Re: [PATCH v7 03/19] xfs: Add xfs_has_attr and subroutines

Allison Collins
2020-02-26T02:20:05Z

On 2/25/20 3:15 AM, Chandan Rajendra wrote:
> On Tuesday, February 25, 2020 3:19 PM Chandan Rajendra wrote:
>> On Sunday, February 23, 2020 7:35 AM Allison Collins wrote:
>>> From: Allison Henderson <allison.henderson@oracle.com>
>>>
>>> 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.
>>> Common code that appears in existing attr add and remove functions have been
>>> factored out to help reduce the appearance of duplicated code. We will need these
>>> routines later for delayed attributes since delayed operations cannot return error
>>> codes.
>>>
>>> Signed-off-by: Allison Collins <allison.henderson@oracle.com>
>>> ---
>>> fs/xfs/libxfs/xfs_attr.c | 171 ++++++++++++++++++++++++++++--------------
>>> fs/xfs/libxfs/xfs_attr.h | 1 +
>>> fs/xfs/libxfs/xfs_attr_leaf.c | 111 +++++++++++++++++----------
>>> fs/xfs/libxfs/xfs_attr_leaf.h | 3 +
>>> 4 files changed, 188 insertions(+), 98 deletions(-)
>>>
>>> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
>>> index 9acdb23..2255060 100644
>>> --- a/fs/xfs/libxfs/xfs_attr.c
>>> +++ b/fs/xfs/libxfs/xfs_attr.c
>>> @@ -46,6 +46,7 @@ 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);
>>> STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
>>> +STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp);
>>>
>>> /*
>>> * Internal routines when attribute list is more than one block.
>>> @@ -53,6 +54,8 @@ STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
>>> STATIC int xfs_attr_node_get(xfs_da_args_t *args);
>>> STATIC int xfs_attr_node_addname(xfs_da_args_t *args);
>>> STATIC int xfs_attr_node_removename(xfs_da_args_t *args);
>>> +STATIC int xfs_attr_node_hasname(xfs_da_args_t *args,
>>> + struct xfs_da_state **state);
>>> STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
>>> STATIC int xfs_attr_refillstate(xfs_da_state_t *state);
>>>
>>> @@ -310,6 +313,37 @@ xfs_attr_set_args(
>>> }
>>>
>>> /*
>>> + * Return EEXIST if attr is found, or ENOATTR if not
>>> + */
>>> +int
>>> +xfs_has_attr(
>>> + struct xfs_da_args *args)
>>> +{
>>> + struct xfs_inode *dp = args->dp;
>>> + struct xfs_buf *bp = NULL;
>>> + int error;
>>> +
>>> + if (!xfs_inode_hasattr(dp))
>>> + return -ENOATTR;
>>> +
>>> + if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
>>> + ASSERT(dp->i_afp->if_flags & XFS_IFINLINE);
>>> + return xfs_attr_sf_findname(args, NULL, NULL);
>>> + }
>>> +
>>> + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
>>> + error = xfs_attr_leaf_hasname(args, &bp);
>>> +
>>> + if (bp)
>>> + xfs_trans_brelse(args->trans, bp);
>>> +
>>> + return error;
>>> + }
>>> +
>>> + return xfs_attr_node_hasname(args, NULL);
>>> +}
>>> +
>>> +/*
>>> * Remove the attribute specified in @args.
>>> */
>>> int
>>> @@ -583,26 +617,20 @@ STATIC int
>>> xfs_attr_leaf_addname(
>>> struct xfs_da_args *args)
>>> {
>>> - struct xfs_inode *dp;
>>> struct xfs_buf *bp;
>>> int retval, error, forkoff;
>>> + struct xfs_inode *dp = args->dp;
>>>
>>> trace_xfs_attr_leaf_addname(args);
>>>
>>> /*
>>> - * Read the (only) block in the attribute list in.
>>> - */
>>> - dp = args->dp;
>>> - args->blkno = 0;
>>> - error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, &bp);
>>> - if (error)
>>> - return error;
>>> -
>>> - /*
>>> * Look up the given attribute in the leaf block. Figure out if
>>> * the given flags produce an error or call for an atomic rename.
>>> */
>>> - retval = xfs_attr3_leaf_lookup_int(bp, args);
>>> + retval = xfs_attr_leaf_hasname(args, &bp);
>>> + if (retval != -ENOATTR && retval != -EEXIST)
>>> + return retval;
>>> +
>>> if ((args->name.type & ATTR_REPLACE) && (retval == -ENOATTR)) {
>>> xfs_trans_brelse(args->trans, bp);
>>> return retval;
>>> @@ -754,6 +782,27 @@ xfs_attr_leaf_addname(
>>> }
>>>
>>> /*
>>> + * Return EEXIST if attr is found, or ENOATTR if not
>>> + */
>>> +STATIC int
>>> +xfs_attr_leaf_hasname(
>>> + struct xfs_da_args *args,
>>> + struct xfs_buf **bp)
>>> +{
>>> + int error = 0;
>>> +
>>> + error = xfs_attr3_leaf_read(args->trans, args->dp, 0, bp);
>>> + if (error)
>>> + return error;
>>> +
>>> + error = xfs_attr3_leaf_lookup_int(*bp, args);
>>> + if (error != -ENOATTR && error != -EEXIST)
>>> + 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
>>> @@ -773,12 +822,11 @@ xfs_attr_leaf_removename(
>>> * Remove the attribute.
>>> */
>>> dp = args->dp;
>>> - args->blkno = 0;
>>> - error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, &bp);
>>> - if (error)
>>> +
>>> + error = xfs_attr_leaf_hasname(args, &bp);
>>> + if (error != -ENOATTR && error != -EEXIST)
>>> return error;
>>>
>>> - error = xfs_attr3_leaf_lookup_int(bp, args);
>>> if (error == -ENOATTR) {
>>> xfs_trans_brelse(args->trans, bp);
>>> return error;
>>> @@ -817,12 +865,10 @@ xfs_attr_leaf_get(xfs_da_args_t *args)
>>>
>>> trace_xfs_attr_leaf_get(args);
>>>
>>> - args->blkno = 0;
>>> - error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, &bp);
>>> - if (error)
>>> + error = xfs_attr_leaf_hasname(args, &bp);
>>> + if (error != -ENOATTR && error != -EEXIST)
>>> return error;
>>>
>>> - error = xfs_attr3_leaf_lookup_int(bp, args);
>>> if (error != -EEXIST) {
>>> xfs_trans_brelse(args->trans, bp);
>>> return error;
>>> @@ -832,6 +878,41 @@ xfs_attr_leaf_get(xfs_da_args_t *args)
>>> return error;
>>> }
>>>
>>> +/*
>>> + * Return EEXIST if attr is found, or ENOATTR if not
>>> + * statep: If not null is set to point at the found state. Caller will
>>> + * be responsible for freeing the state in this case.
>>> + */
>>> +STATIC int
>>> +xfs_attr_node_hasname(
>>> + struct xfs_da_args *args,
>>> + struct xfs_da_state **statep)
>>> +{
>>> + struct xfs_da_state *state;
>>> + int retval, error;
>>> +
>>> + state = xfs_da_state_alloc();
>>> + state->args = args;
>>> + state->mp = args->dp->i_mount;
>>> +
>>> + if (statep != NULL)
>>> + *statep = NULL;
>>> +
>>> + /*
>>> + * Search to see if name exists, and get back a pointer to it.
>>> + */
>>> + error = xfs_da3_node_lookup_int(state, &retval);
>>> + if (error == 0) {
>>> + if (statep != NULL)
>>> + *statep = state;
>>> + return retval;
>>> + }
>>
>> If 'statep' were NULL, then this would leak the memory pointed to by 'state'
>> right?
>>
> Apart from the above, the remaining changes look good to me.
>
> Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
>
Alrighty, will fix. Thanks!

Allison