[1/2] erofs: clean up erofs_iget()
Commit Message
Move inode hash function into inode.c and simplify erofs_iget().
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
fs/erofs/inode.c | 40 +++++++++++++++++++++-------------------
fs/erofs/internal.h | 9 ---------
2 files changed, 21 insertions(+), 28 deletions(-)
Comments
On Fri, 13 Jan 2023 14:52:25 +0800
Gao Xiang <hsiangkao@linux.alibaba.com> wrote:
> Move inode hash function into inode.c and simplify erofs_iget().
>
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
On 1/13/23 2:52 PM, Gao Xiang wrote:
> Move inode hash function into inode.c and simplify erofs_iget().
>
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
> ---
> fs/erofs/inode.c | 40 +++++++++++++++++++++-------------------
> fs/erofs/internal.h | 9 ---------
> 2 files changed, 21 insertions(+), 28 deletions(-)
>
> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> index d3b8736fa124..57328691582e 100644
> --- a/fs/erofs/inode.c
> +++ b/fs/erofs/inode.c
> @@ -308,47 +308,49 @@ static int erofs_fill_inode(struct inode *inode)
> }
>
> /*
> - * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
> - * we should do more for 32-bit platform to find the right inode.
> + * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
> + * so that it will fit.
> */
> -static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
> +static ino_t erofs_squash_ino(erofs_nid_t nid)
> {
> - const erofs_nid_t nid = *(erofs_nid_t *)opaque;
> + ino_t ino = (ino_t)nid;
> +
> + if (sizeof(ino_t) < sizeof(erofs_nid_t))
> + ino ^= nid >> (sizeof(erofs_nid_t) - sizeof(ino_t)) * 8;
Shouldn't we do:
ino ^= nid >> sizeof(ino_t) * 8
?
On 2023/1/13 15:41, Jingbo Xu wrote:
>
>
> On 1/13/23 2:52 PM, Gao Xiang wrote:
>> Move inode hash function into inode.c and simplify erofs_iget().
>>
>> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
>> ---
>> fs/erofs/inode.c | 40 +++++++++++++++++++++-------------------
>> fs/erofs/internal.h | 9 ---------
>> 2 files changed, 21 insertions(+), 28 deletions(-)
>>
>> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
>> index d3b8736fa124..57328691582e 100644
>> --- a/fs/erofs/inode.c
>> +++ b/fs/erofs/inode.c
>> @@ -308,47 +308,49 @@ static int erofs_fill_inode(struct inode *inode)
>> }
>>
>> /*
>> - * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
>> - * we should do more for 32-bit platform to find the right inode.
>> + * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
>> + * so that it will fit.
>> */
>> -static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
>> +static ino_t erofs_squash_ino(erofs_nid_t nid)
>> {
>> - const erofs_nid_t nid = *(erofs_nid_t *)opaque;
>> + ino_t ino = (ino_t)nid;
>> +
>> + if (sizeof(ino_t) < sizeof(erofs_nid_t))
>> + ino ^= nid >> (sizeof(erofs_nid_t) - sizeof(ino_t)) * 8;
>
> Shouldn't we do:
>
> ino ^= nid >> sizeof(ino_t) * 8
Actually I copied it from fuse, for 64-bit erofs_nid_t it has no difference
though. I will also update it as your suggestion in v2.
Thanks,
Gao Xiang
> ?
>
>
On 1/13/23 2:52 PM, Gao Xiang wrote:
> Move inode hash function into inode.c and simplify erofs_iget().
>
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Since the v2 triggers the compiling error, this v1 is also acceptable
for me.
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
> ---
> fs/erofs/inode.c | 40 +++++++++++++++++++++-------------------
> fs/erofs/internal.h | 9 ---------
> 2 files changed, 21 insertions(+), 28 deletions(-)
>
> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> index d3b8736fa124..57328691582e 100644
> --- a/fs/erofs/inode.c
> +++ b/fs/erofs/inode.c
> @@ -308,47 +308,49 @@ static int erofs_fill_inode(struct inode *inode)
> }
>
> /*
> - * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
> - * we should do more for 32-bit platform to find the right inode.
> + * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
> + * so that it will fit.
> */
> -static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
> +static ino_t erofs_squash_ino(erofs_nid_t nid)
> {
> - const erofs_nid_t nid = *(erofs_nid_t *)opaque;
> + ino_t ino = (ino_t)nid;
> +
> + if (sizeof(ino_t) < sizeof(erofs_nid_t))
> + ino ^= nid >> (sizeof(erofs_nid_t) - sizeof(ino_t)) * 8;
> + return ino;
> +}
>
> - return EROFS_I(inode)->nid == nid;
> +static int erofs_iget5_eq(struct inode *inode, void *opaque)
> +{
> + return EROFS_I(inode)->nid == *(erofs_nid_t *)opaque;
> }
>
> -static int erofs_iget_set_actor(struct inode *inode, void *opaque)
> +static int erofs_iget5_set(struct inode *inode, void *opaque)
> {
> const erofs_nid_t nid = *(erofs_nid_t *)opaque;
>
> - inode->i_ino = erofs_inode_hash(nid);
> + inode->i_ino = erofs_squash_ino(nid);
> + EROFS_I(inode)->nid = nid;
> return 0;
> }
>
> struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid)
> {
> - const unsigned long hashval = erofs_inode_hash(nid);
> struct inode *inode;
>
> - inode = iget5_locked(sb, hashval, erofs_ilookup_test_actor,
> - erofs_iget_set_actor, &nid);
> + inode = iget5_locked(sb, erofs_squash_ino(nid), erofs_iget5_eq,
> + erofs_iget5_set, &nid);
> if (!inode)
> return ERR_PTR(-ENOMEM);
>
> if (inode->i_state & I_NEW) {
> - int err;
> - struct erofs_inode *vi = EROFS_I(inode);
> -
> - vi->nid = nid;
> + int err = erofs_fill_inode(inode);
>
> - err = erofs_fill_inode(inode);
> - if (!err) {
> - unlock_new_inode(inode);
> - } else {
> + if (err) {
> iget_failed(inode);
> - inode = ERR_PTR(err);
> + return ERR_PTR(err);
> }
> + unlock_new_inode(inode);
> }
> return inode;
> }
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index bb8501c0ff5b..168c21f16383 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -480,15 +480,6 @@ int erofs_map_blocks(struct inode *inode,
> struct erofs_map_blocks *map, int flags);
>
> /* inode.c */
> -static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
> -{
> -#if BITS_PER_LONG == 32
> - return (nid >> 32) ^ (nid & 0xffffffff);
> -#else
> - return nid;
> -#endif
> -}
> -
> extern const struct inode_operations erofs_generic_iops;
> extern const struct inode_operations erofs_symlink_iops;
> extern const struct inode_operations erofs_fast_symlink_iops;
On 2023/1/13 14:52, Gao Xiang wrote:
> Move inode hash function into inode.c and simplify erofs_iget().
>
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Thanks,
@@ -308,47 +308,49 @@ static int erofs_fill_inode(struct inode *inode)
}
/*
- * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
- * we should do more for 32-bit platform to find the right inode.
+ * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
+ * so that it will fit.
*/
-static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
+static ino_t erofs_squash_ino(erofs_nid_t nid)
{
- const erofs_nid_t nid = *(erofs_nid_t *)opaque;
+ ino_t ino = (ino_t)nid;
+
+ if (sizeof(ino_t) < sizeof(erofs_nid_t))
+ ino ^= nid >> (sizeof(erofs_nid_t) - sizeof(ino_t)) * 8;
+ return ino;
+}
- return EROFS_I(inode)->nid == nid;
+static int erofs_iget5_eq(struct inode *inode, void *opaque)
+{
+ return EROFS_I(inode)->nid == *(erofs_nid_t *)opaque;
}
-static int erofs_iget_set_actor(struct inode *inode, void *opaque)
+static int erofs_iget5_set(struct inode *inode, void *opaque)
{
const erofs_nid_t nid = *(erofs_nid_t *)opaque;
- inode->i_ino = erofs_inode_hash(nid);
+ inode->i_ino = erofs_squash_ino(nid);
+ EROFS_I(inode)->nid = nid;
return 0;
}
struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid)
{
- const unsigned long hashval = erofs_inode_hash(nid);
struct inode *inode;
- inode = iget5_locked(sb, hashval, erofs_ilookup_test_actor,
- erofs_iget_set_actor, &nid);
+ inode = iget5_locked(sb, erofs_squash_ino(nid), erofs_iget5_eq,
+ erofs_iget5_set, &nid);
if (!inode)
return ERR_PTR(-ENOMEM);
if (inode->i_state & I_NEW) {
- int err;
- struct erofs_inode *vi = EROFS_I(inode);
-
- vi->nid = nid;
+ int err = erofs_fill_inode(inode);
- err = erofs_fill_inode(inode);
- if (!err) {
- unlock_new_inode(inode);
- } else {
+ if (err) {
iget_failed(inode);
- inode = ERR_PTR(err);
+ return ERR_PTR(err);
}
+ unlock_new_inode(inode);
}
return inode;
}
@@ -480,15 +480,6 @@ int erofs_map_blocks(struct inode *inode,
struct erofs_map_blocks *map, int flags);
/* inode.c */
-static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
-{
-#if BITS_PER_LONG == 32
- return (nid >> 32) ^ (nid & 0xffffffff);
-#else
- return nid;
-#endif
-}
-
extern const struct inode_operations erofs_generic_iops;
extern const struct inode_operations erofs_symlink_iops;
extern const struct inode_operations erofs_fast_symlink_iops;