#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);
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);
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);
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);
}
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;
}
iput(inode);
return res;
}
-EXPORT_SYMBOL_GPL(d_obtain_alias);
+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);
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:
*
* 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.
* 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.
spin_unlock(&dcache_lock);
}
-#define do_switch(x,y) do { \
- __typeof__ (x) __tmp = x; \
- x = y; y = __tmp; } while (0)
-
/*
* When switching names, the actual string doesn't strictly have to
* be preserved in the target - because we're dropping the target
/*
* 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);
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;
}
* 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.
*/
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;
int result;
unsigned long seq;
- /* FIXME: This is old behavior, needed? Please check callers. */
if (new_dentry == old_dentry)
return 1;
/* 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(d_genocide);
void __init vfs_caches_init_early(void)
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);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff