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authorAl Viro <viro@zeniv.linux.org.uk>2021-05-18 03:16:51 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2021-05-18 04:13:57 +0300
commit3a291c974cf7ffb4fad4df6911b912536e511c9d (patch)
tree9901bc4e013eed1f9a0c492687b32aa91a6a86f1 /fs/d_path.c
parentdfe5087675e66f3cce8d98447bf01602f3cdea24 (diff)
downloadlinux-3a291c974cf7ffb4fad4df6911b912536e511c9d.tar.xz
d_path: saner calling conventions for __dentry_path()
1) lift NUL-termination into the callers 2) pass pointer to the end of buffer instead of that to beginning. (1) allows to simplify dentry_path() - we don't need to play silly games with restoring the leading / of "//deleted" after __dentry_path() would've overwritten it with NUL. We also do not need to check if (either) prepend() in there fails - if the buffer is not large enough, we'll end with negative buflen after prepend() and __dentry_path() will return the right value (ERR_PTR(-ENAMETOOLONG)) just fine. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/d_path.c')
-rw-r--r--fs/d_path.c33
1 files changed, 13 insertions, 20 deletions
diff --git a/fs/d_path.c b/fs/d_path.c
index 01df5dfa1f88..1a1cf05e7780 100644
--- a/fs/d_path.c
+++ b/fs/d_path.c
@@ -326,22 +326,21 @@ char *simple_dname(struct dentry *dentry, char *buffer, int buflen)
/*
* Write full pathname from the root of the filesystem into the buffer.
*/
-static char *__dentry_path(const struct dentry *d, char *buf, int buflen)
+static char *__dentry_path(const struct dentry *d, char *p, int buflen)
{
const struct dentry *dentry;
char *end, *retval;
int len, seq = 0;
int error = 0;
- if (buflen < 2)
+ if (buflen < 1)
goto Elong;
rcu_read_lock();
restart:
dentry = d;
- end = buf + buflen;
+ end = p;
len = buflen;
- prepend(&end, &len, "", 1);
/* Get '/' right */
retval = end-1;
*retval = '/';
@@ -373,27 +372,21 @@ Elong:
char *dentry_path_raw(const struct dentry *dentry, char *buf, int buflen)
{
- return __dentry_path(dentry, buf, buflen);
+ char *p = buf + buflen;
+ prepend(&p, &buflen, "", 1);
+ return __dentry_path(dentry, p, buflen);
}
EXPORT_SYMBOL(dentry_path_raw);
char *dentry_path(const struct dentry *dentry, char *buf, int buflen)
{
- char *p = NULL;
- char *retval;
-
- if (d_unlinked(dentry)) {
- p = buf + buflen;
- if (prepend(&p, &buflen, "//deleted", 10) != 0)
- goto Elong;
- buflen++;
- }
- retval = __dentry_path(dentry, buf, buflen);
- if (!IS_ERR(retval) && p)
- *p = '/'; /* restore '/' overriden with '\0' */
- return retval;
-Elong:
- return ERR_PTR(-ENAMETOOLONG);
+ char *p = buf + buflen;
+
+ if (unlikely(d_unlinked(dentry)))
+ prepend(&p, &buflen, "//deleted", 10);
+ else
+ prepend(&p, &buflen, "", 1);
+ return __dentry_path(dentry, p, buflen);
}
static void get_fs_root_and_pwd_rcu(struct fs_struct *fs, struct path *root,