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afs: Adjust the directory XDR structures
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Adjust the AFS directory XDR structures in a number of superficial ways:

 (1) Rename them to all begin afs_xdr_.

 (2) Use u8 instead of uint8_t.

 (3) Mark the structures as __packed so they don't get rearranged by the
     compiler.

 (4) Rename the hdr member of afs_xdr_dir_block to meta.

 (5) Rename the pagehdr member of afs_xdr_dir_block to hdr.

Signed-off-by: David Howells <dhowells@redhat.com>
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David Howells committed Apr 9, 2018
1 parent 4ea219a commit 0031763
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Showing 2 changed files with 53 additions and 53 deletions.
62 changes: 31 additions & 31 deletions fs/afs/dir.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -111,7 +111,7 @@ struct afs_lookup_cookie {
static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
loff_t i_size)
{
struct afs_dir_page *dbuf;
struct afs_xdr_dir_page *dbuf;
loff_t latter, off;
int tmp, qty;

Expand All @@ -127,15 +127,15 @@ static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
qty = PAGE_SIZE;
else
qty = latter;
qty /= sizeof(union afs_dir_block);
qty /= sizeof(union afs_xdr_dir_block);

/* check them */
dbuf = page_address(page);
for (tmp = 0; tmp < qty; tmp++) {
if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) {
if (dbuf->blocks[tmp].hdr.magic != AFS_DIR_MAGIC) {
printk("kAFS: %s(%lx): bad magic %d/%d is %04hx\n",
__func__, dvnode->vfs_inode.i_ino, tmp, qty,
ntohs(dbuf->blocks[tmp].pagehdr.magic));
ntohs(dbuf->blocks[tmp].hdr.magic));
trace_afs_dir_check_failed(dvnode, off, i_size);
goto error;
}
Expand All @@ -156,8 +156,8 @@ static int afs_dir_open(struct inode *inode, struct file *file)
{
_enter("{%lu}", inode->i_ino);

BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
BUILD_BUG_ON(sizeof(union afs_xdr_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_xdr_dirent) != 32);

if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags))
return -ENOENT;
Expand Down Expand Up @@ -310,17 +310,17 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
* deal with one block in an AFS directory
*/
static int afs_dir_iterate_block(struct dir_context *ctx,
union afs_dir_block *block,
union afs_xdr_dir_block *block,
unsigned blkoff)
{
union afs_dirent *dire;
union afs_xdr_dirent *dire;
unsigned offset, next, curr;
size_t nlen;
int tmp;

_enter("%u,%x,%p,,",(unsigned)ctx->pos,blkoff,block);

curr = (ctx->pos - blkoff) / sizeof(union afs_dirent);
curr = (ctx->pos - blkoff) / sizeof(union afs_xdr_dirent);

/* walk through the block, an entry at a time */
for (offset = (blkoff == 0 ? AFS_DIR_RESV_BLOCKS0 : AFS_DIR_RESV_BLOCKS);
Expand All @@ -330,48 +330,48 @@ static int afs_dir_iterate_block(struct dir_context *ctx,
next = offset + 1;

/* skip entries marked unused in the bitmap */
if (!(block->pagehdr.bitmap[offset / 8] &
if (!(block->hdr.bitmap[offset / 8] &
(1 << (offset % 8)))) {
_debug("ENT[%zu.%u]: unused",
blkoff / sizeof(union afs_dir_block), offset);
blkoff / sizeof(union afs_xdr_dir_block), offset);
if (offset >= curr)
ctx->pos = blkoff +
next * sizeof(union afs_dirent);
next * sizeof(union afs_xdr_dirent);
continue;
}

/* got a valid entry */
dire = &block->dirents[offset];
nlen = strnlen(dire->u.name,
sizeof(*block) -
offset * sizeof(union afs_dirent));
offset * sizeof(union afs_xdr_dirent));

_debug("ENT[%zu.%u]: %s %zu \"%s\"",
blkoff / sizeof(union afs_dir_block), offset,
blkoff / sizeof(union afs_xdr_dir_block), offset,
(offset < curr ? "skip" : "fill"),
nlen, dire->u.name);

/* work out where the next possible entry is */
for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) {
for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_xdr_dirent)) {
if (next >= AFS_DIR_SLOTS_PER_BLOCK) {
_debug("ENT[%zu.%u]:"
" %u travelled beyond end dir block"
" (len %u/%zu)",
blkoff / sizeof(union afs_dir_block),
blkoff / sizeof(union afs_xdr_dir_block),
offset, next, tmp, nlen);
return -EIO;
}
if (!(block->pagehdr.bitmap[next / 8] &
if (!(block->hdr.bitmap[next / 8] &
(1 << (next % 8)))) {
_debug("ENT[%zu.%u]:"
" %u unmarked extension (len %u/%zu)",
blkoff / sizeof(union afs_dir_block),
blkoff / sizeof(union afs_xdr_dir_block),
offset, next, tmp, nlen);
return -EIO;
}

_debug("ENT[%zu.%u]: ext %u/%zu",
blkoff / sizeof(union afs_dir_block),
blkoff / sizeof(union afs_xdr_dir_block),
next, tmp, nlen);
next++;
}
Expand All @@ -390,7 +390,7 @@ static int afs_dir_iterate_block(struct dir_context *ctx,
return 0;
}

ctx->pos = blkoff + next * sizeof(union afs_dirent);
ctx->pos = blkoff + next * sizeof(union afs_xdr_dirent);
}

_leave(" = 1 [more]");
Expand All @@ -404,8 +404,8 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
struct key *key)
{
struct afs_vnode *dvnode = AFS_FS_I(dir);
union afs_dir_block *dblock;
struct afs_dir_page *dbuf;
struct afs_xdr_dir_page *dbuf;
union afs_xdr_dir_block *dblock;
struct afs_read *req;
struct page *page;
unsigned blkoff, limit;
Expand All @@ -423,13 +423,13 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
return PTR_ERR(req);

/* round the file position up to the next entry boundary */
ctx->pos += sizeof(union afs_dirent) - 1;
ctx->pos &= ~(sizeof(union afs_dirent) - 1);
ctx->pos += sizeof(union afs_xdr_dirent) - 1;
ctx->pos &= ~(sizeof(union afs_xdr_dirent) - 1);

/* walk through the blocks in sequence */
ret = 0;
while (ctx->pos < req->actual_len) {
blkoff = ctx->pos & ~(sizeof(union afs_dir_block) - 1);
blkoff = ctx->pos & ~(sizeof(union afs_xdr_dir_block) - 1);

/* Fetch the appropriate page from the directory and re-add it
* to the LRU.
Expand All @@ -448,14 +448,14 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
/* deal with the individual blocks stashed on this page */
do {
dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
sizeof(union afs_dir_block)];
sizeof(union afs_xdr_dir_block)];
ret = afs_dir_iterate_block(ctx, dblock, blkoff);
if (ret != 1) {
kunmap(page);
goto out;
}

blkoff += sizeof(union afs_dir_block);
blkoff += sizeof(union afs_xdr_dir_block);

} while (ctx->pos < dir->i_size && blkoff < limit);

Expand Down Expand Up @@ -493,8 +493,8 @@ static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name,
(unsigned long long) ino, dtype);

/* insanity checks first */
BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
BUILD_BUG_ON(sizeof(union afs_xdr_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_xdr_dirent) != 32);

if (cookie->name.len != nlen ||
memcmp(cookie->name.name, name, nlen) != 0) {
Expand Down Expand Up @@ -562,8 +562,8 @@ static int afs_lookup_filldir(struct dir_context *ctx, const char *name,
(unsigned long long) ino, dtype);

/* insanity checks first */
BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
BUILD_BUG_ON(sizeof(union afs_xdr_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_xdr_dirent) != 32);

if (cookie->found) {
if (cookie->nr_fids < 50) {
Expand Down
44 changes: 22 additions & 22 deletions fs/afs/xdr_fs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -51,53 +51,53 @@ struct afs_xdr_AFSFetchStatus {
/*
* Directory entry structure.
*/
union afs_dirent {
union afs_xdr_dirent {
struct {
uint8_t valid;
uint8_t unused[1];
u8 valid;
u8 unused[1];
__be16 hash_next;
__be32 vnode;
__be32 unique;
uint8_t name[16];
uint8_t overflow[4]; /* if any char of the name (inc
u8 name[16];
u8 overflow[4]; /* if any char of the name (inc
* NUL) reaches here, consume
* the next dirent too */
} u;
uint8_t extended_name[32];
};
u8 extended_name[32];
} __packed;

/*
* Directory page header (one at the beginning of every 2048-byte chunk).
* Directory block header (one at the beginning of every 2048-byte block).
*/
struct afs_dir_pagehdr {
struct afs_xdr_dir_hdr {
__be16 npages;
__be16 magic;
#define AFS_DIR_MAGIC htons(1234)
uint8_t reserved;
uint8_t bitmap[8];
uint8_t pad[19];
};
u8 reserved;
u8 bitmap[8];
u8 pad[19];
} __packed;

/*
* Directory block layout
*/
union afs_dir_block {
struct afs_dir_pagehdr pagehdr;
union afs_xdr_dir_block {
struct afs_xdr_dir_hdr hdr;

struct {
struct afs_dir_pagehdr pagehdr;
uint8_t alloc_ctrs[AFS_DIR_MAX_BLOCKS];
struct afs_xdr_dir_hdr hdr;
u8 alloc_ctrs[AFS_DIR_MAX_BLOCKS];
__be16 hashtable[AFS_DIR_HASHTBL_SIZE];
} hdr;
} meta;

union afs_dirent dirents[AFS_DIR_SLOTS_PER_BLOCK];
};
union afs_xdr_dirent dirents[AFS_DIR_SLOTS_PER_BLOCK];
} __packed;

/*
* Directory layout on a linux VM page.
*/
struct afs_dir_page {
union afs_dir_block blocks[AFS_DIR_BLOCKS_PER_PAGE];
struct afs_xdr_dir_page {
union afs_xdr_dir_block blocks[AFS_DIR_BLOCKS_PER_PAGE];
};

#endif /* XDR_FS_H */

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