diff options
Diffstat (limited to 'debian/patches/debian/Revert-udev-make-algorithm-that-selects-highest-priority-.patch')
| -rw-r--r-- | debian/patches/debian/Revert-udev-make-algorithm-that-selects-highest-priority-.patch | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/debian/patches/debian/Revert-udev-make-algorithm-that-selects-highest-priority-.patch b/debian/patches/debian/Revert-udev-make-algorithm-that-selects-highest-priority-.patch new file mode 100644 index 0000000..36bdbb5 --- /dev/null +++ b/debian/patches/debian/Revert-udev-make-algorithm-that-selects-highest-priority-.patch @@ -0,0 +1,163 @@ +From: Michael Biebl <biebl@debian.org> +Date: Sat, 25 Sep 2021 21:08:36 +0200 +Subject: Revert "udev: make algorithm that selects highest priority devlink + less susceptible to race conditions" + +This reverts commit 30f6dce62cb3a738b20253f2192270607c31b55b. +--- + src/udev/udev-event.c | 7 ----- + src/udev/udev-node.c | 75 +++++++++++---------------------------------------- + 2 files changed, 15 insertions(+), 67 deletions(-) + +diff --git a/src/udev/udev-event.c b/src/udev/udev-event.c +index 5159d19..9cf5190 100644 +--- a/src/udev/udev-event.c ++++ b/src/udev/udev-event.c +@@ -1041,13 +1041,6 @@ int udev_event_execute_rules(UdevEvent *event, + if (r < 0) + return log_device_debug_errno(dev, r, "Failed to update database under /run/udev/data/: %m"); + +- /* Yes, we run update_devnode() twice, because in the first invocation, that is before update of udev database, +- * it could happen that two contenders are replacing each other's symlink. Hence we run it again to make sure +- * symlinks point to devices that claim them with the highest priority. */ +- r = update_devnode(event); +- if (r < 0) +- return r; +- + device_set_is_initialized(dev); + + return 0; +diff --git a/src/udev/udev-node.c b/src/udev/udev-node.c +index bde18f7..9d4b7d9 100644 +--- a/src/udev/udev-node.c ++++ b/src/udev/udev-node.c +@@ -20,15 +20,12 @@ + #include "path-util.h" + #include "selinux-util.h" + #include "smack-util.h" +-#include "stat-util.h" + #include "stdio-util.h" + #include "string-util.h" + #include "strxcpyx.h" + #include "udev-node.h" + #include "user-util.h" + +-#define LINK_UPDATE_MAX_RETRIES 128 +- + static int node_symlink(sd_device *dev, const char *node, const char *slink) { + _cleanup_free_ char *slink_dirname = NULL, *target = NULL; + const char *id_filename, *slink_tmp; +@@ -102,9 +99,7 @@ static int node_symlink(sd_device *dev, const char *node, const char *slink) { + if (rename(slink_tmp, slink) < 0) { + r = log_device_error_errno(dev, errno, "Failed to rename '%s' to '%s': %m", slink_tmp, slink); + (void) unlink(slink_tmp); +- } else +- /* Tell caller that we replaced already existing symlink. */ +- r = 1; ++ } + + return r; + } +@@ -197,7 +192,7 @@ static int link_update(sd_device *dev, const char *slink, bool add) { + _cleanup_free_ char *target = NULL, *filename = NULL, *dirname = NULL; + char name_enc[PATH_MAX]; + const char *id_filename; +- int i, r, retries; ++ int r; + + assert(dev); + assert(slink); +@@ -217,6 +212,14 @@ static int link_update(sd_device *dev, const char *slink, bool add) { + if (!add && unlink(filename) == 0) + (void) rmdir(dirname); + ++ r = link_find_prioritized(dev, add, dirname, &target); ++ if (r < 0) { ++ log_device_debug(dev, "No reference left, removing '%s'", slink); ++ if (unlink(slink) == 0) ++ (void) rmdir_parents(slink, "/"); ++ } else ++ (void) node_symlink(dev, target, slink); ++ + if (add) + do { + _cleanup_close_ int fd = -1; +@@ -229,49 +232,7 @@ static int link_update(sd_device *dev, const char *slink, bool add) { + r = -errno; + } while (r == -ENOENT); + +- /* If the database entry is not written yet we will just do one iteration and possibly wrong symlink +- * will be fixed in the second invocation. */ +- retries = sd_device_get_is_initialized(dev) > 0 ? LINK_UPDATE_MAX_RETRIES : 1; +- +- for (i = 0; i < retries; i++) { +- struct stat st1 = {}, st2 = {}; +- +- r = stat(dirname, &st1); +- if (r < 0 && errno != ENOENT) +- return -errno; +- +- r = link_find_prioritized(dev, add, dirname, &target); +- if (r == -ENOENT) { +- log_device_debug(dev, "No reference left, removing '%s'", slink); +- if (unlink(slink) == 0) +- (void) rmdir_parents(slink, "/"); +- +- break; +- } else if (r < 0) +- return log_device_error_errno(dev, r, "Failed to determine highest priority symlink: %m"); +- +- r = node_symlink(dev, target, slink); +- if (r < 0) { +- (void) unlink(filename); +- break; +- } else if (r == 1) +- /* We have replaced already existing symlink, possibly there is some other device trying +- * to claim the same symlink. Let's do one more iteration to give us a chance to fix +- * the error if other device actually claims the symlink with higher priority. */ +- continue; +- +- /* Skip the second stat() if the first failed, stat_inode_unmodified() would return false regardless. */ +- if ((st1.st_mode & S_IFMT) != 0) { +- r = stat(dirname, &st2); +- if (r < 0 && errno != ENOENT) +- return -errno; +- +- if (stat_inode_unmodified(&st1, &st2)) +- break; +- } +- } +- +- return i < LINK_UPDATE_MAX_RETRIES ? 0 : -ELOOP; ++ return r; + } + + int udev_node_update_old_links(sd_device *dev, sd_device *dev_old) { +@@ -490,11 +451,8 @@ int udev_node_add(sd_device *dev, bool apply, + (void) node_symlink(dev, devnode, filename); + + /* create/update symlinks, add symlinks to name index */ +- FOREACH_DEVICE_DEVLINK(dev, devlink) { +- r = link_update(dev, devlink, true); +- if (r < 0) +- log_device_info_errno(dev, r, "Failed to update device symlinks: %m"); +- } ++ FOREACH_DEVICE_DEVLINK(dev, devlink) ++ (void) link_update(dev, devlink, true); + + return 0; + } +@@ -507,11 +465,8 @@ int udev_node_remove(sd_device *dev) { + assert(dev); + + /* remove/update symlinks, remove symlinks from name index */ +- FOREACH_DEVICE_DEVLINK(dev, devlink) { +- r = link_update(dev, devlink, false); +- if (r < 0) +- log_device_info_errno(dev, r, "Failed to update device symlinks: %m"); +- } ++ FOREACH_DEVICE_DEVLINK(dev, devlink) ++ (void) link_update(dev, devlink, false); + + r = xsprintf_dev_num_path_from_sd_device(dev, &filename); + if (r < 0) |