diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig index 7dcdce660cac98..1428d0530e1cb4 100644 --- a/fs/erofs/Kconfig +++ b/fs/erofs/Kconfig @@ -74,6 +74,23 @@ config EROFS_FS_SECURITY If you are not using a security module, say N. +config EROFS_FS_BACKED_BY_FILE + bool "File-backed EROFS filesystem support" + depends on EROFS_FS + default y + help + This allows EROFS to use filesystem image files directly, without + the intercession of loopback block devices or likewise. It is + particularly useful for container images with numerous blobs and + other sandboxes, where loop devices behave intricately. It can also + be used to simplify error-prone lifetime management of unnecessary + virtual block devices. + + Note that this feature, along with ongoing fanotify pre-content + hooks, will eventually replace "EROFS over fscache." + + If you don't want to enable this feature, say N. + config EROFS_FS_ZIP bool "EROFS Data Compression Support" depends on EROFS_FS diff --git a/fs/erofs/data.c b/fs/erofs/data.c index 1b7eba38ba1e42..0fb31c588ae02a 100644 --- a/fs/erofs/data.c +++ b/fs/erofs/data.c @@ -59,8 +59,12 @@ void *erofs_bread(struct erofs_buf *buf, erofs_off_t offset, void erofs_init_metabuf(struct erofs_buf *buf, struct super_block *sb) { - if (erofs_is_fscache_mode(sb)) - buf->mapping = EROFS_SB(sb)->s_fscache->inode->i_mapping; + struct erofs_sb_info *sbi = EROFS_SB(sb); + + if (erofs_is_fileio_mode(sbi)) + buf->mapping = file_inode(sbi->fdev)->i_mapping; + else if (erofs_is_fscache_mode(sb)) + buf->mapping = sbi->s_fscache->inode->i_mapping; else buf->mapping = sb->s_bdev->bd_mapping; } @@ -189,10 +193,22 @@ int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map) return err; } +static void erofs_fill_from_devinfo(struct erofs_map_dev *map, + struct erofs_device_info *dif) +{ + map->m_bdev = NULL; + if (dif->file && S_ISBLK(file_inode(dif->file)->i_mode)) + map->m_bdev = file_bdev(dif->file); + map->m_daxdev = dif->dax_dev; + map->m_dax_part_off = dif->dax_part_off; + map->m_fscache = dif->fscache; +} + int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map) { struct erofs_dev_context *devs = EROFS_SB(sb)->devs; struct erofs_device_info *dif; + erofs_off_t startoff, length; int id; map->m_bdev = sb->s_bdev; @@ -212,29 +228,20 @@ int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map) up_read(&devs->rwsem); return 0; } - map->m_bdev = dif->bdev_file ? file_bdev(dif->bdev_file) : NULL; - map->m_daxdev = dif->dax_dev; - map->m_dax_part_off = dif->dax_part_off; - map->m_fscache = dif->fscache; + erofs_fill_from_devinfo(map, dif); up_read(&devs->rwsem); } else if (devs->extra_devices && !devs->flatdev) { down_read(&devs->rwsem); idr_for_each_entry(&devs->tree, dif, id) { - erofs_off_t startoff, length; - if (!dif->mapped_blkaddr) continue; + startoff = erofs_pos(sb, dif->mapped_blkaddr); length = erofs_pos(sb, dif->blocks); - if (map->m_pa >= startoff && map->m_pa < startoff + length) { map->m_pa -= startoff; - map->m_bdev = dif->bdev_file ? - file_bdev(dif->bdev_file) : NULL; - map->m_daxdev = dif->dax_dev; - map->m_dax_part_off = dif->dax_part_off; - map->m_fscache = dif->fscache; + erofs_fill_from_devinfo(map, dif); break; } } diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c index 419432be3223b7..d05b9e59f12283 100644 --- a/fs/erofs/inode.c +++ b/fs/erofs/inode.c @@ -258,7 +258,10 @@ static int erofs_fill_inode(struct inode *inode) } mapping_set_large_folios(inode->i_mapping); - if (erofs_inode_is_data_compressed(vi->datalayout)) { + if (erofs_is_fileio_mode(EROFS_SB(inode->i_sb))) { + /* XXX: data I/Os will be implemented in the following patches */ + err = -EOPNOTSUPP; + } else if (erofs_inode_is_data_compressed(vi->datalayout)) { #ifdef CONFIG_EROFS_FS_ZIP DO_ONCE_LITE_IF(inode->i_blkbits != PAGE_SHIFT, erofs_info, inode->i_sb, diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 45dc15ebd870dd..9bf4fb1cfa0996 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -49,7 +49,7 @@ typedef u32 erofs_blk_t; struct erofs_device_info { char *path; struct erofs_fscache *fscache; - struct file *bdev_file; + struct file *file; struct dax_device *dax_dev; u64 dax_part_off; @@ -130,6 +130,7 @@ struct erofs_sb_info { struct erofs_sb_lz4_info lz4; #endif /* CONFIG_EROFS_FS_ZIP */ + struct file *fdev; struct inode *packed_inode; struct erofs_dev_context *devs; struct dax_device *dax_dev; @@ -190,9 +191,15 @@ struct erofs_sb_info { #define set_opt(opt, option) ((opt)->mount_opt |= EROFS_MOUNT_##option) #define test_opt(opt, option) ((opt)->mount_opt & EROFS_MOUNT_##option) +static inline bool erofs_is_fileio_mode(struct erofs_sb_info *sbi) +{ + return IS_ENABLED(CONFIG_EROFS_FS_BACKED_BY_FILE) && sbi->fdev; +} + static inline bool erofs_is_fscache_mode(struct super_block *sb) { - return IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && !sb->s_bdev; + return IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && + !erofs_is_fileio_mode(EROFS_SB(sb)) && !sb->s_bdev; } enum { diff --git a/fs/erofs/super.c b/fs/erofs/super.c index aae3fd15899a99..8e92ad3fbead01 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -10,6 +10,7 @@ #include #include #include +#include #include "xattr.h" #define CREATE_TRACE_POINTS @@ -161,7 +162,7 @@ static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb, struct erofs_sb_info *sbi = EROFS_SB(sb); struct erofs_fscache *fscache; struct erofs_deviceslot *dis; - struct file *bdev_file; + struct file *file; dis = erofs_read_metabuf(buf, sb, *pos, EROFS_KMAP); if (IS_ERR(dis)) @@ -183,13 +184,17 @@ static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb, return PTR_ERR(fscache); dif->fscache = fscache; } else if (!sbi->devs->flatdev) { - bdev_file = bdev_file_open_by_path(dif->path, BLK_OPEN_READ, - sb->s_type, NULL); - if (IS_ERR(bdev_file)) - return PTR_ERR(bdev_file); - dif->bdev_file = bdev_file; - dif->dax_dev = fs_dax_get_by_bdev(file_bdev(bdev_file), - &dif->dax_part_off, NULL, NULL); + file = erofs_is_fileio_mode(sbi) ? + filp_open(dif->path, O_RDONLY, 0) : + bdev_file_open_by_path(dif->path, + BLK_OPEN_READ, sb->s_type, NULL); + if (IS_ERR(file)) + return PTR_ERR(file); + + dif->file = file; + if (!erofs_is_fileio_mode(sbi)) + dif->dax_dev = fs_dax_get_by_bdev(file_bdev(file), + &dif->dax_part_off, NULL, NULL); } dif->blocks = le32_to_cpu(dis->blocks); @@ -566,15 +571,16 @@ static void erofs_set_sysfs_name(struct super_block *sb) { struct erofs_sb_info *sbi = EROFS_SB(sb); - if (erofs_is_fscache_mode(sb)) { - if (sbi->domain_id) - super_set_sysfs_name_generic(sb, "%s,%s",sbi->domain_id, - sbi->fsid); - else - super_set_sysfs_name_generic(sb, "%s", sbi->fsid); - return; - } - super_set_sysfs_name_id(sb); + if (sbi->domain_id) + super_set_sysfs_name_generic(sb, "%s,%s", sbi->domain_id, + sbi->fsid); + else if (sbi->fsid) + super_set_sysfs_name_generic(sb, "%s", sbi->fsid); + else if (erofs_is_fileio_mode(sbi)) + super_set_sysfs_name_generic(sb, "%s", + bdi_dev_name(sb->s_bdi)); + else + super_set_sysfs_name_id(sb); } static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) @@ -589,14 +595,15 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) sb->s_op = &erofs_sops; sbi->blkszbits = PAGE_SHIFT; - if (erofs_is_fscache_mode(sb)) { + if (!sb->s_bdev) { sb->s_blocksize = PAGE_SIZE; sb->s_blocksize_bits = PAGE_SHIFT; - err = erofs_fscache_register_fs(sb); - if (err) - return err; - + if (erofs_is_fscache_mode(sb)) { + err = erofs_fscache_register_fs(sb); + if (err) + return err; + } err = super_setup_bdi(sb); if (err) return err; @@ -693,11 +700,24 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) static int erofs_fc_get_tree(struct fs_context *fc) { struct erofs_sb_info *sbi = fc->s_fs_info; + int ret; if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && sbi->fsid) return get_tree_nodev(fc, erofs_fc_fill_super); - return get_tree_bdev(fc, erofs_fc_fill_super); + ret = get_tree_bdev(fc, erofs_fc_fill_super); +#ifdef CONFIG_EROFS_FS_BACKED_BY_FILE + if (ret == -ENOTBLK) { + if (!fc->source) + return invalf(fc, "No source specified"); + sbi->fdev = filp_open(fc->source, O_RDONLY, 0); + if (IS_ERR(sbi->fdev)) + return PTR_ERR(sbi->fdev); + + return get_tree_nodev(fc, erofs_fc_fill_super); + } +#endif + return ret; } static int erofs_fc_reconfigure(struct fs_context *fc) @@ -727,8 +747,8 @@ 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_file) - fput(dif->bdev_file); + if (dif->file) + fput(dif->file); erofs_fscache_unregister_cookie(dif->fscache); dif->fscache = NULL; kfree(dif->path); @@ -801,6 +821,8 @@ static void erofs_kill_sb(struct super_block *sb) erofs_fscache_unregister_fs(sb); kfree(sbi->fsid); kfree(sbi->domain_id); + if (sbi->fdev) + fput(sbi->fdev); kfree(sbi); sb->s_fs_info = NULL; } @@ -903,7 +925,7 @@ static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf) buf->f_namelen = EROFS_NAME_LEN; if (uuid_is_null(&sb->s_uuid)) - buf->f_fsid = u64_to_fsid(erofs_is_fscache_mode(sb) ? 0 : + buf->f_fsid = u64_to_fsid(!sb->s_bdev ? 0 : huge_encode_dev(sb->s_bdev->bd_dev)); else buf->f_fsid = uuid_to_fsid(sb->s_uuid.b);