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-rw-r--r--fs/dcache.c90
-rw-r--r--fs/seq_file.c65
-rw-r--r--include/linux/dcache.h1
-rw-r--r--include/linux/seq_file.h2
4 files changed, 118 insertions, 40 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index 43455776711e..635c2aa427ed 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1746,6 +1746,17 @@ shouldnt_be_hashed:
goto shouldnt_be_hashed;
}
+static int prepend(char **buffer, int *buflen, const char *str,
+ int namelen)
+{
+ *buflen -= namelen;
+ if (*buflen < 0)
+ return -ENAMETOOLONG;
+ *buffer -= namelen;
+ memcpy(*buffer, str, namelen);
+ return 0;
+}
+
/**
* d_path - return the path of a dentry
* @dentry: dentry to report
@@ -1767,17 +1778,11 @@ static char *__d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
{
char * end = buffer+buflen;
char * retval;
- int namelen;
-
- *--end = '\0';
- buflen--;
- if (!IS_ROOT(dentry) && d_unhashed(dentry)) {
- buflen -= 10;
- end -= 10;
- if (buflen < 0)
+
+ prepend(&end, &buflen, "\0", 1);
+ if (!IS_ROOT(dentry) && d_unhashed(dentry) &&
+ (prepend(&end, &buflen, " (deleted)", 10) != 0))
goto Elong;
- memcpy(end, " (deleted)", 10);
- }
if (buflen < 1)
goto Elong;
@@ -1804,13 +1809,10 @@ static char *__d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
}
parent = dentry->d_parent;
prefetch(parent);
- namelen = dentry->d_name.len;
- buflen -= namelen + 1;
- if (buflen < 0)
+ if ((prepend(&end, &buflen, dentry->d_name.name,
+ dentry->d_name.len) != 0) ||
+ (prepend(&end, &buflen, "/", 1) != 0))
goto Elong;
- end -= namelen;
- memcpy(end, dentry->d_name.name, namelen);
- *--end = '/';
retval = end;
dentry = parent;
}
@@ -1818,12 +1820,10 @@ static char *__d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
return retval;
global_root:
- namelen = dentry->d_name.len;
- buflen -= namelen;
- if (buflen < 0)
+ retval += 1; /* hit the slash */
+ if (prepend(&retval, &buflen, dentry->d_name.name,
+ dentry->d_name.len) != 0)
goto Elong;
- retval -= namelen-1; /* hit the slash */
- memcpy(retval, dentry->d_name.name, namelen);
return retval;
Elong:
return ERR_PTR(-ENAMETOOLONG);
@@ -1859,7 +1859,7 @@ char *d_path(struct path *path, char *buf, int buflen)
read_lock(&current->fs->lock);
root = current->fs->root;
- path_get(&current->fs->root);
+ path_get(&root);
read_unlock(&current->fs->lock);
spin_lock(&dcache_lock);
res = __d_path(path->dentry, path->mnt, &root, buf, buflen);
@@ -1890,6 +1890,48 @@ char *dynamic_dname(struct dentry *dentry, char *buffer, int buflen,
}
/*
+ * Write full pathname from the root of the filesystem into the buffer.
+ */
+char *dentry_path(struct dentry *dentry, char *buf, int buflen)
+{
+ char *end = buf + buflen;
+ char *retval;
+
+ spin_lock(&dcache_lock);
+ prepend(&end, &buflen, "\0", 1);
+ if (!IS_ROOT(dentry) && d_unhashed(dentry) &&
+ (prepend(&end, &buflen, "//deleted", 9) != 0))
+ goto Elong;
+ if (buflen < 1)
+ goto Elong;
+ /* Get '/' right */
+ retval = end-1;
+ *retval = '/';
+
+ for (;;) {
+ struct dentry *parent;
+ if (IS_ROOT(dentry))
+ break;
+
+ parent = dentry->d_parent;
+ prefetch(parent);
+
+ if ((prepend(&end, &buflen, dentry->d_name.name,
+ dentry->d_name.len) != 0) ||
+ (prepend(&end, &buflen, "/", 1) != 0))
+ goto Elong;
+
+ retval = end;
+ dentry = parent;
+ }
+ spin_unlock(&dcache_lock);
+ return retval;
+Elong:
+ spin_unlock(&dcache_lock);
+ return ERR_PTR(-ENAMETOOLONG);
+}
+
+/*
* NOTE! The user-level library version returns a
* character pointer. The kernel system call just
* returns the length of the buffer filled (which
@@ -1918,9 +1960,9 @@ asmlinkage long sys_getcwd(char __user *buf, unsigned long size)
read_lock(&current->fs->lock);
pwd = current->fs->pwd;
- path_get(&current->fs->pwd);
+ path_get(&pwd);
root = current->fs->root;
- path_get(&current->fs->root);
+ path_get(&root);
read_unlock(&current->fs->lock);
error = -ENOENT;
diff --git a/fs/seq_file.c b/fs/seq_file.c
index cdfd996ca6ef..ae59f5a6c5c1 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -350,28 +350,40 @@ int seq_printf(struct seq_file *m, const char *f, ...)
}
EXPORT_SYMBOL(seq_printf);
+static char *mangle_path(char *s, char *p, char *esc)
+{
+ while (s <= p) {
+ char c = *p++;
+ if (!c) {
+ return s;
+ } else if (!strchr(esc, c)) {
+ *s++ = c;
+ } else if (s + 4 > p) {
+ break;
+ } else {
+ *s++ = '\\';
+ *s++ = '0' + ((c & 0300) >> 6);
+ *s++ = '0' + ((c & 070) >> 3);
+ *s++ = '0' + (c & 07);
+ }
+ }
+ return NULL;
+}
+
+/*
+ * return the absolute path of 'dentry' residing in mount 'mnt'.
+ */
int seq_path(struct seq_file *m, struct path *path, char *esc)
{
if (m->count < m->size) {
char *s = m->buf + m->count;
char *p = d_path(path, s, m->size - m->count);
if (!IS_ERR(p)) {
- while (s <= p) {
- char c = *p++;
- if (!c) {
- p = m->buf + m->count;
- m->count = s - m->buf;
- return s - p;
- } else if (!strchr(esc, c)) {
- *s++ = c;
- } else if (s + 4 > p) {
- break;
- } else {
- *s++ = '\\';
- *s++ = '0' + ((c & 0300) >> 6);
- *s++ = '0' + ((c & 070) >> 3);
- *s++ = '0' + (c & 07);
- }
+ s = mangle_path(s, p, esc);
+ if (s) {
+ p = m->buf + m->count;
+ m->count = s - m->buf;
+ return s - p;
}
}
}
@@ -380,6 +392,27 @@ int seq_path(struct seq_file *m, struct path *path, char *esc)
}
EXPORT_SYMBOL(seq_path);
+/*
+ * returns the path of the 'dentry' from the root of its filesystem.
+ */
+int seq_dentry(struct seq_file *m, struct dentry *dentry, char *esc)
+{
+ if (m->count < m->size) {
+ char *s = m->buf + m->count;
+ char *p = dentry_path(dentry, s, m->size - m->count);
+ if (!IS_ERR(p)) {
+ s = mangle_path(s, p, esc);
+ if (s) {
+ p = m->buf + m->count;
+ m->count = s - m->buf;
+ return s - p;
+ }
+ }
+ }
+ m->count = m->size;
+ return -1;
+}
+
static void *single_start(struct seq_file *p, loff_t *pos)
{
return NULL + (*pos == 0);
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index fabd16d03a27..63960033b6f5 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -302,6 +302,7 @@ extern int d_validate(struct dentry *, struct dentry *);
extern char *dynamic_dname(struct dentry *, char *, int, const char *, ...);
extern char *d_path(struct path *, char *, int);
+extern char *dentry_path(struct dentry *, char *, int);
/* Allocation counts.. */
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index d65796dc26d9..11676ccef7b3 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -10,6 +10,7 @@ struct seq_operations;
struct file;
struct path;
struct inode;
+struct dentry;
struct seq_file {
char *buf;
@@ -44,6 +45,7 @@ int seq_printf(struct seq_file *, const char *, ...)
__attribute__ ((format (printf,2,3)));
int seq_path(struct seq_file *, struct path *, char *);
+int seq_dentry(struct seq_file *, struct dentry *, char *);
int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
int single_release(struct inode *, struct file *);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-10 15:03:32 +0000