diff --git a/fs/incfs/data_mgmt.c b/fs/incfs/data_mgmt.c index 074a733c70017..e0705be44fb22 100644 --- a/fs/incfs/data_mgmt.c +++ b/fs/incfs/data_mgmt.c @@ -144,7 +144,7 @@ struct data_file *incfs_open_data_file(struct mount_info *mi, struct file *bf) if (!S_ISREG(bf->f_inode->i_mode)) return ERR_PTR(-EBADF); - bfc = incfs_alloc_bfc(bf); + bfc = incfs_alloc_bfc(mi, bf); if (IS_ERR(bfc)) return ERR_CAST(bfc); @@ -199,6 +199,7 @@ void incfs_free_data_file(struct data_file *df) for (i = 0; i < ARRAY_SIZE(df->df_segments); i++) data_file_segment_destroy(&df->df_segments[i]); incfs_free_bfc(df->df_backing_file_context); + kfree(df->df_signature); kfree(df); } @@ -387,8 +388,8 @@ static void log_block_read(struct mount_info *mi, incfs_uuid_t *id, schedule_delayed_work(&log->ml_wakeup_work, msecs_to_jiffies(16)); } -static int validate_hash_tree(struct file *bf, struct file *f, int block_index, - struct mem_range data, u8 *buf) +static int validate_hash_tree(struct backing_file_context *bfc, struct file *f, + int block_index, struct mem_range data, u8 *buf) { struct data_file *df = get_incfs_data_file(f); u8 stored_digest[INCFS_MAX_HASH_SIZE] = {}; @@ -445,7 +446,7 @@ static int validate_hash_tree(struct file *bf, struct file *f, int block_index, if (page) put_page(page); - res = incfs_kread(bf, buf, INCFS_DATA_FILE_BLOCK_SIZE, + res = incfs_kread(bfc, buf, INCFS_DATA_FILE_BLOCK_SIZE, hash_block_offset[lvl] + sig->hash_offset); if (res < 0) return res; @@ -918,7 +919,7 @@ ssize_t incfs_read_data_file_block(struct mem_range dst, struct file *f, ssize_t result; size_t bytes_to_read; struct mount_info *mi = NULL; - struct file *bf = NULL; + struct backing_file_context *bfc = NULL; struct data_file_block block = {}; struct data_file *df = get_incfs_data_file(f); @@ -929,7 +930,7 @@ ssize_t incfs_read_data_file_block(struct mem_range dst, struct file *f, return -ERANGE; mi = df->df_mount_info; - bf = df->df_backing_file_context->bc_file; + bfc = df->df_backing_file_context; result = wait_for_data_block(df, index, timeout_ms, &block); if (result < 0) @@ -938,20 +939,20 @@ ssize_t incfs_read_data_file_block(struct mem_range dst, struct file *f, pos = block.db_backing_file_data_offset; if (block.db_comp_alg == COMPRESSION_NONE) { bytes_to_read = min(dst.len, block.db_stored_size); - result = incfs_kread(bf, dst.data, bytes_to_read, pos); + result = incfs_kread(bfc, dst.data, bytes_to_read, pos); /* Some data was read, but not enough */ if (result >= 0 && result != bytes_to_read) result = -EIO; } else { bytes_to_read = min(tmp.len, block.db_stored_size); - result = incfs_kread(bf, tmp.data, bytes_to_read, pos); + result = incfs_kread(bfc, tmp.data, bytes_to_read, pos); if (result == bytes_to_read) { result = decompress(range(tmp.data, bytes_to_read), dst); if (result < 0) { const char *name = - bf->f_path.dentry->d_name.name; + bfc->bc_file->f_path.dentry->d_name.name; pr_warn_once("incfs: Decompression error. %s", name); @@ -963,7 +964,7 @@ ssize_t incfs_read_data_file_block(struct mem_range dst, struct file *f, } if (result > 0) { - int err = validate_hash_tree(bf, f, index, dst, tmp.data); + int err = validate_hash_tree(bfc, f, index, dst, tmp.data); if (err < 0) result = err; @@ -1026,14 +1027,13 @@ int incfs_process_new_data_block(struct data_file *df, unlock: mutex_unlock(&segment->blockmap_mutex); if (error) - pr_debug("incfs: %s %d error: %d\n", __func__, - block->block_index, error); + pr_debug("%d error: %d\n", block->block_index, error); return error; } int incfs_read_file_signature(struct data_file *df, struct mem_range dst) { - struct file *bf = df->df_backing_file_context->bc_file; + struct backing_file_context *bfc = df->df_backing_file_context; struct incfs_df_signature *sig; int read_res = 0; @@ -1047,7 +1047,7 @@ int incfs_read_file_signature(struct data_file *df, struct mem_range dst) if (dst.len < sig->sig_size) return -E2BIG; - read_res = incfs_kread(bf, dst.data, sig->sig_size, sig->sig_offset); + read_res = incfs_kread(bfc, dst.data, sig->sig_size, sig->sig_offset); if (read_res < 0) return read_res; @@ -1173,7 +1173,7 @@ static int process_file_signature_md(struct incfs_file_signature *sg, goto out; } - read = incfs_kread(df->df_backing_file_context->bc_file, buf, + read = incfs_kread(df->df_backing_file_context, buf, signature->sig_size, signature->sig_offset); if (read < 0) { error = read; diff --git a/fs/incfs/format.c b/fs/incfs/format.c index c56e559b68938..d326415fc6de2 100644 --- a/fs/incfs/format.c +++ b/fs/incfs/format.c @@ -15,7 +15,8 @@ #include "format.h" #include "data_mgmt.h" -struct backing_file_context *incfs_alloc_bfc(struct file *backing_file) +struct backing_file_context *incfs_alloc_bfc(struct mount_info *mi, + struct file *backing_file) { struct backing_file_context *result = NULL; @@ -24,6 +25,7 @@ struct backing_file_context *incfs_alloc_bfc(struct file *backing_file) return ERR_PTR(-ENOMEM); result->bc_file = get_file(backing_file); + result->bc_cred = mi->mi_owner; mutex_init(&result->bc_mutex); return result; } @@ -116,7 +118,7 @@ static int append_zeros(struct backing_file_context *bfc, size_t len) static int write_to_bf(struct backing_file_context *bfc, const void *buf, size_t count, loff_t pos) { - ssize_t res = incfs_kwrite(bfc->bc_file, buf, count, pos); + ssize_t res = incfs_kwrite(bfc, buf, count, pos); if (res < 0) return res; @@ -531,8 +533,7 @@ int incfs_read_blockmap_entries(struct backing_file_context *bfc, if (start_index < 0 || bm_base_off <= 0) return -ENODATA; - result = incfs_kread(bfc->bc_file, entries, bytes_to_read, - bm_entry_off); + result = incfs_kread(bfc, entries, bytes_to_read, bm_entry_off); if (result < 0) return result; return result / sizeof(*entries); @@ -548,8 +549,7 @@ int incfs_read_file_header(struct backing_file_context *bfc, if (!bfc || !first_md_off) return -EFAULT; - LOCK_REQUIRED(bfc->bc_mutex); - bytes_read = incfs_kread(bfc->bc_file, &fh, sizeof(fh), 0); + bytes_read = incfs_kread(bfc, &fh, sizeof(fh), 0); if (bytes_read < 0) return bytes_read; @@ -603,8 +603,8 @@ int incfs_read_next_metadata_record(struct backing_file_context *bfc, return -EPERM; memset(&handler->md_buffer, 0, max_md_size); - bytes_read = incfs_kread(bfc->bc_file, &handler->md_buffer, - max_md_size, handler->md_record_offset); + bytes_read = incfs_kread(bfc, &handler->md_buffer, max_md_size, + handler->md_record_offset); if (bytes_read < 0) return bytes_read; if (bytes_read < sizeof(*md_hdr)) @@ -680,12 +680,22 @@ int incfs_read_next_metadata_record(struct backing_file_context *bfc, return res; } -ssize_t incfs_kread(struct file *f, void *buf, size_t size, loff_t pos) +ssize_t incfs_kread(struct backing_file_context *bfc, void *buf, size_t size, + loff_t pos) { - return kernel_read(f, buf, size, &pos); + const struct cred *old_cred = override_creds(bfc->bc_cred); + int ret = kernel_read(bfc->bc_file, buf, size, &pos); + + revert_creds(old_cred); + return ret; } -ssize_t incfs_kwrite(struct file *f, const void *buf, size_t size, loff_t pos) +ssize_t incfs_kwrite(struct backing_file_context *bfc, const void *buf, + size_t size, loff_t pos) { - return kernel_write(f, buf, size, &pos); + const struct cred *old_cred = override_creds(bfc->bc_cred); + int ret = kernel_write(bfc->bc_file, buf, size, &pos); + + revert_creds(old_cred); + return ret; } diff --git a/fs/incfs/format.h b/fs/incfs/format.h index 1a83349bb2eb7..a6d3aef6b3583 100644 --- a/fs/incfs/format.h +++ b/fs/incfs/format.h @@ -256,6 +256,13 @@ struct backing_file_context { * 0 means there are no metadata records. */ loff_t bc_last_md_record_offset; + + /* + * Credentials to set before reads/writes + * Note that this is a pointer to the mount_info mi_owner field so + * there is no need to get/put the creds + */ + const struct cred *bc_cred; }; struct metadata_handler { @@ -283,7 +290,9 @@ struct metadata_handler { loff_t incfs_get_end_offset(struct file *f); /* Backing file context management */ -struct backing_file_context *incfs_alloc_bfc(struct file *backing_file); +struct mount_info; +struct backing_file_context *incfs_alloc_bfc(struct mount_info *mi, + struct file *backing_file); void incfs_free_bfc(struct backing_file_context *bfc); @@ -334,7 +343,9 @@ int incfs_read_blockmap_entries(struct backing_file_context *bfc, int incfs_read_next_metadata_record(struct backing_file_context *bfc, struct metadata_handler *handler); -ssize_t incfs_kread(struct file *f, void *buf, size_t size, loff_t pos); -ssize_t incfs_kwrite(struct file *f, const void *buf, size_t size, loff_t pos); +ssize_t incfs_kread(struct backing_file_context *bfc, void *buf, size_t size, + loff_t pos); +ssize_t incfs_kwrite(struct backing_file_context *bfc, const void *buf, + size_t size, loff_t pos); #endif /* _INCFS_FORMAT_H */ diff --git a/fs/incfs/main.c b/fs/incfs/main.c index 7c4ec4fa13d8d..0fde230d53373 100644 --- a/fs/incfs/main.c +++ b/fs/incfs/main.c @@ -30,8 +30,18 @@ static ssize_t corefs_show(struct kobject *kobj, static struct kobj_attribute corefs_attr = __ATTR_RO(corefs); +static ssize_t mounter_context_for_backing_rw_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buff) +{ + return snprintf(buff, PAGE_SIZE, "supported\n"); +} + +static struct kobj_attribute mounter_context_for_backing_rw_attr = + __ATTR_RO(mounter_context_for_backing_rw); + static struct attribute *attributes[] = { &corefs_attr.attr, + &mounter_context_for_backing_rw_attr.attr, NULL, }; diff --git a/fs/incfs/vfs.c b/fs/incfs/vfs.c index 582448ccdaefc..d7a7502909530 100644 --- a/fs/incfs/vfs.c +++ b/fs/incfs/vfs.c @@ -898,14 +898,14 @@ static int init_new_file(struct mount_info *mi, struct dentry *dentry, .dentry = dentry }; new_file = dentry_open(&path, O_RDWR | O_NOATIME | O_LARGEFILE, - mi->mi_owner); + current_cred()); if (IS_ERR(new_file)) { error = PTR_ERR(new_file); goto out; } - bfc = incfs_alloc_bfc(new_file); + bfc = incfs_alloc_bfc(mi, new_file); fput(new_file); if (IS_ERR(bfc)) { error = PTR_ERR(bfc); @@ -1026,7 +1026,7 @@ static int dir_relative_path_resolve( if (dir_fd < 0) return dir_fd; - dir_f = dentry_open(base_path, O_RDONLY | O_NOATIME, mi->mi_owner); + dir_f = dentry_open(base_path, O_RDONLY | O_NOATIME, current_cred()); if (IS_ERR(dir_f)) { error = PTR_ERR(dir_f); @@ -1904,10 +1904,13 @@ static int file_open(struct inode *inode, struct file *file) struct file *backing_file = NULL; struct path backing_path = {}; int err = 0; + const struct cred *old_cred; get_incfs_backing_path(file->f_path.dentry, &backing_path); - backing_file = dentry_open( - &backing_path, O_RDWR | O_NOATIME | O_LARGEFILE, mi->mi_owner); + old_cred = override_creds(mi->mi_owner); + backing_file = dentry_open(&backing_path, + O_RDWR | O_NOATIME | O_LARGEFILE, current_cred()); + revert_creds(old_cred); path_put(&backing_path); if (IS_ERR(backing_file)) {