[PATCH 13/19] fs: ramfs: Switch to dcache implementation
Sascha Hauer
s.hauer at pengutronix.de
Tue Apr 3 00:48:45 PDT 2018
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
fs/Kconfig | 1 -
fs/ramfs.c | 412 +++++++++++++++----------------------------------------------
2 files changed, 101 insertions(+), 312 deletions(-)
diff --git a/fs/Kconfig b/fs/Kconfig
index c3a78eaae5..9638e27dbd 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -20,7 +20,6 @@ source fs/ext4/Kconfig
config FS_RAMFS
bool
default y
- depends on BROKEN
prompt "ramfs support"
config FS_DEVFS
diff --git a/fs/ramfs.c b/fs/ramfs.c
index a97f0a6ebf..d346a4e755 100644
--- a/fs/ramfs.c
+++ b/fs/ramfs.c
@@ -35,6 +35,7 @@ struct ramfs_chunk {
};
struct ramfs_inode {
+ struct inode inode;
char *name;
struct ramfs_inode *parent;
struct ramfs_inode *next;
@@ -52,84 +53,52 @@ struct ramfs_inode {
struct ramfs_chunk *recent_chunkp;
};
+static inline struct ramfs_inode *to_ramfs_inode(struct inode *inode)
+{
+ return container_of(inode, struct ramfs_inode, inode);
+}
+
struct ramfs_priv {
struct ramfs_inode root;
};
/* ---------------------------------------------------------------*/
-static struct ramfs_inode * lookup(struct ramfs_inode *node, const char *name)
-{
- debug("lookup: %s in %p\n",name, node);
- if(!S_ISDIR(node->mode))
- return NULL;
- node = node->child;
- if (!node)
- return NULL;
+static const struct super_operations ramfs_ops;
+static const struct inode_operations ramfs_dir_inode_operations;
+static const struct inode_operations ramfs_file_inode_operations;
+static const struct inode_operations ramfs_symlink_inode_operations;
+static const struct file_operations ramfs_file_operations;
- while (node) {
- debug("lookup: %s\n", node->name);
- if (!strcmp(node->name, name)) {
- debug("lookup: found: 0x%p\n",node);
- return node;
- }
- node = node->next;
- }
- return NULL;
-}
-
-static struct ramfs_inode* rlookup(struct ramfs_priv *priv, const char *path)
+static struct inode *ramfs_get_inode(struct super_block *sb, const struct inode *dir,
+ umode_t mode)
{
- struct ramfs_inode *node = &priv->root;
- static char *buf;
- char *part;
-
- debug("rlookup %s in %p\n",path, node);
- buf = strdup(path);
-
- part = strtok(buf, "/");
- if (!part)
- goto out;
-
- do {
- node = lookup(node, part);
- if (!node)
- goto out;
- part = strtok(NULL, "/");
- } while(part);
-
-out:
- free(buf);
- return node;
-}
+ struct inode *inode = new_inode(sb);
-static struct ramfs_inode* rlookup_parent(struct ramfs_priv *priv, const char *pathname, char **file)
-{
- char *path;
- struct ramfs_inode *node;
-
- pathname++;
- path = strdup(pathname);
+ if (!inode)
+ return NULL;
- if ((*file = strrchr((char *) pathname, '/'))) {
- char *tmp;
- (*file)++;
+ inode->i_ino = get_next_ino();
+ inode->i_mode = mode;
- tmp = strrchr(path, '/');
- *tmp = 0;
- node = rlookup(priv, path);
- if (!node) {
- errno = -ENOENT;
- goto out;
- }
- } else {
- *file = (char *)pathname;
- node = &priv->root;
+ switch (mode & S_IFMT) {
+ default:
+ return NULL;
+ case S_IFREG:
+ inode->i_op = &ramfs_file_inode_operations;
+ inode->i_fop = &ramfs_file_operations;
+ break;
+ case S_IFDIR:
+ inode->i_op = &ramfs_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ inc_nlink(inode);
+ break;
+ case S_IFLNK:
+ inode->i_op = &ramfs_symlink_inode_operations;
+ break;
}
-out:
- free(path);
- return node;
+ return inode;
}
static int chunks = 0;
@@ -158,168 +127,75 @@ static void ramfs_put_chunk(struct ramfs_chunk *data)
chunks--;
}
-static struct ramfs_inode* ramfs_get_inode(void)
-{
- struct ramfs_inode *node = xzalloc(sizeof(struct ramfs_inode));
- return node;
-}
-
-static void ramfs_put_inode(struct ramfs_inode *node)
-{
- struct ramfs_chunk *data = node->data;
-
- while (data) {
- struct ramfs_chunk *tmp = data->next;
- ramfs_put_chunk(data);
- data = tmp;
- }
-
- free(node->symlink);
- free(node->name);
- free(node);
-}
-
-static struct ramfs_inode* node_insert(struct ramfs_inode *parent_node, const char *filename, ulong mode)
-{
- struct ramfs_inode *node, *new_node = ramfs_get_inode();
- new_node->name = strdup(filename);
- new_node->mode = mode;
-
- node = parent_node->child;
-
- if (S_ISDIR(mode)) {
- struct ramfs_inode *n = ramfs_get_inode();
- n->name = strdup(".");
- n->mode = S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO;
- n->child = n;
- n->parent = new_node;
- new_node->child = n;
- n = ramfs_get_inode();
- n->name = strdup("..");
- n->mode = S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO;
- n->parent = new_node;
- n->child = parent_node->child;
- new_node->child->next = n;
- }
-
- while (node->next)
- node = node->next;
-
- node->next = new_node;
- return new_node;
-}
-
/* ---------------------------------------------------------------*/
-static int __ramfs_create(struct device_d *dev, const char *pathname,
- mode_t mode, const char *symlink)
+static int
+ramfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode)
{
- struct ramfs_priv *priv = dev->priv;
- struct ramfs_inode *node;
- char *file;
- char *__symlink = NULL;
-
- node = rlookup_parent(priv, pathname, &file);
- if (!node)
- return -ENOENT;
+ struct inode *inode = ramfs_get_inode(dir->i_sb, dir, mode);
- if (symlink) {
- __symlink = strdup(symlink);
- if (!__symlink)
- return -ENOMEM;
- }
+ if (!inode)
+ return -ENOSPC;
- node = node_insert(node, file, mode);
- if (!node) {
- free(__symlink);
- return -ENOMEM;
+ if (inode) {
+ d_instantiate(dentry, inode);
+ dget(dentry); /* Extra count - pin the dentry in core */
}
- node->symlink = __symlink;
-
return 0;
}
-static int ramfs_create(struct device_d *dev, const char *pathname, mode_t mode)
+static int ramfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
- return __ramfs_create(dev, pathname, mode, NULL);
-}
+ int ret;
-static int ramfs_unlink(struct device_d *dev, const char *pathname)
-{
- struct ramfs_priv *priv = dev->priv;
- struct ramfs_inode *node, *lastnode;
- char *file;
-
- node = rlookup_parent(priv, pathname, &file);
-
- lastnode = node->child->next;
- node = lastnode->next;
-
- while (node) {
- if (!strcmp(node->name, file)) {
- struct ramfs_inode *tmp;
- tmp = node;
- lastnode->next = node->next;
- ramfs_put_inode(tmp);
- return 0;
- }
- lastnode = node;
- node = node->next;
- };
- return -ENOENT;
-}
+ ret = ramfs_mknod(dir, dentry, mode | S_IFDIR);
+ if (!ret)
+ inc_nlink(dir);
-static int ramfs_mkdir(struct device_d *dev, const char *pathname)
-{
- return ramfs_create(dev, pathname, S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO);
+ return ret;
}
-static int ramfs_rmdir(struct device_d *dev, const char *pathname)
+static int ramfs_create(struct inode *dir, struct dentry *dentry, umode_t mode)
{
- struct ramfs_priv *priv = dev->priv;
- struct ramfs_inode *node, *lastnode;
- char *file;
-
- node = rlookup_parent(priv, pathname, &file);
-
- lastnode = node->child->next;
- node = lastnode->next;
-
- while (node) {
- if (!strcmp(node->name, file)) {
- struct ramfs_inode *tmp;
- tmp = node;
- lastnode->next = node->next;
- ramfs_put_inode(tmp->child->next);
- ramfs_put_inode(tmp->child);
- ramfs_put_inode(tmp);
- return 0;
- }
- lastnode = node;
- node = node->next;
- };
- return -ENOENT;
+ return ramfs_mknod(dir, dentry, mode | S_IFREG);
}
-static int ramfs_open(struct device_d *dev, FILE *file, const char *filename)
+static int ramfs_symlink(struct inode *dir, struct dentry *dentry,
+ const char *symname)
{
- struct ramfs_priv *priv = dev->priv;
- struct ramfs_inode *node = rlookup(priv, filename);
+ struct inode *inode;
- if (!node)
- return -ENOENT;
+ inode = ramfs_get_inode(dir->i_sb, dir, S_IFLNK | S_IRWXG);
+ if (!inode)
+ return -ENOSPC;
+
+ inode->i_link = xstrdup(symname);
+ d_instantiate(dentry, inode);
- file->size = node->size;
- file->priv = node;
return 0;
}
-static int ramfs_close(struct device_d *dev, FILE *f)
+static const char *ramfs_get_link(struct dentry *dentry, struct inode *inode)
{
- return 0;
+ return inode->i_link;
}
+static const struct inode_operations ramfs_symlink_inode_operations =
+{
+ .get_link = ramfs_get_link,
+};
+
+static const struct inode_operations ramfs_dir_inode_operations =
+{
+ .lookup = simple_lookup,
+ .symlink = ramfs_symlink,
+ .mkdir = ramfs_mkdir,
+ .rmdir = simple_rmdir,
+ .unlink = simple_unlink,
+ .create = ramfs_create,
+};
+
static struct ramfs_chunk *ramfs_find_chunk(struct ramfs_inode *node, int chunk)
{
struct ramfs_chunk *data;
@@ -351,7 +227,8 @@ static struct ramfs_chunk *ramfs_find_chunk(struct ramfs_inode *node, int chunk)
static int ramfs_read(struct device_d *_dev, FILE *f, void *buf, size_t insize)
{
- struct ramfs_inode *node = f->priv;
+ struct inode *inode = f->f_inode;
+ struct ramfs_inode *node = to_ramfs_inode(inode);
int chunk;
struct ramfs_chunk *data;
int ofs;
@@ -359,12 +236,12 @@ static int ramfs_read(struct device_d *_dev, FILE *f, void *buf, size_t insize)
int pos = f->pos;
int size = insize;
- chunk = f->pos / CHUNK_SIZE;
+ chunk = pos / CHUNK_SIZE;
debug("%s: reading from chunk %d\n", __FUNCTION__, chunk);
/* Position ourself in stream */
data = ramfs_find_chunk(node, chunk);
- ofs = f->pos % CHUNK_SIZE;
+ ofs = pos % CHUNK_SIZE;
/* Read till end of current chunk */
if (ofs) {
@@ -400,7 +277,8 @@ static int ramfs_read(struct device_d *_dev, FILE *f, void *buf, size_t insize)
static int ramfs_write(struct device_d *_dev, FILE *f, const void *buf, size_t insize)
{
- struct ramfs_inode *node = f->priv;
+ struct inode *inode = f->f_inode;
+ struct ramfs_inode *node = to_ramfs_inode(inode);
int chunk;
struct ramfs_chunk *data;
int ofs;
@@ -447,15 +325,10 @@ static int ramfs_write(struct device_d *_dev, FILE *f, const void *buf, size_t i
return insize;
}
-static loff_t ramfs_lseek(struct device_d *dev, FILE *f, loff_t pos)
-{
- f->pos = pos;
- return f->pos;
-}
-
static int ramfs_truncate(struct device_d *dev, FILE *f, ulong size)
{
- struct ramfs_inode *node = f->priv;
+ struct inode *inode = f->f_inode;
+ struct ramfs_inode *node = to_ramfs_inode(inode);
int oldchunks, newchunks;
struct ramfs_chunk *data = node->data;
@@ -502,108 +375,38 @@ static int ramfs_truncate(struct device_d *dev, FILE *f, ulong size)
return 0;
}
-static DIR* ramfs_opendir(struct device_d *dev, const char *pathname)
+static struct inode *ramfs_alloc_inode(struct super_block *sb)
{
- DIR *dir;
- struct ramfs_priv *priv = dev->priv;
struct ramfs_inode *node;
- debug("opendir: %s\n", pathname);
-
- node = rlookup(priv, pathname);
-
+ node = xzalloc(sizeof(*node));
if (!node)
return NULL;
- if (!S_ISDIR(node->mode))
- return NULL;
-
- dir = xmalloc(sizeof(DIR));
-
- dir->priv = node->child;
-
- return dir;
-}
-
-static struct dirent* ramfs_readdir(struct device_d *dev, DIR *dir)
-{
- struct ramfs_inode *node = dir->priv;
-
- if (node) {
- strcpy(dir->d.d_name, node->name);
- dir->priv = node->next;
- return &dir->d;
- }
- return NULL;
-}
-
-static int ramfs_closedir(struct device_d *dev, DIR *dir)
-{
- free(dir);
- return 0;
-}
-
-static int ramfs_stat(struct device_d *dev, const char *filename, struct stat *s)
-{
- struct ramfs_priv *priv = dev->priv;
- struct ramfs_inode *node = rlookup(priv, filename);
-
- if (!node)
- return -ENOENT;
-
- s->st_size = node->symlink ? strlen(node->symlink) : node->size;
- s->st_mode = node->mode;
-
- return 0;
-}
-
-static int ramfs_symlink(struct device_d *dev, const char *pathname,
- const char *newpath)
-{
- mode_t mode = S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
-
- return __ramfs_create(dev, newpath, mode, pathname);
+ return &node->inode;
}
-static int ramfs_readlink(struct device_d *dev, const char *pathname,
- char *buf, size_t bufsiz)
-{
- struct ramfs_priv *priv = dev->priv;
- struct ramfs_inode *node = rlookup(priv, pathname);
- int len;
-
- if (!node || !node->symlink)
- return -ENOENT;
-
- len = min(bufsiz, strlen(node->symlink));
-
- memcpy(buf, node->symlink, len);
-
- return 0;
-}
+static const struct super_operations ramfs_ops = {
+ .alloc_inode = ramfs_alloc_inode,
+};
static int ramfs_probe(struct device_d *dev)
{
- struct ramfs_inode *n;
+ struct inode *inode;
struct ramfs_priv *priv = xzalloc(sizeof(struct ramfs_priv));
+ struct fs_device_d *fsdev = dev_to_fs_device(dev);
+ struct super_block *sb = &fsdev->sb;
dev->priv = priv;
priv->root.name = "/";
priv->root.mode = S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO;
priv->root.parent = &priv->root;
- n = ramfs_get_inode();
- n->name = strdup(".");
- n->mode = S_IFDIR;
- n->parent = &priv->root;
- n->child = n;
- priv->root.child = n;
- n = ramfs_get_inode();
- n->name = strdup("..");
- n->mode = S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO;
- n->parent = &priv->root;
- n->child = priv->root.child;
- priv->root.child->next = n;
+
+ sb->s_op = &ramfs_ops;
+
+ inode = ramfs_get_inode(sb, NULL, S_IFDIR);
+ sb->s_root = d_make_root(inode);
return 0;
}
@@ -614,22 +417,9 @@ static void ramfs_remove(struct device_d *dev)
}
static struct fs_driver_d ramfs_driver = {
- .create = ramfs_create,
- .unlink = ramfs_unlink,
- .open = ramfs_open,
- .close = ramfs_close,
- .truncate = ramfs_truncate,
- .read = ramfs_read,
- .write = ramfs_write,
- .lseek = ramfs_lseek,
- .mkdir = ramfs_mkdir,
- .rmdir = ramfs_rmdir,
- .opendir = ramfs_opendir,
- .readdir = ramfs_readdir,
- .closedir = ramfs_closedir,
- .stat = ramfs_stat,
- .symlink = ramfs_symlink,
- .readlink = ramfs_readlink,
+ .read = ramfs_read,
+ .write = ramfs_write,
+ .truncate = ramfs_truncate,
.flags = FS_DRIVER_NO_DEV,
.drv = {
.probe = ramfs_probe,
--
2.16.1
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