On 4/19/21 03:28, Christoph Hellwig wrote: > 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> Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Thanks, Christoph. -- Gustavo > --- > 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); >
