Re: [PATCH 6/9] xfs: Add xfs_has_attr and subroutines

Allison Henderson
2019-04-15T20:13:28Z

On 4/14/19 7:46 PM, Su Yue wrote:
>
>
> On 2019/4/13 6:50 AM, Allison Henderson wrote:
>> This patch adds a new functions to check for the existence of
>> an attribute.  Subroutines are also added to handle the cases
>> of leaf blocks, nodes or shortform.  We will need this later
>> for delayed attributes since delayed operations cannot return
>> error codes.
>>
>> Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
>> ---
>>   fs/xfs/libxfs/xfs_attr.c      | 78
>> +++++++++++++++++++++++++++++++++++++++++++
>>   fs/xfs/libxfs/xfs_attr.h      |  1 +
>>   fs/xfs/libxfs/xfs_attr_leaf.c | 33 ++++++++++++++++++
>>   fs/xfs/libxfs/xfs_attr_leaf.h |  1 +
>>   4 files changed, 113 insertions(+)
>>
>> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
>> index c3477fa7..0042708 100644
>> --- a/fs/xfs/libxfs/xfs_attr.c
>> +++ b/fs/xfs/libxfs/xfs_attr.c
>> @@ -53,6 +53,7 @@ STATIC int xfs_attr_shortform_addname(xfs_da_args_t
>> *args);
>>   STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
>>   STATIC int xfs_attr_leaf_addname(xfs_da_args_t *args, bool roll_trans);
>>   STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args, bool
>> roll_trans);
>> +STATIC int xfs_leaf_has_attr(xfs_da_args_t *args);
>>
>>   /*
>>    * Internal routines when attribute list is more than one block.
>> @@ -60,6 +61,7 @@ STATIC int xfs_attr_leaf_removename(xfs_da_args_t
>> *args, bool roll_trans);
>>   STATIC int xfs_attr_node_get(xfs_da_args_t *args);
>>   STATIC int xfs_attr_node_addname(xfs_da_args_t *args, bool roll_trans);
>>   STATIC int xfs_attr_node_removename(xfs_da_args_t *args, bool
>> roll_trans);
>> +STATIC int xfs_attr_node_hasname(xfs_da_args_t *args);
>>   STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
>>   STATIC int xfs_attr_refillstate(xfs_da_state_t *state);
>>
>> @@ -301,6 +303,29 @@ xfs_attr_set_args(
>>   }
>>
>>   /*
>> + * Return successful if attr is found, or ENOATTR if not
>> + */
>> +int
>> +xfs_has_attr(
>> +    struct xfs_da_args      *args)
>> +{
>> +    struct xfs_inode        *dp = args->dp;
>> +    int                     error;
>> +
>> +    if (!xfs_inode_hasattr(dp))
>> +        error = -ENOATTR;
>> +    else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
>> +        ASSERT(dp->i_afp->if_flags & XFS_IFINLINE);
>> +        error = xfs_shortform_has_attr(args);
>> +    } else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
>> +        error = xfs_leaf_has_attr(args);
>> +    else
>> +        error = xfs_attr_node_hasname(args);
>> +
>> +    return error;
>> +}
>> +
>> +/*
>>    * Remove the attribute specified in @args.
>>    */
>>   int
>> @@ -836,6 +861,29 @@ xfs_attr_leaf_addname(
>>   }
>>
>>   /*
>> + * Return successful if attr is found, or ENOATTR if not
>> + */
>> +STATIC int
>> +xfs_leaf_has_attr(
>> +    struct xfs_da_args      *args)
>> +{
>> +    struct xfs_buf          *bp;
>> +    int                     error = 0;
>> +
>> +    args->blkno = 0;
>> +    error = xfs_attr3_leaf_read(args->trans, args->dp,
>> +            args->blkno, -1, &bp);
>> +    if (error)
>> +        return error;
>> +
>> +    error = xfs_attr3_leaf_lookup_int(bp, args);
>> +    error = (error == -ENOATTR) ? -ENOATTR : 0;
>> +    xfs_trans_brelse(args->trans, bp);
>> +
>> +    return error;
>> +}
>> +
>> +/*
>>    * Remove a name from the leaf attribute list structure
>>    *
>>    * This leaf block cannot have a "remote" value, we only call this
>> routine
>> @@ -1166,6 +1214,36 @@ xfs_attr_node_addname(
>>   }
>>
>>   /*
>> + * Return successful if attr is found, or ENOATTR if not
>> + */
>> +STATIC int
>> +xfs_attr_node_hasname(
>> +    struct xfs_da_args    *args)
>> +{
>> +    struct xfs_da_state    *state;
>> +    struct xfs_inode    *dp;
>> +    int            retval, error;
>> +
>> +    /*
>> +     * Tie a string around our finger to remind us where we are.
>> +     */
>> +    dp = args->dp;
>> +    state = xfs_da_state_alloc();
>
> The corresponding xfs_da_state_free(state) seems lost...
>
> ---
> Su

Good catch, you are right. I will add that in the next version.

Thanks!
Allison

>> +    state->args = args;
>> +    state->mp = dp->i_mount;
>> +
>> +    /*
>> +     * Search to see if name exists, and get back a pointer to it.
>> +     */
>> +    error = xfs_da3_node_lookup_int(state, &retval);
>> +    if (error || (retval != -EEXIST)) {
>> +        if (error == 0)
>> +            error = retval;
>> +    }
>> +    return error;
>> +}
>> +
>> +/*
>>    * Remove a name from a B-tree attribute list.
>>    *
>>    * This will involve walking down the Btree, and may involve joining
>> diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
>> index 83b3621..974c963 100644
>> --- a/fs/xfs/libxfs/xfs_attr.h
>> +++ b/fs/xfs/libxfs/xfs_attr.h
>> @@ -168,6 +168,7 @@ int xfs_attr_set_args(struct xfs_da_args *args,
>> struct xfs_buf **leaf_bp,
>>            bool roll_trans);
>>   int xfs_attr_remove(struct xfs_inode *dp, const unsigned char *name,
>>               size_t namelen, int flags);
>> +int xfs_has_attr(struct xfs_da_args *args);
>>   int xfs_attr_remove_args(struct xfs_da_args *args, bool roll_trans);
>>   int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
>>             int flags, struct attrlist_cursor_kern *cursor);
>> diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c
>> b/fs/xfs/libxfs/xfs_attr_leaf.c
>> index 128bfe9..e9f2f53 100644
>> --- a/fs/xfs/libxfs/xfs_attr_leaf.c
>> +++ b/fs/xfs/libxfs/xfs_attr_leaf.c
>> @@ -622,6 +622,39 @@ xfs_attr_fork_remove(
>>   }
>>
>>   /*
>> + * Return successful if attr is found, or ENOATTR if not
>> + */
>> +int
>> +xfs_shortform_has_attr(
>> +    struct xfs_da_args     *args)
>> +{
>> +    struct xfs_attr_shortform *sf;
>> +    struct xfs_attr_sf_entry *sfe;
>> +    int            base = sizeof(struct xfs_attr_sf_hdr);
>> +    int            size = 0;
>> +    int            end;
>> +    int            i;
>> +
>> +    sf = (struct xfs_attr_shortform *)args->dp->i_afp->if_u1.if_data;
>> +    sfe = &sf->list[0];
>> +    end = sf->hdr.count;
>> +    for (i = 0; i < end; sfe = XFS_ATTR_SF_NEXTENTRY(sfe),
>> +            base += size, i++) {
>> +        size = XFS_ATTR_SF_ENTSIZE(sfe);
>> +        if (sfe->namelen != args->namelen)
>> +            continue;
>> +        if (memcmp(sfe->nameval, args->name, args->namelen) != 0)
>> +            continue;
>> +        if (!xfs_attr_namesp_match(args->flags, sfe->flags))
>> +            continue;
>> +        break;
>> +    }
>> +    if (i == end)
>> +        return -ENOATTR;
>> +    return 0;
>> +}
>> +
>> +/*
>>    * Remove an attribute from the shortform attribute list structure.
>>    */
>>   int
>> diff --git a/fs/xfs/libxfs/xfs_attr_leaf.h
>> b/fs/xfs/libxfs/xfs_attr_leaf.h
>> index 9d830ec..98dd169 100644
>> --- a/fs/xfs/libxfs/xfs_attr_leaf.h
>> +++ b/fs/xfs/libxfs/xfs_attr_leaf.h
>> @@ -39,6 +39,7 @@ int    xfs_attr_shortform_getvalue(struct
>> xfs_da_args *args);
>>   int    xfs_attr_shortform_to_leaf(struct xfs_da_args *args,
>>               struct xfs_buf **leaf_bp);
>>   int    xfs_attr_shortform_remove(struct xfs_da_args *args);
>> +int    xfs_shortform_has_attr(struct xfs_da_args *args);
>>   int    xfs_attr_shortform_allfit(struct xfs_buf *bp, struct
>> xfs_inode *dp);
>>   int    xfs_attr_shortform_bytesfit(struct xfs_inode *dp, int bytes);
>>   xfs_failaddr_t xfs_attr_shortform_verify(struct xfs_inode *ip);
>>