Some fixes for pstore
1) Change from ->get_sb() to ->mount() 2) Use mount_single() instead of mount_nodev() 3) Pulled in ramfs_get_inode() & trimmed to what I need for pstore 4) Drop the ugly pstore_writefile() Just save data using kmalloc() and provide a pstore_file_read() that uses simple_read_from_buffer(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Tony Luck
Al Viro
parent
474a00ee13
commit
fbe0aa1f3d
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@ -40,9 +40,29 @@
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struct pstore_private {
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u64 id;
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int (*erase)(u64);
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ssize_t size;
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char data[];
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};
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#define pstore_get_inode ramfs_get_inode
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static int pstore_file_open(struct inode *inode, struct file *file)
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{
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file->private_data = inode->i_private;
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return 0;
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}
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static ssize_t pstore_file_read(struct file *file, char __user *userbuf,
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size_t count, loff_t *ppos)
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{
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struct pstore_private *ps = file->private_data;
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return simple_read_from_buffer(userbuf, count, ppos, ps->data, ps->size);
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}
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static const struct file_operations pstore_file_operations = {
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.open = pstore_file_open,
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.read = pstore_file_read,
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.llseek = default_llseek,
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};
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/*
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* When a file is unlinked from our file system we call the
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@ -63,6 +83,30 @@ static const struct inode_operations pstore_dir_inode_operations = {
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.unlink = pstore_unlink,
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};
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static struct inode *pstore_get_inode(struct super_block *sb,
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const struct inode *dir, int mode, dev_t dev)
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{
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struct inode *inode = new_inode(sb);
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if (inode) {
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inode->i_ino = get_next_ino();
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inode->i_uid = inode->i_gid = 0;
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inode->i_mode = mode;
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inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
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switch (mode & S_IFMT) {
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case S_IFREG:
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inode->i_fop = &pstore_file_operations;
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break;
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case S_IFDIR:
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inode->i_op = &pstore_dir_inode_operations;
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inode->i_fop = &simple_dir_operations;
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inc_nlink(inode);
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break;
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}
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}
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return inode;
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}
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static const struct super_operations pstore_ops = {
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.statfs = simple_statfs,
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.drop_inode = generic_delete_inode,
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@ -70,37 +114,10 @@ static const struct super_operations pstore_ops = {
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};
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static struct super_block *pstore_sb;
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static struct vfsmount *pstore_mnt;
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int pstore_is_mounted(void)
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{
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return pstore_mnt != NULL;
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}
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/*
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* Set up a file structure as if we had opened this file and
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* write our data to it.
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*/
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static int pstore_writefile(struct inode *inode, struct dentry *dentry,
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char *data, size_t size)
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{
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struct file f;
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ssize_t n;
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mm_segment_t old_fs = get_fs();
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memset(&f, '0', sizeof f);
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f.f_mapping = inode->i_mapping;
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f.f_path.dentry = dentry;
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f.f_path.mnt = pstore_mnt;
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f.f_pos = 0;
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f.f_op = inode->i_fop;
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set_fs(KERNEL_DS);
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n = do_sync_write(&f, data, size, &f.f_pos);
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set_fs(old_fs);
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fsnotify_modify(&f);
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return n == size;
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return pstore_sb != NULL;
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}
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/*
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@ -123,8 +140,7 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
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inode = pstore_get_inode(pstore_sb, root->d_inode, S_IFREG | 0444, 0);
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if (!inode)
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goto fail;
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inode->i_uid = inode->i_gid = 0;
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private = kmalloc(sizeof *private, GFP_KERNEL);
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private = kmalloc(sizeof *private + size, GFP_KERNEL);
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if (!private)
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goto fail_alloc;
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private->id = id;
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@ -152,28 +168,19 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
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if (IS_ERR(dentry))
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goto fail_lockedalloc;
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d_add(dentry, inode);
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mutex_unlock(&root->d_inode->i_mutex);
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if (!pstore_writefile(inode, dentry, data, size))
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goto fail_write;
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memcpy(private->data, data, size);
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inode->i_size = private->size = size;
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inode->i_private = private;
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if (time.tv_sec)
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inode->i_mtime = inode->i_ctime = time;
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return 0;
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d_add(dentry, inode);
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fail_write:
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kfree(private);
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inode->i_nlink--;
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mutex_lock(&root->d_inode->i_mutex);
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d_delete(dentry);
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dput(dentry);
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mutex_unlock(&root->d_inode->i_mutex);
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goto fail;
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return 0;
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fail_lockedalloc:
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mutex_unlock(&root->d_inode->i_mutex);
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@ -225,32 +232,21 @@ fail:
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return err;
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}
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static int pstore_get_sb(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data, struct vfsmount *mnt)
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static struct dentry *pstore_mount(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data)
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{
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struct dentry *root;
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root = mount_nodev(fs_type, flags, data, pstore_fill_super);
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if (IS_ERR(root))
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return -ENOMEM;
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mnt->mnt_root = root;
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mnt->mnt_sb = root->d_sb;
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pstore_mnt = mnt;
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return 0;
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return mount_single(fs_type, flags, data, pstore_fill_super);
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}
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static void pstore_kill_sb(struct super_block *sb)
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{
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kill_litter_super(sb);
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pstore_sb = NULL;
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pstore_mnt = NULL;
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}
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static struct file_system_type pstore_fs_type = {
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.name = "pstore",
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.get_sb = pstore_get_sb,
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.mount = pstore_mount,
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.kill_sb = pstore_kill_sb,
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};
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