#include <linux/mutex.h>
#include <linux/namei.h>
#include <linux/exportfs.h>
+#include <linux/iversion.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h> /* sync_mapping_buffers */
#include <linux/fs_context.h>
#include <linux/fsnotify.h>
#include <linux/unicode.h>
#include <linux/fscrypt.h>
+#include <linux/pidfs.h>
#include <linux/uaccess.h>
#include "internal.h"
-int simple_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int simple_getattr(struct mnt_idmap *idmap, const struct path *path,
struct kstat *stat, u32 request_mask,
unsigned int query_flags)
{
struct inode *inode = d_inode(path->dentry);
- generic_fillattr(&init_user_ns, inode, stat);
+ generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
stat->blocks = inode->i_mapping->nrpages << (PAGE_SHIFT - 9);
return 0;
}
int simple_statfs(struct dentry *dentry, struct kstatfs *buf)
{
+ u64 id = huge_encode_dev(dentry->d_sb->s_dev);
+
+ buf->f_fsid = u64_to_fsid(id);
buf->f_type = dentry->d_sb->s_magic;
buf->f_bsize = PAGE_SIZE;
buf->f_namelen = NAME_MAX;
* If no such element exists, NULL is returned.
*/
static struct dentry *scan_positives(struct dentry *cursor,
- struct list_head *p,
+ struct hlist_node **p,
loff_t count,
struct dentry *last)
{
struct dentry *dentry = cursor->d_parent, *found = NULL;
spin_lock(&dentry->d_lock);
- while ((p = p->next) != &dentry->d_subdirs) {
- struct dentry *d = list_entry(p, struct dentry, d_child);
+ while (*p) {
+ struct dentry *d = hlist_entry(*p, struct dentry, d_sib);
+ p = &d->d_sib.next;
// we must at least skip cursors, to avoid livelocks
if (d->d_flags & DCACHE_DENTRY_CURSOR)
continue;
count = 1;
}
if (need_resched()) {
- list_move(&cursor->d_child, p);
- p = &cursor->d_child;
+ if (!hlist_unhashed(&cursor->d_sib))
+ __hlist_del(&cursor->d_sib);
+ hlist_add_behind(&cursor->d_sib, &d->d_sib);
+ p = &cursor->d_sib.next;
spin_unlock(&dentry->d_lock);
cond_resched();
spin_lock(&dentry->d_lock);
inode_lock_shared(dentry->d_inode);
if (offset > 2)
- to = scan_positives(cursor, &dentry->d_subdirs,
+ to = scan_positives(cursor, &dentry->d_children.first,
offset - 2, NULL);
spin_lock(&dentry->d_lock);
+ hlist_del_init(&cursor->d_sib);
if (to)
- list_move(&cursor->d_child, &to->d_child);
- else
- list_del_init(&cursor->d_child);
+ hlist_add_behind(&cursor->d_sib, &to->d_sib);
spin_unlock(&dentry->d_lock);
dput(to);
}
EXPORT_SYMBOL(dcache_dir_lseek);
-/* Relationship between i_mode and the DT_xxx types */
-static inline unsigned char dt_type(struct inode *inode)
-{
- return (inode->i_mode >> 12) & 15;
-}
-
/*
* Directory is locked and all positive dentries in it are safe, since
* for ramfs-type trees they can't go away without unlink() or rmdir(),
{
struct dentry *dentry = file->f_path.dentry;
struct dentry *cursor = file->private_data;
- struct list_head *anchor = &dentry->d_subdirs;
struct dentry *next = NULL;
- struct list_head *p;
+ struct hlist_node **p;
if (!dir_emit_dots(file, ctx))
return 0;
if (ctx->pos == 2)
- p = anchor;
- else if (!list_empty(&cursor->d_child))
- p = &cursor->d_child;
+ p = &dentry->d_children.first;
else
- return 0;
+ p = &cursor->d_sib.next;
while ((next = scan_positives(cursor, p, 1, next)) != NULL) {
if (!dir_emit(ctx, next->d_name.name, next->d_name.len,
- d_inode(next)->i_ino, dt_type(d_inode(next))))
+ d_inode(next)->i_ino,
+ fs_umode_to_dtype(d_inode(next)->i_mode)))
break;
ctx->pos++;
- p = &next->d_child;
+ p = &next->d_sib.next;
}
spin_lock(&dentry->d_lock);
+ hlist_del_init(&cursor->d_sib);
if (next)
- list_move_tail(&cursor->d_child, &next->d_child);
- else
- list_del_init(&cursor->d_child);
+ hlist_add_before(&cursor->d_sib, &next->d_sib);
spin_unlock(&dentry->d_lock);
dput(next);
};
EXPORT_SYMBOL(simple_dir_inode_operations);
+/* 0 is '.', 1 is '..', so always start with offset 2 or more */
+enum {
+ DIR_OFFSET_MIN = 2,
+};
+
+static void offset_set(struct dentry *dentry, long offset)
+{
+ dentry->d_fsdata = (void *)offset;
+}
+
+static long dentry2offset(struct dentry *dentry)
+{
+ return (long)dentry->d_fsdata;
+}
+
+static struct lock_class_key simple_offset_lock_class;
+
+/**
+ * simple_offset_init - initialize an offset_ctx
+ * @octx: directory offset map to be initialized
+ *
+ */
+void simple_offset_init(struct offset_ctx *octx)
+{
+ mt_init_flags(&octx->mt, MT_FLAGS_ALLOC_RANGE);
+ lockdep_set_class(&octx->mt.ma_lock, &simple_offset_lock_class);
+ octx->next_offset = DIR_OFFSET_MIN;
+}
+
+/**
+ * simple_offset_add - Add an entry to a directory's offset map
+ * @octx: directory offset ctx to be updated
+ * @dentry: new dentry being added
+ *
+ * Returns zero on success. @octx and the dentry's offset are updated.
+ * Otherwise, a negative errno value is returned.
+ */
+int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry)
+{
+ unsigned long offset;
+ int ret;
+
+ if (dentry2offset(dentry) != 0)
+ return -EBUSY;
+
+ ret = mtree_alloc_cyclic(&octx->mt, &offset, dentry, DIR_OFFSET_MIN,
+ LONG_MAX, &octx->next_offset, GFP_KERNEL);
+ if (ret < 0)
+ return ret;
+
+ offset_set(dentry, offset);
+ return 0;
+}
+
+/**
+ * simple_offset_remove - Remove an entry to a directory's offset map
+ * @octx: directory offset ctx to be updated
+ * @dentry: dentry being removed
+ *
+ */
+void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry)
+{
+ long offset;
+
+ offset = dentry2offset(dentry);
+ if (offset == 0)
+ return;
+
+ mtree_erase(&octx->mt, offset);
+ offset_set(dentry, 0);
+}
+
+/**
+ * simple_offset_empty - Check if a dentry can be unlinked
+ * @dentry: dentry to be tested
+ *
+ * Returns 0 if @dentry is a non-empty directory; otherwise returns 1.
+ */
+int simple_offset_empty(struct dentry *dentry)
+{
+ struct inode *inode = d_inode(dentry);
+ struct offset_ctx *octx;
+ struct dentry *child;
+ unsigned long index;
+ int ret = 1;
+
+ if (!inode || !S_ISDIR(inode->i_mode))
+ return ret;
+
+ index = DIR_OFFSET_MIN;
+ octx = inode->i_op->get_offset_ctx(inode);
+ mt_for_each(&octx->mt, child, index, LONG_MAX) {
+ spin_lock(&child->d_lock);
+ if (simple_positive(child)) {
+ spin_unlock(&child->d_lock);
+ ret = 0;
+ break;
+ }
+ spin_unlock(&child->d_lock);
+ }
+
+ return ret;
+}
+
+/**
+ * simple_offset_rename_exchange - exchange rename with directory offsets
+ * @old_dir: parent of dentry being moved
+ * @old_dentry: dentry being moved
+ * @new_dir: destination parent
+ * @new_dentry: destination dentry
+ *
+ * Returns zero on success. Otherwise a negative errno is returned and the
+ * rename is rolled back.
+ */
+int simple_offset_rename_exchange(struct inode *old_dir,
+ struct dentry *old_dentry,
+ struct inode *new_dir,
+ struct dentry *new_dentry)
+{
+ struct offset_ctx *old_ctx = old_dir->i_op->get_offset_ctx(old_dir);
+ struct offset_ctx *new_ctx = new_dir->i_op->get_offset_ctx(new_dir);
+ long old_index = dentry2offset(old_dentry);
+ long new_index = dentry2offset(new_dentry);
+ int ret;
+
+ simple_offset_remove(old_ctx, old_dentry);
+ simple_offset_remove(new_ctx, new_dentry);
+
+ ret = simple_offset_add(new_ctx, old_dentry);
+ if (ret)
+ goto out_restore;
+
+ ret = simple_offset_add(old_ctx, new_dentry);
+ if (ret) {
+ simple_offset_remove(new_ctx, old_dentry);
+ goto out_restore;
+ }
+
+ ret = simple_rename_exchange(old_dir, old_dentry, new_dir, new_dentry);
+ if (ret) {
+ simple_offset_remove(new_ctx, old_dentry);
+ simple_offset_remove(old_ctx, new_dentry);
+ goto out_restore;
+ }
+ return 0;
+
+out_restore:
+ offset_set(old_dentry, old_index);
+ mtree_store(&old_ctx->mt, old_index, old_dentry, GFP_KERNEL);
+ offset_set(new_dentry, new_index);
+ mtree_store(&new_ctx->mt, new_index, new_dentry, GFP_KERNEL);
+ return ret;
+}
+
+/**
+ * simple_offset_destroy - Release offset map
+ * @octx: directory offset ctx that is about to be destroyed
+ *
+ * During fs teardown (eg. umount), a directory's offset map might still
+ * contain entries. xa_destroy() cleans out anything that remains.
+ */
+void simple_offset_destroy(struct offset_ctx *octx)
+{
+ mtree_destroy(&octx->mt);
+}
+
+/**
+ * offset_dir_llseek - Advance the read position of a directory descriptor
+ * @file: an open directory whose position is to be updated
+ * @offset: a byte offset
+ * @whence: enumerator describing the starting position for this update
+ *
+ * SEEK_END, SEEK_DATA, and SEEK_HOLE are not supported for directories.
+ *
+ * Returns the updated read position if successful; otherwise a
+ * negative errno is returned and the read position remains unchanged.
+ */
+static loff_t offset_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+ switch (whence) {
+ case SEEK_CUR:
+ offset += file->f_pos;
+ fallthrough;
+ case SEEK_SET:
+ if (offset >= 0)
+ break;
+ fallthrough;
+ default:
+ return -EINVAL;
+ }
+
+ /* In this case, ->private_data is protected by f_pos_lock */
+ file->private_data = NULL;
+ return vfs_setpos(file, offset, LONG_MAX);
+}
+
+static struct dentry *offset_find_next(struct offset_ctx *octx, loff_t offset)
+{
+ MA_STATE(mas, &octx->mt, offset, offset);
+ struct dentry *child, *found = NULL;
+
+ rcu_read_lock();
+ child = mas_find(&mas, LONG_MAX);
+ if (!child)
+ goto out;
+ spin_lock(&child->d_lock);
+ if (simple_positive(child))
+ found = dget_dlock(child);
+ spin_unlock(&child->d_lock);
+out:
+ rcu_read_unlock();
+ return found;
+}
+
+static bool offset_dir_emit(struct dir_context *ctx, struct dentry *dentry)
+{
+ struct inode *inode = d_inode(dentry);
+ long offset = dentry2offset(dentry);
+
+ return ctx->actor(ctx, dentry->d_name.name, dentry->d_name.len, offset,
+ inode->i_ino, fs_umode_to_dtype(inode->i_mode));
+}
+
+static void *offset_iterate_dir(struct inode *inode, struct dir_context *ctx)
+{
+ struct offset_ctx *octx = inode->i_op->get_offset_ctx(inode);
+ struct dentry *dentry;
+
+ while (true) {
+ dentry = offset_find_next(octx, ctx->pos);
+ if (!dentry)
+ return ERR_PTR(-ENOENT);
+
+ if (!offset_dir_emit(ctx, dentry)) {
+ dput(dentry);
+ break;
+ }
+
+ ctx->pos = dentry2offset(dentry) + 1;
+ dput(dentry);
+ }
+ return NULL;
+}
+
+/**
+ * offset_readdir - Emit entries starting at offset @ctx->pos
+ * @file: an open directory to iterate over
+ * @ctx: directory iteration context
+ *
+ * Caller must hold @file's i_rwsem to prevent insertion or removal of
+ * entries during this call.
+ *
+ * On entry, @ctx->pos contains an offset that represents the first entry
+ * to be read from the directory.
+ *
+ * The operation continues until there are no more entries to read, or
+ * until the ctx->actor indicates there is no more space in the caller's
+ * output buffer.
+ *
+ * On return, @ctx->pos contains an offset that will read the next entry
+ * in this directory when offset_readdir() is called again with @ctx.
+ *
+ * Return values:
+ * %0 - Complete
+ */
+static int offset_readdir(struct file *file, struct dir_context *ctx)
+{
+ struct dentry *dir = file->f_path.dentry;
+
+ lockdep_assert_held(&d_inode(dir)->i_rwsem);
+
+ if (!dir_emit_dots(file, ctx))
+ return 0;
+
+ /* In this case, ->private_data is protected by f_pos_lock */
+ if (ctx->pos == DIR_OFFSET_MIN)
+ file->private_data = NULL;
+ else if (file->private_data == ERR_PTR(-ENOENT))
+ return 0;
+ file->private_data = offset_iterate_dir(d_inode(dir), ctx);
+ return 0;
+}
+
+const struct file_operations simple_offset_dir_operations = {
+ .llseek = offset_dir_llseek,
+ .iterate_shared = offset_readdir,
+ .read = generic_read_dir,
+ .fsync = noop_fsync,
+};
+
static struct dentry *find_next_child(struct dentry *parent, struct dentry *prev)
{
- struct dentry *child = NULL;
- struct list_head *p = prev ? &prev->d_child : &parent->d_subdirs;
+ struct dentry *child = NULL, *d;
spin_lock(&parent->d_lock);
- while ((p = p->next) != &parent->d_subdirs) {
- struct dentry *d = container_of(p, struct dentry, d_child);
+ d = prev ? d_next_sibling(prev) : d_first_child(parent);
+ hlist_for_each_entry_from(d, d_sib) {
if (simple_positive(d)) {
spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
if (simple_positive(d))
while ((child = find_next_child(this, victim)) == NULL) {
// kill and ascend
// update metadata while it's still locked
- inode->i_ctime = current_time(inode);
+ inode_set_ctime_current(inode);
clear_nlink(inode);
inode_unlock(inode);
victim = this;
dput(victim); // unpin it
}
if (victim == dentry) {
- inode->i_ctime = inode->i_mtime =
- current_time(inode);
+ inode_set_mtime_to_ts(inode,
+ inode_set_ctime_current(inode));
if (d_is_dir(dentry))
drop_nlink(inode);
inode_unlock(inode);
*/
root->i_ino = 1;
root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR;
- root->i_atime = root->i_mtime = root->i_ctime = current_time(root);
+ simple_inode_init_ts(root);
s->s_root = d_make_root(root);
if (!s->s_root)
return -ENOMEM;
{
struct inode *inode = d_inode(old_dentry);
- inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
+ inode_set_mtime_to_ts(dir,
+ inode_set_ctime_to_ts(dir, inode_set_ctime_current(inode)));
inc_nlink(inode);
ihold(inode);
dget(dentry);
int ret = 0;
spin_lock(&dentry->d_lock);
- list_for_each_entry(child, &dentry->d_subdirs, d_child) {
+ hlist_for_each_entry(child, &dentry->d_children, d_sib) {
spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
if (simple_positive(child)) {
spin_unlock(&child->d_lock);
{
struct inode *inode = d_inode(dentry);
- inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
+ inode_set_mtime_to_ts(dir,
+ inode_set_ctime_to_ts(dir, inode_set_ctime_current(inode)));
drop_nlink(inode);
dput(dentry);
return 0;
}
EXPORT_SYMBOL(simple_rmdir);
+/**
+ * simple_rename_timestamp - update the various inode timestamps for rename
+ * @old_dir: old parent directory
+ * @old_dentry: dentry that is being renamed
+ * @new_dir: new parent directory
+ * @new_dentry: target for rename
+ *
+ * POSIX mandates that the old and new parent directories have their ctime and
+ * mtime updated, and that inodes of @old_dentry and @new_dentry (if any), have
+ * their ctime updated.
+ */
+void simple_rename_timestamp(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct inode *newino = d_inode(new_dentry);
+
+ inode_set_mtime_to_ts(old_dir, inode_set_ctime_current(old_dir));
+ if (new_dir != old_dir)
+ inode_set_mtime_to_ts(new_dir,
+ inode_set_ctime_current(new_dir));
+ inode_set_ctime_current(d_inode(old_dentry));
+ if (newino)
+ inode_set_ctime_current(newino);
+}
+EXPORT_SYMBOL_GPL(simple_rename_timestamp);
+
int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
inc_nlink(old_dir);
}
}
- old_dir->i_ctime = old_dir->i_mtime =
- new_dir->i_ctime = new_dir->i_mtime =
- d_inode(old_dentry)->i_ctime =
- d_inode(new_dentry)->i_ctime = current_time(old_dir);
-
+ simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
return 0;
}
EXPORT_SYMBOL_GPL(simple_rename_exchange);
-int simple_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+int simple_rename(struct mnt_idmap *idmap, struct inode *old_dir,
struct dentry *old_dentry, struct inode *new_dir,
struct dentry *new_dentry, unsigned int flags)
{
- struct inode *inode = d_inode(old_dentry);
int they_are_dirs = d_is_dir(old_dentry);
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
inc_nlink(new_dir);
}
- old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime =
- new_dir->i_mtime = inode->i_ctime = current_time(old_dir);
-
+ simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
return 0;
}
EXPORT_SYMBOL(simple_rename);
/**
* simple_setattr - setattr for simple filesystem
- * @mnt_userns: user namespace of the target mount
+ * @idmap: idmap of the target mount
* @dentry: dentry
* @iattr: iattr structure
*
* on simple regular filesystems. Anything that needs to change on-disk
* or wire state on size changes needs its own setattr method.
*/
-int simple_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int simple_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
struct iattr *iattr)
{
struct inode *inode = d_inode(dentry);
int error;
- error = setattr_prepare(mnt_userns, dentry, iattr);
+ error = setattr_prepare(idmap, dentry, iattr);
if (error)
return error;
if (iattr->ia_valid & ATTR_SIZE)
truncate_setsize(inode, iattr->ia_size);
- setattr_copy(mnt_userns, inode, iattr);
+ setattr_copy(idmap, inode, iattr);
mark_inode_dirty(inode);
return 0;
}
loff_t pos, unsigned len,
struct page **pagep, void **fsdata)
{
- struct page *page;
- pgoff_t index;
+ struct folio *folio;
- index = pos >> PAGE_SHIFT;
+ folio = __filemap_get_folio(mapping, pos / PAGE_SIZE, FGP_WRITEBEGIN,
+ mapping_gfp_mask(mapping));
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);
- page = grab_cache_page_write_begin(mapping, index);
- if (!page)
- return -ENOMEM;
+ *pagep = &folio->page;
- *pagep = page;
+ if (!folio_test_uptodate(folio) && (len != folio_size(folio))) {
+ size_t from = offset_in_folio(folio, pos);
- if (!PageUptodate(page) && (len != PAGE_SIZE)) {
- unsigned from = pos & (PAGE_SIZE - 1);
-
- zero_user_segments(page, 0, from, from + len, PAGE_SIZE);
+ folio_zero_segments(folio, 0, from,
+ from + len, folio_size(folio));
}
return 0;
}
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
- struct inode *inode = page->mapping->host;
+ struct folio *folio = page_folio(page);
+ struct inode *inode = folio->mapping->host;
loff_t last_pos = pos + copied;
- /* zero the stale part of the page if we did a short copy */
- if (!PageUptodate(page)) {
+ /* zero the stale part of the folio if we did a short copy */
+ if (!folio_test_uptodate(folio)) {
if (copied < len) {
- unsigned from = pos & (PAGE_SIZE - 1);
+ size_t from = offset_in_folio(folio, pos);
- zero_user(page, from + copied, len - copied);
+ folio_zero_range(folio, from + copied, len - copied);
}
- SetPageUptodate(page);
+ folio_mark_uptodate(folio);
}
/*
* No need to use i_size_read() here, the i_size
if (last_pos > inode->i_size)
i_size_write(inode, last_pos);
- set_page_dirty(page);
- unlock_page(page);
- put_page(page);
+ folio_mark_dirty(folio);
+ folio_unlock(folio);
+ folio_put(folio);
return copied;
}
const struct tree_descr *files)
{
struct inode *inode;
- struct dentry *root;
struct dentry *dentry;
int i;
*/
inode->i_ino = 1;
inode->i_mode = S_IFDIR | 0755;
- inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+ simple_inode_init_ts(inode);
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
set_nlink(inode, 2);
- root = d_make_root(inode);
- if (!root)
+ s->s_root = d_make_root(inode);
+ if (!s->s_root)
return -ENOMEM;
for (i = 0; !files->name || files->name[0]; i++, files++) {
if (!files->name)
"with an index of 1!\n", __func__,
s->s_type->name);
- dentry = d_alloc_name(root, files->name);
+ dentry = d_alloc_name(s->s_root, files->name);
if (!dentry)
- goto out;
+ return -ENOMEM;
inode = new_inode(s);
if (!inode) {
dput(dentry);
- goto out;
+ return -ENOMEM;
}
inode->i_mode = S_IFREG | files->mode;
- inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+ simple_inode_init_ts(inode);
inode->i_fop = files->ops;
inode->i_ino = i;
d_add(dentry, inode);
}
- s->s_root = root;
return 0;
-out:
- d_genocide(root);
- shrink_dcache_parent(root);
- dput(root);
- return -ENOMEM;
}
EXPORT_SYMBOL(simple_fill_super);
EXPORT_SYMBOL_GPL(simple_attr_read);
/* interpret the buffer as a number to call the set function with */
-ssize_t simple_attr_write(struct file *file, const char __user *buf,
- size_t len, loff_t *ppos)
+static ssize_t simple_attr_write_xsigned(struct file *file, const char __user *buf,
+ size_t len, loff_t *ppos, bool is_signed)
{
struct simple_attr *attr;
unsigned long long val;
goto out;
attr->set_buf[size] = '\0';
- ret = kstrtoull(attr->set_buf, 0, &val);
+ if (is_signed)
+ ret = kstrtoll(attr->set_buf, 0, &val);
+ else
+ ret = kstrtoull(attr->set_buf, 0, &val);
if (ret)
goto out;
ret = attr->set(attr->data, val);
mutex_unlock(&attr->mutex);
return ret;
}
+
+ssize_t simple_attr_write(struct file *file, const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ return simple_attr_write_xsigned(file, buf, len, ppos, false);
+}
EXPORT_SYMBOL_GPL(simple_attr_write);
+ssize_t simple_attr_write_signed(struct file *file, const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ return simple_attr_write_xsigned(file, buf, len, ppos, true);
+}
+EXPORT_SYMBOL_GPL(simple_attr_write_signed);
+
+/**
+ * generic_encode_ino32_fh - generic export_operations->encode_fh function
+ * @inode: the object to encode
+ * @fh: where to store the file handle fragment
+ * @max_len: maximum length to store there (in 4 byte units)
+ * @parent: parent directory inode, if wanted
+ *
+ * This generic encode_fh function assumes that the 32 inode number
+ * is suitable for locating an inode, and that the generation number
+ * can be used to check that it is still valid. It places them in the
+ * filehandle fragment where export_decode_fh expects to find them.
+ */
+int generic_encode_ino32_fh(struct inode *inode, __u32 *fh, int *max_len,
+ struct inode *parent)
+{
+ struct fid *fid = (void *)fh;
+ int len = *max_len;
+ int type = FILEID_INO32_GEN;
+
+ if (parent && (len < 4)) {
+ *max_len = 4;
+ return FILEID_INVALID;
+ } else if (len < 2) {
+ *max_len = 2;
+ return FILEID_INVALID;
+ }
+
+ len = 2;
+ fid->i32.ino = inode->i_ino;
+ fid->i32.gen = inode->i_generation;
+ if (parent) {
+ fid->i32.parent_ino = parent->i_ino;
+ fid->i32.parent_gen = parent->i_generation;
+ len = 4;
+ type = FILEID_INO32_GEN_PARENT;
+ }
+ *max_len = len;
+ return type;
+}
+EXPORT_SYMBOL_GPL(generic_encode_ino32_fh);
+
/**
* generic_fh_to_dentry - generic helper for the fh_to_dentry export operation
* @sb: filesystem to do the file handle conversion on
inode->i_uid = current_fsuid();
inode->i_gid = current_fsgid();
inode->i_flags |= S_PRIVATE;
- inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+ simple_inode_init_ts(inode);
return inode;
}
EXPORT_SYMBOL(alloc_anon_inode);
* All arguments are ignored and it just returns -EINVAL.
*/
int
-simple_nosetlease(struct file *filp, long arg, struct file_lock **flp,
+simple_nosetlease(struct file *filp, int arg, struct file_lease **flp,
void **priv)
{
return -EINVAL;
return ERR_PTR(-ENOENT);
}
-static int empty_dir_getattr(struct user_namespace *mnt_userns,
+static int empty_dir_getattr(struct mnt_idmap *idmap,
const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int query_flags)
{
struct inode *inode = d_inode(path->dentry);
- generic_fillattr(&init_user_ns, inode, stat);
+ generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
return 0;
}
-static int empty_dir_setattr(struct user_namespace *mnt_userns,
+static int empty_dir_setattr(struct mnt_idmap *idmap,
struct dentry *dentry, struct iattr *attr)
{
return -EPERM;
}
#if IS_ENABLED(CONFIG_UNICODE)
-/*
- * Determine if the name of a dentry should be casefolded.
- *
- * Return: if names will need casefolding
- */
-static bool needs_casefold(const struct inode *dir)
-{
- return IS_CASEFOLDED(dir) && dir->i_sb->s_encoding;
-}
-
/**
* generic_ci_d_compare - generic d_compare implementation for casefolding filesystems
* @dentry: dentry whose name we are checking against
static int generic_ci_d_compare(const struct dentry *dentry, unsigned int len,
const char *str, const struct qstr *name)
{
- const struct dentry *parent = READ_ONCE(dentry->d_parent);
- const struct inode *dir = READ_ONCE(parent->d_inode);
- const struct super_block *sb = dentry->d_sb;
- const struct unicode_map *um = sb->s_encoding;
- struct qstr qstr = QSTR_INIT(str, len);
+ const struct dentry *parent;
+ const struct inode *dir;
char strbuf[DNAME_INLINE_LEN];
- int ret;
+ struct qstr qstr;
+
+ /*
+ * Attempt a case-sensitive match first. It is cheaper and
+ * should cover most lookups, including all the sane
+ * applications that expect a case-sensitive filesystem.
+ *
+ * This comparison is safe under RCU because the caller
+ * guarantees the consistency between str and len. See
+ * __d_lookup_rcu_op_compare() for details.
+ */
+ if (len == name->len && !memcmp(str, name->name, len))
+ return 0;
+
+ parent = READ_ONCE(dentry->d_parent);
+ dir = READ_ONCE(parent->d_inode);
+ if (!dir || !IS_CASEFOLDED(dir))
+ return 1;
- if (!dir || !needs_casefold(dir))
- goto fallback;
/*
* If the dentry name is stored in-line, then it may be concurrently
* modified by a rename. If this happens, the VFS will eventually retry
if (len <= DNAME_INLINE_LEN - 1) {
memcpy(strbuf, str, len);
strbuf[len] = 0;
- qstr.name = strbuf;
+ str = strbuf;
/* prevent compiler from optimizing out the temporary buffer */
barrier();
}
- ret = utf8_strncasecmp(um, name, &qstr);
- if (ret >= 0)
- return ret;
+ qstr.len = len;
+ qstr.name = str;
- if (sb_has_strict_encoding(sb))
- return -EINVAL;
-fallback:
- if (len != name->len)
- return 1;
- return !!memcmp(str, name->name, len);
+ return utf8_strncasecmp(dentry->d_sb->s_encoding, name, &qstr);
}
/**
const struct inode *dir = READ_ONCE(dentry->d_inode);
struct super_block *sb = dentry->d_sb;
const struct unicode_map *um = sb->s_encoding;
- int ret = 0;
+ int ret;
- if (!dir || !needs_casefold(dir))
+ if (!dir || !IS_CASEFOLDED(dir))
return 0;
ret = utf8_casefold_hash(um, dentry, str);
static const struct dentry_operations generic_ci_dentry_ops = {
.d_hash = generic_ci_d_hash,
.d_compare = generic_ci_d_compare,
-};
-#endif
-
#ifdef CONFIG_FS_ENCRYPTION
-static const struct dentry_operations generic_encrypted_dentry_ops = {
.d_revalidate = fscrypt_d_revalidate,
+#endif
};
#endif
-#if defined(CONFIG_FS_ENCRYPTION) && IS_ENABLED(CONFIG_UNICODE)
-static const struct dentry_operations generic_encrypted_ci_dentry_ops = {
- .d_hash = generic_ci_d_hash,
- .d_compare = generic_ci_d_compare,
+#ifdef CONFIG_FS_ENCRYPTION
+static const struct dentry_operations generic_encrypted_dentry_ops = {
.d_revalidate = fscrypt_d_revalidate,
};
#endif
/**
- * generic_set_encrypted_ci_d_ops - helper for setting d_ops for given dentry
- * @dentry: dentry to set ops on
- *
- * Casefolded directories need d_hash and d_compare set, so that the dentries
- * contained in them are handled case-insensitively. Note that these operations
- * are needed on the parent directory rather than on the dentries in it, and
- * while the casefolding flag can be toggled on and off on an empty directory,
- * dentry_operations can't be changed later. As a result, if the filesystem has
- * casefolding support enabled at all, we have to give all dentries the
- * casefolding operations even if their inode doesn't have the casefolding flag
- * currently (and thus the casefolding ops would be no-ops for now).
+ * generic_set_sb_d_ops - helper for choosing the set of
+ * filesystem-wide dentry operations for the enabled features
+ * @sb: superblock to be configured
*
- * Encryption works differently in that the only dentry operation it needs is
- * d_revalidate, which it only needs on dentries that have the no-key name flag.
- * The no-key flag can't be set "later", so we don't have to worry about that.
- *
- * Finally, to maximize compatibility with overlayfs (which isn't compatible
- * with certain dentry operations) and to avoid taking an unnecessary
- * performance hit, we use custom dentry_operations for each possible
- * combination rather than always installing all operations.
+ * Filesystems supporting casefolding and/or fscrypt can call this
+ * helper at mount-time to configure sb->s_d_op to best set of dentry
+ * operations required for the enabled features. The helper must be
+ * called after these have been configured, but before the root dentry
+ * is created.
*/
-void generic_set_encrypted_ci_d_ops(struct dentry *dentry)
+void generic_set_sb_d_ops(struct super_block *sb)
{
-#ifdef CONFIG_FS_ENCRYPTION
- bool needs_encrypt_ops = dentry->d_flags & DCACHE_NOKEY_NAME;
-#endif
#if IS_ENABLED(CONFIG_UNICODE)
- bool needs_ci_ops = dentry->d_sb->s_encoding;
-#endif
-#if defined(CONFIG_FS_ENCRYPTION) && IS_ENABLED(CONFIG_UNICODE)
- if (needs_encrypt_ops && needs_ci_ops) {
- d_set_d_op(dentry, &generic_encrypted_ci_dentry_ops);
+ if (sb->s_encoding) {
+ sb->s_d_op = &generic_ci_dentry_ops;
return;
}
#endif
#ifdef CONFIG_FS_ENCRYPTION
- if (needs_encrypt_ops) {
- d_set_d_op(dentry, &generic_encrypted_dentry_ops);
+ if (sb->s_cop) {
+ sb->s_d_op = &generic_encrypted_dentry_ops;
return;
}
#endif
-#if IS_ENABLED(CONFIG_UNICODE)
- if (needs_ci_ops) {
- d_set_d_op(dentry, &generic_ci_dentry_ops);
- return;
+}
+EXPORT_SYMBOL(generic_set_sb_d_ops);
+
+/**
+ * inode_maybe_inc_iversion - increments i_version
+ * @inode: inode with the i_version that should be updated
+ * @force: increment the counter even if it's not necessary?
+ *
+ * Every time the inode is modified, the i_version field must be seen to have
+ * changed by any observer.
+ *
+ * If "force" is set or the QUERIED flag is set, then ensure that we increment
+ * the value, and clear the queried flag.
+ *
+ * In the common case where neither is set, then we can return "false" without
+ * updating i_version.
+ *
+ * If this function returns false, and no other metadata has changed, then we
+ * can avoid logging the metadata.
+ */
+bool inode_maybe_inc_iversion(struct inode *inode, bool force)
+{
+ u64 cur, new;
+
+ /*
+ * The i_version field is not strictly ordered with any other inode
+ * information, but the legacy inode_inc_iversion code used a spinlock
+ * to serialize increments.
+ *
+ * Here, we add full memory barriers to ensure that any de-facto
+ * ordering with other info is preserved.
+ *
+ * This barrier pairs with the barrier in inode_query_iversion()
+ */
+ smp_mb();
+ cur = inode_peek_iversion_raw(inode);
+ do {
+ /* If flag is clear then we needn't do anything */
+ if (!force && !(cur & I_VERSION_QUERIED))
+ return false;
+
+ /* Since lowest bit is flag, add 2 to avoid it */
+ new = (cur & ~I_VERSION_QUERIED) + I_VERSION_INCREMENT;
+ } while (!atomic64_try_cmpxchg(&inode->i_version, &cur, new));
+ return true;
+}
+EXPORT_SYMBOL(inode_maybe_inc_iversion);
+
+/**
+ * inode_query_iversion - read i_version for later use
+ * @inode: inode from which i_version should be read
+ *
+ * Read the inode i_version counter. This should be used by callers that wish
+ * to store the returned i_version for later comparison. This will guarantee
+ * that a later query of the i_version will result in a different value if
+ * anything has changed.
+ *
+ * In this implementation, we fetch the current value, set the QUERIED flag and
+ * then try to swap it into place with a cmpxchg, if it wasn't already set. If
+ * that fails, we try again with the newly fetched value from the cmpxchg.
+ */
+u64 inode_query_iversion(struct inode *inode)
+{
+ u64 cur, new;
+
+ cur = inode_peek_iversion_raw(inode);
+ do {
+ /* If flag is already set, then no need to swap */
+ if (cur & I_VERSION_QUERIED) {
+ /*
+ * This barrier (and the implicit barrier in the
+ * cmpxchg below) pairs with the barrier in
+ * inode_maybe_inc_iversion().
+ */
+ smp_mb();
+ break;
+ }
+
+ new = cur | I_VERSION_QUERIED;
+ } while (!atomic64_try_cmpxchg(&inode->i_version, &cur, new));
+ return cur >> I_VERSION_QUERIED_SHIFT;
+}
+EXPORT_SYMBOL(inode_query_iversion);
+
+ssize_t direct_write_fallback(struct kiocb *iocb, struct iov_iter *iter,
+ ssize_t direct_written, ssize_t buffered_written)
+{
+ struct address_space *mapping = iocb->ki_filp->f_mapping;
+ loff_t pos = iocb->ki_pos - buffered_written;
+ loff_t end = iocb->ki_pos - 1;
+ int err;
+
+ /*
+ * If the buffered write fallback returned an error, we want to return
+ * the number of bytes which were written by direct I/O, or the error
+ * code if that was zero.
+ *
+ * Note that this differs from normal direct-io semantics, which will
+ * return -EFOO even if some bytes were written.
+ */
+ if (unlikely(buffered_written < 0)) {
+ if (direct_written)
+ return direct_written;
+ return buffered_written;
}
-#endif
+
+ /*
+ * We need to ensure that the page cache pages are written to disk and
+ * invalidated to preserve the expected O_DIRECT semantics.
+ */
+ err = filemap_write_and_wait_range(mapping, pos, end);
+ if (err < 0) {
+ /*
+ * We don't know how much we wrote, so just return the number of
+ * bytes which were direct-written
+ */
+ iocb->ki_pos -= buffered_written;
+ if (direct_written)
+ return direct_written;
+ return err;
+ }
+ invalidate_mapping_pages(mapping, pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
+ return direct_written + buffered_written;
+}
+EXPORT_SYMBOL_GPL(direct_write_fallback);
+
+/**
+ * simple_inode_init_ts - initialize the timestamps for a new inode
+ * @inode: inode to be initialized
+ *
+ * When a new inode is created, most filesystems set the timestamps to the
+ * current time. Add a helper to do this.
+ */
+struct timespec64 simple_inode_init_ts(struct inode *inode)
+{
+ struct timespec64 ts = inode_set_ctime_current(inode);
+
+ inode_set_atime_to_ts(inode, ts);
+ inode_set_mtime_to_ts(inode, ts);
+ return ts;
+}
+EXPORT_SYMBOL(simple_inode_init_ts);
+
+static inline struct dentry *get_stashed_dentry(struct dentry *stashed)
+{
+ struct dentry *dentry;
+
+ guard(rcu)();
+ dentry = READ_ONCE(stashed);
+ if (!dentry)
+ return NULL;
+ if (!lockref_get_not_dead(&dentry->d_lockref))
+ return NULL;
+ return dentry;
+}
+
+static struct dentry *prepare_anon_dentry(struct dentry **stashed,
+ struct super_block *sb,
+ void *data)
+{
+ struct dentry *dentry;
+ struct inode *inode;
+ const struct stashed_operations *sops = sb->s_fs_info;
+ int ret;
+
+ inode = new_inode_pseudo(sb);
+ if (!inode) {
+ sops->put_data(data);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ inode->i_flags |= S_IMMUTABLE;
+ inode->i_mode = S_IFREG;
+ simple_inode_init_ts(inode);
+
+ ret = sops->init_inode(inode, data);
+ if (ret < 0) {
+ iput(inode);
+ return ERR_PTR(ret);
+ }
+
+ /* Notice when this is changed. */
+ WARN_ON_ONCE(!S_ISREG(inode->i_mode));
+ WARN_ON_ONCE(!IS_IMMUTABLE(inode));
+
+ dentry = d_alloc_anon(sb);
+ if (!dentry) {
+ iput(inode);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ /* Store address of location where dentry's supposed to be stashed. */
+ dentry->d_fsdata = stashed;
+
+ /* @data is now owned by the fs */
+ d_instantiate(dentry, inode);
+ return dentry;
+}
+
+static struct dentry *stash_dentry(struct dentry **stashed,
+ struct dentry *dentry)
+{
+ guard(rcu)();
+ for (;;) {
+ struct dentry *old;
+
+ /* Assume any old dentry was cleared out. */
+ old = cmpxchg(stashed, NULL, dentry);
+ if (likely(!old))
+ return dentry;
+
+ /* Check if somebody else installed a reusable dentry. */
+ if (lockref_get_not_dead(&old->d_lockref))
+ return old;
+
+ /* There's an old dead dentry there, try to take it over. */
+ if (likely(try_cmpxchg(stashed, &old, dentry)))
+ return dentry;
+ }
+}
+
+/**
+ * path_from_stashed - create path from stashed or new dentry
+ * @stashed: where to retrieve or stash dentry
+ * @mnt: mnt of the filesystems to use
+ * @data: data to store in inode->i_private
+ * @path: path to create
+ *
+ * The function tries to retrieve a stashed dentry from @stashed. If the dentry
+ * is still valid then it will be reused. If the dentry isn't able the function
+ * will allocate a new dentry and inode. It will then check again whether it
+ * can reuse an existing dentry in case one has been added in the meantime or
+ * update @stashed with the newly added dentry.
+ *
+ * Special-purpose helper for nsfs and pidfs.
+ *
+ * Return: On success zero and on failure a negative error is returned.
+ */
+int path_from_stashed(struct dentry **stashed, struct vfsmount *mnt, void *data,
+ struct path *path)
+{
+ struct dentry *dentry;
+ const struct stashed_operations *sops = mnt->mnt_sb->s_fs_info;
+
+ /* See if dentry can be reused. */
+ path->dentry = get_stashed_dentry(*stashed);
+ if (path->dentry) {
+ sops->put_data(data);
+ goto out_path;
+ }
+
+ /* Allocate a new dentry. */
+ dentry = prepare_anon_dentry(stashed, mnt->mnt_sb, data);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+
+ /* Added a new dentry. @data is now owned by the filesystem. */
+ path->dentry = stash_dentry(stashed, dentry);
+ if (path->dentry != dentry)
+ dput(dentry);
+
+out_path:
+ WARN_ON_ONCE(path->dentry->d_fsdata != stashed);
+ WARN_ON_ONCE(d_inode(path->dentry)->i_private != data);
+ path->mnt = mntget(mnt);
+ return 0;
+}
+
+void stashed_dentry_prune(struct dentry *dentry)
+{
+ struct dentry **stashed = dentry->d_fsdata;
+ struct inode *inode = d_inode(dentry);
+
+ if (WARN_ON_ONCE(!stashed))
+ return;
+
+ if (!inode)
+ return;
+
+ /*
+ * Only replace our own @dentry as someone else might've
+ * already cleared out @dentry and stashed their own
+ * dentry in there.
+ */
+ cmpxchg(stashed, dentry, NULL);
}
-EXPORT_SYMBOL(generic_set_encrypted_ci_d_ops);
projects / linux-2.6-microblaze.git / blobdiff