diff options
Diffstat (limited to 'fs/erofs/super.c')
| -rw-r--r-- | fs/erofs/super.c | 1126 |
1 files changed, 1126 insertions, 0 deletions
diff --git a/fs/erofs/super.c b/fs/erofs/super.c new file mode 100644 index 000000000..bd8bf8fc2 --- /dev/null +++ b/fs/erofs/super.c @@ -0,0 +1,1126 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017-2018 HUAWEI, Inc. + * https://www.huawei.com/ + * Copyright (C) 2021, Alibaba Cloud + */ +#include <linux/module.h> +#include <linux/buffer_head.h> +#include <linux/statfs.h> +#include <linux/parser.h> +#include <linux/seq_file.h> +#include <linux/crc32c.h> +#include <linux/fs_context.h> +#include <linux/fs_parser.h> +#include <linux/dax.h> +#include <linux/exportfs.h> +#include "xattr.h" + +#define CREATE_TRACE_POINTS +#include <trace/events/erofs.h> + +static struct kmem_cache *erofs_inode_cachep __read_mostly; + +void _erofs_err(struct super_block *sb, const char *function, + const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + pr_err("(device %s): %s: %pV", sb->s_id, function, &vaf); + va_end(args); +} + +void _erofs_info(struct super_block *sb, const char *function, + const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + pr_info("(device %s): %pV", sb->s_id, &vaf); + va_end(args); +} + +static int erofs_superblock_csum_verify(struct super_block *sb, void *sbdata) +{ + struct erofs_super_block *dsb; + u32 expected_crc, crc; + + dsb = kmemdup(sbdata + EROFS_SUPER_OFFSET, + EROFS_BLKSIZ - EROFS_SUPER_OFFSET, GFP_KERNEL); + if (!dsb) + return -ENOMEM; + + expected_crc = le32_to_cpu(dsb->checksum); + dsb->checksum = 0; + /* to allow for x86 boot sectors and other oddities. */ + crc = crc32c(~0, dsb, EROFS_BLKSIZ - EROFS_SUPER_OFFSET); + kfree(dsb); + + if (crc != expected_crc) { + erofs_err(sb, "invalid checksum 0x%08x, 0x%08x expected", + crc, expected_crc); + return -EBADMSG; + } + return 0; +} + +static void erofs_inode_init_once(void *ptr) +{ + struct erofs_inode *vi = ptr; + + inode_init_once(&vi->vfs_inode); +} + +static struct inode *erofs_alloc_inode(struct super_block *sb) +{ + struct erofs_inode *vi = + alloc_inode_sb(sb, erofs_inode_cachep, GFP_KERNEL); + + if (!vi) + return NULL; + + /* zero out everything except vfs_inode */ + memset(vi, 0, offsetof(struct erofs_inode, vfs_inode)); + return &vi->vfs_inode; +} + +static void erofs_free_inode(struct inode *inode) +{ + struct erofs_inode *vi = EROFS_I(inode); + + /* be careful of RCU symlink path */ + if (inode->i_op == &erofs_fast_symlink_iops) + kfree(inode->i_link); + kfree(vi->xattr_shared_xattrs); + + kmem_cache_free(erofs_inode_cachep, vi); +} + +static bool check_layout_compatibility(struct super_block *sb, + struct erofs_super_block *dsb) +{ + const unsigned int feature = le32_to_cpu(dsb->feature_incompat); + + EROFS_SB(sb)->feature_incompat = feature; + + /* check if current kernel meets all mandatory requirements */ + if (feature & (~EROFS_ALL_FEATURE_INCOMPAT)) { + erofs_err(sb, + "unidentified incompatible feature %x, please upgrade kernel version", + feature & ~EROFS_ALL_FEATURE_INCOMPAT); + return false; + } + return true; +} + +#ifdef CONFIG_EROFS_FS_ZIP +/* read variable-sized metadata, offset will be aligned by 4-byte */ +static void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf, + erofs_off_t *offset, int *lengthp) +{ + u8 *buffer, *ptr; + int len, i, cnt; + + *offset = round_up(*offset, 4); + ptr = erofs_read_metabuf(buf, sb, erofs_blknr(*offset), EROFS_KMAP); + if (IS_ERR(ptr)) + return ptr; + + len = le16_to_cpu(*(__le16 *)&ptr[erofs_blkoff(*offset)]); + if (!len) + len = U16_MAX + 1; + buffer = kmalloc(len, GFP_KERNEL); + if (!buffer) + return ERR_PTR(-ENOMEM); + *offset += sizeof(__le16); + *lengthp = len; + + for (i = 0; i < len; i += cnt) { + cnt = min(EROFS_BLKSIZ - (int)erofs_blkoff(*offset), len - i); + ptr = erofs_read_metabuf(buf, sb, erofs_blknr(*offset), + EROFS_KMAP); + if (IS_ERR(ptr)) { + kfree(buffer); + return ptr; + } + memcpy(buffer + i, ptr + erofs_blkoff(*offset), cnt); + *offset += cnt; + } + return buffer; +} + +static int erofs_load_compr_cfgs(struct super_block *sb, + struct erofs_super_block *dsb) +{ + struct erofs_sb_info *sbi = EROFS_SB(sb); + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; + unsigned int algs, alg; + erofs_off_t offset; + int size, ret = 0; + + sbi->available_compr_algs = le16_to_cpu(dsb->u1.available_compr_algs); + if (sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS) { + erofs_err(sb, "try to load compressed fs with unsupported algorithms %x", + sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS); + return -EINVAL; + } + + offset = EROFS_SUPER_OFFSET + sbi->sb_size; + alg = 0; + for (algs = sbi->available_compr_algs; algs; algs >>= 1, ++alg) { + void *data; + + if (!(algs & 1)) + continue; + + data = erofs_read_metadata(sb, &buf, &offset, &size); + if (IS_ERR(data)) { + ret = PTR_ERR(data); + break; + } + + switch (alg) { + case Z_EROFS_COMPRESSION_LZ4: + ret = z_erofs_load_lz4_config(sb, dsb, data, size); + break; + case Z_EROFS_COMPRESSION_LZMA: + ret = z_erofs_load_lzma_config(sb, dsb, data, size); + break; + default: + DBG_BUGON(1); + ret = -EFAULT; + } + kfree(data); + if (ret) + break; + } + erofs_put_metabuf(&buf); + return ret; +} +#else +static int erofs_load_compr_cfgs(struct super_block *sb, + struct erofs_super_block *dsb) +{ + if (dsb->u1.available_compr_algs) { + erofs_err(sb, "try to load compressed fs when compression is disabled"); + return -EINVAL; + } + return 0; +} +#endif + +static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb, + struct erofs_device_info *dif, erofs_off_t *pos) +{ + struct erofs_sb_info *sbi = EROFS_SB(sb); + struct erofs_fscache *fscache; + struct erofs_deviceslot *dis; + struct block_device *bdev; + void *ptr; + + ptr = erofs_read_metabuf(buf, sb, erofs_blknr(*pos), EROFS_KMAP); + if (IS_ERR(ptr)) + return PTR_ERR(ptr); + dis = ptr + erofs_blkoff(*pos); + + if (!dif->path) { + if (!dis->tag[0]) { + erofs_err(sb, "empty device tag @ pos %llu", *pos); + return -EINVAL; + } + dif->path = kmemdup_nul(dis->tag, sizeof(dis->tag), GFP_KERNEL); + if (!dif->path) + return -ENOMEM; + } + + if (erofs_is_fscache_mode(sb)) { + fscache = erofs_fscache_register_cookie(sb, dif->path, 0); + if (IS_ERR(fscache)) + return PTR_ERR(fscache); + dif->fscache = fscache; + } else { + bdev = blkdev_get_by_path(dif->path, FMODE_READ | FMODE_EXCL, + sb->s_type); + if (IS_ERR(bdev)) + return PTR_ERR(bdev); + dif->bdev = bdev; + dif->dax_dev = fs_dax_get_by_bdev(bdev, &dif->dax_part_off, + NULL, NULL); + } + + dif->blocks = le32_to_cpu(dis->blocks); + dif->mapped_blkaddr = le32_to_cpu(dis->mapped_blkaddr); + sbi->total_blocks += dif->blocks; + *pos += EROFS_DEVT_SLOT_SIZE; + return 0; +} + +static int erofs_scan_devices(struct super_block *sb, + struct erofs_super_block *dsb) +{ + struct erofs_sb_info *sbi = EROFS_SB(sb); + unsigned int ondisk_extradevs; + erofs_off_t pos; + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; + struct erofs_device_info *dif; + int id, err = 0; + + sbi->total_blocks = sbi->primarydevice_blocks; + if (!erofs_sb_has_device_table(sbi)) + ondisk_extradevs = 0; + else + ondisk_extradevs = le16_to_cpu(dsb->extra_devices); + + if (sbi->devs->extra_devices && + ondisk_extradevs != sbi->devs->extra_devices) { + erofs_err(sb, "extra devices don't match (ondisk %u, given %u)", + ondisk_extradevs, sbi->devs->extra_devices); + return -EINVAL; + } + if (!ondisk_extradevs) + return 0; + + sbi->device_id_mask = roundup_pow_of_two(ondisk_extradevs + 1) - 1; + pos = le16_to_cpu(dsb->devt_slotoff) * EROFS_DEVT_SLOT_SIZE; + down_read(&sbi->devs->rwsem); + if (sbi->devs->extra_devices) { + idr_for_each_entry(&sbi->devs->tree, dif, id) { + err = erofs_init_device(&buf, sb, dif, &pos); + if (err) + break; + } + } else { + for (id = 0; id < ondisk_extradevs; id++) { + dif = kzalloc(sizeof(*dif), GFP_KERNEL); + if (!dif) { + err = -ENOMEM; + break; + } + + err = idr_alloc(&sbi->devs->tree, dif, 0, 0, GFP_KERNEL); + if (err < 0) { + kfree(dif); + break; + } + ++sbi->devs->extra_devices; + + err = erofs_init_device(&buf, sb, dif, &pos); + if (err) + break; + } + } + up_read(&sbi->devs->rwsem); + erofs_put_metabuf(&buf); + return err; +} + +static int erofs_read_superblock(struct super_block *sb) +{ + struct erofs_sb_info *sbi; + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; + struct erofs_super_block *dsb; + unsigned int blkszbits; + void *data; + int ret; + + data = erofs_read_metabuf(&buf, sb, 0, EROFS_KMAP); + if (IS_ERR(data)) { + erofs_err(sb, "cannot read erofs superblock"); + return PTR_ERR(data); + } + + sbi = EROFS_SB(sb); + dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET); + + ret = -EINVAL; + if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) { + erofs_err(sb, "cannot find valid erofs superblock"); + goto out; + } + + sbi->feature_compat = le32_to_cpu(dsb->feature_compat); + if (erofs_sb_has_sb_chksum(sbi)) { + ret = erofs_superblock_csum_verify(sb, data); + if (ret) + goto out; + } + + ret = -EINVAL; + blkszbits = dsb->blkszbits; + /* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */ + if (blkszbits != LOG_BLOCK_SIZE) { + erofs_err(sb, "blkszbits %u isn't supported on this platform", + blkszbits); + goto out; + } + + if (!check_layout_compatibility(sb, dsb)) + goto out; + + sbi->sb_size = 128 + dsb->sb_extslots * EROFS_SB_EXTSLOT_SIZE; + if (sbi->sb_size > EROFS_BLKSIZ) { + erofs_err(sb, "invalid sb_extslots %u (more than a fs block)", + sbi->sb_size); + goto out; + } + sbi->primarydevice_blocks = le32_to_cpu(dsb->blocks); + sbi->meta_blkaddr = le32_to_cpu(dsb->meta_blkaddr); +#ifdef CONFIG_EROFS_FS_XATTR + sbi->xattr_blkaddr = le32_to_cpu(dsb->xattr_blkaddr); +#endif + sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact)); + sbi->root_nid = le16_to_cpu(dsb->root_nid); + sbi->packed_nid = le64_to_cpu(dsb->packed_nid); + sbi->inos = le64_to_cpu(dsb->inos); + + sbi->build_time = le64_to_cpu(dsb->build_time); + sbi->build_time_nsec = le32_to_cpu(dsb->build_time_nsec); + + memcpy(&sb->s_uuid, dsb->uuid, sizeof(dsb->uuid)); + + ret = strscpy(sbi->volume_name, dsb->volume_name, + sizeof(dsb->volume_name)); + if (ret < 0) { /* -E2BIG */ + erofs_err(sb, "bad volume name without NIL terminator"); + ret = -EFSCORRUPTED; + goto out; + } + + /* parse on-disk compression configurations */ + if (erofs_sb_has_compr_cfgs(sbi)) + ret = erofs_load_compr_cfgs(sb, dsb); + else + ret = z_erofs_load_lz4_config(sb, dsb, NULL, 0); + if (ret < 0) + goto out; + + /* handle multiple devices */ + ret = erofs_scan_devices(sb, dsb); + + if (erofs_sb_has_ztailpacking(sbi)) + erofs_info(sb, "EXPERIMENTAL compressed inline data feature in use. Use at your own risk!"); + if (erofs_is_fscache_mode(sb)) + erofs_info(sb, "EXPERIMENTAL fscache-based on-demand read feature in use. Use at your own risk!"); + if (erofs_sb_has_fragments(sbi)) + erofs_info(sb, "EXPERIMENTAL compressed fragments feature in use. Use at your own risk!"); + if (erofs_sb_has_dedupe(sbi)) + erofs_info(sb, "EXPERIMENTAL global deduplication feature in use. Use at your own risk!"); +out: + erofs_put_metabuf(&buf); + return ret; +} + +/* set up default EROFS parameters */ +static void erofs_default_options(struct erofs_fs_context *ctx) +{ +#ifdef CONFIG_EROFS_FS_ZIP + ctx->opt.cache_strategy = EROFS_ZIP_CACHE_READAROUND; + ctx->opt.max_sync_decompress_pages = 3; + ctx->opt.sync_decompress = EROFS_SYNC_DECOMPRESS_AUTO; +#endif +#ifdef CONFIG_EROFS_FS_XATTR + set_opt(&ctx->opt, XATTR_USER); +#endif +#ifdef CONFIG_EROFS_FS_POSIX_ACL + set_opt(&ctx->opt, POSIX_ACL); +#endif +} + +enum { + Opt_user_xattr, + Opt_acl, + Opt_cache_strategy, + Opt_dax, + Opt_dax_enum, + Opt_device, + Opt_fsid, + Opt_domain_id, + Opt_err +}; + +static const struct constant_table erofs_param_cache_strategy[] = { + {"disabled", EROFS_ZIP_CACHE_DISABLED}, + {"readahead", EROFS_ZIP_CACHE_READAHEAD}, + {"readaround", EROFS_ZIP_CACHE_READAROUND}, + {} +}; + +static const struct constant_table erofs_dax_param_enums[] = { + {"always", EROFS_MOUNT_DAX_ALWAYS}, + {"never", EROFS_MOUNT_DAX_NEVER}, + {} +}; + +static const struct fs_parameter_spec erofs_fs_parameters[] = { + fsparam_flag_no("user_xattr", Opt_user_xattr), + fsparam_flag_no("acl", Opt_acl), + fsparam_enum("cache_strategy", Opt_cache_strategy, + erofs_param_cache_strategy), + fsparam_flag("dax", Opt_dax), + fsparam_enum("dax", Opt_dax_enum, erofs_dax_param_enums), + fsparam_string("device", Opt_device), + fsparam_string("fsid", Opt_fsid), + fsparam_string("domain_id", Opt_domain_id), + {} +}; + +static bool erofs_fc_set_dax_mode(struct fs_context *fc, unsigned int mode) +{ +#ifdef CONFIG_FS_DAX + struct erofs_fs_context *ctx = fc->fs_private; + + switch (mode) { + case EROFS_MOUNT_DAX_ALWAYS: + warnfc(fc, "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"); + set_opt(&ctx->opt, DAX_ALWAYS); + clear_opt(&ctx->opt, DAX_NEVER); + return true; + case EROFS_MOUNT_DAX_NEVER: + set_opt(&ctx->opt, DAX_NEVER); + clear_opt(&ctx->opt, DAX_ALWAYS); + return true; + default: + DBG_BUGON(1); + return false; + } +#else + errorfc(fc, "dax options not supported"); + return false; +#endif +} + +static int erofs_fc_parse_param(struct fs_context *fc, + struct fs_parameter *param) +{ + struct erofs_fs_context *ctx = fc->fs_private; + struct fs_parse_result result; + struct erofs_device_info *dif; + int opt, ret; + + opt = fs_parse(fc, erofs_fs_parameters, param, &result); + if (opt < 0) + return opt; + + switch (opt) { + case Opt_user_xattr: +#ifdef CONFIG_EROFS_FS_XATTR + if (result.boolean) + set_opt(&ctx->opt, XATTR_USER); + else + clear_opt(&ctx->opt, XATTR_USER); +#else + errorfc(fc, "{,no}user_xattr options not supported"); +#endif + break; + case Opt_acl: +#ifdef CONFIG_EROFS_FS_POSIX_ACL + if (result.boolean) + set_opt(&ctx->opt, POSIX_ACL); + else + clear_opt(&ctx->opt, POSIX_ACL); +#else + errorfc(fc, "{,no}acl options not supported"); +#endif + break; + case Opt_cache_strategy: +#ifdef CONFIG_EROFS_FS_ZIP + ctx->opt.cache_strategy = result.uint_32; +#else + errorfc(fc, "compression not supported, cache_strategy ignored"); +#endif + break; + case Opt_dax: + if (!erofs_fc_set_dax_mode(fc, EROFS_MOUNT_DAX_ALWAYS)) + return -EINVAL; + break; + case Opt_dax_enum: + if (!erofs_fc_set_dax_mode(fc, result.uint_32)) + return -EINVAL; + break; + case Opt_device: + dif = kzalloc(sizeof(*dif), GFP_KERNEL); + if (!dif) + return -ENOMEM; + dif->path = kstrdup(param->string, GFP_KERNEL); + if (!dif->path) { + kfree(dif); + return -ENOMEM; + } + down_write(&ctx->devs->rwsem); + ret = idr_alloc(&ctx->devs->tree, dif, 0, 0, GFP_KERNEL); + up_write(&ctx->devs->rwsem); + if (ret < 0) { + kfree(dif->path); + kfree(dif); + return ret; + } + ++ctx->devs->extra_devices; + break; +#ifdef CONFIG_EROFS_FS_ONDEMAND + case Opt_fsid: + kfree(ctx->fsid); + ctx->fsid = kstrdup(param->string, GFP_KERNEL); + if (!ctx->fsid) + return -ENOMEM; + break; + case Opt_domain_id: + kfree(ctx->domain_id); + ctx->domain_id = kstrdup(param->string, GFP_KERNEL); + if (!ctx->domain_id) + return -ENOMEM; + break; +#else + case Opt_fsid: + case Opt_domain_id: + errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name); + break; +#endif + default: + return -ENOPARAM; + } + return 0; +} + +#ifdef CONFIG_EROFS_FS_ZIP +static const struct address_space_operations managed_cache_aops; + +static bool erofs_managed_cache_release_folio(struct folio *folio, gfp_t gfp) +{ + bool ret = true; + struct address_space *const mapping = folio->mapping; + + DBG_BUGON(!folio_test_locked(folio)); + DBG_BUGON(mapping->a_ops != &managed_cache_aops); + + if (folio_test_private(folio)) + ret = erofs_try_to_free_cached_page(&folio->page); + + return ret; +} + +/* + * It will be called only on inode eviction. In case that there are still some + * decompression requests in progress, wait with rescheduling for a bit here. + * We could introduce an extra locking instead but it seems unnecessary. + */ +static void erofs_managed_cache_invalidate_folio(struct folio *folio, + size_t offset, size_t length) +{ + const size_t stop = length + offset; + + DBG_BUGON(!folio_test_locked(folio)); + + /* Check for potential overflow in debug mode */ + DBG_BUGON(stop > folio_size(folio) || stop < length); + + if (offset == 0 && stop == folio_size(folio)) + while (!erofs_managed_cache_release_folio(folio, GFP_NOFS)) + cond_resched(); +} + +static const struct address_space_operations managed_cache_aops = { + .release_folio = erofs_managed_cache_release_folio, + .invalidate_folio = erofs_managed_cache_invalidate_folio, +}; + +static int erofs_init_managed_cache(struct super_block *sb) +{ + struct erofs_sb_info *const sbi = EROFS_SB(sb); + struct inode *const inode = new_inode(sb); + + if (!inode) + return -ENOMEM; + + set_nlink(inode, 1); + inode->i_size = OFFSET_MAX; + + inode->i_mapping->a_ops = &managed_cache_aops; + mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS); + sbi->managed_cache = inode; + return 0; +} +#else +static int erofs_init_managed_cache(struct super_block *sb) { return 0; } +#endif + +static struct inode *erofs_nfs_get_inode(struct super_block *sb, + u64 ino, u32 generation) +{ + return erofs_iget(sb, ino); +} + +static struct dentry *erofs_fh_to_dentry(struct super_block *sb, + struct fid *fid, int fh_len, int fh_type) +{ + return generic_fh_to_dentry(sb, fid, fh_len, fh_type, + erofs_nfs_get_inode); +} + +static struct dentry *erofs_fh_to_parent(struct super_block *sb, + struct fid *fid, int fh_len, int fh_type) +{ + return generic_fh_to_parent(sb, fid, fh_len, fh_type, + erofs_nfs_get_inode); +} + +static struct dentry *erofs_get_parent(struct dentry *child) +{ + erofs_nid_t nid; + unsigned int d_type; + int err; + + err = erofs_namei(d_inode(child), &dotdot_name, &nid, &d_type); + if (err) + return ERR_PTR(err); + return d_obtain_alias(erofs_iget(child->d_sb, nid)); +} + +static const struct export_operations erofs_export_ops = { + .fh_to_dentry = erofs_fh_to_dentry, + .fh_to_parent = erofs_fh_to_parent, + .get_parent = erofs_get_parent, +}; + +static int erofs_fc_fill_pseudo_super(struct super_block *sb, struct fs_context *fc) +{ + static const struct tree_descr empty_descr = {""}; + + return simple_fill_super(sb, EROFS_SUPER_MAGIC, &empty_descr); +} + +static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) +{ + struct inode *inode; + struct erofs_sb_info *sbi; + struct erofs_fs_context *ctx = fc->fs_private; + int err; + + sb->s_magic = EROFS_SUPER_MAGIC; + sb->s_flags |= SB_RDONLY | SB_NOATIME; + sb->s_maxbytes = MAX_LFS_FILESIZE; + sb->s_op = &erofs_sops; + + sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); + if (!sbi) + return -ENOMEM; + + sb->s_fs_info = sbi; + sbi->opt = ctx->opt; + sbi->devs = ctx->devs; + ctx->devs = NULL; + sbi->fsid = ctx->fsid; + ctx->fsid = NULL; + sbi->domain_id = ctx->domain_id; + ctx->domain_id = NULL; + + if (erofs_is_fscache_mode(sb)) { + sb->s_blocksize = EROFS_BLKSIZ; + sb->s_blocksize_bits = LOG_BLOCK_SIZE; + + err = erofs_fscache_register_fs(sb); + if (err) + return err; + + err = super_setup_bdi(sb); + if (err) + return err; + } else { + if (!sb_set_blocksize(sb, EROFS_BLKSIZ)) { + erofs_err(sb, "failed to set erofs blksize"); + return -EINVAL; + } + + sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev, + &sbi->dax_part_off, + NULL, NULL); + } + + err = erofs_read_superblock(sb); + if (err) + return err; + + if (test_opt(&sbi->opt, DAX_ALWAYS)) { + BUILD_BUG_ON(EROFS_BLKSIZ != PAGE_SIZE); + + if (!sbi->dax_dev) { + errorfc(fc, "DAX unsupported by block device. Turning off DAX."); + clear_opt(&sbi->opt, DAX_ALWAYS); + } + } + + sb->s_time_gran = 1; + sb->s_xattr = erofs_xattr_handlers; + sb->s_export_op = &erofs_export_ops; + + if (test_opt(&sbi->opt, POSIX_ACL)) + sb->s_flags |= SB_POSIXACL; + else + sb->s_flags &= ~SB_POSIXACL; + +#ifdef CONFIG_EROFS_FS_ZIP + xa_init(&sbi->managed_pslots); +#endif + + /* get the root inode */ + inode = erofs_iget(sb, ROOT_NID(sbi)); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + if (!S_ISDIR(inode->i_mode)) { + erofs_err(sb, "rootino(nid %llu) is not a directory(i_mode %o)", + ROOT_NID(sbi), inode->i_mode); + iput(inode); + return -EINVAL; + } + + sb->s_root = d_make_root(inode); + if (!sb->s_root) + return -ENOMEM; + + erofs_shrinker_register(sb); + /* sb->s_umount is already locked, SB_ACTIVE and SB_BORN are not set */ +#ifdef CONFIG_EROFS_FS_ZIP + if (erofs_sb_has_fragments(sbi) && sbi->packed_nid) { + sbi->packed_inode = erofs_iget(sb, sbi->packed_nid); + if (IS_ERR(sbi->packed_inode)) { + err = PTR_ERR(sbi->packed_inode); + sbi->packed_inode = NULL; + return err; + } + } +#endif + err = erofs_init_managed_cache(sb); + if (err) + return err; + + err = erofs_register_sysfs(sb); + if (err) + return err; + + erofs_info(sb, "mounted with root inode @ nid %llu.", ROOT_NID(sbi)); + return 0; +} + +static int erofs_fc_anon_get_tree(struct fs_context *fc) +{ + return get_tree_nodev(fc, erofs_fc_fill_pseudo_super); +} + +static int erofs_fc_get_tree(struct fs_context *fc) +{ + struct erofs_fs_context *ctx = fc->fs_private; + + if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && ctx->fsid) + return get_tree_nodev(fc, erofs_fc_fill_super); + + return get_tree_bdev(fc, erofs_fc_fill_super); +} + +static int erofs_fc_reconfigure(struct fs_context *fc) +{ + struct super_block *sb = fc->root->d_sb; + struct erofs_sb_info *sbi = EROFS_SB(sb); + struct erofs_fs_context *ctx = fc->fs_private; + + DBG_BUGON(!sb_rdonly(sb)); + + if (ctx->fsid || ctx->domain_id) + erofs_info(sb, "ignoring reconfiguration for fsid|domain_id."); + + if (test_opt(&ctx->opt, POSIX_ACL)) + fc->sb_flags |= SB_POSIXACL; + else + fc->sb_flags &= ~SB_POSIXACL; + + sbi->opt = ctx->opt; + + fc->sb_flags |= SB_RDONLY; + return 0; +} + +static int erofs_release_device_info(int id, void *ptr, void *data) +{ + struct erofs_device_info *dif = ptr; + + fs_put_dax(dif->dax_dev, NULL); + if (dif->bdev) + blkdev_put(dif->bdev, FMODE_READ | FMODE_EXCL); + erofs_fscache_unregister_cookie(dif->fscache); + dif->fscache = NULL; + kfree(dif->path); + kfree(dif); + return 0; +} + +static void erofs_free_dev_context(struct erofs_dev_context *devs) +{ + if (!devs) + return; + idr_for_each(&devs->tree, &erofs_release_device_info, NULL); + idr_destroy(&devs->tree); + kfree(devs); +} + +static void erofs_fc_free(struct fs_context *fc) +{ + struct erofs_fs_context *ctx = fc->fs_private; + + erofs_free_dev_context(ctx->devs); + kfree(ctx->fsid); + kfree(ctx->domain_id); + kfree(ctx); +} + +static const struct fs_context_operations erofs_context_ops = { + .parse_param = erofs_fc_parse_param, + .get_tree = erofs_fc_get_tree, + .reconfigure = erofs_fc_reconfigure, + .free = erofs_fc_free, +}; + +static const struct fs_context_operations erofs_anon_context_ops = { + .get_tree = erofs_fc_anon_get_tree, +}; + +static int erofs_init_fs_context(struct fs_context *fc) +{ + struct erofs_fs_context *ctx; + + /* pseudo mount for anon inodes */ + if (fc->sb_flags & SB_KERNMOUNT) { + fc->ops = &erofs_anon_context_ops; + return 0; + } + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + ctx->devs = kzalloc(sizeof(struct erofs_dev_context), GFP_KERNEL); + if (!ctx->devs) { + kfree(ctx); + return -ENOMEM; + } + fc->fs_private = ctx; + + idr_init(&ctx->devs->tree); + init_rwsem(&ctx->devs->rwsem); + erofs_default_options(ctx); + fc->ops = &erofs_context_ops; + return 0; +} + +/* + * could be triggered after deactivate_locked_super() + * is called, thus including umount and failed to initialize. + */ +static void erofs_kill_sb(struct super_block *sb) +{ + struct erofs_sb_info *sbi; + + WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC); + + /* pseudo mount for anon inodes */ + if (sb->s_flags & SB_KERNMOUNT) { + kill_anon_super(sb); + return; + } + + if (erofs_is_fscache_mode(sb)) + kill_anon_super(sb); + else + kill_block_super(sb); + + sbi = EROFS_SB(sb); + if (!sbi) + return; + + erofs_free_dev_context(sbi->devs); + fs_put_dax(sbi->dax_dev, NULL); + erofs_fscache_unregister_fs(sb); + kfree(sbi->fsid); + kfree(sbi->domain_id); + kfree(sbi); + sb->s_fs_info = NULL; +} + +/* called when ->s_root is non-NULL */ +static void erofs_put_super(struct super_block *sb) +{ + struct erofs_sb_info *const sbi = EROFS_SB(sb); + + DBG_BUGON(!sbi); + + erofs_unregister_sysfs(sb); + erofs_shrinker_unregister(sb); +#ifdef CONFIG_EROFS_FS_ZIP + iput(sbi->managed_cache); + sbi->managed_cache = NULL; + iput(sbi->packed_inode); + sbi->packed_inode = NULL; +#endif + erofs_fscache_unregister_fs(sb); +} + +struct file_system_type erofs_fs_type = { + .owner = THIS_MODULE, + .name = "erofs", + .init_fs_context = erofs_init_fs_context, + .kill_sb = erofs_kill_sb, + .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, +}; +MODULE_ALIAS_FS("erofs"); + +static int __init erofs_module_init(void) +{ + int err; + + erofs_check_ondisk_layout_definitions(); + + erofs_inode_cachep = kmem_cache_create("erofs_inode", + sizeof(struct erofs_inode), 0, + SLAB_RECLAIM_ACCOUNT, + erofs_inode_init_once); + if (!erofs_inode_cachep) { + err = -ENOMEM; + goto icache_err; + } + + err = erofs_init_shrinker(); + if (err) + goto shrinker_err; + + err = z_erofs_lzma_init(); + if (err) + goto lzma_err; + + erofs_pcpubuf_init(); + err = z_erofs_init_zip_subsystem(); + if (err) + goto zip_err; + + err = erofs_init_sysfs(); + if (err) + goto sysfs_err; + + err = register_filesystem(&erofs_fs_type); + if (err) + goto fs_err; + + return 0; + +fs_err: + erofs_exit_sysfs(); +sysfs_err: + z_erofs_exit_zip_subsystem(); +zip_err: + z_erofs_lzma_exit(); +lzma_err: + erofs_exit_shrinker(); +shrinker_err: + kmem_cache_destroy(erofs_inode_cachep); +icache_err: + return err; +} + +static void __exit erofs_module_exit(void) +{ + unregister_filesystem(&erofs_fs_type); + + /* Ensure all RCU free inodes / pclusters are safe to be destroyed. */ + rcu_barrier(); + + erofs_exit_sysfs(); + z_erofs_exit_zip_subsystem(); + z_erofs_lzma_exit(); + erofs_exit_shrinker(); + kmem_cache_destroy(erofs_inode_cachep); + erofs_pcpubuf_exit(); +} + +/* get filesystem statistics */ +static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf) +{ + struct super_block *sb = dentry->d_sb; + struct erofs_sb_info *sbi = EROFS_SB(sb); + u64 id = 0; + + if (!erofs_is_fscache_mode(sb)) + id = huge_encode_dev(sb->s_bdev->bd_dev); + + buf->f_type = sb->s_magic; + buf->f_bsize = EROFS_BLKSIZ; + buf->f_blocks = sbi->total_blocks; + buf->f_bfree = buf->f_bavail = 0; + + buf->f_files = ULLONG_MAX; + buf->f_ffree = ULLONG_MAX - sbi->inos; + + buf->f_namelen = EROFS_NAME_LEN; + + buf->f_fsid = u64_to_fsid(id); + return 0; +} + +static int erofs_show_options(struct seq_file *seq, struct dentry *root) +{ + struct erofs_sb_info *sbi = EROFS_SB(root->d_sb); + struct erofs_mount_opts *opt = &sbi->opt; + +#ifdef CONFIG_EROFS_FS_XATTR + if (test_opt(opt, XATTR_USER)) + seq_puts(seq, ",user_xattr"); + else + seq_puts(seq, ",nouser_xattr"); +#endif +#ifdef CONFIG_EROFS_FS_POSIX_ACL + if (test_opt(opt, POSIX_ACL)) + seq_puts(seq, ",acl"); + else + seq_puts(seq, ",noacl"); +#endif +#ifdef CONFIG_EROFS_FS_ZIP + if (opt->cache_strategy == EROFS_ZIP_CACHE_DISABLED) + seq_puts(seq, ",cache_strategy=disabled"); + else if (opt->cache_strategy == EROFS_ZIP_CACHE_READAHEAD) + seq_puts(seq, ",cache_strategy=readahead"); + else if (opt->cache_strategy == EROFS_ZIP_CACHE_READAROUND) + seq_puts(seq, ",cache_strategy=readaround"); +#endif + if (test_opt(opt, DAX_ALWAYS)) + seq_puts(seq, ",dax=always"); + if (test_opt(opt, DAX_NEVER)) + seq_puts(seq, ",dax=never"); +#ifdef CONFIG_EROFS_FS_ONDEMAND + if (sbi->fsid) + seq_printf(seq, ",fsid=%s", sbi->fsid); + if (sbi->domain_id) + seq_printf(seq, ",domain_id=%s", sbi->domain_id); +#endif + return 0; +} + +const struct super_operations erofs_sops = { + .put_super = erofs_put_super, + .alloc_inode = erofs_alloc_inode, + .free_inode = erofs_free_inode, + .statfs = erofs_statfs, + .show_options = erofs_show_options, +}; + +module_init(erofs_module_init); +module_exit(erofs_module_exit); + +MODULE_DESCRIPTION("Enhanced ROM File System"); +MODULE_AUTHOR("Gao Xiang, Chao Yu, Miao Xie, CONSUMER BG, HUAWEI Inc."); +MODULE_LICENSE("GPL"); |