Re: [PATCH][next] xfs: Replace one-element arrays with flexible-array members
From: Darrick J. Wong
Date: Tue Mar 09 2021 - 16:27:54 EST
On Tue, Mar 09, 2021 at 01:57:36PM -0600, Gustavo A. R. Silva wrote:
> Hi Darrick,
>
> Please, see my comments below...
>
> On 3/9/21 11:42, Darrick J. Wong wrote:
> > On Tue, Mar 02, 2021 at 09:05:58AM -0600, Gustavo A. R. Silva wrote:
> >> 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 multiple
> >> structures that contain flexible-array members.
> >>
> >> Below are the results of running xfstests for groups shutdown and log
> >> with the following configuration in local.config:
> >>
> >> export TEST_DEV=/dev/sda3
> >> export TEST_DIR=/mnt/test
> >> export SCRATCH_DEV=/dev/sda4
> >> export SCRATCH_MNT=/mnt/scratch
> >>
> >> The size for both partitions /dev/sda3 and /dev/sda4 is 25GB.
> >>
> >> These are the results of running ./check -g shutdown and ./check -g
> >> log, respectively, on 5.11.0-next-20210301 kernel _without_ this patch
> >> applied:
> >>
> >> gustavo@beefy:~/git/xfstests$ time sudo ./check -g shutdown 2>&1 | tee xfs-shutdown-no-patch.out
> >> FSTYP -- xfs (debug)
> >> PLATFORM -- Linux/x86_64 beefy 5.11.0-next-20210301 #4 SMP Mon Mar 1 05:42:06 CST 2021
> >> MKFS_OPTIONS -- -f -bsize=4096 /dev/sda4
> >> MOUNT_OPTIONS -- /dev/sda4 /mnt/scratch
> >>
> >> generic/042 2s ... 2s
> >> generic/043 13s ... 13s
> >> generic/044 14s ... 14s
> >> generic/045 18s ... 18s
> >> generic/046 14s ... 14s
> >> generic/047 20s ... 22s
> >> generic/048 51s ... 50s
> >> generic/049 9s ... 8s
> >> generic/050 2s ... 1s
> >> generic/051 76s ... 75s
> >> generic/052 1s ... 2s
> >> generic/054 31s ... 30s
> >> generic/055 16s ... 21s
> >> generic/388 89s ... 75s
> >> generic/392 5s ... 5s
> >> generic/417 11s ... 11s
> >> generic/461 21s ... 22s
> >> generic/468 3s ... 3s
> >> generic/474 1s ... 1s
> >> generic/475 86s ... 93s
> >> generic/505 2s ... 2s
> >> generic/506 2s ... 2s
> >> generic/507 [not run] file system doesn't support chattr +AsSu
> >> generic/508 1s ... 1s
> >> generic/530 10s ... 10s
> >> generic/536 3s ... 2s
> >> generic/599 1s ... 1s
> >> generic/622 23s ... 24s
> >> xfs/051 18s ... 18s
> >> xfs/079 15s ... 14s
> >> xfs/121 6s ... 16s
> >> xfs/181 12s ... 15s
> >> xfs/212 1s ... 3s
> >> Ran: generic/042 generic/043 generic/044 generic/045 generic/046 generic/047 generic/048 generic/049 generic/050 generic/051 generic/052 generic/054 generic/055 generic/388 generic/392 generic/417 generic/461 generic/468 generic/474 generic/475 generic/505 generic/506 generic/507 generic/508 generic/530 generic/536 generic/599 generic/622 xfs/051 xfs/079 xfs/121 xfs/181 xfs/212
> >> Not run: generic/507
> >> Passed all 33 tests
> >>
> >> gustavo@beefy:~/git/xfstests$ time sudo ./check -g log 2>&1 | tee xfs-log-no-patch.out
> >> FSTYP -- xfs (debug)
> >> PLATFORM -- Linux/x86_64 beefy 5.11.0-next-20210301 #4 SMP Mon Mar 1 05:42:06 CST 2021
> >> MKFS_OPTIONS -- -f -bsize=4096 /dev/sda4
> >> MOUNT_OPTIONS -- /dev/sda4 /mnt/scratch
> >>
> >> generic/034 1s ... 1s
> >> generic/039 1s ... 1s
> >> generic/040 5s ... 5s
> >> generic/041 7s ... 7s
> >> generic/043 13s ... 13s
> >> generic/044 14s ... 14s
> >> generic/045 18s ... 18s
> >> generic/046 14s ... 14s
> >> generic/051 76s ... 76s
> >> generic/052 1s ... 2s
> >> generic/054 30s ... 48s
> >> generic/055 23s ... 15s
> >> generic/056 1s ... 1s
> >> generic/057 1s ... 1s
> >> generic/059 2s ... 2s
> >> generic/065 1s ... 1s
> >> generic/066 1s ... 2s
> >> generic/073 1s ... 1s
> >> generic/090 1s ... 1s
> >> generic/101 1s ... 1s
> >> generic/104 1s ... 1s
> >> generic/106 1s ... 1s
> >> generic/107 1s ... 1s
> >> generic/177 1s ... 1s
> >> generic/311 67s ... 67s
> >> generic/321 2s ... 2s
> >> generic/322 1s ... 2s
> >> generic/325 1s ... 1s
> >> generic/335 1s ... 1s
> >> generic/336 2s ... 1s
> >> generic/341 1s ... 1s
> >> generic/342 1s ... 1s
> >> generic/343 1s ... 1s
> >> generic/376 1s ... 1s
> >> generic/388 75s ... 97s
> >> generic/417 15s ... 12s
> >> generic/455 [not run] This test requires a valid $LOGWRITES_DEV
> >> generic/457 [not run] This test requires a valid $LOGWRITES_DEV
> >> generic/475 88s ... 89s
> >> generic/479 2s ... 2s
> >> generic/480 1s ... 1s
> >> generic/481 1s ... 1s
> >> generic/483 7s ... 6s
> >> generic/489 1s ... 1s
> >> generic/498 1s ... 1s
> >> generic/501 61s ... 63s
> >> generic/502 1s ... 1s
> >> generic/509 1s ... 1s
> >> generic/510 1s ... 1s
> >> generic/512 1s ... 1s
> >> generic/520 16s ... 17s
> >> generic/526 2s ... 1s
> >> generic/527 0s ... 1s
> >> generic/534 0s ... 1s
> >> generic/535 2s ... 1s
> >> generic/546 3s ... 3s
> >> generic/547 2s ... 2s
> >> generic/552 1s ... 1s
> >> generic/557 1s ... 2s
> >> generic/588 2s ... 1s
> >> shared/002 9s ... 9s
> >> xfs/011 18s ... 18s
> >> xfs/029 1s ... 1s
> >> xfs/051 18s ... 18s
> >> xfs/057 23s ... 23s
> >> xfs/079 14s ... 14s
> >> xfs/095 1s ... 1s
> >> xfs/119 3s ... 3s
> >> xfs/121 6s ... 6s
> >> xfs/141 14s ... 26s
> >> xfs/181 14s ... 14s
> >> xfs/216 3s ... 2s
> >> xfs/217 2s ... 2s
> >> xfs/439 [not run] test requires XFS bug_on_assert to be off, turn it off to run the test
> >> Ran: generic/034 generic/039 generic/040 generic/041 generic/043 generic/044 generic/045 generic/046 generic/051 generic/052 generic/054 generic/055 generic/056 generic/057 generic/059 generic/065 generic/066 generic/073 generic/090 generic/101 generic/104 generic/106 generic/107 generic/177 generic/311 generic/321 generic/322 generic/325 generic/335 generic/336 generic/341 generic/342 generic/343 generic/376 generic/388 generic/417 generic/455 generic/457 generic/475 generic/479 generic/480 generic/481 generic/483 generic/489 generic/498 generic/501 generic/502 generic/509 generic/510 generic/512 generic/520 generic/526 generic/527 generic/534 generic/535 generic/546 generic/547 generic/552 generic/557 generic/588 shared/002 xfs/011 xfs/029 xfs/051 xfs/057 xfs/079 xfs/095 xfs/119 xfs/121 xfs/141 xfs/181 xfs/216 xfs/217 xfs/439
> >> Not run: generic/455 generic/457 xfs/439
> >> Passed all 74 tests
> >>
> >> These are the results of running ./check -g shutdown and ./check -g
> >> log, respectively, on 5.11.0-xfstests-patched-next-20210301+ kernel
> >> _with_ this patch applied on top:
> >>
> >> gustavo@beefy:~/git/xfstests$ time sudo ./check -g shutdown 2>&1 | tee xfs-shutdown-patched.out
> >> FSTYP -- xfs (debug)
> >> PLATFORM -- Linux/x86_64 beefy 5.11.0-xfstests-patched-next-20210301+ #10 SMP Mon Mar 1 17:36:20 CST 2021
> >> MKFS_OPTIONS -- -f -bsize=4096 /dev/sda4
> >> MOUNT_OPTIONS -- /dev/sda4 /mnt/scratch
> >>
> >> generic/042 2s ... 3s
> >> generic/043 13s ... 12s
> >> generic/044 14s ... 15s
> >> generic/045 18s ... 18s
> >> generic/046 14s ... 15s
> >> generic/047 21s ... 21s
> >> generic/048 51s ... 51s
> >> generic/049 9s ... 8s
> >> generic/050 1s ... 2s
> >> generic/051 76s ... 77s
> >> generic/052 6s ... 2s
> >> generic/054 35s ... 48s
> >> generic/055 16s ... 17s
> >> generic/388 77s ... 73s
> >> generic/392 7s ... 5s
> >> generic/417 13s ... 11s
> >> generic/461 22s ... 21s
> >> generic/468 2s ... 3s
> >> generic/474 2s ... 1s
> >> generic/475 90s ... 96s
> >> generic/505 3s ... 3s
> >> generic/506 1s ... 2s
> >> generic/507 [not run] file system doesn't support chattr +AsSu
> >> generic/508 2s ... 10s
> >> generic/530 9s ... 13s
> >> generic/536 2s ... 1s
> >> generic/599 1s ... 1s
> >> generic/622 24s ... 25s
> >> xfs/051 18s ... 18s
> >> xfs/079 14s ... 13s
> >> xfs/121 6s ... 8s
> >> xfs/181 11s ... 14s
> >> xfs/212 2s ... 1s
> >> Ran: generic/042 generic/043 generic/044 generic/045 generic/046 generic/047 generic/048 generic/049 generic/050 generic/051 generic/052 generic/054 generic/055 generic/388 generic/392 generic/417 generic/461 generic/468 generic/474 generic/475 generic/505 generic/506 generic/507 generic/508 generic/530 generic/536 generic/599 generic/622 xfs/051 xfs/079 xfs/121 xfs/181 xfs/212
> >> Not run: generic/507
> >> Passed all 33 tests
> >>
> >> gustavo@beefy:~/git/xfstests$ time sudo ./check -g log 2>&1 | tee xfs-log-patched.out
> >> FSTYP -- xfs (debug)
> >> PLATFORM -- Linux/x86_64 beefy 5.11.0-xfstests-patched-next-20210301+ #10 SMP Mon Mar 1 17:36:20 CST 2021
> >> MKFS_OPTIONS -- -f -bsize=4096 /dev/sda4
> >> MOUNT_OPTIONS -- /dev/sda4 /mnt/scratch
> >>
> >> generic/034 1s ... 1s
> >> generic/039 1s ... 1s
> >> generic/040 5s ... 5s
> >> generic/041 7s ... 7s
> >> generic/043 12s ... 13s
> >> generic/044 15s ... 15s
> >> generic/045 18s ... 18s
> >> generic/046 15s ... 14s
> >> generic/051 77s ... 76s
> >> generic/052 2s ... 1s
> >> generic/054 48s ... 29s
> >> generic/055 17s ... 16s
> >> generic/056 1s ... 1s
> >> generic/057 1s ... 1s
> >> generic/059 2s ... 2s
> >> generic/065 1s ... 1s
> >> generic/066 1s ... 1s
> >> generic/073 1s ... 1s
> >> generic/090 1s ... 1s
> >> generic/101 1s ... 1s
> >> generic/104 1s ... 1s
> >> generic/106 1s ... 1s
> >> generic/107 1s ... 1s
> >> generic/177 1s ... 1s
> >> generic/311 68s ... 68s
> >> generic/321 2s ... 2s
> >> generic/322 1s ... 1s
> >> generic/325 2s ... 1s
> >> generic/335 1s ... 1s
> >> generic/336 1s ... 1s
> >> generic/341 1s ... 1s
> >> generic/342 1s ... 1s
> >> generic/343 1s ... 1s
> >> generic/376 1s ... 1s
> >> generic/388 73s ... 83s
> >> generic/417 11s ... 11s
> >> generic/455 [not run] This test requires a valid $LOGWRITES_DEV
> >> generic/457 [not run] This test requires a valid $LOGWRITES_DEV
> >> generic/475 96s ... 83s
> >> generic/479 2s
> >> generic/480 2s ... 1s
> >> generic/481 0s ... 1s
> >> generic/483 7s ... 7s
> >> generic/489 1s ... 1s
> >> generic/498 1s ... 1s
> >> generic/501 63s ... 61s
> >> generic/502 1s ... 1s
> >> generic/509 1s ... 1s
> >> generic/510 1s ... 1s
> >> generic/512 1s ... 1s
> >> generic/520 16s ... 16s
> >> generic/526 1s ... 1s
> >> generic/527 1s ... 1s
> >> generic/534 1s ... 1s
> >> generic/535 1s ... 1s
> >> generic/546 4s ... 4s
> >> generic/547 2s ... 2s
> >> generic/552 1s ... 1s
> >> generic/557 1s ... 1s
> >> generic/588 2s ... 1s
> >> shared/002 8s ... 9s
> >> xfs/011 18s ... 18s
> >> xfs/029 1s ... 1s
> >> xfs/051 18s ... 18s
> >> xfs/057 23s ... 24s
> >> xfs/079 13s ... 14s
> >> xfs/095 2s ... 1s
> >> xfs/119 3s ... 3s
> >> xfs/121 8s ... 6s
> >> xfs/141 18s ... 12s
> >> xfs/181 14s ... 12s
> >> xfs/216 3s ... 2s
> >> xfs/217 2s ... 2s
> >> xfs/439 [not run] test requires XFS bug_on_assert to be off, turn it off to run the test
> >> Ran: generic/034 generic/039 generic/040 generic/041 generic/043 generic/044 generic/045 generic/046 generic/051 generic/052 generic/054 generic/055 generic/056 generic/057 generic/059 generic/065 generic/066 generic/073 generic/090 generic/101 generic/104 generic/106 generic/107 generic/177 generic/311 generic/321 generic/322 generic/325 generic/335 generic/336 generic/341 generic/342 generic/343 generic/376 generic/388 generic/417 generic/455 generic/457 generic/475 generic/479 generic/480 generic/481 generic/483 generic/489 generic/498 generic/501 generic/502 generic/509 generic/510 generic/512 generic/520 generic/526 generic/527 generic/534 generic/535 generic/546 generic/547 generic/552 generic/557 generic/588 shared/002 xfs/011 xfs/029 xfs/051 xfs/057 xfs/079 xfs/095 xfs/119 xfs/121 xfs/141 xfs/181 xfs/216 xfs/217 xfs/439
> >> Not run: generic/455 generic/457 xfs/439
> >> Passed all 74 tests
> >>
> >> Notice that the test results before and after this patch is applied are
> >> identical and successful. Other tests might need to be run in order to
> >> verify everything is working as expected. For such tests, the intervention
> >> of the maintainers might be needed.
> >>
> >> [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
> >>
> >> Link: https://github.com/KSPP/linux/issues/79
> >> Build-tested-by: kernel test robot <lkp@xxxxxxxxx>
> >> Link: https://lore.kernel.org/lkml/603e3177.WsvTXRpcLn5wdYW6%25lkp@xxxxxxxxx/
> >> Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
> >> ---
> >> fs/xfs/libxfs/xfs_log_format.h | 12 +++++------
> >> fs/xfs/xfs_extfree_item.c | 39 +++++++++++++++-------------------
> >> fs/xfs/xfs_ondisk.h | 8 +++----
> >> 3 files changed, 27 insertions(+), 32 deletions(-)
> >>
> >> diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h
> >> index 8bd00da6d2a4..9934a465b441 100644
> >> --- a/fs/xfs/libxfs/xfs_log_format.h
> >> +++ b/fs/xfs/libxfs/xfs_log_format.h
> >> @@ -574,7 +574,7 @@ typedef 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 */
> >> - xfs_extent_t efi_extents[1]; /* array of extents to free */
> >> + xfs_extent_t efi_extents[]; /* array of extents to free */
> >> } xfs_efi_log_format_t;
> >>
> >> typedef struct xfs_efi_log_format_32 {
> >> @@ -582,7 +582,7 @@ typedef 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 */
> >> - xfs_extent_32_t efi_extents[1]; /* array of extents to free */
> >> + xfs_extent_32_t efi_extents[]; /* array of extents to free */
> >> } __attribute__((packed)) xfs_efi_log_format_32_t;
> >>
> >> typedef struct xfs_efi_log_format_64 {
> >> @@ -590,7 +590,7 @@ typedef struct xfs_efi_log_format_64 {
> >> uint16_t efi_size; /* size of this item */
> >> uint32_t efi_nextents; /* # extents to free */
> >> uint64_t efi_id; /* efi identifier */
> >> - xfs_extent_64_t efi_extents[1]; /* array of extents to free */
> >> + xfs_extent_64_t efi_extents[]; /* array of extents to free */
> >> } xfs_efi_log_format_64_t;
> >>
> >> /*
> >> @@ -603,7 +603,7 @@ typedef 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 */
> >> - xfs_extent_t efd_extents[1]; /* array of extents freed */
> >> + xfs_extent_t efd_extents[]; /* array of extents freed */
> >> } xfs_efd_log_format_t;
> >>
> >> typedef struct xfs_efd_log_format_32 {
> >> @@ -611,7 +611,7 @@ typedef struct xfs_efd_log_format_32 {
> >> uint16_t efd_size; /* size of this item */
> >> uint32_t efd_nextents; /* # of extents freed */
> >> uint64_t efd_efi_id; /* id of corresponding efi */
> >> - xfs_extent_32_t efd_extents[1]; /* array of extents freed */
> >> + xfs_extent_32_t efd_extents[]; /* array of extents freed */
> >> } __attribute__((packed)) xfs_efd_log_format_32_t;
> >>
> >> typedef struct xfs_efd_log_format_64 {
> >> @@ -619,7 +619,7 @@ typedef struct xfs_efd_log_format_64 {
> >> uint16_t efd_size; /* size of this item */
> >> uint32_t efd_nextents; /* # of extents freed */
> >> uint64_t efd_efi_id; /* id of corresponding efi */
> >> - xfs_extent_64_t efd_extents[1]; /* array of extents freed */
> >> + xfs_extent_64_t efd_extents[]; /* array of extents freed */
> >> } xfs_efd_log_format_64_t;
> >>
> >> /*
> >> diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c
> >> index 93223ebb3372..5ed3ea93071c 100644
> >> --- a/fs/xfs/xfs_extfree_item.c
> >> +++ b/fs/xfs/xfs_extfree_item.c
> >> @@ -73,8 +73,8 @@ static inline int
> >> xfs_efi_item_sizeof(
> >> struct xfs_efi_log_item *efip)
> >> {
> >> - return sizeof(struct xfs_efi_log_format) +
> >> - (efip->efi_format.efi_nextents - 1) * sizeof(xfs_extent_t);
> >> + return struct_size(&efip->efi_format, efi_extents,
> >> + efip->efi_format.efi_nextents);
> >> }
> >>
> >> STATIC void
> >> @@ -153,17 +153,14 @@ xfs_efi_init(
> >>
> >> {
> >> struct xfs_efi_log_item *efip;
> >> - uint size;
> >>
> >> ASSERT(nextents > 0);
> >> - if (nextents > XFS_EFI_MAX_FAST_EXTENTS) {
> >> - size = (uint)(sizeof(struct xfs_efi_log_item) +
> >> - ((nextents - 1) * sizeof(xfs_extent_t)));
> >> - efip = kmem_zalloc(size, 0);
> >> - } else {
> >> + if (nextents > XFS_EFI_MAX_FAST_EXTENTS)
> >> + efip = kmem_zalloc(struct_size(efip, efi_format.efi_extents,
> >> + nextents), 0);
> >> + else
> >> efip = kmem_cache_zalloc(xfs_efi_zone,
> >> GFP_KERNEL | __GFP_NOFAIL);
> >> - }
> >>
> >> xfs_log_item_init(mp, &efip->efi_item, XFS_LI_EFI, &xfs_efi_item_ops);
> >> efip->efi_format.efi_nextents = nextents;
> >> @@ -186,12 +183,12 @@ xfs_efi_copy_format(xfs_log_iovec_t *buf, xfs_efi_log_format_t *dst_efi_fmt)
> >> {
> >> xfs_efi_log_format_t *src_efi_fmt = buf->i_addr;
> >> uint i;
> >> - uint len = sizeof(xfs_efi_log_format_t) +
> >> - (src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_t);
> >> + size_t len = struct_size(src_efi_fmt, efi_extents,
> >> + src_efi_fmt->efi_nextents);
> >> uint len32 = sizeof(xfs_efi_log_format_32_t) +
> >> - (src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_32_t);
> >> + src_efi_fmt->efi_nextents * sizeof(xfs_extent_32_t);
> >
> > Shouldn't these be converted to struct_size() too?
> >
> > It seems to work all right for casted NULL pointers, and then we get all
> > the typechecking and multiplication overflow checking, e.g.:
> >
> > size_t len64 = struct_size((struct xfs_efi_log_format_32 *)NULL,
> > efi_extents src_efi_fmt->efi_nextents);
>
> Yeah; in that case, what do you think about casting 0, instead of NULL:
>
> uint len32 = struct_size((xfs_efi_log_format_32_t *)0, efi_extents,
> src_efi_fmt->efi_nextents);
> uint len64 = struct_size((xfs_efi_log_format_64_t *)0, efi_extents,
> src_efi_fmt->efi_nextents);
I don't have a preference either way, either here or for the half-dozen
more of these scattered elsewhere in the file.
--D
> Thanks
> --
> Gustavo
>
> >
> > --D
> >
> >> uint len64 = sizeof(xfs_efi_log_format_64_t) +
> >> - (src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_64_t);
> >> + src_efi_fmt->efi_nextents * sizeof(xfs_extent_64_t);
> >>
> >> if (buf->i_len == len) {
> >> memcpy((char *)dst_efi_fmt, (char*)src_efi_fmt, len);
> >> @@ -254,7 +251,7 @@ xfs_efd_item_sizeof(
> >> struct xfs_efd_log_item *efdp)
> >> {
> >> return sizeof(xfs_efd_log_format_t) +
> >> - (efdp->efd_format.efd_nextents - 1) * sizeof(xfs_extent_t);
> >> + efdp->efd_format.efd_nextents * sizeof(xfs_extent_t);
> >> }
> >>
> >> STATIC void
> >> @@ -328,14 +325,12 @@ xfs_trans_get_efd(
> >>
> >> ASSERT(nextents > 0);
> >>
> >> - if (nextents > XFS_EFD_MAX_FAST_EXTENTS) {
> >> - efdp = kmem_zalloc(sizeof(struct xfs_efd_log_item) +
> >> - (nextents - 1) * sizeof(struct xfs_extent),
> >> - 0);
> >> - } else {
> >> + if (nextents > XFS_EFD_MAX_FAST_EXTENTS)
> >> + efdp = kmem_zalloc(struct_size(efip, efi_format.efi_extents,
> >> + nextents), 0);
> >> + else
> >> efdp = kmem_cache_zalloc(xfs_efd_zone,
> >> GFP_KERNEL | __GFP_NOFAIL);
> >> - }
> >>
> >> xfs_log_item_init(tp->t_mountp, &efdp->efd_item, XFS_LI_EFD,
> >> &xfs_efd_item_ops);
> >> @@ -747,9 +742,9 @@ xlog_recover_efd_commit_pass2(
> >>
> >> efd_formatp = item->ri_buf[0].i_addr;
> >> ASSERT((item->ri_buf[0].i_len == (sizeof(xfs_efd_log_format_32_t) +
> >> - ((efd_formatp->efd_nextents - 1) * sizeof(xfs_extent_32_t)))) ||
> >> + (efd_formatp->efd_nextents * sizeof(xfs_extent_32_t)))) ||
> >> (item->ri_buf[0].i_len == (sizeof(xfs_efd_log_format_64_t) +
> >> - ((efd_formatp->efd_nextents - 1) * sizeof(xfs_extent_64_t)))));
> >> + (efd_formatp->efd_nextents * sizeof(xfs_extent_64_t)))));
> >>
> >> xlog_recover_release_intent(log, XFS_LI_EFI, efd_formatp->efd_efi_id);
> >> return 0;
> >> diff --git a/fs/xfs/xfs_ondisk.h b/fs/xfs/xfs_ondisk.h
> >> index 0aa87c210104..f58e0510385a 100644
> >> --- a/fs/xfs/xfs_ondisk.h
> >> +++ b/fs/xfs/xfs_ondisk.h
> >> @@ -118,10 +118,10 @@ 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, 28);
> >> - XFS_CHECK_STRUCT_SIZE(struct xfs_efd_log_format_64, 32);
> >> - XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_32, 28);
> >> - XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_64, 32);
> >> + XFS_CHECK_STRUCT_SIZE(struct xfs_efd_log_format_32, 16);
> >> + XFS_CHECK_STRUCT_SIZE(struct xfs_efd_log_format_64, 16);
> >> + XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_32, 16);
> >> + XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_64, 16);
> >> XFS_CHECK_STRUCT_SIZE(struct xfs_extent_32, 12);
> >> XFS_CHECK_STRUCT_SIZE(struct xfs_extent_64, 16);
> >> XFS_CHECK_STRUCT_SIZE(struct xfs_log_dinode, 176);
> >> --
> >> 2.27.0
> >>