diff options
| -rw-r--r-- | arch/um/os-Linux/umid.c | 48 |
1 files changed, 29 insertions, 19 deletions
diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c index 362db059fe30..d5811710126e 100644 --- a/arch/um/os-Linux/umid.c +++ b/arch/um/os-Linux/umid.c | |||
| @@ -103,9 +103,10 @@ static int actually_do_remove(char *dir) | |||
| 103 | * something other than UML sticking stuff in the directory | 103 | * something other than UML sticking stuff in the directory |
| 104 | * this boot racing with a shutdown of the other UML | 104 | * this boot racing with a shutdown of the other UML |
| 105 | * In any of these cases, the directory isn't useful for anything else. | 105 | * In any of these cases, the directory isn't useful for anything else. |
| 106 | * | ||
| 107 | * Boolean return: 1 if in use, 0 otherwise. | ||
| 106 | */ | 108 | */ |
| 107 | 109 | static inline int is_umdir_used(char *dir) | |
| 108 | static int not_dead_yet(char *dir) | ||
| 109 | { | 110 | { |
| 110 | char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")]; | 111 | char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")]; |
| 111 | char pid[sizeof("nnnnn\0")], *end; | 112 | char pid[sizeof("nnnnn\0")], *end; |
| @@ -113,7 +114,7 @@ static int not_dead_yet(char *dir) | |||
| 113 | 114 | ||
| 114 | n = snprintf(file, sizeof(file), "%s/pid", dir); | 115 | n = snprintf(file, sizeof(file), "%s/pid", dir); |
| 115 | if(n >= sizeof(file)){ | 116 | if(n >= sizeof(file)){ |
| 116 | printk("not_dead_yet - pid filename too long\n"); | 117 | printk("is_umdir_used - pid filename too long\n"); |
| 117 | err = -E2BIG; | 118 | err = -E2BIG; |
| 118 | goto out; | 119 | goto out; |
| 119 | } | 120 | } |
| @@ -123,7 +124,7 @@ static int not_dead_yet(char *dir) | |||
| 123 | if(fd < 0) { | 124 | if(fd < 0) { |
| 124 | fd = -errno; | 125 | fd = -errno; |
| 125 | if(fd != -ENOENT){ | 126 | if(fd != -ENOENT){ |
| 126 | printk("not_dead_yet : couldn't open pid file '%s', " | 127 | printk("is_umdir_used : couldn't open pid file '%s', " |
| 127 | "err = %d\n", file, -fd); | 128 | "err = %d\n", file, -fd); |
| 128 | } | 129 | } |
| 129 | goto out; | 130 | goto out; |
| @@ -132,18 +133,18 @@ static int not_dead_yet(char *dir) | |||
| 132 | err = 0; | 133 | err = 0; |
| 133 | n = read(fd, pid, sizeof(pid)); | 134 | n = read(fd, pid, sizeof(pid)); |
| 134 | if(n < 0){ | 135 | if(n < 0){ |
| 135 | printk("not_dead_yet : couldn't read pid file '%s', " | 136 | printk("is_umdir_used : couldn't read pid file '%s', " |
| 136 | "err = %d\n", file, errno); | 137 | "err = %d\n", file, errno); |
| 137 | goto out_close; | 138 | goto out_close; |
| 138 | } else if(n == 0){ | 139 | } else if(n == 0){ |
| 139 | printk("not_dead_yet : couldn't read pid file '%s', " | 140 | printk("is_umdir_used : couldn't read pid file '%s', " |
| 140 | "0-byte read\n", file); | 141 | "0-byte read\n", file); |
| 141 | goto out_close; | 142 | goto out_close; |
| 142 | } | 143 | } |
| 143 | 144 | ||
| 144 | p = strtoul(pid, &end, 0); | 145 | p = strtoul(pid, &end, 0); |
| 145 | if(end == pid){ | 146 | if(end == pid){ |
| 146 | printk("not_dead_yet : couldn't parse pid file '%s', " | 147 | printk("is_umdir_used : couldn't parse pid file '%s', " |
| 147 | "errno = %d\n", file, errno); | 148 | "errno = %d\n", file, errno); |
| 148 | goto out_close; | 149 | goto out_close; |
| 149 | } | 150 | } |
| @@ -153,19 +154,32 @@ static int not_dead_yet(char *dir) | |||
| 153 | return 1; | 154 | return 1; |
| 154 | } | 155 | } |
| 155 | 156 | ||
| 156 | err = actually_do_remove(dir); | ||
| 157 | if(err) | ||
| 158 | printk("not_dead_yet - actually_do_remove failed with " | ||
| 159 | "err = %d\n", err); | ||
| 160 | |||
| 161 | return err; | ||
| 162 | |||
| 163 | out_close: | 157 | out_close: |
| 164 | close(fd); | 158 | close(fd); |
| 165 | out: | 159 | out: |
| 166 | return 0; | 160 | return 0; |
| 167 | } | 161 | } |
| 168 | 162 | ||
| 163 | /* | ||
| 164 | * Try to remove the directory @dir unless it's in use. | ||
| 165 | * Precondition: @dir exists. | ||
| 166 | * Returns 0 for success, < 0 for failure in removal or if the directory is in | ||
| 167 | * use. | ||
| 168 | */ | ||
| 169 | static int umdir_take_if_dead(char *dir) | ||
| 170 | { | ||
| 171 | int ret; | ||
| 172 | if (is_umdir_used(dir)) | ||
| 173 | return -EEXIST; | ||
| 174 | |||
| 175 | ret = actually_do_remove(dir); | ||
| 176 | if (ret) { | ||
| 177 | printk("is_umdir_used - actually_do_remove failed with " | ||
| 178 | "err = %d\n", ret); | ||
| 179 | } | ||
| 180 | return ret; | ||
| 181 | } | ||
| 182 | |||
| 169 | static void __init create_pid_file(void) | 183 | static void __init create_pid_file(void) |
| 170 | { | 184 | { |
| 171 | char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")]; | 185 | char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")]; |
| @@ -244,11 +258,7 @@ int __init make_umid(void) | |||
| 244 | if(err != -EEXIST) | 258 | if(err != -EEXIST) |
| 245 | goto err; | 259 | goto err; |
| 246 | 260 | ||
| 247 | /* 1 -> this umid is already in use | 261 | if (umdir_take_if_dead(tmp) < 0) |
| 248 | * < 0 -> we couldn't remove the umid directory | ||
| 249 | * In either case, we can't use this umid, so return -EEXIST. | ||
| 250 | */ | ||
| 251 | if(not_dead_yet(tmp) != 0) | ||
| 252 | goto err; | 262 | goto err; |
| 253 | 263 | ||
| 254 | err = mkdir(tmp, 0777); | 264 | err = mkdir(tmp, 0777); |
