#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>
#include <linux/seqlock.h>
#include <linux/swap.h>
#include <linux/bootmem.h>
+#include <linux/fs_struct.h>
+#include <linux/hardirq.h>
#include "internal.h"
-
int sysctl_vfs_cache_pressure __read_mostly = 100;
EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
static void __d_free(struct dentry *dentry)
{
+ WARN_ON(!list_empty(&dentry->d_alias));
if (dname_external(dentry))
kfree(dentry->d_name.name);
kmem_cache_free(dentry_cache, dentry);
dentry_stat.nr_dentry--; /* For d_free, below */
/*drops the locks, at that point nobody can reach this dentry */
dentry_iput(dentry);
- parent = dentry->d_parent;
+ if (IS_ROOT(dentry))
+ parent = NULL;
+ else
+ parent = dentry->d_parent;
d_free(dentry);
- return dentry == parent ? NULL : parent;
+ return parent;
}
/*
if (dentry)
goto repeat;
}
+EXPORT_SYMBOL(dput);
/**
* d_invalidate - invalidate a dentry
spin_unlock(&dcache_lock);
return 0;
}
+EXPORT_SYMBOL(d_invalidate);
/* This should be called _only_ with dcache_lock held */
{
return __dget_locked(dentry);
}
+EXPORT_SYMBOL(dget_locked);
/**
* d_find_alias - grab a hashed alias of inode
}
return de;
}
+EXPORT_SYMBOL(d_find_alias);
/*
* Try to kill dentries associated with this inode.
}
spin_unlock(&dcache_lock);
}
+EXPORT_SYMBOL(d_prune_aliases);
/*
* Throw away a dentry - free the inode, dput the parent. This requires that
if ((flags & DCACHE_REFERENCED)
&& (dentry->d_flags & DCACHE_REFERENCED)) {
dentry->d_flags &= ~DCACHE_REFERENCED;
- list_move_tail(&dentry->d_lru, &referenced);
+ list_move(&dentry->d_lru, &referenced);
spin_unlock(&dentry->d_lock);
} else {
list_move_tail(&dentry->d_lru, &tmp);
{
__shrink_dcache_sb(sb, NULL, 0);
}
+EXPORT_SYMBOL(shrink_dcache_sb);
/*
* destroy a single subtree of dentries for unmount
BUG();
}
- parent = dentry->d_parent;
- if (parent == dentry)
+ if (IS_ROOT(dentry))
parent = NULL;
- else
+ else {
+ parent = dentry->d_parent;
atomic_dec(&parent->d_count);
+ }
list_del(&dentry->d_u.d_child);
detached++;
spin_unlock(&dcache_lock);
return 1;
}
+EXPORT_SYMBOL(have_submounts);
/*
* Search the dentry child list for the specified parent,
while ((found = select_parent(parent)) != 0)
__shrink_dcache_sb(sb, &found, 0);
}
+EXPORT_SYMBOL(shrink_dcache_parent);
/*
* Scan `nr' dentries and return the number which remain.
dentry->d_op = NULL;
dentry->d_fsdata = NULL;
dentry->d_mounted = 0;
-#ifdef CONFIG_PROFILING
- dentry->d_cookie = NULL;
-#endif
INIT_HLIST_NODE(&dentry->d_hash);
INIT_LIST_HEAD(&dentry->d_lru);
INIT_LIST_HEAD(&dentry->d_subdirs);
return dentry;
}
+EXPORT_SYMBOL(d_alloc);
struct dentry *d_alloc_name(struct dentry *parent, const char *name)
{
q.hash = full_name_hash(q.name, q.len);
return d_alloc(parent, &q);
}
+EXPORT_SYMBOL(d_alloc_name);
+
+/* the caller must hold dcache_lock */
+static void __d_instantiate(struct dentry *dentry, struct inode *inode)
+{
+ if (inode)
+ list_add(&dentry->d_alias, &inode->i_dentry);
+ dentry->d_inode = inode;
+ fsnotify_d_instantiate(dentry, inode);
+}
/**
* d_instantiate - fill in inode information for a dentry
{
BUG_ON(!list_empty(&entry->d_alias));
spin_lock(&dcache_lock);
- if (inode)
- list_add(&entry->d_alias, &inode->i_dentry);
- entry->d_inode = inode;
- fsnotify_d_instantiate(entry, inode);
+ __d_instantiate(entry, inode);
spin_unlock(&dcache_lock);
security_d_instantiate(entry, inode);
}
+EXPORT_SYMBOL(d_instantiate);
/**
* d_instantiate_unique - instantiate a non-aliased dentry
unsigned int hash = entry->d_name.hash;
if (!inode) {
- entry->d_inode = NULL;
+ __d_instantiate(entry, NULL);
return NULL;
}
return alias;
}
- list_add(&entry->d_alias, &inode->i_dentry);
- entry->d_inode = inode;
- fsnotify_d_instantiate(entry, inode);
+ __d_instantiate(entry, inode);
return NULL;
}
}
return res;
}
+EXPORT_SYMBOL(d_alloc_root);
static inline struct hlist_head *d_hash(struct dentry *parent,
unsigned long hash)
}
/**
- * d_alloc_anon - allocate an anonymous dentry
+ * d_obtain_alias - find or allocate a dentry for a given inode
* @inode: inode to allocate the dentry for
*
- * This is similar to d_alloc_root. It is used by filesystems when
- * creating a dentry for a given inode, often in the process of
- * mapping a filehandle to a dentry. The returned dentry may be
- * anonymous, or may have a full name (if the inode was already
- * in the cache). The file system may need to make further
- * efforts to connect this dentry into the dcache properly.
+ * Obtain a dentry for an inode resulting from NFS filehandle conversion or
+ * similar open by handle operations. The returned dentry may be anonymous,
+ * or may have a full name (if the inode was already in the cache).
*
- * When called on a directory inode, we must ensure that
- * the inode only ever has one dentry. If a dentry is
- * found, that is returned instead of allocating a new one.
+ * When called on a directory inode, we must ensure that the inode only ever
+ * has one dentry. If a dentry is found, that is returned instead of
+ * allocating a new one.
*
* On successful return, the reference to the inode has been transferred
- * to the dentry. If %NULL is returned (indicating kmalloc failure),
- * the reference on the inode has not been released.
+ * to the dentry. In case of an error the reference on the inode is released.
+ * To make it easier to use in export operations a %NULL or IS_ERR inode may
+ * be passed in and will be the error will be propagate to the return value,
+ * with a %NULL @inode replaced by ERR_PTR(-ESTALE).
*/
-
-struct dentry * d_alloc_anon(struct inode *inode)
+struct dentry *d_obtain_alias(struct inode *inode)
{
static const struct qstr anonstring = { .name = "" };
struct dentry *tmp;
struct dentry *res;
- if ((res = d_find_alias(inode))) {
- iput(inode);
- return res;
- }
+ if (!inode)
+ return ERR_PTR(-ESTALE);
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
- tmp = d_alloc(NULL, &anonstring);
- if (!tmp)
- return NULL;
+ res = d_find_alias(inode);
+ if (res)
+ goto out_iput;
+ tmp = d_alloc(NULL, &anonstring);
+ if (!tmp) {
+ res = ERR_PTR(-ENOMEM);
+ goto out_iput;
+ }
tmp->d_parent = tmp; /* make sure dput doesn't croak */
-
+
spin_lock(&dcache_lock);
res = __d_find_alias(inode, 0);
- if (!res) {
- /* attach a disconnected dentry */
- res = tmp;
- tmp = NULL;
- spin_lock(&res->d_lock);
- res->d_sb = inode->i_sb;
- res->d_parent = res;
- res->d_inode = inode;
- res->d_flags |= DCACHE_DISCONNECTED;
- res->d_flags &= ~DCACHE_UNHASHED;
- list_add(&res->d_alias, &inode->i_dentry);
- hlist_add_head(&res->d_hash, &inode->i_sb->s_anon);
- spin_unlock(&res->d_lock);
-
- inode = NULL; /* don't drop reference */
+ if (res) {
+ spin_unlock(&dcache_lock);
+ dput(tmp);
+ goto out_iput;
}
+
+ /* attach a disconnected dentry */
+ spin_lock(&tmp->d_lock);
+ tmp->d_sb = inode->i_sb;
+ tmp->d_inode = inode;
+ tmp->d_flags |= DCACHE_DISCONNECTED;
+ tmp->d_flags &= ~DCACHE_UNHASHED;
+ list_add(&tmp->d_alias, &inode->i_dentry);
+ hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon);
+ spin_unlock(&tmp->d_lock);
+
spin_unlock(&dcache_lock);
+ return tmp;
- if (inode)
- iput(inode);
- if (tmp)
- dput(tmp);
+ out_iput:
+ iput(inode);
return res;
}
-
+EXPORT_SYMBOL(d_obtain_alias);
/**
* d_splice_alias - splice a disconnected dentry into the tree if one exists
new = __d_find_alias(inode, 1);
if (new) {
BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
- fsnotify_d_instantiate(new, inode);
spin_unlock(&dcache_lock);
security_d_instantiate(new, inode);
- d_rehash(dentry);
d_move(new, dentry);
iput(inode);
} else {
- /* d_instantiate takes dcache_lock, so we do it by hand */
- list_add(&dentry->d_alias, &inode->i_dentry);
- dentry->d_inode = inode;
- fsnotify_d_instantiate(dentry, inode);
+ /* already taking dcache_lock, so d_add() by hand */
+ __d_instantiate(dentry, inode);
spin_unlock(&dcache_lock);
security_d_instantiate(dentry, inode);
d_rehash(dentry);
d_add(dentry, inode);
return new;
}
+EXPORT_SYMBOL(d_splice_alias);
/**
* d_add_ci - lookup or allocate new dentry with case-exact name
struct dentry *found;
struct dentry *new;
- /* Does a dentry matching the name exist already? */
+ /*
+ * First check if a dentry matching the name already exists,
+ * if not go ahead and create it now.
+ */
found = d_hash_and_lookup(dentry->d_parent, name);
- /* If not, create it now and return */
if (!found) {
new = d_alloc(dentry->d_parent, name);
if (!new) {
error = -ENOMEM;
goto err_out;
}
+
found = d_splice_alias(inode, new);
if (found) {
dput(new);
}
return new;
}
- /* Matching dentry exists, check if it is negative. */
+
+ /*
+ * If a matching dentry exists, and it's not negative use it.
+ *
+ * Decrement the reference count to balance the iget() done
+ * earlier on.
+ */
if (found->d_inode) {
if (unlikely(found->d_inode != inode)) {
/* This can't happen because bad inodes are unhashed. */
BUG_ON(!is_bad_inode(inode));
BUG_ON(!is_bad_inode(found->d_inode));
}
- /*
- * Already have the inode and the dentry attached, decrement
- * the reference count to balance the iget() done
- * earlier on. We found the dentry using d_lookup() so it
- * cannot be disconnected and thus we do not need to worry
- * about any NFS/disconnectedness issues here.
- */
iput(inode);
return found;
}
+
/*
* Negative dentry: instantiate it unless the inode is a directory and
- * has a 'disconnected' dentry (i.e. IS_ROOT and DCACHE_DISCONNECTED),
- * in which case d_move() that in place of the found dentry.
+ * already has a dentry.
*/
- if (!S_ISDIR(inode->i_mode)) {
- /* Not a directory; everything is easy. */
- d_instantiate(found, inode);
- return found;
- }
spin_lock(&dcache_lock);
- if (list_empty(&inode->i_dentry)) {
- /*
- * Directory without a 'disconnected' dentry; we need to do
- * d_instantiate() by hand because it takes dcache_lock which
- * we already hold.
- */
- list_add(&found->d_alias, &inode->i_dentry);
- found->d_inode = inode;
+ if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) {
+ __d_instantiate(found, inode);
spin_unlock(&dcache_lock);
security_d_instantiate(found, inode);
return found;
}
+
/*
- * Directory with a 'disconnected' dentry; get a reference to the
- * 'disconnected' dentry.
+ * In case a directory already has a (disconnected) entry grab a
+ * reference to it, move it in place and use it.
*/
new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
dget_locked(new);
spin_unlock(&dcache_lock);
- /* Do security vodoo. */
security_d_instantiate(found, inode);
- /* Move new in place of found. */
d_move(new, found);
- /* Balance the iget() we did above. */
iput(inode);
- /* Throw away found. */
dput(found);
- /* Use new as the actual dentry. */
return new;
err_out:
iput(inode);
return ERR_PTR(error);
}
+EXPORT_SYMBOL(d_add_ci);
/**
* d_lookup - search for a dentry
*
* Searches the children of the parent dentry for the name in question. If
* the dentry is found its reference count is incremented and the dentry
- * is returned. The caller must use d_put to free the entry when it has
+ * is returned. The caller must use dput to free the entry when it has
* finished using it. %NULL is returned on failure.
*
* __d_lookup is dcache_lock free. The hash list is protected using RCU.
} while (read_seqretry(&rename_lock, seq));
return dentry;
}
+EXPORT_SYMBOL(d_lookup);
struct dentry * __d_lookup(struct dentry * parent, struct qstr * name)
{
* d_validate - verify dentry provided from insecure source
* @dentry: The dentry alleged to be valid child of @dparent
* @dparent: The parent dentry (known to be valid)
- * @hash: Hash of the dentry
- * @len: Length of the name
*
* An insecure source has sent us a dentry, here we verify it and dget() it.
* This is used by ncpfs in its readdir implementation.
out:
return 0;
}
+EXPORT_SYMBOL(d_validate);
/*
* When a file is deleted, we have two options:
fsnotify_nameremove(dentry, isdir);
}
+EXPORT_SYMBOL(d_delete);
static void __d_rehash(struct dentry * entry, struct hlist_head *list)
{
spin_unlock(&entry->d_lock);
spin_unlock(&dcache_lock);
}
-
-#define do_switch(x,y) do { \
- __typeof__ (x) __tmp = x; \
- x = y; y = __tmp; } while (0)
+EXPORT_SYMBOL(d_rehash);
/*
* When switching names, the actual string doesn't strictly have to
/*
* Both external: swap the pointers
*/
- do_switch(target->d_name.name, dentry->d_name.name);
+ swap(target->d_name.name, dentry->d_name.name);
} else {
/*
* dentry:internal, target:external. Steal target's
*/
memcpy(dentry->d_iname, target->d_name.name,
target->d_name.len + 1);
+ dentry->d_name.len = target->d_name.len;
+ return;
}
}
+ swap(dentry->d_name.len, target->d_name.len);
}
/*
/* Switch the names.. */
switch_names(dentry, target);
- do_switch(dentry->d_name.len, target->d_name.len);
- do_switch(dentry->d_name.hash, target->d_name.hash);
+ swap(dentry->d_name.hash, target->d_name.hash);
/* ... and switch the parents */
if (IS_ROOT(dentry)) {
target->d_parent = target;
INIT_LIST_HEAD(&target->d_u.d_child);
} else {
- do_switch(dentry->d_parent, target->d_parent);
+ swap(dentry->d_parent, target->d_parent);
/* And add them back to the (new) parent lists */
list_add(&target->d_u.d_child, &target->d_parent->d_subdirs);
d_move_locked(dentry, target);
spin_unlock(&dcache_lock);
}
+EXPORT_SYMBOL(d_move);
-/*
- * Helper that returns 1 if p1 is a parent of p2, else 0
+/**
+ * d_ancestor - search for an ancestor
+ * @p1: ancestor dentry
+ * @p2: child dentry
+ *
+ * Returns the ancestor dentry of p2 which is a child of p1, if p1 is
+ * an ancestor of p2, else NULL.
*/
-static int d_isparent(struct dentry *p1, struct dentry *p2)
+struct dentry *d_ancestor(struct dentry *p1, struct dentry *p2)
{
struct dentry *p;
- for (p = p2; p->d_parent != p; p = p->d_parent) {
+ for (p = p2; !IS_ROOT(p); p = p->d_parent) {
if (p->d_parent == p1)
- return 1;
+ return p;
}
- return 0;
+ return NULL;
}
/*
/* Check for loops */
ret = ERR_PTR(-ELOOP);
- if (d_isparent(alias, dentry))
+ if (d_ancestor(alias, dentry))
goto out_err;
/* See lock_rename() */
struct dentry *dparent, *aparent;
switch_names(dentry, anon);
- do_switch(dentry->d_name.len, anon->d_name.len);
- do_switch(dentry->d_name.hash, anon->d_name.hash);
+ swap(dentry->d_name.hash, anon->d_name.hash);
dparent = dentry->d_parent;
aparent = anon->d_parent;
if (!inode) {
actual = dentry;
- dentry->d_inode = NULL;
+ __d_instantiate(dentry, NULL);
goto found_lock;
}
spin_unlock(&dcache_lock);
BUG();
}
+EXPORT_SYMBOL_GPL(d_materialise_unique);
static int prepend(char **buffer, int *buflen, const char *str, int namelen)
{
* Convert a dentry into an ASCII path name. If the entry has been deleted
* the string " (deleted)" is appended. Note that this is ambiguous.
*
- * Returns the buffer or an error code if the path was too long.
+ * Returns a pointer into the buffer or an error code if the
+ * path was too long.
*
* "buflen" should be positive. Caller holds the dcache_lock.
*
spin_lock(&vfsmount_lock);
prepend(&end, &buflen, "\0", 1);
- if (!IS_ROOT(dentry) && d_unhashed(dentry) &&
+ if (d_unlinked(dentry) &&
(prepend(&end, &buflen, " (deleted)", 10) != 0))
goto Elong;
* Convert a dentry into an ASCII path name. If the entry has been deleted
* the string " (deleted)" is appended. Note that this is ambiguous.
*
- * Returns the buffer or an error code if the path was too long.
+ * Returns a pointer into the buffer or an error code if the path was
+ * too long. Note: Callers should use the returned pointer, not the passed
+ * in buffer, to use the name! The implementation often starts at an offset
+ * into the buffer, and may leave 0 bytes at the start.
*
* "buflen" should be positive.
*/
path_put(&root);
return res;
}
+EXPORT_SYMBOL(d_path);
/*
* Helper function for dentry_operations.d_dname() members
spin_lock(&dcache_lock);
prepend(&end, &buflen, "\0", 1);
- if (!IS_ROOT(dentry) && d_unhashed(dentry) &&
+ if (d_unlinked(dentry) &&
(prepend(&end, &buflen, "//deleted", 9) != 0))
goto Elong;
if (buflen < 1)
* return NULL;
* }
*/
-asmlinkage long sys_getcwd(char __user *buf, unsigned long size)
+SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
{
int error;
struct path pwd, root;
read_unlock(¤t->fs->lock);
error = -ENOENT;
- /* Has the current directory has been unlinked? */
spin_lock(&dcache_lock);
- if (IS_ROOT(pwd.dentry) || !d_unhashed(pwd.dentry)) {
+ if (!d_unlinked(pwd.dentry)) {
unsigned long len;
struct path tmp = root;
char * cwd;
* Caller must ensure that "new_dentry" is pinned before calling is_subdir()
*/
-int is_subdir(struct dentry * new_dentry, struct dentry * old_dentry)
+int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
{
int result;
- struct dentry * saved = new_dentry;
unsigned long seq;
- /* need rcu_readlock to protect against the d_parent trashing due to
- * d_move
+ if (new_dentry == old_dentry)
+ return 1;
+
+ /*
+ * Need rcu_readlock to protect against the d_parent trashing
+ * due to d_move
*/
rcu_read_lock();
- do {
+ do {
/* for restarting inner loop in case of seq retry */
- new_dentry = saved;
- result = 0;
seq = read_seqbegin(&rename_lock);
- for (;;) {
- if (new_dentry != old_dentry) {
- struct dentry * parent = new_dentry->d_parent;
- if (parent == new_dentry)
- break;
- new_dentry = parent;
- continue;
- }
+ if (d_ancestor(old_dentry, new_dentry))
result = 1;
- break;
- }
+ else
+ result = 0;
} while (read_seqretry(&rename_lock, seq));
rcu_read_unlock();
return result;
}
+int path_is_under(struct path *path1, struct path *path2)
+{
+ struct vfsmount *mnt = path1->mnt;
+ struct dentry *dentry = path1->dentry;
+ int res;
+ spin_lock(&vfsmount_lock);
+ if (mnt != path2->mnt) {
+ for (;;) {
+ if (mnt->mnt_parent == mnt) {
+ spin_unlock(&vfsmount_lock);
+ return 0;
+ }
+ if (mnt->mnt_parent == path2->mnt)
+ break;
+ mnt = mnt->mnt_parent;
+ }
+ dentry = mnt->mnt_mountpoint;
+ }
+ res = is_subdir(dentry, path2->dentry);
+ spin_unlock(&vfsmount_lock);
+ return res;
+}
+EXPORT_SYMBOL(path_is_under);
+
void d_genocide(struct dentry *root)
{
struct dentry *this_parent = root;
}
return ino;
}
+EXPORT_SYMBOL(find_inode_number);
static __initdata unsigned long dhash_entries;
static int __init set_dhash_entries(char *str)
/* SLAB cache for __getname() consumers */
struct kmem_cache *names_cachep __read_mostly;
-
-/* SLAB cache for file structures */
-struct kmem_cache *filp_cachep __read_mostly;
+EXPORT_SYMBOL(names_cachep);
EXPORT_SYMBOL(d_genocide);
names_cachep = kmem_cache_create("names_cache", PATH_MAX, 0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
- filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0,
- SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
-
dcache_init();
inode_init();
files_init(mempages);
bdev_cache_init();
chrdev_init();
}
-
-EXPORT_SYMBOL(d_alloc);
-EXPORT_SYMBOL(d_alloc_anon);
-EXPORT_SYMBOL(d_alloc_root);
-EXPORT_SYMBOL(d_delete);
-EXPORT_SYMBOL(d_find_alias);
-EXPORT_SYMBOL(d_instantiate);
-EXPORT_SYMBOL(d_invalidate);
-EXPORT_SYMBOL(d_lookup);
-EXPORT_SYMBOL(d_move);
-EXPORT_SYMBOL_GPL(d_materialise_unique);
-EXPORT_SYMBOL(d_path);
-EXPORT_SYMBOL(d_prune_aliases);
-EXPORT_SYMBOL(d_rehash);
-EXPORT_SYMBOL(d_splice_alias);
-EXPORT_SYMBOL(d_add_ci);
-EXPORT_SYMBOL(d_validate);
-EXPORT_SYMBOL(dget_locked);
-EXPORT_SYMBOL(dput);
-EXPORT_SYMBOL(find_inode_number);
-EXPORT_SYMBOL(have_submounts);
-EXPORT_SYMBOL(names_cachep);
-EXPORT_SYMBOL(shrink_dcache_parent);
-EXPORT_SYMBOL(shrink_dcache_sb);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff