shared/sleep-config: get rid of explicit allocation size calculation

diff --git a/src/shared/sleep-config.c b/src/shared/sleep-config.c
index fdaa3f39b3a33fdd75979c0aa9a54a732a373575..15cd439c2a5eb205cf8b063245f1b5b5255d48bf 100644 (file)
--- a/src/shared/sleep-config.c
+++ b/src/shared/sleep-config.c
@@ -4,9 +4,23 @@
 
   Copyright 2013 Zbigniew Jędrzejewski-Szmek
   Copyright 2018 Dell Inc.
+
+  elogind is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  elogind is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with elogind; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
 //#include <errno.h>
+//#include <linux/fs.h>
 //#include <stdbool.h>
 //#include <stddef.h>
 //#include <stdio.h>
@@ -180,13 +194,10 @@ int can_sleep_disk(char **types) {
 
 #define HIBERNATION_SWAP_THRESHOLD 0.98
 
-static int hibernation_partition_size(size_t *size, size_t *used) {
+int find_hibernate_location(char **device, char **type, size_t *size, size_t *used) {
         _cleanup_fclose_ FILE *f;
         unsigned i;
 
-        assert(size);
-        assert(used);
-
         f = fopen("/proc/swaps", "re");
         if (!f) {
                 log_full(errno == ENOENT ? LOG_DEBUG : LOG_WARNING,
@@ -198,7 +209,7 @@ static int hibernation_partition_size(size_t *size, size_t *used) {
         (void) fscanf(f, "%*s %*s %*s %*s %*s\n");
 
         for (i = 1;; i++) {
-                _cleanup_free_ char *dev = NULL, *type = NULL;
+                _cleanup_free_ char *dev_field = NULL, *type_field = NULL;
                 size_t size_field, used_field;
                 int k;
 
@@ -208,7 +219,7 @@ static int hibernation_partition_size(size_t *size, size_t *used) {
                            "%zu "   /* swap size */
                            "%zu "   /* used */
                            "%*i\n", /* priority */
-                           &dev, &type, &size_field, &used_field);
+                           &dev_field, &type_field, &size_field, &used_field);
                 if (k != 4) {
                         if (k == EOF)
                                 break;
@@ -217,13 +228,18 @@ static int hibernation_partition_size(size_t *size, size_t *used) {
                         continue;
                 }
 
-                if (streq(type, "partition") && endswith(dev, "\\040(deleted)")) {
-                        log_warning("Ignoring deleted swapfile '%s'.", dev);
+                if (streq(type_field, "partition") && endswith(dev_field, "\\040(deleted)")) {
+                        log_warning("Ignoring deleted swapfile '%s'.", dev_field);
                         continue;
                 }
-
-                *size = size_field;
-                *used = used_field;
+                if (device)
+                        *device = TAKE_PTR(dev_field);
+                if (type)
+                        *type = TAKE_PTR(type_field);
+                if (size)
+                        *size = size_field;
+                if (used)
+                        *used = used_field;
                 return 0;
         }
 
@@ -242,7 +258,7 @@ static bool enough_memory_for_hibernation(void) {
                 return true;
 #endif // 0
 
-        r = hibernation_partition_size(&size, &used);
+        r = find_hibernate_location(NULL, NULL, &size, &used);
         if (r < 0)
                 return false;
 
@@ -266,6 +282,89 @@ static bool enough_memory_for_hibernation(void) {
         return r;
 }
 
+int read_fiemap(int fd, struct fiemap **ret) {
+        _cleanup_free_ struct fiemap *fiemap = NULL, *result_fiemap = NULL;
+        struct stat statinfo;
+        uint32_t result_extents = 0;
+        uint64_t fiemap_start = 0, fiemap_length;
+        const size_t n_extra = DIV_ROUND_UP(sizeof(struct fiemap), sizeof(struct fiemap_extent));
+        size_t fiemap_allocated = n_extra, result_fiemap_allocated = n_extra;
+
+        if (fstat(fd, &statinfo) < 0)
+                return log_debug_errno(errno, "Cannot determine file size: %m");
+        if (!S_ISREG(statinfo.st_mode))
+                return -ENOTTY;
+        fiemap_length = statinfo.st_size;
+
+        /* Zero this out in case we run on a file with no extents */
+        fiemap = calloc(n_extra, sizeof(struct fiemap_extent));
+        if (!fiemap)
+                return -ENOMEM;
+
+        result_fiemap = malloc_multiply(n_extra, sizeof(struct fiemap_extent));
+        if (!result_fiemap)
+                return -ENOMEM;
+
+        /*  XFS filesystem has incorrect implementation of fiemap ioctl and
+         *  returns extents for only one block-group at a time, so we need
+         *  to handle it manually, starting the next fiemap call from the end
+         *  of the last extent
+         */
+        while (fiemap_start < fiemap_length) {
+                *fiemap = (struct fiemap) {
+                        .fm_start = fiemap_start,
+                        .fm_length = fiemap_length,
+                        .fm_flags = FIEMAP_FLAG_SYNC,
+                };
+
+                /* Find out how many extents there are */
+                if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < 0)
+                        return log_debug_errno(errno, "Failed to read extents: %m");
+
+                /* Nothing to process */
+                if (fiemap->fm_mapped_extents == 0)
+                        break;
+
+                /* Resize fiemap to allow us to read in the extents, result fiemap has to hold all
+                 * the extents for the whole file. Add space for the initial struct fiemap. */
+                if (!greedy_realloc0((void**) &fiemap, &fiemap_allocated,
+                                     n_extra + fiemap->fm_mapped_extents, sizeof(struct fiemap_extent)))
+                        return -ENOMEM;
+
+                fiemap->fm_extent_count = fiemap->fm_mapped_extents;
+                fiemap->fm_mapped_extents = 0;
+
+                if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < 0)
+                        return log_debug_errno(errno, "Failed to read extents: %m");
+
+                /* Resize result_fiemap to allow us to copy in the extents */
+                if (!greedy_realloc((void**) &result_fiemap, &result_fiemap_allocated,
+                                    n_extra + result_extents + fiemap->fm_mapped_extents, sizeof(struct fiemap_extent)))
+                        return -ENOMEM;
+
+                memcpy(result_fiemap->fm_extents + result_extents,
+                       fiemap->fm_extents,
+                       sizeof(struct fiemap_extent) * fiemap->fm_mapped_extents);
+
+                result_extents += fiemap->fm_mapped_extents;
+
+                /* Highly unlikely that it is zero */
+                if (_likely_(fiemap->fm_mapped_extents > 0)) {
+                        uint32_t i = fiemap->fm_mapped_extents - 1;
+
+                        fiemap_start = fiemap->fm_extents[i].fe_logical +
+                                       fiemap->fm_extents[i].fe_length;
+
+                        if (fiemap->fm_extents[i].fe_flags & FIEMAP_EXTENT_LAST)
+                                break;
+                }
+        }
+
+        memcpy(result_fiemap, fiemap, sizeof(struct fiemap));
+        result_fiemap->fm_mapped_extents = result_extents;
+        *ret = TAKE_PTR(result_fiemap);
+        return 0;
+}
 
 #if 0 /// elogind has to do, or better, *can* do it differently
 static bool can_s2h(void) {