diff options
Diffstat (limited to 'src/basic/mount-util.c')
| -rw-r--r-- | src/basic/mount-util.c | 71 |
1 files changed, 48 insertions, 23 deletions
diff --git a/src/basic/mount-util.c b/src/basic/mount-util.c index bfa04394fe..b9affb4e70 100644 --- a/src/basic/mount-util.c +++ b/src/basic/mount-util.c @@ -36,6 +36,7 @@ #include "set.h" #include "stdio-util.h" #include "string-util.h" +#include "strv.h" static int fd_fdinfo_mnt_id(int fd, const char *filename, int flags, int *mnt_id) { char path[strlen("/proc/self/fdinfo/") + DECIMAL_STR_MAX(int)]; @@ -287,10 +288,12 @@ int umount_recursive(const char *prefix, int flags) { continue; if (umount2(p, flags) < 0) { - r = -errno; + r = log_debug_errno(errno, "Failed to umount %s: %m", p); continue; } + log_debug("Successfully unmounted %s", p); + again = true; n++; @@ -311,24 +314,21 @@ static int get_mount_flags(const char *path, unsigned long *flags) { return 0; } -int bind_remount_recursive(const char *prefix, bool ro) { +int bind_remount_recursive(const char *prefix, bool ro, char **blacklist) { _cleanup_set_free_free_ Set *done = NULL; _cleanup_free_ char *cleaned = NULL; int r; - /* Recursively remount a directory (and all its submounts) - * read-only or read-write. If the directory is already - * mounted, we reuse the mount and simply mark it - * MS_BIND|MS_RDONLY (or remove the MS_RDONLY for read-write - * operation). If it isn't we first make it one. Afterwards we - * apply MS_BIND|MS_RDONLY (or remove MS_RDONLY) to all - * submounts we can access, too. When mounts are stacked on - * the same mount point we only care for each individual - * "top-level" mount on each point, as we cannot - * influence/access the underlying mounts anyway. We do not - * have any effect on future submounts that might get - * propagated, they migt be writable. This includes future - * submounts that have been triggered via autofs. */ + /* Recursively remount a directory (and all its submounts) read-only or read-write. If the directory is already + * mounted, we reuse the mount and simply mark it MS_BIND|MS_RDONLY (or remove the MS_RDONLY for read-write + * operation). If it isn't we first make it one. Afterwards we apply MS_BIND|MS_RDONLY (or remove MS_RDONLY) to + * all submounts we can access, too. When mounts are stacked on the same mount point we only care for each + * individual "top-level" mount on each point, as we cannot influence/access the underlying mounts anyway. We + * do not have any effect on future submounts that might get propagated, they migt be writable. This includes + * future submounts that have been triggered via autofs. + * + * If the "blacklist" parameter is specified it may contain a list of subtrees to exclude from the + * remount operation. Note that we'll ignore the blacklist for the top-level path. */ cleaned = strdup(prefix); if (!cleaned) @@ -385,6 +385,33 @@ int bind_remount_recursive(const char *prefix, bool ro) { if (r < 0) return r; + if (!path_startswith(p, cleaned)) + continue; + + /* Ignore this mount if it is blacklisted, but only if it isn't the top-level mount we shall + * operate on. */ + if (!path_equal(cleaned, p)) { + bool blacklisted = false; + char **i; + + STRV_FOREACH(i, blacklist) { + + if (path_equal(*i, cleaned)) + continue; + + if (!path_startswith(*i, cleaned)) + continue; + + if (path_startswith(p, *i)) { + blacklisted = true; + log_debug("Not remounting %s, because blacklisted by %s, called for %s", p, *i, cleaned); + break; + } + } + if (blacklisted) + continue; + } + /* Let's ignore autofs mounts. If they aren't * triggered yet, we want to avoid triggering * them, as we don't make any guarantees for @@ -396,12 +423,9 @@ int bind_remount_recursive(const char *prefix, bool ro) { continue; } - if (path_startswith(p, cleaned) && - !set_contains(done, p)) { - + if (!set_contains(done, p)) { r = set_consume(todo, p); p = NULL; - if (r == -EEXIST) continue; if (r < 0) @@ -418,8 +442,7 @@ int bind_remount_recursive(const char *prefix, bool ro) { if (!set_contains(done, cleaned) && !set_contains(todo, cleaned)) { - /* The prefix directory itself is not yet a - * mount, make it one. */ + /* The prefix directory itself is not yet a mount, make it one. */ if (mount(cleaned, cleaned, NULL, MS_BIND|MS_REC, NULL) < 0) return -errno; @@ -430,6 +453,8 @@ int bind_remount_recursive(const char *prefix, bool ro) { if (mount(NULL, prefix, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) return -errno; + log_debug("Made top-level directory %s a mount point.", prefix); + x = strdup(cleaned); if (!x) return -ENOMEM; @@ -447,8 +472,7 @@ int bind_remount_recursive(const char *prefix, bool ro) { if (r < 0) return r; - /* Deal with mount points that are obstructed by a - * later mount */ + /* Deal with mount points that are obstructed by a later mount */ r = path_is_mount_point(x, 0); if (r == -ENOENT || r == 0) continue; @@ -463,6 +487,7 @@ int bind_remount_recursive(const char *prefix, bool ro) { if (mount(NULL, x, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) return -errno; + log_debug("Remounted %s read-only.", x); } } } |