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xfs: cleanup __xfs_dir3_data_check

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Use an offset as the main means for iteration, and only do pointer
arithmetics to find the data/unused entries.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Christoph Hellwig 2019-11-08 15:05:35 -08:00 committed by Darrick J. Wong
parent 62479f5734
commit 48a71399e7
1 changed files with 33 additions and 26 deletions
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59
fs/xfs/libxfs/xfs_dir2_data.c
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@ -23,6 +23,22 @@ static xfs_failaddr_t xfs_dir2_data_freefind_verify(
struct xfs_dir2_data_unused *dup,
struct xfs_dir2_data_free **bf_ent);
/*
* The number of leaf entries is limited by the size of the block and the amount
* of space used by the data entries. We don't know how much space is used by
* the data entries yet, so just ensure that the count falls somewhere inside
* the block right now.
*/
static inline unsigned int
xfs_dir2_data_max_leaf_entries(
const struct xfs_dir_ops *ops,
struct xfs_da_geometry *geo)
{
return (geo->blksize - sizeof(struct xfs_dir2_block_tail) -
ops->data_entry_offset) /
sizeof(struct xfs_dir2_leaf_entry);
}
/*
* Check the consistency of the data block.
* The input can also be a block-format directory.
@ -38,23 +54,20 @@ __xfs_dir3_data_check(
xfs_dir2_block_tail_t *btp=NULL; /* block tail */
int count; /* count of entries found */
xfs_dir2_data_hdr_t *hdr; /* data block header */
xfs_dir2_data_entry_t *dep; /* data entry */
xfs_dir2_data_free_t *dfp; /* bestfree entry */
xfs_dir2_data_unused_t *dup; /* unused entry */
char *endp; /* end of useful data */
void *endp; /* end of useful data */
int freeseen; /* mask of bestfrees seen */
xfs_dahash_t hash; /* hash of current name */
int i; /* leaf index */
int lastfree; /* last entry was unused */
xfs_dir2_leaf_entry_t *lep=NULL; /* block leaf entries */
struct xfs_mount *mp = bp->b_mount;
char *p; /* current data position */
int stale; /* count of stale leaves */
struct xfs_name name;
unsigned int offset;
unsigned int end;
const struct xfs_dir_ops *ops;
struct xfs_da_geometry *geo;
geo = mp->m_dir_geo;
struct xfs_da_geometry *geo = mp->m_dir_geo;
/*
* We can be passed a null dp here from a verifier, so we need to go the
@ -71,7 +84,7 @@ __xfs_dir3_data_check(
return __this_address;
hdr = bp->b_addr;
p = (char *)ops->data_entry_p(hdr);
offset = ops->data_entry_offset;
switch (hdr->magic) {
case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
@ -79,15 +92,8 @@ __xfs_dir3_data_check(
btp = xfs_dir2_block_tail_p(geo, hdr);
lep = xfs_dir2_block_leaf_p(btp);
/*
* The number of leaf entries is limited by the size of the
* block and the amount of space used by the data entries.
* We don't know how much space is used by the data entries yet,
* so just ensure that the count falls somewhere inside the
* block right now.
*/
if (be32_to_cpu(btp->count) >=
((char *)btp - p) / sizeof(struct xfs_dir2_leaf_entry))
xfs_dir2_data_max_leaf_entries(ops, geo))
return __this_address;
break;
case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
@ -99,6 +105,7 @@ __xfs_dir3_data_check(
endp = xfs_dir3_data_endp(geo, hdr);
if (!endp)
return __this_address;
end = endp - bp->b_addr;
/*
* Account for zero bestfree entries.
@ -128,8 +135,10 @@ __xfs_dir3_data_check(
/*
* Loop over the data/unused entries.
*/
while (p < endp) {
dup = (xfs_dir2_data_unused_t *)p;
while (offset < end) {
struct xfs_dir2_data_unused *dup = bp->b_addr + offset;
struct xfs_dir2_data_entry *dep = bp->b_addr + offset;
/*
* If it's unused, look for the space in the bestfree table.
* If we find it, account for that, else make sure it
@ -140,10 +149,10 @@ __xfs_dir3_data_check(
if (lastfree != 0)
return __this_address;
if (endp < p + be16_to_cpu(dup->length))
if (offset + be16_to_cpu(dup->length) > end)
return __this_address;
if (be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) !=
(char *)dup - (char *)hdr)
offset)
return __this_address;
fa = xfs_dir2_data_freefind_verify(hdr, bf, dup, &dfp);
if (fa)
@ -158,7 +167,7 @@ __xfs_dir3_data_check(
be16_to_cpu(bf[2].length))
return __this_address;
}
p += be16_to_cpu(dup->length);
offset += be16_to_cpu(dup->length);
lastfree = 1;
continue;
}
@ -168,15 +177,13 @@ __xfs_dir3_data_check(
* in the leaf section of the block.
* The linear search is crude but this is DEBUG code.
*/
dep = (xfs_dir2_data_entry_t *)p;
if (dep->namelen == 0)
return __this_address;
if (xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)))
return __this_address;
if (endp < p + ops->data_entsize(dep->namelen))
if (offset + ops->data_entsize(dep->namelen) > end)
return __this_address;
if (be16_to_cpu(*ops->data_entry_tag_p(dep)) !=
(char *)dep - (char *)hdr)
if (be16_to_cpu(*ops->data_entry_tag_p(dep)) != offset)
return __this_address;
if (ops->data_get_ftype(dep) >= XFS_DIR3_FT_MAX)
return __this_address;
@ -198,7 +205,7 @@ __xfs_dir3_data_check(
if (i >= be32_to_cpu(btp->count))
return __this_address;
}
p += ops->data_entsize(dep->namelen);
offset += ops->data_entsize(dep->namelen);
}
/*
* Need to have seen all the entries and all the bestfree slots.