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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright 2019 Google LLC
*/
#ifndef _INCFS_DATA_MGMT_H
#define _INCFS_DATA_MGMT_H
#include <linux/cred.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <linux/completion.h>
#include <linux/wait.h>
#include <linux/zstd.h>
#include <crypto/hash.h>
#include <linux/rwsem.h>
#include <uapi/linux/incrementalfs.h>
#include "internal.h"
#include "pseudo_files.h"
#define SEGMENTS_PER_FILE 3
enum LOG_RECORD_TYPE {
FULL,
SAME_FILE,
SAME_FILE_CLOSE_BLOCK,
SAME_FILE_CLOSE_BLOCK_SHORT,
SAME_FILE_NEXT_BLOCK,
SAME_FILE_NEXT_BLOCK_SHORT,
};
struct full_record {
enum LOG_RECORD_TYPE type : 3; /* FULL */
u32 block_index : 29;
incfs_uuid_t file_id;
u64 absolute_ts_us;
uid_t uid;
} __packed; /* 32 bytes */
struct same_file {
enum LOG_RECORD_TYPE type : 3; /* SAME_FILE */
u32 block_index : 29;
uid_t uid;
u16 relative_ts_us; /* max 2^16 us ~= 64 ms */
} __packed; /* 10 bytes */
struct same_file_close_block {
enum LOG_RECORD_TYPE type : 3; /* SAME_FILE_CLOSE_BLOCK */
u16 relative_ts_us : 13; /* max 2^13 us ~= 8 ms */
s16 block_index_delta;
} __packed; /* 4 bytes */
struct same_file_close_block_short {
enum LOG_RECORD_TYPE type : 3; /* SAME_FILE_CLOSE_BLOCK_SHORT */
u8 relative_ts_tens_us : 5; /* max 2^5*10 us ~= 320 us */
s8 block_index_delta;
} __packed; /* 2 bytes */
struct same_file_next_block {
enum LOG_RECORD_TYPE type : 3; /* SAME_FILE_NEXT_BLOCK */
u16 relative_ts_us : 13; /* max 2^13 us ~= 8 ms */
} __packed; /* 2 bytes */
struct same_file_next_block_short {
enum LOG_RECORD_TYPE type : 3; /* SAME_FILE_NEXT_BLOCK_SHORT */
u8 relative_ts_tens_us : 5; /* max 2^5*10 us ~= 320 us */
} __packed; /* 1 byte */
union log_record {
struct full_record full_record;
struct same_file same_file;
struct same_file_close_block same_file_close_block;
struct same_file_close_block_short same_file_close_block_short;
struct same_file_next_block same_file_next_block;
struct same_file_next_block_short same_file_next_block_short;
};
struct read_log_state {
/* Log buffer generation id, incremented on configuration changes */
u32 generation_id;
/* Offset in rl_ring_buf to write into. */
u32 next_offset;
/* Current number of writer passes over rl_ring_buf */
u32 current_pass_no;
/* Current full_record to diff against */
struct full_record base_record;
/* Current record number counting from configuration change */
u64 current_record_no;
};
/* A ring buffer to save records about data blocks which were recently read. */
struct read_log {
void *rl_ring_buf;
int rl_size;
struct read_log_state rl_head;
struct read_log_state rl_tail;
/* A lock to protect the above fields */
spinlock_t rl_lock;
/* A queue of waiters who want to be notified about reads */
wait_queue_head_t ml_notif_wq;
/* A work item to wake up those waiters without slowing down readers */
struct delayed_work ml_wakeup_work;
};
struct mount_options {
unsigned int read_timeout_ms;
unsigned int readahead_pages;
unsigned int read_log_pages;
unsigned int read_log_wakeup_count;
bool report_uid;
char *sysfs_name;
};
struct mount_info {
struct super_block *mi_sb;
struct path mi_backing_dir_path;
struct dentry *mi_index_dir;
/* For stacking mounts, if true, this indicates if the index dir needs
* to be freed for this SB otherwise it was created by lower level SB */
bool mi_index_free;
struct dentry *mi_incomplete_dir;
/* For stacking mounts, if true, this indicates if the incomplete dir
* needs to be freed for this SB. Similar to mi_index_free */
bool mi_incomplete_free;
const struct cred *mi_owner;
struct mount_options mi_options;
/* This mutex is to be taken before create, rename, delete */
struct mutex mi_dir_struct_mutex;
/*
* A queue of waiters who want to be notified about new pending reads.
*/
wait_queue_head_t mi_pending_reads_notif_wq;
/*
* Protects - RCU safe:
* - reads_list_head
* - mi_pending_reads_count
* - mi_last_pending_read_number
* - data_file_segment.reads_list_head
*/
spinlock_t pending_read_lock;
/* List of active pending_read objects */
struct list_head mi_reads_list_head;
/* Total number of items in reads_list_head */
int mi_pending_reads_count;
/*
* Last serial number that was assigned to a pending read.
* 0 means no pending reads have been seen yet.
*/
int mi_last_pending_read_number;
/* Temporary buffer for read logger. */
struct read_log mi_log;
/* SELinux needs special xattrs on our pseudo files */
struct mem_range pseudo_file_xattr[PSEUDO_FILE_COUNT];
/* A queue of waiters who want to be notified about blocks_written */
wait_queue_head_t mi_blocks_written_notif_wq;
/* Number of blocks written since mount */
atomic_t mi_blocks_written;
/* Per UID read timeouts */
spinlock_t mi_per_uid_read_timeouts_lock;
struct incfs_per_uid_read_timeouts *mi_per_uid_read_timeouts;
int mi_per_uid_read_timeouts_size;
/* zstd workspace */
struct mutex mi_zstd_workspace_mutex;
void *mi_zstd_workspace;
ZSTD_DStream *mi_zstd_stream;
struct delayed_work mi_zstd_cleanup_work;
/* sysfs node */
struct incfs_sysfs_node *mi_sysfs_node;
/* Last error information */
struct mutex mi_le_mutex;
incfs_uuid_t mi_le_file_id;
u64 mi_le_time_us;
u32 mi_le_page;
u32 mi_le_errno;
uid_t mi_le_uid;
/* Number of reads timed out */
u32 mi_reads_failed_timed_out;
/* Number of reads failed because hash verification failed */
u32 mi_reads_failed_hash_verification;
/* Number of reads failed for another reason */
u32 mi_reads_failed_other;
/* Number of reads delayed because page had to be fetched */
u32 mi_reads_delayed_pending;
/* Total time waiting for pages to be fetched */
u64 mi_reads_delayed_pending_us;
/*
* Number of reads delayed because of per-uid min_time_us or
* min_pending_time_us settings
*/
u32 mi_reads_delayed_min;
/* Total time waiting because of per-uid min_time_us or
* min_pending_time_us settings.
*
* Note that if a read is initially delayed because we have to wait for
* the page, then further delayed because of min_pending_time_us
* setting, this counter gets incremented by only the further delay
* time.
*/
u64 mi_reads_delayed_min_us;
};
struct data_file_block {
loff_t db_backing_file_data_offset;
size_t db_stored_size;
enum incfs_compression_alg db_comp_alg;
};
struct pending_read {
incfs_uuid_t file_id;
s64 timestamp_us;
atomic_t done;
int block_index;
int serial_number;
uid_t uid;
struct list_head mi_reads_list;
struct list_head segment_reads_list;
struct rcu_head rcu;
};
struct data_file_segment {
wait_queue_head_t new_data_arrival_wq;
/* Protects reads and writes from the blockmap */
struct rw_semaphore rwsem;
/* List of active pending_read objects belonging to this segment */
/* Protected by mount_info.pending_reads_mutex */
struct list_head reads_list_head;
};
/*
* Extra info associated with a file. Just a few bytes set by a user.
*/
struct file_attr {
loff_t fa_value_offset;
size_t fa_value_size;
u32 fa_crc;
};
struct data_file {
struct backing_file_context *df_backing_file_context;
struct mount_info *df_mount_info;
incfs_uuid_t df_id;
/*
* Array of segments used to reduce lock contention for the file.
* Segment is chosen for a block depends on the block's index.
*/
struct data_file_segment df_segments[SEGMENTS_PER_FILE];
/* Base offset of the first metadata record. */
loff_t df_metadata_off;
/* Base offset of the block map. */
loff_t df_blockmap_off;
/* File size in bytes */
loff_t df_size;
/* File header flags */
u32 df_header_flags;
/* File size in DATA_FILE_BLOCK_SIZE blocks */
int df_data_block_count;
/* Total number of blocks, data + hash */
int df_total_block_count;
/* For mapped files, the offset into the actual file */
loff_t df_mapped_offset;
/* Number of data blocks written to file */
atomic_t df_data_blocks_written;
/* Number of data blocks in the status block */
u32 df_initial_data_blocks_written;
/* Number of hash blocks written to file */
atomic_t df_hash_blocks_written;
/* Number of hash blocks in the status block */
u32 df_initial_hash_blocks_written;
/* Offset to status metadata header */
loff_t df_status_offset;
/*
* Mutex acquired while enabling verity. Note that df_hash_tree is set
* by enable verity.
*
* The backing file mutex bc_mutex may be taken while this mutex is
* held.
*/
struct mutex df_enable_verity;
/*
* Set either at construction time or during enabling verity. In the
* latter case, set via smp_store_release, so use smp_load_acquire to
* read it.
*/
struct mtree *df_hash_tree;
/* Guaranteed set if df_hash_tree is set. */
struct incfs_df_signature *df_signature;
/*
* The verity file digest, set when verity is enabled and the file has
* been opened
*/
struct mem_range df_verity_file_digest;
struct incfs_df_verity_signature *df_verity_signature;
};
struct dir_file {
struct mount_info *mount_info;
struct file *backing_dir;
};
struct inode_info {
struct mount_info *n_mount_info; /* A mount, this file belongs to */
struct inode *n_backing_inode;
struct data_file *n_file;
struct inode n_vfs_inode;
};
struct dentry_info {
struct path backing_path;
};
enum FILL_PERMISSION {
CANT_FILL = 0,
CAN_FILL = 1,
};
struct incfs_file_data {
/* Does this file handle have INCFS_IOC_FILL_BLOCKS permission */
enum FILL_PERMISSION fd_fill_permission;
/* If INCFS_IOC_GET_FILLED_BLOCKS has been called, where are we */
int fd_get_block_pos;
/* And how many filled blocks are there up to that point */
int fd_filled_data_blocks;
int fd_filled_hash_blocks;
};
struct mount_info *incfs_alloc_mount_info(struct super_block *sb,
struct mount_options *options,
struct path *backing_dir_path);
int incfs_realloc_mount_info(struct mount_info *mi,
struct mount_options *options);
void incfs_free_mount_info(struct mount_info *mi);
char *file_id_to_str(incfs_uuid_t id);
struct dentry *incfs_lookup_dentry(struct dentry *parent, const char *name);
struct data_file *incfs_open_data_file(struct mount_info *mi, struct file *bf);
void incfs_free_data_file(struct data_file *df);
struct dir_file *incfs_open_dir_file(struct mount_info *mi, struct file *bf);
void incfs_free_dir_file(struct dir_file *dir);
struct incfs_read_data_file_timeouts {
u32 min_time_us;
u32 min_pending_time_us;
u32 max_pending_time_us;
};
ssize_t incfs_read_data_file_block(struct mem_range dst, struct file *f,
int index, struct mem_range tmp,
struct incfs_read_data_file_timeouts *timeouts,
unsigned int *delayed_min_us);
ssize_t incfs_read_merkle_tree_blocks(struct mem_range dst,
struct data_file *df, size_t offset);
int incfs_get_filled_blocks(struct data_file *df,
struct incfs_file_data *fd,
struct incfs_get_filled_blocks_args *arg);
int incfs_read_file_signature(struct data_file *df, struct mem_range dst);
int incfs_process_new_data_block(struct data_file *df,
struct incfs_fill_block *block, u8 *data,
bool *complete);
int incfs_process_new_hash_block(struct data_file *df,
struct incfs_fill_block *block, u8 *data);
bool incfs_fresh_pending_reads_exist(struct mount_info *mi, int last_number);
/*
* Collects pending reads and saves them into the array (reads/reads_size).
* Only reads with serial_number > sn_lowerbound are reported.
* Returns how many reads were saved into the array.
*/
int incfs_collect_pending_reads(struct mount_info *mi, int sn_lowerbound,
struct incfs_pending_read_info *reads,
struct incfs_pending_read_info2 *reads2,
int reads_size, int *new_max_sn);
int incfs_collect_logged_reads(struct mount_info *mi,
struct read_log_state *start_state,
struct incfs_pending_read_info *reads,
struct incfs_pending_read_info2 *reads2,
int reads_size);
struct read_log_state incfs_get_log_state(struct mount_info *mi);
int incfs_get_uncollected_logs_count(struct mount_info *mi,
const struct read_log_state *state);
static inline struct inode_info *get_incfs_node(struct inode *inode)
{
if (!inode)
return NULL;
if (inode->i_sb->s_magic != INCFS_MAGIC_NUMBER) {
/* This inode doesn't belong to us. */
pr_warn_once("incfs: %s on an alien inode.", __func__);
return NULL;
}
return container_of(inode, struct inode_info, n_vfs_inode);
}
static inline struct data_file *get_incfs_data_file(struct file *f)
{
struct inode_info *node = NULL;
if (!f)
return NULL;
if (!S_ISREG(f->f_inode->i_mode))
return NULL;
node = get_incfs_node(f->f_inode);
if (!node)
return NULL;
return node->n_file;
}
static inline struct dir_file *get_incfs_dir_file(struct file *f)
{
if (!f)
return NULL;
if (!S_ISDIR(f->f_inode->i_mode))
return NULL;
return (struct dir_file *)f->private_data;
}
/*
* Make sure that inode_info.n_file is initialized and inode can be used
* for reading and writing data from/to the backing file.
*/
int make_inode_ready_for_data_ops(struct mount_info *mi,
struct inode *inode,
struct file *backing_file);
static inline struct dentry_info *get_incfs_dentry(const struct dentry *d)
{
if (!d)
return NULL;
return (struct dentry_info *)d->d_fsdata;
}
static inline void get_incfs_backing_path(const struct dentry *d,
struct path *path)
{
struct dentry_info *di = get_incfs_dentry(d);
if (!di) {
*path = (struct path) {};
return;
}
*path = di->backing_path;
path_get(path);
}
static inline int get_blocks_count_for_size(u64 size)
{
if (size == 0)
return 0;
return 1 + (size - 1) / INCFS_DATA_FILE_BLOCK_SIZE;
}
#endif /* _INCFS_DATA_MGMT_H */