diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile index 5e3ac7ec8fa5..bc27757702fe 100644 --- a/fs/xfs/Makefile +++ b/fs/xfs/Makefile @@ -208,6 +208,7 @@ xfs-y += $(addprefix scrub/, \ repair.o \ rmap_repair.o \ tempfile.o \ + xfblob.o \ ) xfs-$(CONFIG_XFS_RT) += $(addprefix scrub/, \ diff --git a/fs/xfs/scrub/xfblob.c b/fs/xfs/scrub/xfblob.c new file mode 100644 index 000000000000..cec668debce5 --- /dev/null +++ b/fs/xfs/scrub/xfblob.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2021-2024 Oracle. All Rights Reserved. + * Author: Darrick J. Wong + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "scrub/scrub.h" +#include "scrub/xfile.h" +#include "scrub/xfarray.h" +#include "scrub/xfblob.h" + +/* + * XFS Blob Storage + * ================ + * Stores and retrieves blobs using an xfile. Objects are appended to the file + * and the offset is returned as a magic cookie for retrieval. + */ + +#define XB_KEY_MAGIC 0xABAADDAD +struct xb_key { + uint32_t xb_magic; /* XB_KEY_MAGIC */ + uint32_t xb_size; /* size of the blob, in bytes */ + loff_t xb_offset; /* byte offset of this key */ + /* blob comes after here */ +} __packed; + +/* Initialize a blob storage object. */ +int +xfblob_create( + const char *description, + struct xfblob **blobp) +{ + struct xfblob *blob; + struct xfile *xfile; + int error; + + error = xfile_create(description, 0, &xfile); + if (error) + return error; + + blob = kmalloc(sizeof(struct xfblob), XCHK_GFP_FLAGS); + if (!blob) { + error = -ENOMEM; + goto out_xfile; + } + + blob->xfile = xfile; + blob->last_offset = PAGE_SIZE; + + *blobp = blob; + return 0; + +out_xfile: + xfile_destroy(xfile); + return error; +} + +/* Destroy a blob storage object. */ +void +xfblob_destroy( + struct xfblob *blob) +{ + xfile_destroy(blob->xfile); + kfree(blob); +} + +/* Retrieve a blob. */ +int +xfblob_load( + struct xfblob *blob, + xfblob_cookie cookie, + void *ptr, + uint32_t size) +{ + struct xb_key key; + int error; + + error = xfile_load(blob->xfile, &key, sizeof(key), cookie); + if (error) + return error; + + if (key.xb_magic != XB_KEY_MAGIC || key.xb_offset != cookie) { + ASSERT(0); + return -ENODATA; + } + if (size < key.xb_size) { + ASSERT(0); + return -EFBIG; + } + + return xfile_load(blob->xfile, ptr, key.xb_size, + cookie + sizeof(key)); +} + +/* Store a blob. */ +int +xfblob_store( + struct xfblob *blob, + xfblob_cookie *cookie, + const void *ptr, + uint32_t size) +{ + struct xb_key key = { + .xb_offset = blob->last_offset, + .xb_magic = XB_KEY_MAGIC, + .xb_size = size, + }; + loff_t pos = blob->last_offset; + int error; + + error = xfile_store(blob->xfile, &key, sizeof(key), pos); + if (error) + return error; + + pos += sizeof(key); + error = xfile_store(blob->xfile, ptr, size, pos); + if (error) + goto out_err; + + *cookie = blob->last_offset; + blob->last_offset += sizeof(key) + size; + return 0; +out_err: + xfile_discard(blob->xfile, blob->last_offset, sizeof(key)); + return error; +} + +/* Free a blob. */ +int +xfblob_free( + struct xfblob *blob, + xfblob_cookie cookie) +{ + struct xb_key key; + int error; + + error = xfile_load(blob->xfile, &key, sizeof(key), cookie); + if (error) + return error; + + if (key.xb_magic != XB_KEY_MAGIC || key.xb_offset != cookie) { + ASSERT(0); + return -ENODATA; + } + + xfile_discard(blob->xfile, cookie, sizeof(key) + key.xb_size); + return 0; +} diff --git a/fs/xfs/scrub/xfblob.h b/fs/xfs/scrub/xfblob.h new file mode 100644 index 000000000000..bd98647407f1 --- /dev/null +++ b/fs/xfs/scrub/xfblob.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (c) 2021-2024 Oracle. All Rights Reserved. + * Author: Darrick J. Wong + */ +#ifndef __XFS_SCRUB_XFBLOB_H__ +#define __XFS_SCRUB_XFBLOB_H__ + +struct xfblob { + struct xfile *xfile; + loff_t last_offset; +}; + +typedef loff_t xfblob_cookie; + +int xfblob_create(const char *descr, struct xfblob **blobp); +void xfblob_destroy(struct xfblob *blob); +int xfblob_load(struct xfblob *blob, xfblob_cookie cookie, void *ptr, + uint32_t size); +int xfblob_store(struct xfblob *blob, xfblob_cookie *cookie, const void *ptr, + uint32_t size); +int xfblob_free(struct xfblob *blob, xfblob_cookie cookie); + +#endif /* __XFS_SCRUB_XFBLOB_H__ */