releases/4.19.31/cifs-do-not-skip-smb2-message-ids-on-send-failures.patch

   1 From c781af7e0c1fed9f1d0e0ec31b86f5b21a8dca17 Mon Sep 17 00:00:00 2001
   2 From: Pavel Shilovsky <piastryyy@gmail.com>
   3 Date: Mon, 4 Mar 2019 14:02:50 -0800
   4 Subject: CIFS: Do not skip SMB2 message IDs on send failures
   5
   6 From: Pavel Shilovsky <piastryyy@gmail.com>
   7
   8 commit c781af7e0c1fed9f1d0e0ec31b86f5b21a8dca17 upstream.
   9
  10 When we hit failures during constructing MIDs or sending PDUs
  11 through the network, we end up not using message IDs assigned
  12 to the packet. The next SMB packet will skip those message IDs
  13 and continue with the next one. This behavior may lead to a server
  14 not granting us credits until we use the skipped IDs. Fix this by
  15 reverting the current ID to the original value if any errors occur
  16 before we push the packet through the network stack.
  17
  18 This patch fixes the generic/310 test from the xfs-tests.
  19
  20 Cc: <stable@vger.kernel.org> # 4.19.x
  21 Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
  22 Signed-off-by: Steve French <stfrench@microsoft.com>
  23 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  24
  25 ---
  26  fs/cifs/cifsglob.h      |   19 +++++++++++++++++++
  27  fs/cifs/smb2ops.c       |   13 +++++++++++++
  28  fs/cifs/smb2transport.c |   14 ++++++++++++--
  29  fs/cifs/transport.c     |    6 +++++-
  30  4 files changed, 49 insertions(+), 3 deletions(-)
  31
  32 --- a/fs/cifs/cifsglob.h
  33 +++ b/fs/cifs/cifsglob.h
  34 @@ -235,6 +235,8 @@ struct smb_version_operations {
  35         int * (*get_credits_field)(struct TCP_Server_Info *, const int);
  36         unsigned int (*get_credits)(struct mid_q_entry *);
  37         __u64 (*get_next_mid)(struct TCP_Server_Info *);
  38 +       void (*revert_current_mid)(struct TCP_Server_Info *server,
  39 +                                  const unsigned int val);
  40         /* data offset from read response message */
  41         unsigned int (*read_data_offset)(char *);
  42         /*
  43 @@ -756,6 +758,22 @@ get_next_mid(struct TCP_Server_Info *ser
  44         return cpu_to_le16(mid);
  45  }
  46
  47 +static inline void
  48 +revert_current_mid(struct TCP_Server_Info *server, const unsigned int val)
  49 +{
  50 +       if (server->ops->revert_current_mid)
  51 +               server->ops->revert_current_mid(server, val);
  52 +}
  53 +
  54 +static inline void
  55 +revert_current_mid_from_hdr(struct TCP_Server_Info *server,
  56 +                           const struct smb2_sync_hdr *shdr)
  57 +{
  58 +       unsigned int num = le16_to_cpu(shdr->CreditCharge);
  59 +
  60 +       return revert_current_mid(server, num > 0 ? num : 1);
  61 +}
  62 +
  63  static inline __u16
  64  get_mid(const struct smb_hdr *smb)
  65  {
  66 @@ -1391,6 +1409,7 @@ struct mid_q_entry {
  67         struct kref refcount;
  68         struct TCP_Server_Info *server; /* server corresponding to this mid */
  69         __u64 mid;              /* multiplex id */
  70 +       __u16 credits;          /* number of credits consumed by this mid */
  71         __u32 pid;              /* process id */
  72         __u32 sequence_number;  /* for CIFS signing */
  73         unsigned long when_alloc;  /* when mid was created */
  74 --- a/fs/cifs/smb2ops.c
  75 +++ b/fs/cifs/smb2ops.c
  76 @@ -204,6 +204,15 @@ smb2_get_next_mid(struct TCP_Server_Info
  77         return mid;
  78  }
  79
  80 +static void
  81 +smb2_revert_current_mid(struct TCP_Server_Info *server, const unsigned int val)
  82 +{
  83 +       spin_lock(&GlobalMid_Lock);
  84 +       if (server->CurrentMid >= val)
  85 +               server->CurrentMid -= val;
  86 +       spin_unlock(&GlobalMid_Lock);
  87 +}
  88 +
  89  static struct mid_q_entry *
  90  smb2_find_mid(struct TCP_Server_Info *server, char *buf)
  91  {
  92 @@ -3256,6 +3265,7 @@ struct smb_version_operations smb20_oper
  93         .get_credits = smb2_get_credits,
  94         .wait_mtu_credits = cifs_wait_mtu_credits,
  95         .get_next_mid = smb2_get_next_mid,
  96 +       .revert_current_mid = smb2_revert_current_mid,
  97         .read_data_offset = smb2_read_data_offset,
  98         .read_data_length = smb2_read_data_length,
  99         .map_error = map_smb2_to_linux_error,
 100 @@ -3350,6 +3360,7 @@ struct smb_version_operations smb21_oper
 101         .get_credits = smb2_get_credits,
 102         .wait_mtu_credits = smb2_wait_mtu_credits,
 103         .get_next_mid = smb2_get_next_mid,
 104 +       .revert_current_mid = smb2_revert_current_mid,
 105         .read_data_offset = smb2_read_data_offset,
 106         .read_data_length = smb2_read_data_length,
 107         .map_error = map_smb2_to_linux_error,
 108 @@ -3445,6 +3456,7 @@ struct smb_version_operations smb30_oper
 109         .get_credits = smb2_get_credits,
 110         .wait_mtu_credits = smb2_wait_mtu_credits,
 111         .get_next_mid = smb2_get_next_mid,
 112 +       .revert_current_mid = smb2_revert_current_mid,
 113         .read_data_offset = smb2_read_data_offset,
 114         .read_data_length = smb2_read_data_length,
 115         .map_error = map_smb2_to_linux_error,
 116 @@ -3549,6 +3561,7 @@ struct smb_version_operations smb311_ope
 117         .get_credits = smb2_get_credits,
 118         .wait_mtu_credits = smb2_wait_mtu_credits,
 119         .get_next_mid = smb2_get_next_mid,
 120 +       .revert_current_mid = smb2_revert_current_mid,
 121         .read_data_offset = smb2_read_data_offset,
 122         .read_data_length = smb2_read_data_length,
 123         .map_error = map_smb2_to_linux_error,
 124 --- a/fs/cifs/smb2transport.c
 125 +++ b/fs/cifs/smb2transport.c
 126 @@ -576,6 +576,7 @@ smb2_mid_entry_alloc(const struct smb2_s
 127                      struct TCP_Server_Info *server)
 128  {
 129         struct mid_q_entry *temp;
 130 +       unsigned int credits = le16_to_cpu(shdr->CreditCharge);
 131
 132         if (server == NULL) {
 133                 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
 134 @@ -586,6 +587,7 @@ smb2_mid_entry_alloc(const struct smb2_s
 135         memset(temp, 0, sizeof(struct mid_q_entry));
 136         kref_init(&temp->refcount);
 137         temp->mid = le64_to_cpu(shdr->MessageId);
 138 +       temp->credits = credits > 0 ? credits : 1;
 139         temp->pid = current->pid;
 140         temp->command = shdr->Command; /* Always LE */
 141         temp->when_alloc = jiffies;
 142 @@ -674,13 +676,18 @@ smb2_setup_request(struct cifs_ses *ses,
 143         smb2_seq_num_into_buf(ses->server, shdr);
 144
 145         rc = smb2_get_mid_entry(ses, shdr, &mid);
 146 -       if (rc)
 147 +       if (rc) {
 148 +               revert_current_mid_from_hdr(ses->server, shdr);
 149                 return ERR_PTR(rc);
 150 +       }
 151 +
 152         rc = smb2_sign_rqst(rqst, ses->server);
 153         if (rc) {
 154 +               revert_current_mid_from_hdr(ses->server, shdr);
 155                 cifs_delete_mid(mid);
 156                 return ERR_PTR(rc);
 157         }
 158 +
 159         return mid;
 160  }
 161
 162 @@ -695,11 +702,14 @@ smb2_setup_async_request(struct TCP_Serv
 163         smb2_seq_num_into_buf(server, shdr);
 164
 165         mid = smb2_mid_entry_alloc(shdr, server);
 166 -       if (mid == NULL)
 167 +       if (mid == NULL) {
 168 +               revert_current_mid_from_hdr(server, shdr);
 169                 return ERR_PTR(-ENOMEM);
 170 +       }
 171
 172         rc = smb2_sign_rqst(rqst, server);
 173         if (rc) {
 174 +               revert_current_mid_from_hdr(server, shdr);
 175                 DeleteMidQEntry(mid);
 176                 return ERR_PTR(rc);
 177         }
 178 --- a/fs/cifs/transport.c
 179 +++ b/fs/cifs/transport.c
 180 @@ -638,6 +638,7 @@ cifs_call_async(struct TCP_Server_Info *
 181         cifs_in_send_dec(server);
 182
 183         if (rc < 0) {
 184 +               revert_current_mid(server, mid->credits);
 185                 server->sequence_number -= 2;
 186                 cifs_delete_mid(mid);
 187         }
 188 @@ -842,6 +843,7 @@ compound_send_recv(const unsigned int xi
 189         for (i = 0; i < num_rqst; i++) {
 190                 midQ[i] = ses->server->ops->setup_request(ses, &rqst[i]);
 191                 if (IS_ERR(midQ[i])) {
 192 +                       revert_current_mid(ses->server, i);
 193                         for (j = 0; j < i; j++)
 194                                 cifs_delete_mid(midQ[j]);
 195                         mutex_unlock(&ses->server->srv_mutex);
 196 @@ -867,8 +869,10 @@ compound_send_recv(const unsigned int xi
 197         for (i = 0; i < num_rqst; i++)
 198                 cifs_save_when_sent(midQ[i]);
 199
 200 -       if (rc < 0)
 201 +       if (rc < 0) {
 202 +               revert_current_mid(ses->server, num_rqst);
 203                 ses->server->sequence_number -= 2;
 204 +       }
 205
 206         mutex_unlock(&ses->server->srv_mutex);
 207