For comparison, here is the output from text_batch.json file for BART (which seems to work well).
{
    "input_ids": [
        "<s> who sings does he love me with reba?</s><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> what is the smallest prime number that is greater than 30?</s><pad><pad><pad><pad><pad><pad>",
        "<s> who introduced the system of civil services in india?</s><pad><pad><pad><pad><pad><pad><pad>",
        "<s> when was the public service commission original version of the upsc set up?</s><pad><pad><pad>",
        "<s> who wrote the song two out of three ain't bad?</s><pad><pad><pad><pad><pad><pad>",
        "<s> who has the most receiving yards in one game?</s><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> how many games to get premier league medal?</s><pad><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> what do they call snowboarders in johnny tsunami?</s><pad><pad><pad><pad><pad><pad>",
        "<s> who is the old man in waiting on a woman?</s><pad><pad><pad><pad><pad><pad><pad>",
        "<s> in attack on titan who is the female titan?</s><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> who got pregnant in gossip girl season 5?</s><pad><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> who sang the theme from the greatest american hero?</s><pad><pad><pad><pad><pad><pad><pad>",
        "<s> who wins the 2017 australian open men's single title?</s><pad><pad><pad><pad><pad>",
        "<s> who does the voice for love island australia?</s><pad><pad><pad><pad><pad><pad><pad>",
        "<s> when did the king kong ride burn down?</s><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> 5 types of control that could be programmed on a gui?</s><pad><pad><pad><pad><pad><pad>",
        "<s> who is the ceo of t rowe price?</s><pad><pad><pad><pad><pad><pad><pad>",
        "<s> who plays chaka in land of the lost?</s><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> who is the head coach of the minnesota timberwolves?</s><pad><pad><pad><pad><pad><pad>",
        "<s> when was the planning commission set up to prepare a blue print of development for the country?</s>",
        "<s> where is the mesophyll located in a plant?</s><pad><pad><pad><pad><pad><pad><pad>",
        "<s> who sings bartender i really did it this time?</s><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> who wrote somebody like you by keith urban?</s><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> in what year did japan attack pearl harbor?</s><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> when is the show six coming back on?</s><pad><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> who does haruhi end up with in ouran highschool host club?</s><pad><pad>",
        "<s> who was the first woman appointed to the supreme court?</s><pad><pad><pad><pad><pad><pad><pad>",
        "<s> who controlled blue cross when it was formed?</s><pad><pad><pad><pad><pad><pad><pad><pad><pad>",
        "<s> the most readily absorbed form of iron in the diet is?</s><pad><pad><pad><pad><pad><pad>",
        "<s> who has the highest minimum wage in the usa?</s><pad><pad><pad><pad><pad><pad><pad>",
        "<s> when does fairy tail dragon cry come out in canada?</s><pad><pad><pad><pad><pad><pad>",
        "<s> who is known as the father of humanism?</s><pad><pad><pad><pad><pad><pad><pad><pad>"
    ],
    "attention_mask": [
        32,
        20
    ],
    "labels": [
        "<s> Linda Davis</s><pad><pad><pad><pad><pad>",
        "<s> 31</s><pad><pad><pad><pad><pad><pad>",
        "<s> Charles Cornwallis</s><pad><pad><pad><pad>",
        "<s> October 1, 1926</s><pad><pad><pad>",
        "<s> Meat Loaf</s><pad><pad><pad><pad>",
        "<s> Flipper Anderson</s><pad><pad><pad><pad>",
        "<s> a minimum of five</s><pad><pad><pad>",
        "<s> Urchins</s><pad><pad><pad><pad>",
        "<s> Andy Griffith</s><pad><pad><pad><pad><pad>",
        "<s> Ymir Fritz</s><pad><pad><pad><pad>",
        "<s> Blair</s><pad><pad><pad><pad><pad><pad>",
        "<s> American singer Joey Scarbury</s><pad><pad>",
        "<s> Roger Federer</s><pad><pad><pad><pad>",
        "<s> Eoghan McDermott</s><pad><pad>",
        "<s> 2008</s><pad><pad><pad><pad><pad><pad>",
        "<s> List box</s><pad><pad><pad><pad><pad>",
        "<s> William Stromberg</s><pad><pad><pad>",
        "<s> Jorma Taccone</s><pad>",
        "<s> Thomas Joseph Thibodeau Jr.</s>",
        "<s> 15 March 1950</s><pad><pad><pad><pad>",
        "<s> In leaves</s><pad><pad><pad><pad><pad>",
        "<s> American southern rock group Rehab</s><pad><pad>",
        "<s> John Shanks</s><pad><pad><pad><pad>",
        "<s> 1941</s><pad><pad><pad><pad><pad><pad>",
        "<s> May 28, 2018</s><pad><pad><pad>",
        "<s> Tamaki</s><pad><pad><pad><pad><pad>",
        "<s> Sandra Day O'Connor</s><pad><pad>",
        "<s> 1929</s><pad><pad><pad><pad><pad><pad>",
        "<s> animal products</s><pad><pad><pad><pad><pad>",
        "<s> Washington</s><pad><pad><pad><pad><pad><pad>",
        "<s> August 14, 2017</s><pad><pad><pad>",
        "<s> Petrarch</s><pad><pad><pad><pad><pad>"
    ],
"ids": [
        "<s>",
        ".",
        " and",
        "-",
        " is",
        " The",
        " it",
        " be",
        " are",
        " (",
        " will",
        " \ufffd",
        "\ufffd",
        " we",
        " had",
        ",\"",
        " can",
        " $",
        ".\"",
        " year",
        " two",
        " our",
        " into",
        " new",
        " In",
        "I",
        "S",
        "'",
        " 1",
        "?",
        " get",
        " back"
    ],
    "decoder_input_ids": [
        "</s><s> Linda Davis</s><pad><pad><pad><pad>",
        "</s><s> 31</s><pad><pad><pad><pad><pad>",
        "</s><s> Charles Cornwallis</s><pad><pad><pad>",
        "</s><s> October 1, 1926</s><pad><pad>",
        "</s><s> Meat Loaf</s><pad><pad><pad>",
        "</s><s> Flipper Anderson</s><pad><pad><pad>",
        "</s><s> a minimum of five</s><pad><pad>",
        "</s><s> Urchins</s><pad><pad><pad>",
        "</s><s> Andy Griffith</s><pad><pad><pad><pad>",
        "</s><s> Ymir Fritz</s><pad><pad><pad>",
        "</s><s> Blair</s><pad><pad><pad><pad><pad>",
        "</s><s> American singer Joey Scarbury</s><pad>",
        "</s><s> Roger Federer</s><pad><pad><pad>",
        "</s><s> Eoghan McDermott</s><pad>",
        "</s><s> 2008</s><pad><pad><pad><pad><pad>",
        "</s><s> List box</s><pad><pad><pad><pad>",
        "</s><s> William Stromberg</s><pad><pad>",
        "</s><s> Jorma Taccone</s>",
        "</s><s> Thomas Joseph Thibodeau Jr.",
        "</s><s> 15 March 1950</s><pad><pad><pad>",
        "</s><s> In leaves</s><pad><pad><pad><pad>",
        "</s><s> American southern rock group Rehab</s><pad>",
        "</s><s> John Shanks</s><pad><pad><pad>",
        "</s><s> 1941</s><pad><pad><pad><pad><pad>",
        "</s><s> May 28, 2018</s><pad><pad>",
        "</s><s> Tamaki</s><pad><pad><pad><pad>",
        "</s><s> Sandra Day O'Connor</s><pad>",
        "</s><s> 1929</s><pad><pad><pad><pad><pad>",
        "</s><s> animal products</s><pad><pad><pad><pad>",
        "</s><s> Washington</s><pad><pad><pad><pad><pad>",
        "</s><s> August 14, 2017</s><pad><pad>",
        "</s><s> Petrarch</s><pad><pad><pad><pad>"
    ]
}

Comparing this output with the file corresponding to t5-small, two things come to my mind:

In text_batch.json of t5-small,  don’t see any <pad> or <s> tags, both among labels and input_ids. Is that normal?
For both models, attention_mask is quite short. Shouldn’t this be a list of 0s and 1s, with the same lengths as input_ids?