |
| #include "btrfs_inode.h" |
| #include "direct-io.h" |
| #include "props.h" |
| #include "xattr.h" |
| #include "bio.h" |
| #include "export.h" |
| #include "compression.h" |
| #include "dev-replace.h" |
| #include "free-space-cache.h" |
| #include "backref.h" |
| #include "space-info.h" |
| #include "sysfs.h" |
| #include "zoned.h" |
| #include "tests/btrfs-tests.h" |
| #include "block-group.h" |
| #include "discard.h" |
| #include "qgroup.h" |
| #include "raid56.h" |
| #include "fs.h" |
| #include "accessors.h" |
| #include "defrag.h" |
| #include "dir-item.h" |
| #include "ioctl.h" |
| #include "scrub.h" |
| #include "verity.h" |
| #include "super.h" |
| #include "extent-tree.h" |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/btrfs.h> |
| |
| static const struct super_operations btrfs_super_ops; |
| static struct file_system_type btrfs_fs_type; |
| |
| static void btrfs_put_super(struct super_block *sb) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| |
| btrfs_info(fs_info, "last unmount of filesystem %pU", fs_info->fs_devices->fsid); |
| close_ctree(fs_info); |
| } |
| |
| /* Store the mount options related information. */ |
| struct btrfs_fs_context { |
| char *subvol_name; |
| u64 subvol_objectid; |
| u64 max_inline; |
| u32 commit_interval; |
| u32 metadata_ratio; |
| u32 thread_pool_size; |
| unsigned long long mount_opt; |
| unsigned long compress_type:4; |
| unsigned int compress_level; |
| refcount_t refs; |
| }; |
| |
| enum { |
| Opt_acl, |
| Opt_clear_cache, |
| Opt_commit_interval, |
| Opt_compress, |
| Opt_compress_force, |
| Opt_compress_force_type, |
| Opt_compress_type, |
| Opt_degraded, |
| Opt_device, |
| Opt_fatal_errors, |
| Opt_flushoncommit, |
| Opt_max_inline, |
| Opt_barrier, |
| Opt_datacow, |
| Opt_datasum, |
| Opt_defrag, |
| Opt_discard, |
| Opt_discard_mode, |
| Opt_ratio, |
| Opt_rescan_uuid_tree, |
| Opt_skip_balance, |
| Opt_space_cache, |
| Opt_space_cache_version, |
| Opt_ssd, |
| Opt_ssd_spread, |
| Opt_subvol, |
| Opt_subvol_empty, |
| Opt_subvolid, |
| Opt_thread_pool, |
| Opt_treelog, |
| Opt_user_subvol_rm_allowed, |
| Opt_norecovery, |
| |
| /* Rescue options */ |
| Opt_rescue, |
| Opt_usebackuproot, |
| Opt_nologreplay, |
| |
| /* Debugging options */ |
| Opt_enospc_debug, |
| #ifdef CONFIG_BTRFS_DEBUG |
| Opt_fragment, Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all, |
| #endif |
| #ifdef CONFIG_BTRFS_FS_REF_VERIFY |
| Opt_ref_verify, |
| #endif |
| Opt_err, |
| }; |
| |
| enum { |
| Opt_fatal_errors_panic, |
| Opt_fatal_errors_bug, |
| }; |
| |
| static const struct constant_table btrfs_parameter_fatal_errors[] = { |
| { "panic", Opt_fatal_errors_panic }, |
| { "bug", Opt_fatal_errors_bug }, |
| {} |
| }; |
| |
| enum { |
| Opt_discard_sync, |
| Opt_discard_async, |
| }; |
| |
| static const struct constant_table btrfs_parameter_discard[] = { |
| { "sync", Opt_discard_sync }, |
| { "async", Opt_discard_async }, |
| {} |
| }; |
| |
| enum { |
| Opt_space_cache_v1, |
| Opt_space_cache_v2, |
| }; |
| |
| static const struct constant_table btrfs_parameter_space_cache[] = { |
| { "v1", Opt_space_cache_v1 }, |
| { "v2", Opt_space_cache_v2 }, |
| {} |
| }; |
| |
| enum { |
| Opt_rescue_usebackuproot, |
| Opt_rescue_nologreplay, |
| Opt_rescue_ignorebadroots, |
| Opt_rescue_ignoredatacsums, |
| Opt_rescue_ignoremetacsums, |
| Opt_rescue_ignoresuperflags, |
| Opt_rescue_parameter_all, |
| }; |
| |
| static const struct constant_table btrfs_parameter_rescue[] = { |
| { "usebackuproot", Opt_rescue_usebackuproot }, |
| { "nologreplay", Opt_rescue_nologreplay }, |
| { "ignorebadroots", Opt_rescue_ignorebadroots }, |
| { "ibadroots", Opt_rescue_ignorebadroots }, |
| { "ignoredatacsums", Opt_rescue_ignoredatacsums }, |
| { "ignoremetacsums", Opt_rescue_ignoremetacsums}, |
| { "ignoresuperflags", Opt_rescue_ignoresuperflags}, |
| { "idatacsums", Opt_rescue_ignoredatacsums }, |
| { "imetacsums", Opt_rescue_ignoremetacsums}, |
| { "isuperflags", Opt_rescue_ignoresuperflags}, |
| { "all", Opt_rescue_parameter_all }, |
| {} |
| }; |
| |
| #ifdef CONFIG_BTRFS_DEBUG |
| enum { |
| Opt_fragment_parameter_data, |
| Opt_fragment_parameter_metadata, |
| Opt_fragment_parameter_all, |
| }; |
| |
| static const struct constant_table btrfs_parameter_fragment[] = { |
| { "data", Opt_fragment_parameter_data }, |
| { "metadata", Opt_fragment_parameter_metadata }, |
| { "all", Opt_fragment_parameter_all }, |
| {} |
| }; |
| #endif |
| |
| static const struct fs_parameter_spec btrfs_fs_parameters[] = { |
| fsparam_flag_no("acl", Opt_acl), |
| fsparam_flag_no("autodefrag", Opt_defrag), |
| fsparam_flag_no("barrier", Opt_barrier), |
| fsparam_flag("clear_cache", Opt_clear_cache), |
| fsparam_u32("commit", Opt_commit_interval), |
| fsparam_flag("compress", Opt_compress), |
| fsparam_string("compress", Opt_compress_type), |
| fsparam_flag("compress-force", Opt_compress_force), |
| fsparam_string("compress-force", Opt_compress_force_type), |
| fsparam_flag_no("datacow", Opt_datacow), |
| fsparam_flag_no("datasum", Opt_datasum), |
| fsparam_flag("degraded", Opt_degraded), |
| fsparam_string("device", Opt_device), |
| fsparam_flag_no("discard", Opt_discard), |
| fsparam_enum("discard", Opt_discard_mode, btrfs_parameter_discard), |
| fsparam_enum("fatal_errors", Opt_fatal_errors, btrfs_parameter_fatal_errors), |
| fsparam_flag_no("flushoncommit", Opt_flushoncommit), |
| fsparam_string("max_inline", Opt_max_inline), |
| fsparam_u32("metadata_ratio", Opt_ratio), |
| fsparam_flag("rescan_uuid_tree", Opt_rescan_uuid_tree), |
| fsparam_flag("skip_balance", Opt_skip_balance), |
| fsparam_flag_no("space_cache", Opt_space_cache), |
| fsparam_enum("space_cache", Opt_space_cache_version, btrfs_parameter_space_cache), |
| fsparam_flag_no("ssd", Opt_ssd), |
| fsparam_flag_no("ssd_spread", Opt_ssd_spread), |
| fsparam_string("subvol", Opt_subvol), |
| fsparam_flag("subvol=", Opt_subvol_empty), |
| fsparam_u64("subvolid", Opt_subvolid), |
| fsparam_u32("thread_pool", Opt_thread_pool), |
| fsparam_flag_no("treelog", Opt_treelog), |
| fsparam_flag("user_subvol_rm_allowed", Opt_user_subvol_rm_allowed), |
| |
| /* Rescue options. */ |
| fsparam_enum("rescue", Opt_rescue, btrfs_parameter_rescue), |
| /* Deprecated, with alias rescue=nologreplay */ |
| __fsparam(NULL, "nologreplay", Opt_nologreplay, fs_param_deprecated, NULL), |
| /* Deprecated, with alias rescue=usebackuproot */ |
| __fsparam(NULL, "usebackuproot", Opt_usebackuproot, fs_param_deprecated, NULL), |
| /* For compatibility only, alias for "rescue=nologreplay". */ |
| fsparam_flag("norecovery", Opt_norecovery), |
| |
| /* Debugging options. */ |
| fsparam_flag_no("enospc_debug", Opt_enospc_debug), |
| #ifdef CONFIG_BTRFS_DEBUG |
| fsparam_enum("fragment", Opt_fragment, btrfs_parameter_fragment), |
| #endif |
| #ifdef CONFIG_BTRFS_FS_REF_VERIFY |
| fsparam_flag("ref_verify", Opt_ref_verify), |
| #endif |
| {} |
| }; |
| |
| /* No support for restricting writes to btrfs devices yet... */ |
| static inline blk_mode_t btrfs_open_mode(struct fs_context *fc) |
| { |
| return sb_open_mode(fc->sb_flags) & ~BLK_OPEN_RESTRICT_WRITES; |
| } |
| |
| static int btrfs_parse_param(struct fs_context *fc, struct fs_parameter *param) |
| { |
| struct btrfs_fs_context *ctx = fc->fs_private; |
| struct fs_parse_result result; |
| int opt; |
| |
| opt = fs_parse(fc, btrfs_fs_parameters, param, &result); |
| if (opt < 0) |
| return opt; |
| |
| switch (opt) { |
| case Opt_degraded: |
| btrfs_set_opt(ctx->mount_opt, DEGRADED); |
| break; |
| case Opt_subvol_empty: |
| /* |
| * This exists because we used to allow it on accident, so we're |
| * keeping it to maintain ABI. See 37becec95ac3 ("Btrfs: allow |
| * empty subvol= again"). |
| */ |
| break; |
| case Opt_subvol: |
| kfree(ctx->subvol_name); |
| ctx->subvol_name = kstrdup(param->string, GFP_KERNEL); |
| if (!ctx->subvol_name) |
| return -ENOMEM; |
| break; |
| case Opt_subvolid: |
| ctx->subvol_objectid = result.uint_64; |
| |
| /* subvolid=0 means give me the original fs_tree. */ |
| if (!ctx->subvol_objectid) |
| ctx->subvol_objectid = BTRFS_FS_TREE_OBJECTID; |
| break; |
| case Opt_device: { |
| struct btrfs_device *device; |
| blk_mode_t mode = btrfs_open_mode(fc); |
| |
| mutex_lock(&uuid_mutex); |
| device = btrfs_scan_one_device(param->string, mode, false); |
| mutex_unlock(&uuid_mutex); |
| if (IS_ERR(device)) |
| return PTR_ERR(device); |
| break; |
| } |
| case Opt_datasum: |
| if (result.negated) { |
| btrfs_set_opt(ctx->mount_opt, NODATASUM); |
| } else { |
| btrfs_clear_opt(ctx->mount_opt, NODATACOW); |
| btrfs_clear_opt(ctx->mount_opt, NODATASUM); |
| } |
| break; |
| case Opt_datacow: |
| if (result.negated) { |
| btrfs_clear_opt(ctx->mount_opt, COMPRESS); |
| btrfs_clear_opt(ctx->mount_opt, FORCE_COMPRESS); |
| btrfs_set_opt(ctx->mount_opt, NODATACOW); |
| btrfs_set_opt(ctx->mount_opt, NODATASUM); |
| } else { |
| btrfs_clear_opt(ctx->mount_opt, NODATACOW); |
| } |
| break; |
| case Opt_compress_force: |
| case Opt_compress_force_type: |
| btrfs_set_opt(ctx->mount_opt, FORCE_COMPRESS); |
| fallthrough; |
| case Opt_compress: |
| case Opt_compress_type: |
| /* |
| * Provide the same semantics as older kernels that don't use fs |
| * context, specifying the "compress" option clears |
| * "force-compress" without the need to pass |
| * "compress-force=[no|none]" before specifying "compress". |
| */ |
| if (opt != Opt_compress_force && opt != Opt_compress_force_type) |
| btrfs_clear_opt(ctx->mount_opt, FORCE_COMPRESS); |
| |
| if (opt == Opt_compress || opt == Opt_compress_force) { |
| ctx->compress_type = BTRFS_COMPRESS_ZLIB; |
| ctx->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL; |
| btrfs_set_opt(ctx->mount_opt, COMPRESS); |
| btrfs_clear_opt(ctx->mount_opt, NODATACOW); |
| btrfs_clear_opt(ctx->mount_opt, NODATASUM); |
| } else if (strncmp(param->string, "zlib", 4) == 0) { |
| ctx->compress_type = BTRFS_COMPRESS_ZLIB; |
| ctx->compress_level = |
| btrfs_compress_str2level(BTRFS_COMPRESS_ZLIB, |
| param->string + 4); |
| btrfs_set_opt(ctx->mount_opt, COMPRESS); |
| btrfs_clear_opt(ctx->mount_opt, NODATACOW); |
| btrfs_clear_opt(ctx->mount_opt, NODATASUM); |
| } else if (strncmp(param->string, "lzo", 3) == 0) { |
| ctx->compress_type = BTRFS_COMPRESS_LZO; |
| ctx->compress_level = 0; |
| btrfs_set_opt(ctx->mount_opt, COMPRESS); |
| btrfs_clear_opt(ctx->mount_opt, NODATACOW); |
| btrfs_clear_opt(ctx->mount_opt, NODATASUM); |
| } else if (strncmp(param->string, "zstd", 4) == 0) { |
| ctx->compress_type = BTRFS_COMPRESS_ZSTD; |
| ctx->compress_level = |
| btrfs_compress_str2level(BTRFS_COMPRESS_ZSTD, |
| param->string + 4); |
| btrfs_set_opt(ctx->mount_opt, COMPRESS); |
| btrfs_clear_opt(ctx->mount_opt, NODATACOW); |
| btrfs_clear_opt(ctx->mount_opt, NODATASUM); |
| } else if (strncmp(param->string, "no", 2) == 0) { |
| ctx->compress_level = 0; |
| ctx->compress_type = 0; |
| btrfs_clear_opt(ctx->mount_opt, COMPRESS); |
| btrfs_clear_opt(ctx->mount_opt, FORCE_COMPRESS); |
| } else { |
| btrfs_err(NULL, "unrecognized compression value %s", |
| param->string); |
| return -EINVAL; |
| } |
| break; |
| case Opt_ssd: |
| if (result.negated) { |
| btrfs_set_opt(ctx->mount_opt, NOSSD); |
| btrfs_clear_opt(ctx->mount_opt, SSD); |
| btrfs_clear_opt(ctx->mount_opt, SSD_SPREAD); |
| } else { |
| btrfs_set_opt(ctx->mount_opt, SSD); |
| btrfs_clear_opt(ctx->mount_opt, NOSSD); |
| } |
| break; |
| case Opt_ssd_spread: |
| if (result.negated) { |
| btrfs_clear_opt(ctx->mount_opt, SSD_SPREAD); |
| } else { |
| btrfs_set_opt(ctx->mount_opt, SSD); |
| btrfs_set_opt(ctx->mount_opt, SSD_SPREAD); |
| btrfs_clear_opt(ctx->mount_opt, NOSSD); |
| } |
| break; |
| case Opt_barrier: |
| if (result.negated) |
| btrfs_set_opt(ctx->mount_opt, NOBARRIER); |
| else |
| btrfs_clear_opt(ctx->mount_opt, NOBARRIER); |
| break; |
| case Opt_thread_pool: |
| if (result.uint_32 == 0) { |
| btrfs_err(NULL, "invalid value 0 for thread_pool"); |
| return -EINVAL; |
| } |
| ctx->thread_pool_size = result.uint_32; |
| break; |
| case Opt_max_inline: |
| ctx->max_inline = memparse(param->string, NULL); |
| break; |
| case Opt_acl: |
| if (result.negated) { |
| fc->sb_flags &= ~SB_POSIXACL; |
| } else { |
| #ifdef CONFIG_BTRFS_FS_POSIX_ACL |
| fc->sb_flags |= SB_POSIXACL; |
| #else |
| btrfs_err(NULL, "support for ACL not compiled in"); |
| return -EINVAL; |
| #endif |
| } |
| /* |
| * VFS limits the ability to toggle ACL on and off via remount, |
| * despite every file system allowing this. This seems to be |
| * an oversight since we all do, but it'll fail if we're |
| * remounting. So don't set the mask here, we'll check it in |
| * btrfs_reconfigure and do the toggling ourselves. |
| */ |
| if (fc->purpose != FS_CONTEXT_FOR_RECONFIGURE) |
| fc->sb_flags_mask |= SB_POSIXACL; |
| break; |
| case Opt_treelog: |
| if (result.negated) |
| btrfs_set_opt(ctx->mount_opt, NOTREELOG); |
| else |
| btrfs_clear_opt(ctx->mount_opt, NOTREELOG); |
| break; |
| case Opt_nologreplay: |
| btrfs_warn(NULL, |
| "'nologreplay' is deprecated, use 'rescue=nologreplay' instead"); |
| btrfs_set_opt(ctx->mount_opt, NOLOGREPLAY); |
| break; |
| case Opt_norecovery: |
| btrfs_info(NULL, |
| "'norecovery' is for compatibility only, recommended to use 'rescue=nologreplay'"); |
| btrfs_set_opt(ctx->mount_opt, NOLOGREPLAY); |
| break; |
| case Opt_flushoncommit: |
| if (result.negated) |
| btrfs_clear_opt(ctx->mount_opt, FLUSHONCOMMIT); |
| else |
| btrfs_set_opt(ctx->mount_opt, FLUSHONCOMMIT); |
| break; |
| case Opt_ratio: |
| ctx->metadata_ratio = result.uint_32; |
| break; |
| case Opt_discard: |
| if (result.negated) { |
| btrfs_clear_opt(ctx->mount_opt, DISCARD_SYNC); |
| btrfs_clear_opt(ctx->mount_opt, DISCARD_ASYNC); |
| btrfs_set_opt(ctx->mount_opt, NODISCARD); |
| } else { |
| btrfs_set_opt(ctx->mount_opt, DISCARD_SYNC); |
| btrfs_clear_opt(ctx->mount_opt, DISCARD_ASYNC); |
| } |
| break; |
| case Opt_discard_mode: |
| switch (result.uint_32) { |
| case Opt_discard_sync: |
| btrfs_clear_opt(ctx->mount_opt, DISCARD_ASYNC); |
| btrfs_set_opt(ctx->mount_opt, DISCARD_SYNC); |
| break; |
| case Opt_discard_async: |
| btrfs_clear_opt(ctx->mount_opt, DISCARD_SYNC); |
| btrfs_set_opt(ctx->mount_opt, DISCARD_ASYNC); |
| break; |
| default: |
| btrfs_err(NULL, "unrecognized discard mode value %s", |
| param->key); |
| return -EINVAL; |
| } |
| btrfs_clear_opt(ctx->mount_opt, NODISCARD); |
| break; |
| case Opt_space_cache: |
| if (result.negated) { |
| btrfs_set_opt(ctx->mount_opt, NOSPACECACHE); |
| btrfs_clear_opt(ctx->mount_opt, SPACE_CACHE); |
| btrfs_clear_opt(ctx->mount_opt, FREE_SPACE_TREE); |
| } else { |
| btrfs_clear_opt(ctx->mount_opt, FREE_SPACE_TREE); |
| btrfs_set_opt(ctx->mount_opt, SPACE_CACHE); |
| } |
| break; |
| case Opt_space_cache_version: |
| switch (result.uint_32) { |
| case Opt_space_cache_v1: |
| btrfs_set_opt(ctx->mount_opt, SPACE_CACHE); |
| btrfs_clear_opt(ctx->mount_opt, FREE_SPACE_TREE); |
| break; |
| case Opt_space_cache_v2: |
| btrfs_clear_opt(ctx->mount_opt, SPACE_CACHE); |
| btrfs_set_opt(ctx->mount_opt, FREE_SPACE_TREE); |
| break; |
| default: |
| btrfs_err(NULL, "unrecognized space_cache value %s", |
| param->key); |
| return -EINVAL; |
| } |
| break; |
| case Opt_rescan_uuid_tree: |
| btrfs_set_opt(ctx->mount_opt, RESCAN_UUID_TREE); |
| break; |
| case Opt_clear_cache: |
| btrfs_set_opt(ctx->mount_opt, CLEAR_CACHE); |
| break; |
| case Opt_user_subvol_rm_allowed: |
| btrfs_set_opt(ctx->mount_opt, USER_SUBVOL_RM_ALLOWED); |
| break; |
| case Opt_enospc_debug: |
| if (result.negated) |
| btrfs_clear_opt(ctx->mount_opt, ENOSPC_DEBUG); |
| else |
| btrfs_set_opt(ctx->mount_opt, ENOSPC_DEBUG); |
| break; |
| case Opt_defrag: |
| if (result.negated) |
| btrfs_clear_opt(ctx->mount_opt, AUTO_DEFRAG); |
| else |
| btrfs_set_opt(ctx->mount_opt, AUTO_DEFRAG); |
| break; |
| case Opt_usebackuproot: |
| btrfs_warn(NULL, |
| "'usebackuproot' is deprecated, use 'rescue=usebackuproot' instead"); |
| btrfs_set_opt(ctx->mount_opt, USEBACKUPROOT); |
| |
| /* If we're loading the backup roots we can't trust the space cache. */ |
| btrfs_set_opt(ctx->mount_opt, CLEAR_CACHE); |
| break; |
| case Opt_skip_balance: |
| btrfs_set_opt(ctx->mount_opt, SKIP_BALANCE); |
| break; |
| case Opt_fatal_errors: |
| switch (result.uint_32) { |
| case Opt_fatal_errors_panic: |
| btrfs_set_opt(ctx->mount_opt, PANIC_ON_FATAL_ERROR); |
| break; |
| case Opt_fatal_errors_bug: |
| btrfs_clear_opt(ctx->mount_opt, PANIC_ON_FATAL_ERROR); |
| break; |
| default: |
| btrfs_err(NULL, "unrecognized fatal_errors value %s", |
| param->key); |
| return -EINVAL; |
| } |
| break; |
| case Opt_commit_interval: |
| ctx->commit_interval = result.uint_32; |
| if (ctx->commit_interval == 0) |
| ctx->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL; |
| break; |
| case Opt_rescue: |
| switch (result.uint_32) { |
| case Opt_rescue_usebackuproot: |
| btrfs_set_opt(ctx->mount_opt, USEBACKUPROOT); |
| break; |
| case Opt_rescue_nologreplay: |
| btrfs_set_opt(ctx->mount_opt, NOLOGREPLAY); |
| break; |
| case Opt_rescue_ignorebadroots: |
| btrfs_set_opt(ctx->mount_opt, IGNOREBADROOTS); |
| break; |
| case Opt_rescue_ignoredatacsums: |
| btrfs_set_opt(ctx->mount_opt, IGNOREDATACSUMS); |
| break; |
| case Opt_rescue_ignoremetacsums: |
| btrfs_set_opt(ctx->mount_opt, IGNOREMETACSUMS); |
| break; |
| case Opt_rescue_ignoresuperflags: |
| btrfs_set_opt(ctx->mount_opt, IGNORESUPERFLAGS); |
| break; |
| case Opt_rescue_parameter_all: |
| btrfs_set_opt(ctx->mount_opt, IGNOREDATACSUMS); |
| btrfs_set_opt(ctx->mount_opt, IGNOREMETACSUMS); |
| btrfs_set_opt(ctx->mount_opt, IGNORESUPERFLAGS); |
| btrfs_set_opt(ctx->mount_opt, IGNOREBADROOTS); |
| btrfs_set_opt(ctx->mount_opt, NOLOGREPLAY); |
| break; |
| default: |
| btrfs_info(NULL, "unrecognized rescue option '%s'", |
| param->key); |
| return -EINVAL; |
| } |
| break; |
| #ifdef CONFIG_BTRFS_DEBUG |
| case Opt_fragment: |
| switch (result.uint_32) { |
| case Opt_fragment_parameter_all: |
| btrfs_set_opt(ctx->mount_opt, FRAGMENT_DATA); |
| btrfs_set_opt(ctx->mount_opt, FRAGMENT_METADATA); |
| break; |
| case Opt_fragment_parameter_metadata: |
| btrfs_set_opt(ctx->mount_opt, FRAGMENT_METADATA); |
| break; |
| case Opt_fragment_parameter_data: |
| btrfs_set_opt(ctx->mount_opt, FRAGMENT_DATA); |
| break; |
| default: |
| btrfs_info(NULL, "unrecognized fragment option '%s'", |
| param->key); |
| return -EINVAL; |
| } |
| break; |
| #endif |
| #ifdef CONFIG_BTRFS_FS_REF_VERIFY |
| case Opt_ref_verify: |
| btrfs_set_opt(ctx->mount_opt, REF_VERIFY); |
| break; |
| #endif |
| default: |
| btrfs_err(NULL, "unrecognized mount option '%s'", param->key); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Some options only have meaning at mount time and shouldn't persist across |
| * remounts, or be displayed. Clear these at the end of mount and remount code |
| * paths. |
| */ |
| static void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info) |
| { |
| btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT); |
| btrfs_clear_opt(fs_info->mount_opt, CLEAR_CACHE); |
| btrfs_clear_opt(fs_info->mount_opt, NOSPACECACHE); |
| } |
| |
| static bool check_ro_option(const struct btrfs_fs_info *fs_info, |
| unsigned long long mount_opt, unsigned long long opt, |
| const char *opt_name) |
| { |
| if (mount_opt & opt) { |
| btrfs_err(fs_info, "%s must be used with ro mount option", |
| opt_name); |
| return true; |
| } |
| return false; |
| } |
| |
| bool btrfs_check_options(const struct btrfs_fs_info *info, |
| unsigned long long *mount_opt, |
| unsigned long flags) |
| { |
| bool ret = true; |
| |
| if (!(flags & SB_RDONLY) && |
| (check_ro_option(info, *mount_opt, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") || |
| check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") || |
| check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums") || |
| check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREMETACSUMS, "ignoremetacsums") || |
| check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNORESUPERFLAGS, "ignoresuperflags"))) |
| ret = false; |
| |
| if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) && |
| !btrfs_raw_test_opt(*mount_opt, FREE_SPACE_TREE) && |
| !btrfs_raw_test_opt(*mount_opt, CLEAR_CACHE)) { |
| btrfs_err(info, "cannot disable free-space-tree"); |
| ret = false; |
| } |
| if (btrfs_fs_compat_ro(info, BLOCK_GROUP_TREE) && |
| !btrfs_raw_test_opt(*mount_opt, FREE_SPACE_TREE)) { |
| btrfs_err(info, "cannot disable free-space-tree with block-group-tree feature"); |
| ret = false; |
| } |
| |
| if (btrfs_check_mountopts_zoned(info, mount_opt)) |
| ret = false; |
| |
| if (!test_bit(BTRFS_FS_STATE_REMOUNTING, &info->fs_state)) { |
| if (btrfs_raw_test_opt(*mount_opt, SPACE_CACHE)) { |
| btrfs_info(info, "disk space caching is enabled"); |
| btrfs_warn(info, |
| "space cache v1 is being deprecated and will be removed in a future release, please use -o space_cache=v2"); |
| } |
| if (btrfs_raw_test_opt(*mount_opt, FREE_SPACE_TREE)) |
| btrfs_info(info, "using free-space-tree"); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * This is subtle, we only call this during open_ctree(). We need to pre-load |
| * the mount options with the on-disk settings. Before the new mount API took |
| * effect we would do this on mount and remount. With the new mount API we'll |
| * only do this on the initial mount. |
| * |
| * This isn't a change in behavior, because we're using the current state of the |
| * file system to set the current mount options. If you mounted with special |
| * options to disable these features and then remounted we wouldn't revert the |
| * settings, because mounting without these features cleared the on-disk |
| * settings, so this being called on re-mount is not needed. |
| */ |
| void btrfs_set_free_space_cache_settings(struct btrfs_fs_info *fs_info) |
| { |
| if (fs_info->sectorsize < PAGE_SIZE) { |
| btrfs_clear_opt(fs_info->mount_opt, SPACE_CACHE); |
| if (!btrfs_test_opt(fs_info, FREE_SPACE_TREE)) { |
| btrfs_info(fs_info, |
| "forcing free space tree for sector size %u with page size %lu", |
| fs_info->sectorsize, PAGE_SIZE); |
| btrfs_set_opt(fs_info->mount_opt, FREE_SPACE_TREE); |
| } |
| } |
| |
| /* |
| * At this point our mount options are populated, so we only mess with |
| * these settings if we don't have any settings already. |
| */ |
| if (btrfs_test_opt(fs_info, FREE_SPACE_TREE)) |
| return; |
| |
| if (btrfs_is_zoned(fs_info) && |
| btrfs_free_space_cache_v1_active(fs_info)) { |
| btrfs_info(fs_info, "zoned: clearing existing space cache"); |
| btrfs_set_super_cache_generation(fs_info->super_copy, 0); |
| return; |
| } |
| |
| if (btrfs_test_opt(fs_info, SPACE_CACHE)) |
| return; |
| |
| if (btrfs_test_opt(fs_info, NOSPACECACHE)) |
| return; |
| |
| /* |
| * At this point we don't have explicit options set by the user, set |
| * them ourselves based on the state of the file system. |
| */ |
| if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) |
| btrfs_set_opt(fs_info->mount_opt, FREE_SPACE_TREE); |
| else if (btrfs_free_space_cache_v1_active(fs_info)) |
| btrfs_set_opt(fs_info->mount_opt, SPACE_CACHE); |
| } |
| |
| static void set_device_specific_options(struct btrfs_fs_info *fs_info) |
| { |
| if (!btrfs_test_opt(fs_info, NOSSD) && |
| !fs_info->fs_devices->rotating) |
| btrfs_set_opt(fs_info->mount_opt, SSD); |
| |
| /* |
| * For devices supporting discard turn on discard=async automatically, |
| * unless it's already set or disabled. This could be turned off by |
| * nodiscard for the same mount. |
| * |
| * The zoned mode piggy backs on the discard functionality for |
| * resetting a zone. There is no reason to delay the zone reset as it is |
| * fast enough. So, do not enable async discard for zoned mode. |
| */ |
| if (!(btrfs_test_opt(fs_info, DISCARD_SYNC) || |
| btrfs_test_opt(fs_info, DISCARD_ASYNC) || |
| btrfs_test_opt(fs_info, NODISCARD)) && |
| fs_info->fs_devices->discardable && |
| !btrfs_is_zoned(fs_info)) |
| btrfs_set_opt(fs_info->mount_opt, DISCARD_ASYNC); |
| } |
| |
| char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, |
| u64 subvol_objectid) |
| { |
| struct btrfs_root *root = fs_info->tree_root; |
| struct btrfs_root *fs_root = NULL; |
| struct btrfs_root_ref *root_ref; |
| struct btrfs_inode_ref *inode_ref; |
| struct btrfs_key key; |
| struct btrfs_path *path = NULL; |
| char *name = NULL, *ptr; |
| u64 dirid; |
| int len; |
| int ret; |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| ret = -ENOMEM; |
| goto err; |
| } |
| |
| name = kmalloc(PATH_MAX, GFP_KERNEL); |
| if (!name) { |
| ret = -ENOMEM; |
| goto err; |
| } |
| ptr = name + PATH_MAX - 1; |
| ptr[0] = '\0'; |
| |
| /* |
| * Walk up the subvolume trees in the tree of tree roots by root |
| * backrefs until we hit the top-level subvolume. |
| */ |
| while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) { |
| key.objectid = subvol_objectid; |
| key.type = BTRFS_ROOT_BACKREF_KEY; |
| key.offset = (u64)-1; |
| |
| ret = btrfs_search_backwards(root, &key, path); |
| if (ret < 0) { |
| goto err; |
| } else if (ret > 0) { |
| ret = -ENOENT; |
| goto err; |
| } |
| |
| subvol_objectid = key.offset; |
| |
| root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| struct btrfs_root_ref); |
| len = btrfs_root_ref_name_len(path->nodes[0], root_ref); |
| ptr -= len + 1; |
| if (ptr < name) { |
| ret = -ENAMETOOLONG; |
| goto err; |
| } |
| read_extent_buffer(path->nodes[0], ptr + 1, |
| (unsigned long)(root_ref + 1), len); |
| ptr[0] = '/'; |
| dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref); |
| btrfs_release_path(path); |
| |
| fs_root = btrfs_get_fs_root(fs_info, subvol_objectid, true); |
| if (IS_ERR(fs_root)) { |
| ret = PTR_ERR(fs_root); |
| fs_root = NULL; |
| goto err; |
| } |
| |
| /* |
| * Walk up the filesystem tree by inode refs until we hit the |
| * root directory. |
| */ |
| while (dirid != BTRFS_FIRST_FREE_OBJECTID) { |
| key.objectid = dirid; |
| key.type = BTRFS_INODE_REF_KEY; |
| key.offset = (u64)-1; |
| |
| ret = btrfs_search_backwards(fs_root, &key, path); |
| if (ret < 0) { |
| goto err; |
| } else if (ret > 0) { |
| ret = -ENOENT; |
| goto err; |
| } |
| |
| dirid = key.offset; |
| |
| inode_ref = btrfs_item_ptr(path->nodes[0], |
| path->slots[0], |
| struct btrfs_inode_ref); |
| len = btrfs_inode_ref_name_len(path->nodes[0], |
| inode_ref); |
| ptr -= len + 1; |
| if (ptr < name) { |
| ret = -ENAMETOOLONG; |
| goto err; |
| } |
| read_extent_buffer(path->nodes[0], ptr + 1, |
| (unsigned long)(inode_ref + 1), len); |
| ptr[0] = '/'; |
| btrfs_release_path(path); |
| } |
| btrfs_put_root(fs_root); |
| fs_root = NULL; |
| } |
| |
| btrfs_free_path(path); |
| if (ptr == name + PATH_MAX - 1) { |
| name[0] = '/'; |
| name[1] = '\0'; |
| } else { |
| memmove(name, ptr, name + PATH_MAX - ptr); |
| } |
| return name; |
| |
| err: |
| btrfs_put_root(fs_root); |
| btrfs_free_path(path); |
| kfree(name); |
| return ERR_PTR(ret); |
| } |
| |
| static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid) |
| { |
| struct btrfs_root *root = fs_info->tree_root; |
| struct btrfs_dir_item *di; |
| struct btrfs_path *path; |
| struct btrfs_key location; |
| struct fscrypt_str name = FSTR_INIT("default", 7); |
| u64 dir_id; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| /* |
| * Find the "default" dir item which points to the root item that we |
| * will mount by default if we haven't been given a specific subvolume |
| * to mount. |
| */ |
| dir_id = btrfs_super_root_dir(fs_info->super_copy); |
| di = btrfs_lookup_dir_item(NULL, root, path, dir_id, &name, 0); |
| if (IS_ERR(di)) { |
| btrfs_free_path(path); |
| return PTR_ERR(di); |
| } |
| if (!di) { |
| /* |
| * Ok the default dir item isn't there. This is weird since |
| * it's always been there, but don't freak out, just try and |
| * mount the top-level subvolume. |
| */ |
| btrfs_free_path(path); |
| *objectid = BTRFS_FS_TREE_OBJECTID; |
| return 0; |
| } |
| |
| btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); |
| btrfs_free_path(path); |
| *objectid = location.objectid; |
| return 0; |
| } |
| |
| static int btrfs_fill_super(struct super_block *sb, |
| struct btrfs_fs_devices *fs_devices, |
| void *data) |
| { |
| struct inode *inode; |
| struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| int err; |
| |
| sb->s_maxbytes = MAX_LFS_FILESIZE; |
| sb->s_magic = BTRFS_SUPER_MAGIC; |
| sb->s_op = &btrfs_super_ops; |
| sb->s_d_op = &btrfs_dentry_operations; |
| sb->s_export_op = &btrfs_export_ops; |
| #ifdef CONFIG_FS_VERITY |
| sb->s_vop = &btrfs_verityops; |
| #endif |
| sb->s_xattr = btrfs_xattr_handlers; |
| sb->s_time_gran = 1; |
| sb->s_iflags |= SB_I_CGROUPWB; |
| |
| err = super_setup_bdi(sb); |
| if (err) { |
| btrfs_err(fs_info, "super_setup_bdi failed"); |
| return err; |
| } |
| |
| err = open_ctree(sb, fs_devices, (char *)data); |
| if (err) { |
| btrfs_err(fs_info, "open_ctree failed"); |
| return err; |
| } |
| |
| inode = btrfs_iget(BTRFS_FIRST_FREE_OBJECTID, fs_info->fs_root); |
| if (IS_ERR(inode)) { |
| err = PTR_ERR(inode); |
| btrfs_handle_fs_error(fs_info, err, NULL); |
| goto fail_close; |
| } |
| |
| sb->s_root = d_make_root(inode); |
| if (!sb->s_root) { |
| err = -ENOMEM; |
| goto fail_close; |
| } |
| |
| sb->s_flags |= SB_ACTIVE; |
| return 0; |
| |
| fail_close: |
| close_ctree(fs_info); |
| return err; |
| } |
| |
| int btrfs_sync_fs(struct super_block *sb, int wait) |
| { |
| struct btrfs_trans_handle *trans; |
| struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| struct btrfs_root *root = fs_info->tree_root; |
| |
| trace_btrfs_sync_fs(fs_info, wait); |
| |
| if (!wait) { |
| filemap_flush(fs_info->btree_inode->i_mapping); |
| return 0; |
| } |
| |
| btrfs_wait_ordered_roots(fs_info, U64_MAX, NULL); |
| |
| trans = btrfs_attach_transaction_barrier(root); |
| if (IS_ERR(trans)) { |
| /* no transaction, don't bother */ |
| if (PTR_ERR(trans) == -ENOENT) { |
| /* |
| * Exit unless we have some pending changes |
| * that need to go through commit |
| */ |
| if (!test_bit(BTRFS_FS_NEED_TRANS_COMMIT, |
| &fs_info->flags)) |
| return 0; |
| /* |
| * A non-blocking test if the fs is frozen. We must not |
| * start a new transaction here otherwise a deadlock |
| * happens. The pending operations are delayed to the |
| * next commit after thawing. |
| */ |
| if (sb_start_write_trylock(sb)) |
| sb_end_write(sb); |
| else |
| return 0; |
| trans = btrfs_start_transaction(root, 0); |
| } |
| if (IS_ERR(trans)) |
| return PTR_ERR(trans); |
| } |
| return btrfs_commit_transaction(trans); |
| } |
| |
| static void print_rescue_option(struct seq_file *seq, const char *s, bool *printed) |
| { |
| seq_printf(seq, "%s%s", (*printed) ? ":" : ",rescue=", s); |
| *printed = true; |
| } |
| |
| static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) |
| { |
| struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); |
| const char *compress_type; |
| const char *subvol_name; |
| bool printed = false; |
| |
| if (btrfs_test_opt(info, DEGRADED)) |
| seq_puts(seq, ",degraded"); |
| if (btrfs_test_opt(info, NODATASUM)) |
| seq_puts(seq, ",nodatasum"); |
| if (btrfs_test_opt(info, NODATACOW)) |
| seq_puts(seq, ",nodatacow"); |
| if (btrfs_test_opt(info, NOBARRIER)) |
| seq_puts(seq, ",nobarrier"); |
| if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE) |
| seq_printf(seq, ",max_inline=%llu", info->max_inline); |
| if (info->thread_pool_size != min_t(unsigned long, |
| num_online_cpus() + 2, 8)) |
| seq_printf(seq, ",thread_pool=%u", info->thread_pool_size); |
| if (btrfs_test_opt(info, COMPRESS)) { |
| compress_type = btrfs_compress_type2str(info->compress_type); |
| if (btrfs_test_opt(info, FORCE_COMPRESS)) |
| seq_printf(seq, ",compress-force=%s", compress_type); |
| else |
| seq_printf(seq, ",compress=%s", compress_type); |
| if (info->compress_level) |
| seq_printf(seq, ":%d", info->compress_level); |
| } |
| if (btrfs_test_opt(info, NOSSD)) |
| seq_puts(seq, ",nossd"); |
| if (btrfs_test_opt(info, SSD_SPREAD)) |
| seq_puts(seq, ",ssd_spread"); |
| else if (btrfs_test_opt(info, SSD)) |
| seq_puts(seq, ",ssd"); |
| if (btrfs_test_opt(info, NOTREELOG)) |
| seq_puts(seq, ",notreelog"); |
| if (btrfs_test_opt(info, NOLOGREPLAY)) |
| print_rescue_option(seq, "nologreplay", &printed); |
| if (btrfs_test_opt(info, USEBACKUPROOT)) |
| print_rescue_option(seq, "usebackuproot", &printed); |
| if (btrfs_test_opt(info, IGNOREBADROOTS)) |
| print_rescue_option(seq, "ignorebadroots", &printed); |
| if (btrfs_test_opt(info, IGNOREDATACSUMS)) |
| print_rescue_option(seq, "ignoredatacsums", &printed); |
| if (btrfs_test_opt(info, IGNOREMETACSUMS)) |
| print_rescue_option(seq, "ignoremetacsums", &printed); |
| if (btrfs_test_opt(info, IGNORESUPERFLAGS)) |
| print_rescue_option(seq, "ignoresuperflags", &printed); |
| if (btrfs_test_opt(info, FLUSHONCOMMIT)) |
| seq_puts(seq, ",flushoncommit"); |
| if (btrfs_test_opt(info, DISCARD_SYNC)) |
| seq_puts(seq, ",discard"); |
| if (btrfs_test_opt(info, DISCARD_ASYNC)) |
| seq_puts(seq, ",discard=async"); |
| if (!(info->sb->s_flags & SB_POSIXACL)) |
| seq_puts(seq, ",noacl"); |
| if (btrfs_free_space_cache_v1_active(info)) |
| seq_puts(seq, ",space_cache"); |
| else if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE)) |
| seq_puts(seq, ",space_cache=v2"); |
| else |
| seq_puts(seq, ",nospace_cache"); |
| if (btrfs_test_opt(info, RESCAN_UUID_TREE)) |
| seq_puts(seq, ",rescan_uuid_tree"); |
| if (btrfs_test_opt(info, CLEAR_CACHE)) |
| seq_puts(seq, ",clear_cache"); |
| if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED)) |
| seq_puts(seq, ",user_subvol_rm_allowed"); |
| if (btrfs_test_opt(info, ENOSPC_DEBUG)) |
| seq_puts(seq, ",enospc_debug"); |
| if (btrfs_test_opt(info, AUTO_DEFRAG)) |
| seq_puts(seq, ",autodefrag"); |
| if (btrfs_test_opt(info, SKIP_BALANCE)) |
| seq_puts(seq, ",skip_balance"); |
| if (info->metadata_ratio) |
| seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio); |
| if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR)) |
| seq_puts(seq, ",fatal_errors=panic"); |
| if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL) |
| seq_printf(seq, ",commit=%u", info->commit_interval); |
| #ifdef CONFIG_BTRFS_DEBUG |
| if (btrfs_test_opt(info, FRAGMENT_DATA)) |
| seq_puts(seq, ",fragment=data"); |
| if (btrfs_test_opt(info, FRAGMENT_METADATA)) |
| seq_puts(seq, ",fragment=metadata"); |
| #endif |
| if (btrfs_test_opt(info, REF_VERIFY)) |
| seq_puts(seq, ",ref_verify"); |
| seq_printf(seq, ",subvolid=%llu", btrfs_root_id(BTRFS_I(d_inode(dentry))->root)); |
| subvol_name = btrfs_get_subvol_name_from_objectid(info, |
| btrfs_root_id(BTRFS_I(d_inode(dentry))->root)); |
| if (!IS_ERR(subvol_name)) { |
| seq_puts(seq, ",subvol="); |
| seq_escape(seq, subvol_name, " \t\n\\"); |
| kfree(subvol_name); |
| } |
| return 0; |
| } |
| |
| /* |
| * subvolumes are identified by ino 256 |
| */ |
| static inline int is_subvolume_inode(struct inode *inode) |
| { |
| if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) |
| return 1; |
| return 0; |
| } |
| |
| static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid, |
| struct vfsmount *mnt) |
| { |
| struct dentry *root; |
| int ret; |
| |
| if (!subvol_name) { |
| if (!subvol_objectid) { |
| ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb), |
| &subvol_objectid); |
| if (ret) { |
| root = ERR_PTR(ret); |
| goto out; |
| } |
| } |
| subvol_name = btrfs_get_subvol_name_from_objectid( |
| btrfs_sb(mnt->mnt_sb), subvol_objectid); |
| if (IS_ERR(subvol_name)) { |
| root = ERR_CAST(subvol_name); |
| subvol_name = NULL; |
| goto out; |
| } |
| |
| } |
| |
| root = mount_subtree(mnt, subvol_name); |
| /* mount_subtree() drops our reference on the vfsmount. */ |
| mnt = NULL; |
| |
| if (!IS_ERR(root)) { |
| struct super_block *s = root->d_sb; |
| struct btrfs_fs_info *fs_info = btrfs_sb(s); |
| struct inode *root_inode = d_inode(root); |
| u64 root_objectid = btrfs_root_id(BTRFS_I(root_inode)->root); |
| |
| ret = 0; |
| if (!is_subvolume_inode(root_inode)) { |
| btrfs_err(fs_info, "'%s' is not a valid subvolume", |
| subvol_name); |
| ret = -EINVAL; |
| } |
| if (subvol_objectid && root_objectid != subvol_objectid) { |
| /* |
| * This will also catch a race condition where a |
| * subvolume which was passed by ID is renamed and |
| * another subvolume is renamed over the old location. |
| */ |
| btrfs_err(fs_info, |
| "subvol '%s' does not match subvolid %llu", |
| subvol_name, subvol_objectid); |
| ret = -EINVAL; |
| } |
| if (ret) { |
| dput(root); |
| root = ERR_PTR(ret); |
| deactivate_locked_super(s); |
| } |
| } |
| |
| out: |
| mntput(mnt); |
| kfree(subvol_name); |
| return root; |
| } |
| |
| static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, |
| u32 new_pool_size, u32 old_pool_size) |
| { |
| if (new_pool_size == old_pool_size) |
| return; |
| |
| fs_info->thread_pool_size = new_pool_size; |
| |
| btrfs_info(fs_info, "resize thread pool %d -> %d", |
| old_pool_size, new_pool_size); |
| |
| btrfs_workqueue_set_max(fs_info->workers, new_pool_size); |
| btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size); |
| btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size); |
| workqueue_set_max_active(fs_info->endio_workers, new_pool_size); |
| workqueue_set_max_active(fs_info->endio_meta_workers, new_pool_size); |
| btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size); |
| btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size); |
| btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size); |
| } |
| |
| static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info, |
| unsigned long long old_opts, int flags) |
| { |
| if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && |
| (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || |
| (flags & SB_RDONLY))) { |
| /* wait for any defraggers to finish */ |
| wait_event(fs_info->transaction_wait, |
| (atomic_read(&fs_info->defrag_running) == 0)); |
| if (flags & SB_RDONLY) |
| sync_filesystem(fs_info->sb); |
| } |
| } |
| |
| static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info, |
| unsigned long long old_opts) |
| { |
| const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE); |
| |
| /* |
| * We need to cleanup all defragable inodes if the autodefragment is |
| * close or the filesystem is read only. |
| */ |
| if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && |
| (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) { |
| btrfs_cleanup_defrag_inodes(fs_info); |
| } |
| |
| /* If we toggled discard async */ |
| if (!btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) && |
| btrfs_test_opt(fs_info, DISCARD_ASYNC)) |
| btrfs_discard_resume(fs_info); |
| else if (btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) && |
| !btrfs_test_opt(fs_info, DISCARD_ASYNC)) |
| btrfs_discard_cleanup(fs_info); |
| |
| /* If we toggled space cache */ |
| if (cache_opt != btrfs_free_space_cache_v1_active(fs_info)) |
| btrfs_set_free_space_cache_v1_active(fs_info, cache_opt); |
| } |
| |
| static int btrfs_remount_rw(struct btrfs_fs_info *fs_info) |
| { |
| int ret; |
| |
| if (BTRFS_FS_ERROR(fs_info)) { |
| btrfs_err(fs_info, |
| "remounting read-write after error is not allowed"); |
| return -EINVAL; |
| } |
| |
| if (fs_info->fs_devices->rw_devices == 0) |
| return -EACCES; |
| |
| if (!btrfs_check_rw_degradable(fs_info, NULL)) { |
| btrfs_warn(fs_info, |
| "too many missing devices, writable remount is not allowed"); |
| return -EACCES; |
| } |
| |
| if (btrfs_super_log_root(fs_info->super_copy) != 0) { |
| btrfs_warn(fs_info, |
| "mount required to replay tree-log, cannot remount read-write"); |
| return -EINVAL; |
| } |
| |
| /* |
| * NOTE: when remounting with a change that does writes, don't put it |
| * anywhere above this point, as we are not sure to be safe to write |
| * until we pass the above checks. |
| */ |
| ret = btrfs_start_pre_rw_mount(fs_info); |
| if (ret) |
| return ret; |
| |
| btrfs_clear_sb_rdonly(fs_info->sb); |
| |
| set_bit(BTRFS_FS_OPEN, &fs_info->flags); |
| |
| /* |
| * If we've gone from readonly -> read-write, we need to get our |
| * sync/async discard lists in the right state. |
| */ |
| btrfs_discard_resume(fs_info); |
| |
| return 0; |
| } |
| |
| static int btrfs_remount_ro(struct btrfs_fs_info *fs_info) |
| { |
| /* |
| * This also happens on 'umount -rf' or on shutdown, when the |
| * filesystem is busy. |
| */ |
| cancel_work_sync(&fs_info->async_reclaim_work); |
| cancel_work_sync(&fs_info->async_data_reclaim_work); |
| |
| btrfs_discard_cleanup(fs_info); |
| |
| /* Wait for the uuid_scan task to finish */ |
| down(&fs_info->uuid_tree_rescan_sem); |
| /* Avoid complains from lockdep et al. */ |
| up(&fs_info->uuid_tree_rescan_sem); |
| |
| btrfs_set_sb_rdonly(fs_info->sb); |
| |
| /* |
| * Setting SB_RDONLY will put the cleaner thread to sleep at the next |
| * loop if it's already active. If it's already asleep, we'll leave |
| * unused block groups on disk until we're mounted read-write again |
| * unless we clean them up here. |
| */ |
| btrfs_delete_unused_bgs(fs_info); |
| |
| /* |
| * The cleaner task could be already running before we set the flag |
| * BTRFS_FS_STATE_RO (and SB_RDONLY in the superblock). We must make |
| * sure that after we finish the remount, i.e. after we call |
| * btrfs_commit_super(), the cleaner can no longer start a transaction |
| * - either because it was dropping a dead root, running delayed iputs |
| * or deleting an unused block group (the cleaner picked a block |
| * group from the list of unused block groups before we were able to |
| * in the previous call to btrfs_delete_unused_bgs()). |
| */ |
| wait_on_bit(&fs_info->flags, BTRFS_FS_CLEANER_RUNNING, TASK_UNINTERRUPTIBLE); |
| |
| /* |
| * We've set the superblock to RO mode, so we might have made the |
| * cleaner task sleep without running all pending delayed iputs. Go |
| * through all the delayed iputs here, so that if an unmount happens |
| * without remounting RW we don't end up at finishing close_ctree() |
| * with a non-empty list of delayed iputs. |
| */ |
| btrfs_run_delayed_iputs(fs_info); |
| |
| btrfs_dev_replace_suspend_for_unmount(fs_info); |
| btrfs_scrub_cancel(fs_info); |
| btrfs_pause_balance(fs_info); |
| |
| /* |
| * Pause the qgroup rescan worker if it is running. We don't want it to |
| * be still running after we are in RO mode, as after that, by the time |
| * we unmount, it might have left a transaction open, so we would leak |
| * the transaction and/or crash. |
| */ |
| btrfs_qgroup_wait_for_completion(fs_info, false); |
| |
| return btrfs_commit_super(fs_info); |
| } |
| |
| static void btrfs_ctx_to_info(struct btrfs_fs_info *fs_info, struct btrfs_fs_context *ctx) |
| { |
| fs_info->max_inline = ctx->max_inline; |
| fs_info->commit_interval = ctx->commit_interval; |
| fs_info->metadata_ratio = ctx->metadata_ratio; |
| fs_info->thread_pool_size = ctx->thread_pool_size; |
| fs_info->mount_opt = ctx->mount_opt; |
| fs_info->compress_type = ctx->compress_type; |
| fs_info->compress_level = ctx->compress_level; |
| } |
| |
| static void btrfs_info_to_ctx(struct btrfs_fs_info *fs_info, struct btrfs_fs_context *ctx) |
| { |
| ctx->max_inline = fs_info->max_inline; |
| ctx->commit_interval = fs_info->commit_interval; |
| ctx->metadata_ratio = fs_info->metadata_ratio; |
| ctx->thread_pool_size = fs_info->thread_pool_size; |
| ctx->mount_opt = fs_info->mount_opt; |
| ctx->compress_type = fs_info->compress_type; |
| ctx->compress_level = fs_info->compress_level; |
| } |
| |
| #define btrfs_info_if_set(fs_info, old_ctx, opt, fmt, args...) \ |
| do { \ |
| if ((!old_ctx || !btrfs_raw_test_opt(old_ctx->mount_opt, opt)) && \ |
| btrfs_raw_test_opt(fs_info->mount_opt, opt)) \ |
| btrfs_info(fs_info, fmt, ##args); \ |
| } while (0) |
| |
| #define btrfs_info_if_unset(fs_info, old_ctx, opt, fmt, args...) \ |
| do { \ |
| if ((old_ctx && btrfs_raw_test_opt(old_ctx->mount_opt, opt)) && \ |
| !btrfs_raw_test_opt(fs_info->mount_opt, opt)) \ |
| btrfs_info(fs_info, fmt, ##args); \ |
| } while (0) |
| |
| static void btrfs_emit_options(struct btrfs_fs_info *info, |
| struct btrfs_fs_context *old) |
| { |
| btrfs_info_if_set(info, old, NODATASUM, "setting nodatasum"); |
| btrfs_info_if_set(info, old, DEGRADED, "allowing degraded mounts"); |
| btrfs_info_if_set(info, old, NODATASUM, "setting nodatasum"); |
| btrfs_info_if_set(info, old, SSD, "enabling ssd optimizations"); |
| btrfs_info_if_set(info, old, SSD_SPREAD, "using spread ssd allocation scheme"); |
| btrfs_info_if_set(info, old, NOBARRIER, "turning off barriers"); |
| btrfs_info_if_set(info, old, NOTREELOG, "disabling tree log"); |
| btrfs_info_if_set(info, old, NOLOGREPLAY, "disabling log replay at mount time"); |
| btrfs_info_if_set(info, old, FLUSHONCOMMIT, "turning on flush-on-commit"); |
| btrfs_info_if_set(info, old, DISCARD_SYNC, "turning on sync discard"); |
| btrfs_info_if_set(info, old, DISCARD_ASYNC, "turning on async discard"); |
| btrfs_info_if_set(info, old, FREE_SPACE_TREE, "enabling free space tree"); |
| btrfs_info_if_set(info, old, SPACE_CACHE, "enabling disk space caching"); |
| btrfs_info_if_set(info, old, CLEAR_CACHE, "force clearing of disk cache"); |
| btrfs_info_if_set(info, old, AUTO_DEFRAG, "enabling auto defrag"); |
| btrfs_info_if_set(info, old, FRAGMENT_DATA, "fragmenting data"); |
| btrfs_info_if_set(info, old, FRAGMENT_METADATA, "fragmenting metadata"); |
| btrfs_info_if_set(info, old, REF_VERIFY, "doing ref verification"); |
| btrfs_info_if_set(info, old, USEBACKUPROOT, "trying to use backup root at mount time"); |
| btrfs_info_if_set(info, old, IGNOREBADROOTS, "ignoring bad roots"); |
| btrfs_info_if_set(info, old, IGNOREDATACSUMS, "ignoring data csums"); |
| btrfs_info_if_set(info, old, IGNOREMETACSUMS, "ignoring meta csums"); |
| btrfs_info_if_set(info, old, IGNORESUPERFLAGS, "ignoring unknown super block flags"); |
| |
| btrfs_info_if_unset(info, old, NODATACOW, "setting datacow"); |
| btrfs_info_if_unset(info, old, SSD, "not using ssd optimizations"); |
| btrfs_info_if_unset(info, old, SSD_SPREAD, "not using spread ssd allocation scheme"); |
| btrfs_info_if_unset(info, old, NOBARRIER, "turning off barriers"); |
| btrfs_info_if_unset(info, old, NOTREELOG, "enabling tree log"); |
| btrfs_info_if_unset(info, old, SPACE_CACHE, "disabling disk space caching"); |
| btrfs_info_if_unset(info, old, FREE_SPACE_TREE, "disabling free space tree"); |
| btrfs_info_if_unset(info, old, AUTO_DEFRAG, "disabling auto defrag"); |
| btrfs_info_if_unset(info, old, COMPRESS, "use no compression"); |
| |
| /* Did the compression settings change? */ |
| if (btrfs_test_opt(info, COMPRESS) && |
| (!old || |
| old->compress_type != info->compress_type || |
| old->compress_level != info->compress_level || |
| (!btrfs_raw_test_opt(old->mount_opt, FORCE_COMPRESS) && |
| btrfs_raw_test_opt(info->mount_opt, FORCE_COMPRESS)))) { |
| const char *compress_type = btrfs_compress_type2str(info->compress_type); |
| |
| btrfs_info(info, "%s %s compression, level %d", |
| btrfs_test_opt(info, FORCE_COMPRESS) ? "force" : "use", |
| compress_type, info->compress_level); |
| } |
| |
| if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE) |
| btrfs_info(info, "max_inline set to %llu", info->max_inline); |
| } |
| |
| static int btrfs_reconfigure(struct fs_context *fc) |
| { |
| struct super_block *sb = fc->root->d_sb; |
| struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| struct btrfs_fs_context *ctx = fc->fs_private; |
| struct btrfs_fs_context old_ctx; |
| int ret = 0; |
| bool mount_reconfigure = (fc->s_fs_info != NULL); |
| |
| btrfs_info_to_ctx(fs_info, &old_ctx); |
| |
| /* |
| * This is our "bind mount" trick, we don't want to allow the user to do |
| * anything other than mount a different ro/rw and a different subvol, |
| * all of the mount options should be maintained. |
| */ |
| if (mount_reconfigure) |
| ctx->mount_opt = old_ctx.mount_opt; |
| |
| sync_filesystem(sb); |
| set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); |
| |
| if (!btrfs_check_options(fs_info, &ctx->mount_opt, fc->sb_flags)) |
| return -EINVAL; |
| |
| ret = btrfs_check_features(fs_info, !(fc->sb_flags & SB_RDONLY)); |
| if (ret < 0) |
| return ret; |
| |
| btrfs_ctx_to_info(fs_info, ctx); |
| btrfs_remount_begin(fs_info, old_ctx.mount_opt, fc->sb_flags); |
| btrfs_resize_thread_pool(fs_info, fs_info->thread_pool_size, |
| old_ctx.thread_pool_size); |
| |
| if ((bool)btrfs_test_opt(fs_info, FREE_SPACE_TREE) != |
| (bool)btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) && |
| (!sb_rdonly(sb) || (fc->sb_flags & SB_RDONLY))) { |
| btrfs_warn(fs_info, |
| "remount supports changing free space tree only from RO to RW"); |
| /* Make sure free space cache options match the state on disk. */ |
| if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) { |
| btrfs_set_opt(fs_info->mount_opt, FREE_SPACE_TREE); |
| btrfs_clear_opt(fs_info->mount_opt, SPACE_CACHE); |
| } |
| if (btrfs_free_space_cache_v1_active(fs_info)) { |
| btrfs_clear_opt(fs_info->mount_opt, FREE_SPACE_TREE); |
| btrfs_set_opt(fs_info->mount_opt, SPACE_CACHE); |
| } |
| } |
| |
| ret = 0; |
| if (!sb_rdonly(sb) && (fc->sb_flags & SB_RDONLY)) |
| ret = btrfs_remount_ro(fs_info); |
| else if (sb_rdonly(sb) && !(fc->sb_flags & SB_RDONLY)) |
| ret = btrfs_remount_rw(fs_info); |
| if (ret) |
| goto restore; |
| |
| /* |
| * If we set the mask during the parameter parsing VFS would reject the |
| * remount. Here we can set the mask and the value will be updated |
| * appropriately. |
| */ |
| if ((fc->sb_flags & SB_POSIXACL) != (sb->s_flags & SB_POSIXACL)) |
| fc->sb_flags_mask |= SB_POSIXACL; |
| |
| btrfs_emit_options(fs_info, &old_ctx); |
| wake_up_process(fs_info->transaction_kthread); |
| btrfs_remount_cleanup(fs_info, old_ctx.mount_opt); |
| btrfs_clear_oneshot_options(fs_info); |
| clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); |
| |
| return 0; |
| restore: |
| btrfs_ctx_to_info(fs_info, &old_ctx); |
| btrfs_remount_cleanup(fs_info, old_ctx.mount_opt); |
| clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); |
| return ret; |
| } |
| |
| /* Used to sort the devices by max_avail(descending sort) */ |
| static int btrfs_cmp_device_free_bytes(const void *a, const void *b) |
| { |
| const struct btrfs_device_info *dev_info1 = a; |
| const struct btrfs_device_info *dev_info2 = b; |
| |
| if (dev_info1->max_avail > dev_info2->max_avail) |
| return -1; |
| else if (dev_info1->max_avail < dev_info2->max_avail) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * sort the devices by max_avail, in which max free extent size of each device |
| * is stored.(Descending Sort) |
| */ |
| static inline void btrfs_descending_sort_devices( |
| struct btrfs_device_info *devices, |
| size_t nr_devices) |
| { |
| sort(devices, nr_devices, sizeof(struct btrfs_device_info), |
| btrfs_cmp_device_free_bytes, NULL); |
| } |
| |
| /* |
| * The helper to calc the free space on the devices that can be used to store |
| * file data. |
| */ |
| static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info, |
| u64 *free_bytes) |
| { |
| struct btrfs_device_info *devices_info; |
| struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; |
| struct btrfs_device *device; |
| u64 type; |
| u64 avail_space; |
| u64 min_stripe_size; |
| int num_stripes = 1; |
| int i = 0, nr_devices; |
| const struct btrfs_raid_attr *rattr; |
| |
| /* |
| * We aren't under the device list lock, so this is racy-ish, but good |
| * enough for our purposes. |
| */ |
| nr_devices = fs_info->fs_devices->open_devices; |
| if (!nr_devices) { |
| smp_mb(); |
| nr_devices = fs_info->fs_devices->open_devices; |
| ASSERT(nr_devices); |
| if (!nr_devices) { |
| *free_bytes = 0; |
| return 0; |
| } |
| } |
| |
| devices_info = kmalloc_array(nr_devices, sizeof(*devices_info), |
| GFP_KERNEL); |
| if (!devices_info) |
| return -ENOMEM; |
| |
| /* calc min stripe number for data space allocation */ |
| type = btrfs_data_alloc_profile(fs_info); |
| rattr = &btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)]; |
| |
| if (type & BTRFS_BLOCK_GROUP_RAID0) |
| num_stripes = nr_devices; |
| else if (type & BTRFS_BLOCK_GROUP_RAID1_MASK) |
| num_stripes = rattr->ncopies; |
| else if (type & BTRFS_BLOCK_GROUP_RAID10) |
| num_stripes = 4; |
| |
| /* Adjust for more than 1 stripe per device */ |
| min_stripe_size = rattr->dev_stripes * BTRFS_STRIPE_LEN; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { |
| if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, |
| &device->dev_state) || |
| !device->bdev || |
| test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) |
| continue; |
| |
| if (i >= nr_devices) |
| break; |
| |
| avail_space = device->total_bytes - device->bytes_used; |
| |
| /* align with stripe_len */ |
| avail_space = rounddown(avail_space, BTRFS_STRIPE_LEN); |
| |
| /* |
| * Ensure we have at least min_stripe_size on top of the |
| * reserved space on the device. |
| */ |
| if (avail_space <= BTRFS_DEVICE_RANGE_RESERVED + min_stripe_size) |
| continue; |
| |
| avail_space -= BTRFS_DEVICE_RANGE_RESERVED; |
| |
| devices_info[i].dev = device; |
| devices_info[i].max_avail = avail_space; |
| |
| i++; |
| } |
| rcu_read_unlock(); |
| |
| nr_devices = i; |
| |
| btrfs_descending_sort_devices(devices_info, nr_devices); |
| |
| i = nr_devices - 1; |
| avail_space = 0; |
| while (nr_devices >= rattr->devs_min) { |
| num_stripes = min(num_stripes, nr_devices); |
| |
| if (devices_info[i].max_avail >= min_stripe_size) { |
| int j; |
| u64 alloc_size; |
| |
| avail_space += devices_info[i].max_avail * num_stripes; |
| alloc_size = devices_info[i].max_avail; |
| for (j = i + 1 - num_stripes; j <= i; j++) |
| devices_info[j].max_avail -= alloc_size; |
| } |
| i--; |
| nr_devices--; |
| } |
| |
| kfree(devices_info); |
| *free_bytes = avail_space; |
| return 0; |
| } |
| |
| /* |
| * Calculate numbers for 'df', pessimistic in case of mixed raid profiles. |
| * |
| * If there's a redundant raid level at DATA block groups, use the respective |
| * multiplier to scale the sizes. |
| * |
| * Unused device space usage is based on simulating the chunk allocator |
| * algorithm that respects the device sizes and order of allocations. This is |
| * a close approximation of the actual use but there are other factors that may |
| * change the result (like a new metadata chunk). |
| * |
| * If metadata is exhausted, f_bavail will be 0. |
| */ |
| static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); |
| struct btrfs_super_block *disk_super = fs_info->super_copy; |
| struct btrfs_space_info *found; |
| u64 total_used = 0; |
| u64 total_free_data = 0; |
| u64 total_free_meta = 0; |
| u32 bits = fs_info->sectorsize_bits; |
| __be32 *fsid = (__be32 *)fs_info->fs_devices->fsid; |
| unsigned factor = 1; |
| struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; |
| int ret; |
| u64 thresh = 0; |
| int mixed = 0; |
| |
| list_for_each_entry(found, &fs_info->space_info, list) { |
| if (found->flags & BTRFS_BLOCK_GROUP_DATA) { |
| int i; |
| |
| total_free_data += found->disk_total - found->disk_used; |
| total_free_data -= |
| btrfs_account_ro_block_groups_free_space(found); |
| |
| for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { |
| if (!list_empty(&found->block_groups[i])) |
| factor = btrfs_bg_type_to_factor( |
| btrfs_raid_array[i].bg_flag); |
| } |
| } |
| |
| /* |
| * Metadata in mixed block group profiles are accounted in data |
| */ |
| if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) { |
| if (found->flags & BTRFS_BLOCK_GROUP_DATA) |
| mixed = 1; |
| else |
| total_free_meta += found->disk_total - |
| found->disk_used; |
| } |
| |
| total_used += found->disk_used; |
| } |
| |
| buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor); |
| buf->f_blocks >>= bits; |
| buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits); |
| |
| /* Account global block reserve as used, it's in logical size already */ |
| spin_lock(&block_rsv->lock); |
| /* Mixed block groups accounting is not byte-accurate, avoid overflow */ |
| if (buf->f_bfree >= block_rsv->size >> bits) |
| buf->f_bfree -= block_rsv->size >> bits; |
| else |
| buf->f_bfree = 0; |
| spin_unlock(&block_rsv->lock); |
| |
| buf->f_bavail = div_u64(total_free_data, factor); |
| ret = btrfs_calc_avail_data_space(fs_info, &total_free_data); |
| if (ret) |
| return ret; |
| buf->f_bavail += div_u64(total_free_data, factor); |
| buf->f_bavail = buf->f_bavail >> bits; |
| |
| /* |
| * We calculate the remaining metadata space minus global reserve. If |
| * this is (supposedly) smaller than zero, there's no space. But this |
| * does not hold in practice, the exhausted state happens where's still |
| * some positive delta. So we apply some guesswork and compare the |
| * delta to a 4M threshold. (Practically observed delta was ~2M.) |
| * |
| * We probably cannot calculate the exact threshold value because this |
| * depends on the internal reservations requested by various |
| * operations, so some operations that consume a few metadata will |
| * succeed even if the Avail is zero. But this is better than the other |
| * way around. |
| */ |
| thresh = SZ_4M; |
| |
| /* |
| * We only want to claim there's no available space if we can no longer |
| * allocate chunks for our metadata profile and our global reserve will |
| * not fit in the free metadata space. If we aren't ->full then we |
| * still can allocate chunks and thus are fine using the currently |
| * calculated f_bavail. |
| */ |
| if (!mixed && block_rsv->space_info->full && |
| (total_free_meta < thresh || total_free_meta - thresh < block_rsv->size)) |
| buf->f_bavail = 0; |
| |
| buf->f_type = BTRFS_SUPER_MAGIC; |
| buf->f_bsize = fs_info->sectorsize; |
| buf->f_namelen = BTRFS_NAME_LEN; |
| |
| /* We treat it as constant endianness (it doesn't matter _which_) |
| because we want the fsid to come out the same whether mounted |
| on a big-endian or little-endian host */ |
| buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); |
| buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); |
| /* Mask in the root object ID too, to disambiguate subvols */ |
| buf->f_fsid.val[0] ^= btrfs_root_id(BTRFS_I(d_inode(dentry))->root) >> 32; |
| buf->f_fsid.val[1] ^= btrfs_root_id(BTRFS_I(d_inode(dentry))->root); |
| |
| return 0; |
| } |
| |
| static int btrfs_fc_test_super(struct super_block *sb, struct fs_context *fc) |
| { |
| struct btrfs_fs_info *p = fc->s_fs_info; |
| struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| |
| return fs_info->fs_devices == p->fs_devices; |
| } |
| |
| static int btrfs_get_tree_super(struct fs_context *fc) |
| { |
| struct btrfs_fs_info *fs_info = fc->s_fs_info; |
| struct btrfs_fs_context *ctx = fc->fs_private; |
| struct btrfs_fs_devices *fs_devices = NULL; |
| struct block_device *bdev; |
| struct btrfs_device *device; |
| struct super_block *sb; |
| blk_mode_t mode = btrfs_open_mode(fc); |
| int ret; |
| |
| btrfs_ctx_to_info(fs_info, ctx); |
| mutex_lock(&uuid_mutex); |
| |
| /* |
| * With 'true' passed to btrfs_scan_one_device() (mount time) we expect |
| * either a valid device or an error. |
| */ |
| device = btrfs_scan_one_device(fc->source, mode, true); |
| ASSERT(device != NULL); |
| if (IS_ERR(device)) { |
| mutex_unlock(&uuid_mutex); |
| return PTR_ERR(device); |
| } |
| |
| fs_devices = device->fs_devices; |
| fs_info->fs_devices = fs_devices; |
| |
| ret = btrfs_open_devices(fs_devices, mode, &btrfs_fs_type); |
| mutex_unlock(&uuid_mutex); |
| if (ret) |
| return ret; |
| |
| if (!(fc->sb_flags & SB_RDONLY) && fs_devices->rw_devices == 0) { |
| ret = -EACCES; |
| goto error; |
| } |
| |
| bdev = fs_devices->latest_dev->bdev; |
| |
| /* |
| * From now on the error handling is not straightforward. |
| * |
| * If successful, this will transfer the fs_info into the super block, |
| * and fc->s_fs_info will be NULL. However if there's an existing |
| * super, we'll still have fc->s_fs_info populated. If we error |
| * completely out it'll be cleaned up when we drop the fs_context, |
| * otherwise it's tied to the lifetime of the super_block. |
| */ |
| sb = sget_fc(fc, btrfs_fc_test_super, set_anon_super_fc); |
| if (IS_ERR(sb)) { |
| ret = PTR_ERR(sb); |
| goto error; |
| } |
| |
| set_device_specific_options(fs_info); |
| |
| if (sb->s_root) { |
| btrfs_close_devices(fs_devices); |
| if ((fc->sb_flags ^ sb->s_flags) & SB_RDONLY) |
| ret = -EBUSY; |
| } else { |
| snprintf(sb->s_id, sizeof(sb->s_id), "%pg", bdev); |
| shrinker_debugfs_rename(sb->s_shrink, "sb-btrfs:%s", sb->s_id); |
| btrfs_sb(sb)->bdev_holder = &btrfs_fs_type; |
| ret = btrfs_fill_super(sb, fs_devices, NULL); |
| } |
| |
| if (ret) { |
| deactivate_locked_super(sb); |
| return ret; |
| } |
| |
| btrfs_clear_oneshot_options(fs_info); |
| |
| fc->root = dget(sb->s_root); |
| return 0; |
| |
| error: |
| btrfs_close_devices(fs_devices); |
| return ret; |
| } |
| |
| /* |
| * Ever since commit 0723a0473fb4 ("btrfs: allow mounting btrfs subvolumes |
| * with different ro/rw options") the following works: |
| * |
| * (i) mount /dev/sda3 -o subvol=foo,ro /mnt/foo |
| * (ii) mount /dev/sda3 -o subvol=bar,rw /mnt/bar |
| * |
| * which looks nice and innocent but is actually pretty intricate and deserves |
| * a long comment. |
| * |
| * On another filesystem a subvolume mount is close to something like: |
| * |
| * (iii) # create rw superblock + initial mount |
| * mount -t xfs /dev/sdb /opt/ |
| * |
| * # create ro bind mount |
| * mount --bind -o ro /opt/foo /mnt/foo |
| * |
| * # unmount initial mount |
| * umount /opt |
| * |
| * Of course, there's some special subvolume sauce and there's the fact that the |
| * sb->s_root dentry is really swapped after mount_subtree(). But conceptually |
| * it's very close and will help us understand the issue. |
| * |
| * The old mount API didn't cleanly distinguish between a mount being made ro |
| * and a superblock being made ro. The only way to change the ro state of |
| * either object was by passing ms_rdonly. If a new mount was created via |
| * mount(2) such as: |
| * |
| * mount("/dev/sdb", "/mnt", "xfs", ms_rdonly, null); |
| * |
| * the MS_RDONLY flag being specified had two effects: |
| * |
| * (1) MNT_READONLY was raised -> the resulting mount got |
| * @mnt->mnt_flags |= MNT_READONLY raised. |
| * |
| * (2) MS_RDONLY was passed to the filesystem's mount method and the filesystems |
| * made the superblock ro. Note, how SB_RDONLY has the same value as |
| * ms_rdonly and is raised whenever MS_RDONLY is passed through mount(2). |
| * |
| * Creating a subtree mount via (iii) ends up leaving a rw superblock with a |
| * subtree mounted ro. |
| * |
| * But consider the effect on the old mount API on btrfs subvolume mounting |
| * which combines the distinct step in (iii) into a single step. |
| * |
| * By issuing (i) both the mount and the superblock are turned ro. Now when (ii) |
| * is issued the superblock is ro and thus even if the mount created for (ii) is |
| * rw it wouldn't help. Hence, btrfs needed to transition the superblock from ro |
| * to rw for (ii) which it did using an internal remount call. |
| * |
| * IOW, subvolume mounting was inherently complicated due to the ambiguity of |
| * MS_RDONLY in mount(2). Note, this ambiguity has mount(8) always translate |
| * "ro" to MS_RDONLY. IOW, in both (i) and (ii) "ro" becomes MS_RDONLY when |
| * passed by mount(8) to mount(2). |
| * |
| * Enter the new mount API. The new mount API disambiguates making a mount ro |
| * and making a superblock ro. |
| * |
| * (3) To turn a mount ro the MOUNT_ATTR_ONLY flag can be used with either |
| * fsmount() or mount_setattr() this is a pure VFS level change for a |
| * specific mount or mount tree that is never seen by the filesystem itself. |
| * |
| * (4) To turn a superblock ro the "ro" flag must be used with |
| * fsconfig(FSCONFIG_SET_FLAG, "ro"). This option is seen by the filesystem |
| * in fc->sb_flags. |
| * |
| * But, currently the util-linux mount command already utilizes the new mount |
| * API and is still setting fsconfig(FSCONFIG_SET_FLAG, "ro") no matter if it's |
| * btrfs or not, setting the whole super block RO. To make per-subvolume mounting |
| * work with different options work we need to keep backward compatibility. |
| */ |
| static struct vfsmount *btrfs_reconfigure_for_mount(struct fs_context *fc) |
| { |
| struct vfsmount *mnt; |
| int ret; |
| const bool ro2rw = !(fc->sb_flags & SB_RDONLY); |
| |
| /* |
| * We got an EBUSY because our SB_RDONLY flag didn't match the existing |
| * super block, so invert our setting here and retry the mount so we |
| * can get our vfsmount. |
| */ |
| if (ro2rw) |
| fc->sb_flags |= SB_RDONLY; |
| else |
| fc->sb_flags &= ~SB_RDONLY; |
| |
| mnt = fc_mount(fc); |
| if (IS_ERR(mnt)) |
| return mnt; |
| |
| if (!ro2rw) |
| return mnt; |
| |
| /* We need to convert to rw, call reconfigure. */ |
| fc->sb_flags &= ~SB_RDONLY; |
| down_write(&mnt->mnt_sb->s_umount); |
| ret = btrfs_reconfigure(fc); |
| up_write(&mnt->mnt_sb->s_umount); |
| if (ret) { |
| mntput(mnt); |
| return ERR_PTR(ret); |
| } |
| return mnt; |
| } |
| |
| static int btrfs_get_tree_subvol(struct fs_context *fc) |
| { |
| struct btrfs_fs_info *fs_info = NULL; |
| struct btrfs_fs_context *ctx = fc->fs_private; |
| struct fs_context *dup_fc; |
| struct dentry *dentry; |
| struct vfsmount *mnt; |
| |
| /* |
| * Setup a dummy root and fs_info for test/set super. This is because |
| * we don't actually fill this stuff out until open_ctree, but we need |
| * then open_ctree will properly initialize the file system specific |
| * settings later. btrfs_init_fs_info initializes the static elements |
| * of the fs_info (locks and such) to make cleanup easier if we find a |
| * superblock with our given fs_devices later on at sget() time. |
| */ |
| fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL); |
| if (!fs_info) |
| return -ENOMEM; |
| |
| fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); |
| fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); |
| if (!fs_info->super_copy || !fs_info->super_for_commit) { |
| btrfs_free_fs_info(fs_info); |
| return -ENOMEM; |
| } |
| btrfs_init_fs_info(fs_info); |
| |
| dup_fc = vfs_dup_fs_context(fc); |
| if (IS_ERR(dup_fc)) { |
| btrfs_free_fs_info(fs_info); |
| return PTR_ERR(dup_fc); |
| } |
| |
| /* |
| * When we do the sget_fc this gets transferred to the sb, so we only |
| * need to set it on the dup_fc as this is what creates the super block. |
| */ |
| dup_fc->s_fs_info = fs_info; |
| |
| /* |
| * We'll do the security settings in our btrfs_get_tree_super() mount |
| * loop, they were duplicated into dup_fc, we can drop the originals |
| * here. |
| */ |
| security_free_mnt_opts(&fc->security); |
| fc->security = NULL; |
| |
| mnt = fc_mount(dup_fc); |
| if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) |
| mnt = btrfs_reconfigure_for_mount(dup_fc); |
| put_fs_context(dup_fc); |
| if (IS_ERR(mnt)) |
| return PTR_ERR(mnt); |
| |
| /* |
| * This free's ->subvol_name, because if it isn't set we have to |
| * allocate a buffer to hold the subvol_name, so we just drop our |
| * reference to it here. |
| */ |
| dentry = mount_subvol(ctx->subvol_name, ctx->subvol_objectid, mnt); |
| ctx->subvol_name = NULL; |
| if (IS_ERR(dentry)) |
| return PTR_ERR(dentry); |
| |
| fc->root = dentry; |
| return 0; |
| } |
| |
| static int btrfs_get_tree(struct fs_context *fc) |
| { |
| /* |
| * Since we use mount_subtree to mount the default/specified subvol, we |
| * have to do mounts in two steps. |
| * |
| * First pass through we call btrfs_get_tree_subvol(), this is just a |
| * wrapper around fc_mount() to call back into here again, and this time |
| * we'll call btrfs_get_tree_super(). This will do the open_ctree() and |
| * everything to open the devices and file system. Then we return back |
| * with a fully constructed vfsmount in btrfs_get_tree_subvol(), and |
| * from there we can do our mount_subvol() call, which will lookup |
| * whichever subvol we're mounting and setup this fc with the |
| * appropriate dentry for the subvol. |
| */ |
| if (fc->s_fs_info) |
| return btrfs_get_tree_super(fc); |
| return btrfs_get_tree_subvol(fc); |
| } |
| |
| static void btrfs_kill_super(struct super_block *sb) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| kill_anon_super(sb); |
| btrfs_free_fs_info(fs_info); |
| } |
| |
| static void btrfs_free_fs_context(struct fs_context *fc) |
| { |
| struct btrfs_fs_context *ctx = fc->fs_private; |
| struct btrfs_fs_info *fs_info = fc->s_fs_info; |
| |
| if (fs_info) |
| btrfs_free_fs_info(fs_info); |
| |
| if (ctx && refcount_dec_and_test(&ctx->refs)) { |
| kfree(ctx->subvol_name); |
| kfree(ctx); |
| } |
| } |
| |
| static int btrfs_dup_fs_context(struct fs_context *fc, struct fs_context *src_fc) |
| { |
| struct btrfs_fs_context *ctx = src_fc->fs_private; |
| |
| /* |
| * Give a ref to our ctx to this dup, as we want to keep it around for |
| * our original fc so we can have the subvolume name or objectid. |
| * |
| * We unset ->source in the original fc because the dup needs it for |
| * mounting, and then once we free the dup it'll free ->source, so we |
| * need to make sure we're only pointing to it in one fc. |
| */ |
| refcount_inc(&ctx->refs); |
| fc->fs_private = ctx; |
| fc->source = src_fc->source; |
| src_fc->source = NULL; |
| return 0; |
| } |
| |
| static const struct fs_context_operations btrfs_fs_context_ops = { |
| .parse_param = btrfs_parse_param, |
| .reconfigure = btrfs_reconfigure, |
| .get_tree = btrfs_get_tree, |
| .dup = btrfs_dup_fs_context, |
| .free = btrfs_free_fs_context, |
| }; |
| |
| static int btrfs_init_fs_context(struct fs_context *fc) |
| { |
| struct btrfs_fs_context *ctx; |
| |
| ctx = kzalloc(sizeof(struct btrfs_fs_context), GFP_KERNEL); |
| if (!ctx) |
| return -ENOMEM; |
| |
| refcount_set(&ctx->refs, 1); |
| fc->fs_private = ctx; |
| fc->ops = &btrfs_fs_context_ops; |
| |
| if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) { |
| btrfs_info_to_ctx(btrfs_sb(fc->root->d_sb), ctx); |
| } else { |
| ctx->thread_pool_size = |
| min_t(unsigned long, num_online_cpus() + 2, 8); |
| ctx->max_inline = BTRFS_DEFAULT_MAX_INLINE; |
| ctx->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL; |
| } |
| |
| #ifdef CONFIG_BTRFS_FS_POSIX_ACL |
| fc->sb_flags |= SB_POSIXACL; |
| #endif |
| fc->sb_flags |= SB_I_VERSION; |
| |
| return 0; |
| } |
| |
| static struct file_system_type btrfs_fs_type = { |
| .owner = THIS_MODULE, |
| .name = "btrfs", |
| .init_fs_context = btrfs_init_fs_context, |
| .parameters = btrfs_fs_parameters, |
| .kill_sb = btrfs_kill_super, |
| .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_ALLOW_IDMAP, |
| }; |
| |
| MODULE_ALIAS_FS("btrfs"); |
| |
| static int btrfs_control_open(struct inode *inode, struct file *file) |
| { |
| /* |
| * The control file's private_data is used to hold the |
| * transaction when it is started and is used to keep |
| * track of whether a transaction is already in progress. |
| */ |
| file->private_data = NULL; |
| return 0; |
| } |
| |
| /* |
| * Used by /dev/btrfs-control for devices ioctls. |
| */ |
| static long btrfs_control_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct btrfs_ioctl_vol_args *vol; |
| struct btrfs_device *device = NULL; |
| dev_t devt = 0; |
| int ret = -ENOTTY; |
| |
| if (!capable(CAP_SYS_ADMIN)) |
| return -EPERM; |
| |
| vol = memdup_user((void __user *)arg, sizeof(*vol)); |
| if (IS_ERR(vol)) |
| return PTR_ERR(vol); |
| ret = btrfs_check_ioctl_vol_args_path(vol); |
| if (ret < 0) |
| goto out; |
| |
| switch (cmd) { |
| case BTRFS_IOC_SCAN_DEV: |
| mutex_lock(&uuid_mutex); |
| /* |
| * Scanning outside of mount can return NULL which would turn |
| * into 0 error code. |
| */ |
| device = btrfs_scan_one_device(vol->name, BLK_OPEN_READ, false); |
| ret = PTR_ERR_OR_ZERO(device); |
| mutex_unlock(&uuid_mutex); |
| break; |
| case BTRFS_IOC_FORGET_DEV: |
| if (vol->name[0] != 0) { |
| ret = lookup_bdev(vol->name, &devt); |
| if (ret) |
| break; |
| } |
| ret = btrfs_forget_devices(devt); |
| break; |
| case BTRFS_IOC_DEVICES_READY: |
| mutex_lock(&uuid_mutex); |
| /* |
| * Scanning outside of mount can return NULL which would turn |
| * into 0 error code. |
| */ |
| device = btrfs_scan_one_device(vol->name, BLK_OPEN_READ, false); |
| if (IS_ERR_OR_NULL(device)) { |
| mutex_unlock(&uuid_mutex); |
| ret = PTR_ERR(device); |
| break; |
| } |
| ret = !(device->fs_devices->num_devices == |
| device->fs_devices->total_devices); |
| mutex_unlock(&uuid_mutex); |
| break; |
| case BTRFS_IOC_GET_SUPPORTED_FEATURES: |
| ret = btrfs_ioctl_get_supported_features((void __user*)arg); |
| break; |
| } |
| |
| out: |
| kfree(vol); |
| return ret; |
| } |
| |
| static int btrfs_freeze(struct super_block *sb) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| |
| set_bit(BTRFS_FS_FROZEN, &fs_info->flags); |
| /* |
| * We don't need a barrier here, we'll wait for any transaction that |
| * could be in progress on other threads (and do delayed iputs that |
| * we want to avoid on a frozen filesystem), or do the commit |
| * ourselves. |
| */ |
| return btrfs_commit_current_transaction(fs_info->tree_root); |
| } |
| |
| static int check_dev_super(struct btrfs_device *dev) |
| { |
| struct btrfs_fs_info *fs_info = dev->fs_info; |
| struct btrfs_super_block *sb; |
| u64 last_trans; |
| u16 csum_type; |
| int ret = 0; |
| |
| /* This should be called with fs still frozen. */ |
| ASSERT(test_bit(BTRFS_FS_FROZEN, &fs_info->flags)); |
| |
| /* Missing dev, no need to check. */ |
| if (!dev->bdev) |
| return 0; |
| |
| /* Only need to check the primary super block. */ |
| sb = btrfs_read_dev_one_super(dev->bdev, 0, true); |
| if (IS_ERR(sb)) |
| return PTR_ERR(sb); |
| |
| /* Verify the checksum. */ |
| csum_type = btrfs_super_csum_type(sb); |
| if (csum_type != btrfs_super_csum_type(fs_info->super_copy)) { |
| btrfs_err(fs_info, "csum type changed, has %u expect %u", |
| csum_type, btrfs_super_csum_type(fs_info->super_copy)); |
| ret = -EUCLEAN; |
| goto out; |
| } |
| |
| if (btrfs_check_super_csum(fs_info, sb)) { |
| btrfs_err(fs_info, "csum for on-disk super block no longer matches"); |
| ret = -EUCLEAN; |
| goto out; |
| } |
| |
| /* Btrfs_validate_super() includes fsid check against super->fsid. */ |
| ret = btrfs_validate_super(fs_info, sb, 0); |
| if (ret < 0) |
| goto out; |
| |
| last_trans = btrfs_get_last_trans_committed(fs_info); |
| if (btrfs_super_generation(sb) != last_trans) { |
| btrfs_err(fs_info, "transid mismatch, has %llu expect %llu", |
| btrfs_super_generation(sb), last_trans); |
| ret = -EUCLEAN; |
| goto out; |
| } |
| out: |
| btrfs_release_disk_super(sb); |
| return ret; |
| } |
| |
| static int btrfs_unfreeze(struct super_block *sb) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| struct btrfs_device *device; |
| int ret = 0; |
| |
| /* |
| * Make sure the fs is not changed by accident (like hibernation then |
| * modified by other OS). |
| * If we found anything wrong, we mark the fs error immediately. |
| * |
| * And since the fs is frozen, no one can modify the fs yet, thus |
| * we don't need to hold device_list_mutex. |
| */ |
| list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) { |
| ret = check_dev_super(device); |
| if (ret < 0) { |
| btrfs_handle_fs_error(fs_info, ret, |
| "super block on devid %llu got modified unexpectedly", |
| device->devid); |
| break; |
| } |
| } |
| clear_bit(BTRFS_FS_FROZEN, &fs_info->flags); |
| |
| /* |
| * We still return 0, to allow VFS layer to unfreeze the fs even the |
| * above checks failed. Since the fs is either fine or read-only, we're |
| * safe to continue, without causing further damage. |
| */ |
| return 0; |
| } |
| |
| static int btrfs_show_devname(struct seq_file *m, struct dentry *root) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb); |
| |
| /* |
| * There should be always a valid pointer in latest_dev, it may be stale |
| * for a short moment in case it's being deleted but still valid until |
| * the end of RCU grace period. |
| */ |
| rcu_read_lock(); |
| seq_escape(m, btrfs_dev_name(fs_info->fs_devices->latest_dev), " \t\n\\"); |
| rcu_read_unlock(); |
| |
| return 0; |
| } |
| |
| static long btrfs_nr_cached_objects(struct super_block *sb, struct shrink_control *sc) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| const s64 nr = percpu_counter_sum_positive(&fs_info->evictable_extent_maps); |
| |
| trace_btrfs_extent_map_shrinker_count(fs_info, nr); |
| |
| /* |
| * Only report the real number for DEBUG builds, as there are reports of |
| * serious performance degradation caused by too frequent shrinks. |
| */ |
| if (IS_ENABLED(CONFIG_BTRFS_DEBUG)) |
| return nr; |
| return 0; |
| } |
| |
| static long btrfs_free_cached_objects(struct super_block *sb, struct shrink_control *sc) |
| { |
| const long nr_to_scan = min_t(unsigned long, LONG_MAX, sc->nr_to_scan); |
| struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| |
| /* |
| * We may be called from any task trying to allocate memory and we don't |
| * want to slow it down with scanning and dropping extent maps. It would |
| * also cause heavy lock contention if many tasks concurrently enter |
| * here. Therefore only allow kswapd tasks to scan and drop extent maps. |
| */ |
| if (!current_is_kswapd()) |
| return 0; |
| |
| return btrfs_free_extent_maps(fs_info, nr_to_scan); |
| } |
| |
| static const struct super_operations btrfs_super_ops = { |
| .drop_inode = btrfs_drop_inode, |
| .evict_inode = btrfs_evict_inode, |
| .put_super = btrfs_put_super, |
| .sync_fs = btrfs_sync_fs, |
| .show_options = btrfs_show_options, |
| .show_devname = btrfs_show_devname, |
| .alloc_inode = btrfs_alloc_inode, |
| .destroy_inode = btrfs_destroy_inode, |
| .free_inode = btrfs_free_inode, |
| .statfs = btrfs_statfs, |
| .freeze_fs = btrfs_freeze, |
| .unfreeze_fs = btrfs_unfreeze, |
| .nr_cached_objects = btrfs_nr_cached_objects, |
| .free_cached_objects = btrfs_free_cached_objects, |
| }; |
| |
| static const struct file_operations btrfs_ctl_fops = { |
| .open = btrfs_control_open, |
| .unlocked_ioctl = btrfs_control_ioctl, |
| .compat_ioctl = compat_ptr_ioctl, |
| .owner = THIS_MODULE, |
| .llseek = noop_llseek, |
| }; |
| |
| static struct miscdevice btrfs_misc = { |
| .minor = BTRFS_MINOR, |
| .name = "btrfs-control", |
| .fops = &btrfs_ctl_fops |
| }; |
| |
| MODULE_ALIAS_MISCDEV(BTRFS_MINOR); |
| MODULE_ALIAS("devname:btrfs-control"); |
| |
| static int __init btrfs_interface_init(void) |
| { |
| return misc_register(&btrfs_misc); |
| } |
| |
| static __cold void btrfs_interface_exit(void) |
| { |
| misc_deregister(&btrfs_misc); |
| } |
| |
| static int __init btrfs_print_mod_info(void) |
| { |
| static const char options[] = "" |
| #ifdef CONFIG_BTRFS_DEBUG |
| ", debug=on" |
| #endif |
| #ifdef CONFIG_BTRFS_ASSERT |
| ", assert=on" |
| #endif |
| #ifdef CONFIG_BTRFS_FS_REF_VERIFY |
| ", ref-verify=on" |
| #endif |
| #ifdef CONFIG_BLK_DEV_ZONED |
| ", zoned=yes" |
| #else |
| ", zoned=no" |
| #endif |
| #ifdef CONFIG_FS_VERITY |
| ", fsverity=yes" |
| #else |
| ", fsverity=no" |
| #endif |
| ; |
| pr_info("Btrfs loaded%s\n", options); |
| return 0; |
| } |
| |
| static int register_btrfs(void) |
| { |
| return register_filesystem(&btrfs_fs_type); |
| } |
| |
| static void unregister_btrfs(void) |
| { |
| unregister_filesystem(&btrfs_fs_type); |
| } |
| |
| /* Helper structure for long init/exit functions. */ |
| struct init_sequence { |
| int (*init_func)(void); |
| /* Can be NULL if the init_func doesn't need cleanup. */ |
| void (*exit_func)(void); |
| }; |
| |
| static const struct init_sequence mod_init_seq[] = { |
| { |
| .init_func = btrfs_props_init, |
| .exit_func = NULL, |
| }, { |
| .init_func = btrfs_init_sysfs, |
| .exit_func = btrfs_exit_sysfs, |
| }, { |
| .init_func = btrfs_init_compress, |
| .exit_func = btrfs_exit_compress, |
| }, { |
| .init_func = btrfs_init_cachep, |
| .exit_func = btrfs_destroy_cachep, |
| }, { |
| .init_func = btrfs_init_dio, |
| .exit_func = btrfs_destroy_dio, |
| }, { |
| .init_func = btrfs_transaction_init, |
| .exit_func = btrfs_transaction_exit, |
| }, { |
| .init_func = btrfs_ctree_init, |
| .exit_func = btrfs_ctree_exit, |
| }, { |
| .init_func = btrfs_free_space_init, |
| .exit_func = btrfs_free_space_exit, |
| }, { |
| .init_func = extent_state_init_cachep, |
| .exit_func = extent_state_free_cachep, |
| }, { |
| .init_func = extent_buffer_init_cachep, |
| .exit_func = extent_buffer_free_cachep, |
| }, { |
| .init_func = btrfs_bioset_init, |
| .exit_func = btrfs_bioset_exit, |
| }, { |
| .init_func = extent_map_init, |
| .exit_func = extent_map_exit, |
| }, { |
| .init_func = ordered_data_init, |
| .exit_func = ordered_data_exit, |
| }, { |
| .init_func = btrfs_delayed_inode_init, |
| .exit_func = btrfs_delayed_inode_exit, |
| }, { |
| .init_func = btrfs_auto_defrag_init, |
| .exit_func = btrfs_auto_defrag_exit, |
| }, { |
| .init_func = btrfs_delayed_ref_init, |
| .exit_func = btrfs_delayed_ref_exit, |
| }, { |
| .init_func = btrfs_prelim_ref_init, |
| .exit_func = btrfs_prelim_ref_exit, |
| }, { |
| .init_func = btrfs_interface_init, |
| .exit_func = btrfs_interface_exit, |
| }, { |
| .init_func = btrfs_print_mod_info, |
| .exit_func = NULL, |
| }, { |
| .init_func = btrfs_run_sanity_tests, |
| .exit_func = NULL, |
| }, { |
| .init_func = register_btrfs, |
| .exit_func = unregister_btrfs, |
| } |
| }; |
| |
| static bool mod_init_result[ARRAY_SIZE(mod_init_seq)]; |
| |
| static __always_inline void btrfs_exit_btrfs_fs(void) |
| { |
| int i; |
| |
| for (i = ARRAY_SIZE(mod_init_seq) - 1; i >= 0; i--) { |
| if (!mod_init_result[i]) |
| continue; |
| if (mod_init_seq[i].exit_func) |
| mod_init_seq[i].exit_func(); |
| mod_init_result[i] = false; |
| } |
| } |
| |
| static void __exit exit_btrfs_fs(void) |
| { |
| btrfs_exit_btrfs_fs(); |
| btrfs_cleanup_fs_uuids(); |
| } |
| |
| static int __init init_btrfs_fs(void) |
| { |
| int ret; |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(mod_init_seq); i++) { |
| ASSERT(!mod_init_result[i]); |
| ret = mod_init_seq[i].init_func(); |
| if (ret < 0) { |
| btrfs_exit_btrfs_fs(); |
| return ret; |
| } |
| mod_init_result[i] = true; |
| } |
| return 0; |
| } |
| |
| late_initcall(init_btrfs_fs); |
| module_exit(exit_btrfs_fs) |
| |
| MODULE_DESCRIPTION("B-Tree File System (BTRFS)"); |
| MODULE_LICENSE("GPL"); |
| MODULE_SOFTDEP("pre: crc32c"); |
| MODULE_SOFTDEP("pre: xxhash64"); |
| MODULE_SOFTDEP("pre: sha256"); |
| MODULE_SOFTDEP("pre: blake2b-256"); |
