LU-16714 utils: Clarify fd/fdv naming

The migrate code uses the deeply opaque 'fd' and 'fdv'
(file-descriptor-volatile) to refer to the source and
destination file descriptors.

Replace these with something that tells a casual reader
what's going on.

Test-parameters: trivial
Signed-off-by: Patrick Farrell <pfarrell@whamcloud.com>
Change-Id: I56f2dfe81bcd4eff1c168f093e8580b373dc1984
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/50546
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Timothy Day <timday@amazon.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/utils/lfs.c b/lustre/utils/lfs.c
index e8f013a..7c36bdc 100644 (file)
--- a/lustre/utils/lfs.c
+++ b/lustre/utils/lfs.c
@@ -144,7 +144,7 @@ enum stats_flag {
        STATS_OFF,
 };
 
-static int lfs_migrate_to_dom(int fd, int fdv, char *name,
+static int lfs_migrate_to_dom(int fd_src, int fd_dst, char *name,
                              __u64 migration_flags,
                              unsigned long long bandwidth_bytes_sec,
                              enum stats_flag stats_flag,
@@ -640,10 +640,11 @@ static const char *error_loc = "syserror";
 static int
 migrate_open_files(const char *name, __u64 migration_flags,
                   const struct llapi_stripe_param *param,
-                  struct llapi_layout *layout, int *fd_src, int *fd_tgt)
+                  struct llapi_layout *layout, int *fd_src_ptr,
+                  int *fd_dst_ptr)
 {
-       int                      fd = -1;
-       int                      fdv = -1;
+       int                      fd_src = -1;
+       int                      fd_dst = -1;
        int                      rflags;
        int                      mdt_index;
        int                      random_value;
@@ -686,8 +687,8 @@ migrate_open_files(const char *name, __u64 migration_flags,
        if (!(migration_flags & LLAPI_MIGRATION_NONDIRECT))
                rflags |= O_DIRECT;
 source_open:
-       fd = open(name, rflags);
-       if (fd < 0) {
+       fd_src = open(name, rflags);
+       if (fd_src < 0) {
                /* If encrypted file without the key,
                 * retry mirror extend in O_DIRECT.
                 */
@@ -701,7 +702,7 @@ source_open:
                return rc;
        }
 
-       rc = llapi_file_fget_mdtidx(fd, &mdt_index);
+       rc = llapi_file_fget_mdtidx(fd_src, &mdt_index);
        if (rc < 0) {
                error_loc = "cannot get MDT index";
                goto out;
@@ -719,7 +720,7 @@ source_open:
                rc = snprintf(volatile_file, sizeof(volatile_file),
                              "%s/%s:%.4X:%.4X:fd=%.2d", parent,
                              LUSTRE_VOLATILE_HDR, mdt_index,
-                             random_value, fd);
+                             random_value, fd_src);
                if (rc >= sizeof(volatile_file)) {
                        rc = -ENAMETOOLONG;
                        break;
@@ -728,16 +729,18 @@ source_open:
                /* create, open a volatile file, use caching (ie no directio) */
                if (layout) {
                        /* Returns -1 and sets errno on error: */
-                       fdv = llapi_layout_file_open(volatile_file, open_flags,
-                                                    open_mode, layout);
-                       if (fdv < 0)
-                               fdv = -errno;
+                       fd_dst = llapi_layout_file_open(volatile_file,
+                                                        open_flags, open_mode,
+                                                        layout);
+                       if (fd_dst < 0)
+                               fd_dst = -errno;
                } else {
                        /* Does the right thing on error: */
-                       fdv = llapi_file_open_param(volatile_file, open_flags,
-                                                   open_mode, param);
+                       fd_dst = llapi_file_open_param(volatile_file,
+                                                       open_flags,
+                                                       open_mode, param);
                }
-       } while (fdv < 0 && (rc = fdv) == -EEXIST);
+       } while (fd_dst < 0 && (rc = fd_dst) == -EEXIST);
 
        if (rc < 0) {
                error_loc = "cannot create volatile file";
@@ -755,14 +758,14 @@ source_open:
         * Need to set owner/group of volatile file like original.
         * This will allow to pass related check during layout_swap.
         */
-       rc = fstat(fd, &st);
+       rc = fstat(fd_src, &st);
        if (rc != 0) {
                rc = -errno;
                error_loc = "cannot stat source file";
                goto out;
        }
 
-       rc = fstat(fdv, &stv);
+       rc = fstat(fd_dst, &stv);
        if (rc != 0) {
                rc = -errno;
                error_loc = "cannot stat volatile";
@@ -770,7 +773,7 @@ source_open:
        }
 
        if (st.st_uid != stv.st_uid || st.st_gid != stv.st_gid) {
-               rc = fchown(fdv, st.st_uid, st.st_gid);
+               rc = fchown(fd_dst, st.st_uid, st.st_gid);
                if (rc != 0) {
                        rc = -errno;
                        error_loc = "cannot change ownwership of volatile";
@@ -780,13 +783,13 @@ source_open:
 
 out:
        if (rc < 0) {
-               if (fd > 0)
-                       close(fd);
-               if (fdv > 0)
-                       close(fdv);
+               if (fd_src > 0)
+                       close(fd_src);
+               if (fd_dst > 0)
+                       close(fd_dst);
        } else {
-               *fd_src = fd;
-               *fd_tgt = fdv;
+               *fd_src_ptr = fd_src;
+               *fd_dst_ptr = fd_dst;
                error_loc = NULL;
        }
        return rc;
@@ -1019,7 +1022,7 @@ static int migrate_set_timestamps(int fd, const struct stat *st)
        return futimes(fd, tv);
 }
 
-static int migrate_block(int fd, int fdv,
+static int migrate_block(int fd_src, int fd_dst,
                         unsigned long long bandwidth_bytes_sec,
                         enum stats_flag stats_flag,
                         long stats_interval_sec)
@@ -1036,13 +1039,13 @@ static int migrate_block(int fd, int fdv,
 
 
        /* The grouplock blocks all concurrent accesses to the file. */
-       rc = llapi_group_lock(fd, gid);
+       rc = llapi_group_lock(fd_src, gid);
        if (rc < 0) {
                error_loc = "cannot get group lock";
                return rc;
        }
 
-       rc = fstat(fd, &st);
+       rc = fstat(fd_src, &st);
        if (rc < 0) {
                error_loc = "cannot stat source file";
                rc = -errno;
@@ -1054,13 +1057,13 @@ static int migrate_block(int fd, int fdv,
         * get extent locks on the OST objects. This will conflict with our
         * extent group locks.
         */
-       rc = llapi_get_data_version(fd, &dv1, 0);
+       rc = llapi_get_data_version(fd_src, &dv1, 0);
        if (rc < 0) {
                error_loc = "cannot get dataversion";
                goto out_unlock;
        }
 
-       rc = migrate_copy_data(fd, fdv, NULL, bandwidth_bytes_sec,
+       rc = migrate_copy_data(fd_src, fd_dst, NULL, bandwidth_bytes_sec,
                               stats_flag, stats_interval_sec,
                               st.st_size);
        if (rc < 0) {
@@ -1069,7 +1072,7 @@ static int migrate_block(int fd, int fdv,
        }
 
        /* Make sure we keep original atime/mtime values */
-       rc = migrate_set_timestamps(fdv, &st);
+       rc = migrate_set_timestamps(fd_dst, &st);
        if (rc < 0) {
                error_loc = "set target file timestamp failed";
                goto out_unlock;
@@ -1082,7 +1085,7 @@ static int migrate_block(int fd, int fdv,
         *
         * Pass in gid=0 since we already own grouplock.
         */
-       rc = llapi_fswap_layouts_grouplock(fd, fdv, dv1, 0, 0,
+       rc = llapi_fswap_layouts_grouplock(fd_src, fd_dst, dv1, 0, 0,
                                           SWAP_LAYOUTS_CHECK_DV1);
        if (rc == -EAGAIN) {
                error_loc = "file changed";
@@ -1093,7 +1096,7 @@ static int migrate_block(int fd, int fdv,
        }
 
 out_unlock:
-       rc2 = llapi_group_unlock(fd, gid);
+       rc2 = llapi_group_unlock(fd_src, gid);
        if (rc2 < 0 && rc == 0) {
                error_loc = "unlock group lock";
                rc = rc2;
@@ -1122,7 +1125,7 @@ static int check_lease(int fd)
        return -EBUSY;
 }
 
-static int migrate_nonblock(int fd, int fdv,
+static int migrate_nonblock(int fd_src, int fd_dst,
                            unsigned long long bandwidth_bytes_sec,
                            enum stats_flag stats_flag,
                            long stats_interval_sec)
@@ -1132,27 +1135,27 @@ static int migrate_nonblock(int fd, int fdv,
        __u64   dv2;
        int     rc;
 
-       rc = fstat(fd, &st);
+       rc = fstat(fd_src, &st);
        if (rc < 0) {
                error_loc = "cannot stat source file";
                return -errno;
        }
 
-       rc = llapi_get_data_version(fd, &dv1, LL_DV_RD_FLUSH);
+       rc = llapi_get_data_version(fd_src, &dv1, LL_DV_RD_FLUSH);
        if (rc < 0) {
                error_loc = "cannot get data version";
                return rc;
        }
 
-       rc = migrate_copy_data(fd, fdv, check_lease, bandwidth_bytes_sec,
-                              stats_flag, stats_interval_sec,
-                              st.st_size);
+       rc = migrate_copy_data(fd_src, fd_dst, check_lease,
+                              bandwidth_bytes_sec, stats_flag,
+                              stats_interval_sec, st.st_size);
        if (rc < 0) {
                error_loc = "data copy failed";
                return rc;
        }
 
-       rc = llapi_get_data_version(fd, &dv2, LL_DV_RD_FLUSH);
+       rc = llapi_get_data_version(fd_src, &dv2, LL_DV_RD_FLUSH);
        if (rc != 0) {
                error_loc = "cannot get data version";
                return rc;
@@ -1165,7 +1168,7 @@ static int migrate_nonblock(int fd, int fdv,
        }
 
        /* Make sure we keep original atime/mtime values */
-       rc = migrate_set_timestamps(fdv, &st);
+       rc = migrate_set_timestamps(fd_dst, &st);
        if (rc < 0) {
                error_loc = "set target file timestamp failed";
                return -errno;
@@ -1357,12 +1360,12 @@ static int lfs_migrate(char *name, __u64 migration_flags,
 {
        struct llapi_layout *existing;
        uint64_t dom_new, dom_cur;
-       int fd = -1;
-       int fdv = -1;
+       int fd_src = -1;
+       int fd_dst = -1;
        int rc;
 
        rc = migrate_open_files(name, migration_flags, param, layout,
-                               &fd, &fdv);
+                               &fd_src, &fd_dst);
        if (rc < 0)
                goto out;
 
@@ -1372,7 +1375,7 @@ static int lfs_migrate(char *name, __u64 migration_flags,
                goto out;
        }
        /* special case for migration to DOM layout*/
-       existing = llapi_layout_get_by_fd(fd, 0);
+       existing = llapi_layout_get_by_fd(fd_src, 0);
        if (!existing) {
                error_loc = "cannot get existing layout";
                goto out;
@@ -1390,7 +1393,7 @@ static int lfs_migrate(char *name, __u64 migration_flags,
         * if new layout used bigger DOM size, then mirroring is used
         */
        if (dom_new > dom_cur) {
-               rc = lfs_migrate_to_dom(fd, fdv, name, migration_flags,
+               rc = lfs_migrate_to_dom(fd_src, fd_dst, name, migration_flags,
                                        bandwidth_bytes_sec, stats_flag,
                                        stats_interval_sec);
                if (rc)
@@ -1408,21 +1411,21 @@ static int lfs_migrate(char *name, __u64 migration_flags,
                 * between a broken lease and a server that does not support
                 * atomic swap/close (LU-6785)
                 */
-               rc = migrate_block(fd, fdv, bandwidth_bytes_sec, stats_flag,
-                                  stats_interval_sec);
+               rc = migrate_block(fd_src, fd_dst, bandwidth_bytes_sec,
+                                  stats_flag, stats_interval_sec);
                goto out;
        }
 
-       rc = llapi_lease_acquire(fd, LL_LEASE_RDLCK);
+       rc = llapi_lease_acquire(fd_src, LL_LEASE_RDLCK);
        if (rc < 0) {
                error_loc = "cannot get lease";
                goto out;
        }
 
-       rc = migrate_nonblock(fd, fdv, bandwidth_bytes_sec, stats_flag,
+       rc = migrate_nonblock(fd_src, fd_dst, bandwidth_bytes_sec, stats_flag,
                              stats_interval_sec);
        if (rc < 0) {
-               llapi_lease_release(fd);
+               llapi_lease_release(fd_src);
                goto out;
        }
 
@@ -1431,18 +1434,18 @@ static int lfs_migrate(char *name, __u64 migration_flags,
         * for a migration we need to check data version on file did
         * not change.
         */
-       rc = llapi_fswap_layouts(fd, fdv, 0, 0, SWAP_LAYOUTS_CLOSE);
+       rc = llapi_fswap_layouts(fd_src, fd_dst, 0, 0, SWAP_LAYOUTS_CLOSE);
        if (rc < 0) {
                error_loc = "cannot swap layout";
                goto out;
        }
 
 out:
-       if (fd >= 0)
-               close(fd);
+       if (fd_src >= 0)
+               close(fd_src);
 
-       if (fdv >= 0)
-               close(fdv);
+       if (fd_dst >= 0)
+               close(fd_dst);
 out_closed:
        if (rc < 0)
                fprintf(stderr, "error: %s: %s: %s: %s\n",
@@ -1812,7 +1815,7 @@ error:
  *
  * \retval bytes number of bytes are the same
  */
-static ssize_t mirror_file_compare(int fd, int fdv)
+static ssize_t mirror_file_compare(int fd_src, int fd_dst)
 {
        const size_t buflen = 4 * 1024 * 1024; /* 4M */
        void *buf;
@@ -1824,16 +1827,16 @@ static ssize_t mirror_file_compare(int fd, int fdv)
                return -ENOMEM;
 
        while (1) {
-               if (!llapi_lease_check(fd)) {
+               if (!llapi_lease_check(fd_src)) {
                        bytes_done = -EBUSY;
                        break;
                }
 
-               bytes_read = read(fd, buf, buflen);
+               bytes_read = read(fd_src, buf, buflen);
                if (bytes_read <= 0)
                        break;
 
-               if (bytes_read != read(fdv, buf + buflen, buflen))
+               if (bytes_read != read(fd_dst, buf + buflen, buflen))
                        break;
 
                /*
@@ -1975,8 +1978,8 @@ static int mirror_extend_layout(char *name, struct llapi_layout *m_layout,
        struct llapi_layout *f_layout = NULL;
        struct ll_ioc_lease *data = NULL;
        struct stat st;
-       int fd = -1;
-       int fdv = -1;
+       int fd_src = -1;
+       int fd_dst = -1;
        int rc = 0;
 
        if (inherit) {
@@ -2004,17 +2007,17 @@ static int mirror_extend_layout(char *name, struct llapi_layout *m_layout,
        llapi_layout_comp_flags_set(m_layout, flags);
        rc = migrate_open_files(name,
                             LLAPI_MIGRATION_NONDIRECT | LLAPI_MIGRATION_MIRROR,
-                            NULL, m_layout, &fd, &fdv);
+                            NULL, m_layout, &fd_src, &fd_dst);
        if (rc < 0)
                goto out;
 
-       rc = llapi_lease_acquire(fd, LL_LEASE_RDLCK);
+       rc = llapi_lease_acquire(fd_src, LL_LEASE_RDLCK);
        if (rc < 0) {
                error_loc = "cannot get lease";
                goto out;
        }
 
-       rc = fstat(fd, &st);
+       rc = fstat(fd_src, &st);
        if (rc < 0) {
                error_loc = "cannot stat source file";
                goto out;
@@ -2023,14 +2026,14 @@ static int mirror_extend_layout(char *name, struct llapi_layout *m_layout,
        if (stats_flag)
                printf("%s:\n", name);
 
-       rc = migrate_nonblock(fd, fdv, bandwidth_bytes_sec, stats_flag,
+       rc = migrate_nonblock(fd_src, fd_dst, bandwidth_bytes_sec, stats_flag,
                              stats_interval_sec);
        if (rc < 0) {
-               llapi_lease_release(fd);
+               llapi_lease_release(fd_src);
                goto out;
        }
 
-       rc = migrate_set_timestamps(fd, &st);
+       rc = migrate_set_timestamps(fd_src, &st);
        if (rc < 0) {
                error_loc = "cannot set source file timestamp";
                goto out;
@@ -2045,8 +2048,8 @@ static int mirror_extend_layout(char *name, struct llapi_layout *m_layout,
        data->lil_mode = LL_LEASE_UNLCK;
        data->lil_flags = LL_LEASE_LAYOUT_MERGE;
        data->lil_count = 1;
-       data->lil_ids[0] = fdv;
-       rc = llapi_lease_set(fd, data);
+       data->lil_ids[0] = fd_dst;
+       rc = llapi_lease_set(fd_src, data);
        if (rc < 0) {
                error_loc = "cannot merge layout";
                goto out;
@@ -2060,10 +2063,10 @@ static int mirror_extend_layout(char *name, struct llapi_layout *m_layout,
 out:
        if (data)
                free(data);
-       if (fd >= 0)
-               close(fd);
-       if (fdv >= 0)
-               close(fdv);
+       if (fd_src >= 0)
+               close(fd_src);
+       if (fd_dst >= 0)
+               close(fd_dst);
        if (rc < 0)
                fprintf(stderr, "error: %s: %s: %s: %s\n",
                        progname, name, error_loc, strerror(-rc));
@@ -2522,7 +2525,7 @@ static inline
 int lfs_mirror_resync_file(const char *fname, struct ll_ioc_lease *ioc,
                           __u16 *mirror_ids, int ids_nr);
 
-static int lfs_migrate_to_dom(int fd, int fdv, char *name,
+static int lfs_migrate_to_dom(int fd_src, int fd_dst, char *name,
                              __u64 migration_flags,
                              unsigned long long bandwidth_bytes_sec,
                              enum stats_flag stats_flag,
@@ -2531,7 +2534,7 @@ static int lfs_migrate_to_dom(int fd, int fdv, char *name,
        struct ll_ioc_lease *data = NULL;
        int rc;
 
-       rc = llapi_lease_acquire(fd, LL_LEASE_RDLCK);
+       rc = llapi_lease_acquire(fd_src, LL_LEASE_RDLCK);
        if (rc < 0) {
                error_loc = "cannot get lease";
                goto out_close;
@@ -2540,7 +2543,7 @@ static int lfs_migrate_to_dom(int fd, int fdv, char *name,
        if (stats_flag)
                printf("%s:\n", name);
 
-       rc = migrate_nonblock(fd, fdv, bandwidth_bytes_sec, stats_flag,
+       rc = migrate_nonblock(fd_src, fd_dst, bandwidth_bytes_sec, stats_flag,
                              stats_interval_sec);
        if (rc < 0)
                goto out_release;
@@ -2554,8 +2557,8 @@ static int lfs_migrate_to_dom(int fd, int fdv, char *name,
        data->lil_mode = LL_LEASE_UNLCK;
        data->lil_flags = LL_LEASE_LAYOUT_MERGE;
        data->lil_count = 1;
-       data->lil_ids[0] = fdv;
-       rc = llapi_lease_set(fd, data);
+       data->lil_ids[0] = fd_dst;
+       rc = llapi_lease_set(fd_src, data);
        if (rc < 0) {
                error_loc = "cannot merge layout";
                goto out_close;
@@ -2564,8 +2567,8 @@ static int lfs_migrate_to_dom(int fd, int fdv, char *name,
                error_loc = "lost lease lock";
                goto out_close;
        }
-       close(fd);
-       close(fdv);
+       close(fd_src);
+       close(fd_dst);
 
        rc = lfs_mirror_resync_file(name, data, NULL, 0);
        if (rc) {
@@ -2580,10 +2583,10 @@ static int lfs_migrate_to_dom(int fd, int fdv, char *name,
        goto out;
 
 out_release:
-       llapi_lease_release(fd);
+       llapi_lease_release(fd_src);
 out_close:
-       close(fd);
-       close(fdv);
+       close(fd_src);
+       close(fd_dst);
 out:
        if (rc < 0)
                fprintf(stderr, "error: %s: %s: %s: %s\n",