#include <linux/syscalls.h>
#include <linux/string.h>
#include <linux/mm.h>
+#include <linux/fdtable.h>
#include <linux/fs.h>
#include <linux/fsnotify.h>
#include <linux/slab.h>
call_rcu(&dentry->d_u.d_rcu, d_callback);
}
+static void dentry_lru_remove(struct dentry *dentry)
+{
+ if (!list_empty(&dentry->d_lru)) {
+ list_del_init(&dentry->d_lru);
+ dentry_stat.nr_unused--;
+ }
+}
+
/*
* Release the dentry's inode, using the filesystem
* d_iput() operation if defined.
- * Called with dcache_lock and per dentry lock held, drops both.
*/
static void dentry_iput(struct dentry * dentry)
+ __releases(dentry->d_lock)
+ __releases(dcache_lock)
{
struct inode *inode = dentry->d_inode;
if (inode) {
* d_kill - kill dentry and return parent
* @dentry: dentry to kill
*
- * Called with dcache_lock and d_lock, releases both. The dentry must
- * already be unhashed and removed from the LRU.
+ * The dentry must already be unhashed and removed from the LRU.
*
* If this is the root of the dentry tree, return NULL.
*/
static struct dentry *d_kill(struct dentry *dentry)
+ __releases(dentry->d_lock)
+ __releases(dcache_lock)
{
struct dentry *parent;
unhash_it:
__d_drop(dentry);
kill_it:
- /* If dentry was on d_lru list
- * delete it from there
- */
- if (!list_empty(&dentry->d_lru)) {
- list_del(&dentry->d_lru);
- dentry_stat.nr_unused--;
- }
+ dentry_lru_remove(dentry);
dentry = d_kill(dentry);
if (dentry)
goto repeat;
static inline struct dentry * __dget_locked(struct dentry *dentry)
{
atomic_inc(&dentry->d_count);
- if (!list_empty(&dentry->d_lru)) {
- dentry_stat.nr_unused--;
- list_del_init(&dentry->d_lru);
- }
+ dentry_lru_remove(dentry);
return dentry;
}
* Try to prune ancestors as well. This is necessary to prevent
* quadratic behavior of shrink_dcache_parent(), but is also expected
* to be beneficial in reducing dentry cache fragmentation.
- *
- * Called with dcache_lock, drops it and then regains.
- * Called with dentry->d_lock held, drops it.
*/
static void prune_one_dentry(struct dentry * dentry)
+ __releases(dentry->d_lock)
+ __releases(dcache_lock)
+ __acquires(dcache_lock)
{
__d_drop(dentry);
dentry = d_kill(dentry);
if (dentry->d_op && dentry->d_op->d_delete)
dentry->d_op->d_delete(dentry);
- if (!list_empty(&dentry->d_lru)) {
- list_del(&dentry->d_lru);
- dentry_stat.nr_unused--;
- }
+ dentry_lru_remove(dentry);
__d_drop(dentry);
dentry = d_kill(dentry);
spin_lock(&dcache_lock);
/* detach this root from the system */
spin_lock(&dcache_lock);
- if (!list_empty(&dentry->d_lru)) {
- dentry_stat.nr_unused--;
- list_del_init(&dentry->d_lru);
- }
+ dentry_lru_remove(dentry);
__d_drop(dentry);
spin_unlock(&dcache_lock);
spin_lock(&dcache_lock);
list_for_each_entry(loop, &dentry->d_subdirs,
d_u.d_child) {
- if (!list_empty(&loop->d_lru)) {
- dentry_stat.nr_unused--;
- list_del_init(&loop->d_lru);
- }
-
+ dentry_lru_remove(loop);
__d_drop(loop);
cond_resched_lock(&dcache_lock);
}
struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
next = tmp->next;
- if (!list_empty(&dentry->d_lru)) {
- dentry_stat.nr_unused--;
- list_del_init(&dentry->d_lru);
- }
+ dentry_lru_remove(dentry);
/*
* move only zero ref count dentries to the end
* of the unused list for prune_dcache
*
* Note: If ever the locking in lock_rename() changes, then please
* remember to update this too...
- *
- * On return, dcache_lock will have been unlocked.
*/
static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
+ __releases(dcache_lock)
{
struct mutex *m1 = NULL, *m2 = NULL;
struct dentry *ret;
shouldnt_be_hashed:
spin_unlock(&dcache_lock);
BUG();
- 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;
+}
+
+static int prepend_name(char **buffer, int *buflen, struct qstr *name)
+{
+ return prepend(buffer, buflen, name->name, name->len);
}
/**
- * d_path - return the path of a dentry
- * @dentry: dentry to report
- * @vfsmnt: vfsmnt to which the dentry belongs
- * @root: root dentry
- * @rootmnt: vfsmnt to which the root dentry belongs
+ * __d_path - return the path of a dentry
+ * @path: the dentry/vfsmount to report
+ * @root: root vfsmnt/dentry (may be modified by this function)
* @buffer: buffer to return value in
* @buflen: buffer length
*
* Returns the buffer or an error code if the path was too long.
*
* "buflen" should be positive. Caller holds the dcache_lock.
+ *
+ * If path is not reachable from the supplied root, then the value of
+ * root is changed (without modifying refcounts).
*/
-static char *__d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
- struct path *root, char *buffer, int buflen)
+char *__d_path(const struct path *path, struct path *root,
+ char *buffer, int buflen)
{
- 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)
+ struct dentry *dentry = path->dentry;
+ struct vfsmount *vfsmnt = path->mnt;
+ char *end = buffer + buflen;
+ char *retval;
+
+ spin_lock(&vfsmount_lock);
+ 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;
break;
if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
/* Global root? */
- spin_lock(&vfsmount_lock);
if (vfsmnt->mnt_parent == vfsmnt) {
- spin_unlock(&vfsmount_lock);
goto global_root;
}
dentry = vfsmnt->mnt_mountpoint;
vfsmnt = vfsmnt->mnt_parent;
- spin_unlock(&vfsmount_lock);
continue;
}
parent = dentry->d_parent;
prefetch(parent);
- namelen = dentry->d_name.len;
- buflen -= namelen + 1;
- if (buflen < 0)
+ if ((prepend_name(&end, &buflen, &dentry->d_name) != 0) ||
+ (prepend(&end, &buflen, "/", 1) != 0))
goto Elong;
- end -= namelen;
- memcpy(end, dentry->d_name.name, namelen);
- *--end = '/';
retval = end;
dentry = parent;
}
+out:
+ spin_unlock(&vfsmount_lock);
return retval;
global_root:
- namelen = dentry->d_name.len;
- buflen -= namelen;
- if (buflen < 0)
+ retval += 1; /* hit the slash */
+ if (prepend_name(&retval, &buflen, &dentry->d_name) != 0)
goto Elong;
- retval -= namelen-1; /* hit the slash */
- memcpy(retval, dentry->d_name.name, namelen);
- return retval;
+ root->mnt = vfsmnt;
+ root->dentry = dentry;
+ goto out;
+
Elong:
- return ERR_PTR(-ENAMETOOLONG);
+ retval = ERR_PTR(-ENAMETOOLONG);
+ goto out;
}
/**
* d_path - return the path of a dentry
- * @dentry: dentry to report
- * @vfsmnt: vfsmnt to which the dentry belongs
+ * @path: path to report
* @buf: buffer to return value in
* @buflen: buffer length
*
*
* Returns the buffer or an error code if the path was too long.
*
- * "buflen" should be positive. Caller holds the dcache_lock.
+ * "buflen" should be positive.
*/
-char *d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
- char *buf, int buflen)
+char *d_path(const struct path *path, char *buf, int buflen)
{
char *res;
struct path root;
+ struct path tmp;
/*
* We have various synthetic filesystems that never get mounted. On
* user wants to identify the object in /proc/pid/fd/. The little hack
* below allows us to generate a name for these objects on demand:
*/
- if (dentry->d_op && dentry->d_op->d_dname)
- return dentry->d_op->d_dname(dentry, buf, buflen);
+ if (path->dentry->d_op && path->dentry->d_op->d_dname)
+ return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
read_lock(¤t->fs->lock);
root = current->fs->root;
- path_get(¤t->fs->root);
+ path_get(&root);
read_unlock(¤t->fs->lock);
spin_lock(&dcache_lock);
- res = __d_path(dentry, vfsmnt, &root, buf, buflen);
+ tmp = root;
+ res = __d_path(path, &tmp, buf, buflen);
spin_unlock(&dcache_lock);
path_put(&root);
return res;
return memcpy(buffer, temp, sz);
}
+/*
+ * 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 = '/';
+
+ while (!IS_ROOT(dentry)) {
+ struct dentry *parent = dentry->d_parent;
+
+ prefetch(parent);
+ if ((prepend_name(&end, &buflen, &dentry->d_name) != 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
read_lock(¤t->fs->lock);
pwd = current->fs->pwd;
- path_get(¤t->fs->pwd);
+ path_get(&pwd);
root = current->fs->root;
- path_get(¤t->fs->root);
+ path_get(&root);
read_unlock(¤t->fs->lock);
error = -ENOENT;
/* Has the current directory has been unlinked? */
spin_lock(&dcache_lock);
- if (pwd.dentry->d_parent == pwd.dentry || !d_unhashed(pwd.dentry)) {
+ if (IS_ROOT(pwd.dentry) || !d_unhashed(pwd.dentry)) {
unsigned long len;
+ struct path tmp = root;
char * cwd;
- cwd = __d_path(pwd.dentry, pwd.mnt, &root, page, PAGE_SIZE);
+ cwd = __d_path(&pwd, &tmp, page, PAGE_SIZE);
spin_unlock(&dcache_lock);
error = PTR_ERR(cwd);
git.openpandora.org / pandora-kernel.git / blobdiff