LU-5095 hsm: Allow receiving messages to be non-blocking

[fs/lustre-release.git] / lustre / utils / liblustreapi_hsm.c

diff --git a/lustre/utils/liblustreapi_hsm.c b/lustre/utils/liblustreapi_hsm.c
index 2ca1756..e47a7d9 100644 (file)
--- a/lustre/utils/liblustreapi_hsm.c
+++ b/lustre/utils/liblustreapi_hsm.c
@@ -641,13 +641,13 @@ out_free:
 /** Register a copytool
  * \param[out] priv Opaque private control structure
  * \param mnt Lustre filesystem mount point
- * \param flags Open flags, currently unused (e.g. O_NONBLOCK)
  * \param archive_count
  * \param archives Which archive numbers this copytool is responsible for
+ * \param rfd_flags flags applied to read fd of pipe (e.g. O_NONBLOCK)
  */
 int llapi_hsm_copytool_register(struct hsm_copytool_private **priv,
-                               const char *mnt, int flags, int archive_count,
-                               int *archives)
+                               const char *mnt, int archive_count,
+                               int *archives, int rfd_flags)
 {
        struct hsm_copytool_private     *ct;
        int                              rc;
@@ -712,7 +712,7 @@ int llapi_hsm_copytool_register(struct hsm_copytool_private **priv,
                ct->archives |= (1 << (archives[rc] - 1));
        }
 
-       rc = libcfs_ukuc_start(&ct->kuc, KUC_GRP_HSM);
+       rc = libcfs_ukuc_start(&ct->kuc, KUC_GRP_HSM, rfd_flags);
        if (rc < 0)
                goto out_err;
 
@@ -794,6 +794,19 @@ int llapi_hsm_copytool_unregister(struct hsm_copytool_private **priv)
        return 0;
 }
 
+/** Returns a file descriptor to poll/select on.
+ * \param ct Opaque private control structure
+ * \retval -EINVAL on error
+ * \retval the file descriptor for reading HSM events from the kernel
+ */
+int llapi_hsm_copytool_get_fd(struct hsm_copytool_private *ct)
+{
+       if (ct == NULL || ct->magic != CT_PRIV_MAGIC)
+               return -EINVAL;
+
+       return libcfs_ukuc_get_rfd(&ct->kuc);
+}
+
 /** Wait for the next hsm_action_list
  * \param ct Opaque private control structure
  * \param halh Action list handle, will be allocated here
@@ -818,6 +831,7 @@ int llapi_hsm_copytool_recv(struct hsm_copytool_private *ct,
 
        kuch = ct->kuch;
 
+repeat:
        rc = libcfs_ukuc_msg_get(&ct->kuc, (char *)kuch,
                                 HAL_MAXSIZE + sizeof(*kuch),
                                 KUC_TRANSPORT_HSM);
@@ -861,9 +875,8 @@ int llapi_hsm_copytool_recv(struct hsm_copytool_private *ct,
                                  " ignoring this request."
                                  " Mask of served archive is 0x%.8X",
                                  hal->hal_archive_id, ct->archives);
-               rc = -EAGAIN;
 
-               goto out_err;
+               goto repeat;
        }
 
        *halh = hal;
@@ -922,10 +935,12 @@ static int ct_open_by_fid(const struct hsm_copytool_private *ct,
                          const struct lu_fid *fid, int open_flags)
 {
        char fid_name[FID_NOBRACE_LEN + 1];
+       int fd;
 
        snprintf(fid_name, sizeof(fid_name), DFID_NOBRACE, PFID(fid));
 
-       return openat(ct->open_by_fid_fd, fid_name, open_flags);
+       fd = openat(ct->open_by_fid_fd, fid_name, open_flags);
+       return fd < 0 ? -errno : fd;
 }
 
 static int ct_stat_by_fid(const struct hsm_copytool_private *ct,
@@ -933,10 +948,12 @@ static int ct_stat_by_fid(const struct hsm_copytool_private *ct,
                          struct stat *buf)
 {
        char fid_name[FID_NOBRACE_LEN + 1];
+       int rc;
 
        snprintf(fid_name, sizeof(fid_name), DFID_NOBRACE, PFID(fid));
 
-       return fstatat(ct->open_by_fid_fd, fid_name, buf, 0);
+       rc = fstatat(ct->open_by_fid_fd, fid_name, buf, 0);
+       return rc ? -errno : 0;
 }
 
 /** Create the destination volatile file for a restore operation.
@@ -1207,17 +1224,20 @@ int llapi_hsm_action_get_dfid(const struct hsm_copyaction_private *hcp,
 int llapi_hsm_action_get_fd(const struct hsm_copyaction_private *hcp)
 {
        const struct hsm_action_item    *hai = &hcp->copy.hc_hai;
+       int fd;
 
        if (hcp->magic != CP_PRIV_MAGIC)
                return -EINVAL;
 
-       if (hai->hai_action == HSMA_ARCHIVE)
+       if (hai->hai_action == HSMA_ARCHIVE) {
                return ct_open_by_fid(hcp->ct_priv, &hai->hai_dfid,
                                O_RDONLY | O_NOATIME | O_NOFOLLOW | O_NONBLOCK);
-       else if (hai->hai_action == HSMA_RESTORE)
-               return dup(hcp->data_fd);
-       else
+       } else if (hai->hai_action == HSMA_RESTORE) {
+               fd = dup(hcp->data_fd);
+               return fd < 0 ? -errno : fd;
+       } else {
                return -EINVAL;
+       }
 }
 
 /**
@@ -1251,9 +1271,9 @@ int llapi_hsm_import(const char *dst, int archive, const struct stat *st,
                                  stripe_pattern | LOV_PATTERN_F_RELEASED,
                                  pool_name);
        if (fd < 0) {
-               llapi_error(LLAPI_MSG_ERROR, -errno,
+               llapi_error(LLAPI_MSG_ERROR, fd,
                            "cannot create '%s' for import", dst);
-               return -errno;
+               return fd;
        }
 
        /* Get the new fid in Lustre. Caller needs to use this fid
@@ -1276,8 +1296,8 @@ int llapi_hsm_import(const char *dst, int archive, const struct stat *st,
        hui.hui_mtime_ns = st->st_mtim.tv_nsec;
        rc = ioctl(fd, LL_IOC_HSM_IMPORT, &hui);
        if (rc != 0) {
-               llapi_error(LLAPI_MSG_ERROR, rc, "cannot import '%s'", dst);
                rc = -errno;
+               llapi_error(LLAPI_MSG_ERROR, rc, "cannot import '%s'", dst);
                goto out_unlink;
        }