diff options
| -rw-r--r-- | Documentation/printk-formats.txt | 9 | ||||
| -rw-r--r-- | lib/vsprintf.c | 82 |
2 files changed, 91 insertions, 0 deletions
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt index 3e8cb73ac43..9552a3299ec 100644 --- a/Documentation/printk-formats.txt +++ b/Documentation/printk-formats.txt @@ -168,6 +168,15 @@ UUID/GUID addresses: Where no additional specifiers are used the default little endian order with lower case hex characters will be printed. +dentry names: + %pd{,2,3,4} + %pD{,2,3,4} + + For printing dentry name; if we race with d_move(), the name might be + a mix of old and new ones, but it won't oops. %pd dentry is a safer + equivalent of %s dentry->d_name.name we used to use, %pd<n> prints + n last components. %pD does the same thing for struct file. + struct va_format: %pV diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 739a36366b7..26559bdb4c4 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -26,6 +26,7 @@ #include <linux/math64.h> #include <linux/uaccess.h> #include <linux/ioport.h> +#include <linux/dcache.h> #include <net/addrconf.h> #include <asm/page.h> /* for PAGE_SIZE */ @@ -532,6 +533,81 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec) return buf; } +static void widen(char *buf, char *end, unsigned len, unsigned spaces) +{ + size_t size; + if (buf >= end) /* nowhere to put anything */ + return; + size = end - buf; + if (size <= spaces) { + memset(buf, ' ', size); + return; + } + if (len) { + if (len > size - spaces) + len = size - spaces; + memmove(buf + spaces, buf, len); + } + memset(buf, ' ', spaces); +} + +static noinline_for_stack +char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec, + const char *fmt) +{ + const char *array[4], *s; + const struct dentry *p; + int depth; + int i, n; + + switch (fmt[1]) { + case '2': case '3': case '4': + depth = fmt[1] - '0'; + break; + default: + depth = 1; + } + + rcu_read_lock(); + for (i = 0; i < depth; i++, d = p) { + p = ACCESS_ONCE(d->d_parent); + array[i] = ACCESS_ONCE(d->d_name.name); + if (p == d) { + if (i) + array[i] = ""; + i++; + break; + } + } + s = array[--i]; + for (n = 0; n != spec.precision; n++, buf++) { + char c = *s++; + if (!c) { + if (!i) + break; + c = '/'; + s = array[--i]; + } + if (buf < end) + *buf = c; + } + rcu_read_unlock(); + if (n < spec.field_width) { + /* we want to pad the sucker */ + unsigned spaces = spec.field_width - n; + if (!(spec.flags & LEFT)) { + widen(buf - n, end, n, spaces); + return buf + spaces; + } + while (spaces--) { + if (buf < end) + *buf = ' '; + ++buf; + } + } + return buf; +} + static noinline_for_stack char *symbol_string(char *buf, char *end, void *ptr, struct printf_spec spec, const char *fmt) @@ -1253,6 +1329,12 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, spec.base = 16; return number(buf, end, (unsigned long long) *((phys_addr_t *)ptr), spec); + case 'd': + return dentry_name(buf, end, ptr, spec, fmt); + case 'D': + return dentry_name(buf, end, + ((const struct file *)ptr)->f_path.dentry, + spec, fmt); } spec.flags |= SMALL; if (spec.field_width == -1) { |