From: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx> There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Refactor the code according to the use of flexible-array members in multiple structures, instead of one-element arrays. Also, make use of the new struct_size() helper to properly calculate the size of some structures that contain flexible-array members. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> [hch: rebased on top of the previous cleanups] Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- fs/xfs/libxfs/xfs_log_format.h | 6 +++--- fs/xfs/xfs_extfree_item.c | 9 +++------ fs/xfs/xfs_extfree_item.h | 4 ++-- fs/xfs/xfs_ondisk.h | 6 +++--- 4 files changed, 11 insertions(+), 14 deletions(-) diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h index 639035052b4f65..9b218c30659ad7 100644 --- a/fs/xfs/libxfs/xfs_log_format.h +++ b/fs/xfs/libxfs/xfs_log_format.h @@ -559,7 +559,7 @@ struct xfs_efi_log_format { uint16_t efi_size; /* size of this item */ uint32_t efi_nextents; /* # extents to free */ uint64_t efi_id; /* efi identifier */ - struct xfs_extent efi_extents[1]; /* array of extents to free */ + struct xfs_extent efi_extents[]; /* array of extents to free */ }; /* @@ -577,7 +577,7 @@ struct xfs_efi_log_format_32 { uint16_t efi_size; /* size of this item */ uint32_t efi_nextents; /* # extents to free */ uint64_t efi_id; /* efi identifier */ - struct xfs_extent_32 efi_extents[1]; /* array of extents to free */ + struct xfs_extent_32 efi_extents[]; /* array of extents to free */ } __attribute__((packed)); /* @@ -590,7 +590,7 @@ struct xfs_efd_log_format { uint16_t efd_size; /* size of this item */ uint32_t efd_nextents; /* # of extents freed */ uint64_t efd_efi_id; /* id of corresponding efi */ - struct xfs_extent efd_extents[1]; /* array of extents freed */ + struct xfs_extent efd_extents[]; /* array of extents freed */ }; /* diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c index a2abdfd3d076bf..8bea9c9ecf2042 100644 --- a/fs/xfs/xfs_extfree_item.c +++ b/fs/xfs/xfs_extfree_item.c @@ -73,8 +73,7 @@ static inline int xfs_efi_log_item_sizeof( struct xfs_efi_log_format *elf) { - return sizeof(*elf) + - (elf->efi_nextents - 1) * sizeof(struct xfs_extent); + return struct_size(elf, efi_extents, elf->efi_nextents); } STATIC void @@ -194,8 +193,7 @@ static inline int xfs_efd_log_item_sizeof( struct xfs_efd_log_format *elf) { - return sizeof(struct xfs_efd_log_format) + - (elf->efd_nextents - 1) * sizeof(struct xfs_extent); + return struct_size(elf, efd_extents, elf->efd_nextents); } STATIC void @@ -636,8 +634,7 @@ xfs_efi_copy_format_32( struct xfs_efi_log_format_32 *src = buf->i_addr; unsigned int i; - if (buf->i_len != sizeof(*src) + - (src->efi_nextents - 1) * sizeof(struct xfs_extent_32)) { + if (buf->i_len != struct_size(src, efi_extents, src->efi_nextents)) { XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, NULL); return -EFSCORRUPTED; } diff --git a/fs/xfs/xfs_extfree_item.h b/fs/xfs/xfs_extfree_item.h index 3bb62ef525f2e0..a01ce86145bb64 100644 --- a/fs/xfs/xfs_extfree_item.h +++ b/fs/xfs/xfs_extfree_item.h @@ -55,7 +55,7 @@ struct xfs_efi_log_item { static inline int xfs_efi_item_sizeof(unsigned int nextents) { return sizeof(struct xfs_efi_log_item) + - (nextents - 1) * sizeof(struct xfs_extent); + nextents * sizeof(struct xfs_extent); } /* @@ -73,7 +73,7 @@ struct xfs_efd_log_item { static inline int xfs_efd_item_sizeof(unsigned int nextents) { return sizeof(struct xfs_efd_log_item) + - (nextents - 1) * sizeof(struct xfs_extent); + nextents * sizeof(struct xfs_extent); } /* diff --git a/fs/xfs/xfs_ondisk.h b/fs/xfs/xfs_ondisk.h index 739476f7dffa21..fa4b590671bf58 100644 --- a/fs/xfs/xfs_ondisk.h +++ b/fs/xfs/xfs_ondisk.h @@ -118,9 +118,9 @@ xfs_check_ondisk_structs(void) /* log structures */ XFS_CHECK_STRUCT_SIZE(struct xfs_buf_log_format, 88); XFS_CHECK_STRUCT_SIZE(struct xfs_dq_logformat, 24); - XFS_CHECK_STRUCT_SIZE(struct xfs_efd_log_format, 32); - XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format, 32); - XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_32, 28); + XFS_CHECK_STRUCT_SIZE(struct xfs_efd_log_format, 16); + XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format, 16); + XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_32, 16); XFS_CHECK_STRUCT_SIZE(struct xfs_extent, 16); XFS_CHECK_STRUCT_SIZE(struct xfs_extent_32, 12); XFS_CHECK_STRUCT_SIZE(struct xfs_log_dinode, 176); -- 2.30.1
