// SPDX-License-Identifier: GPL-2.0
/*
* Simple file system for zoned block devices exposing zones as files.
*
* Copyright (C) 2019 Western Digital Corporation or its affiliates.
*/
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/magic.h>
#include <linux/iomap.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/statfs.h>
#include <linux/writeback.h>
#include <linux/quotaops.h>
#include <linux/seq_file.h>
#include <linux/uio.h>
#include <linux/mman.h>
#include <linux/sched/mm.h>
#include <linux/crc32.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/fs_parser.h>
#include <linux/fs_context.h>
#include "zonefs.h"
#define CREATE_TRACE_POINTS
#include "trace.h"
/*
* Get the name of a zone group directory.
*/
static const char *zonefs_zgroup_name(enum zonefs_ztype ztype)
{
switch (ztype) {
case ZONEFS_ZTYPE_CNV:
return "cnv";
case ZONEFS_ZTYPE_SEQ:
return "seq";
default:
WARN_ON_ONCE(1);
return "???";
}
}
/*
* Manage the active zone count.
*/
static void zonefs_account_active(struct super_block *sb,
struct zonefs_zone *z)
{
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
if (zonefs_zone_is_cnv(z))
return;
/*
* For zones that transitioned to the offline or readonly condition,
* we only need to clear the active state.
*/
if (z->z_flags & (ZONEFS_ZONE_OFFLINE | ZONEFS_ZONE_READONLY))
goto out;
/*
* If the zone is active, that is, if it is explicitly open or
* partially written, check if it was already accounted as active.
*/
if ((z->z_flags & ZONEFS_ZONE_OPEN) ||
(z->z_wpoffset > 0 && z->z_wpoffset < z->z_capacity)) {
if (!(z->z_flags & ZONEFS_ZONE_ACTIVE)) {
z->z_flags |= ZONEFS_ZONE_ACTIVE;
atomic_inc(&sbi->s_active_seq_files);
}
return;
}
out:
/* The zone is not active. If it was, update the active count */
if (z->z_flags & ZONEFS_ZONE_ACTIVE) {
z->z_flags &= ~ZONEFS_ZONE_ACTIVE;
atomic_dec(&sbi->s_active_seq_files);
}
}
/*
* Manage the active zone count. Called with zi->i_truncate_mutex held.
*/
void zonefs_inode_account_active(struct inode *inode)
{
lockdep_assert_held(&ZONEFS_I(inode)->i_truncate_mutex);
return zonefs_account_active(inode->i_sb, zonefs_inode_zone(inode));
}
/*
* Execute a zone management operation.
*/
static int zonefs_zone_mgmt(struct super_block *sb,
struct zonefs_zone *z, enum req_op op)
{
int ret;
/*
* With ZNS drives, closing an explicitly open zone that has not been
* written will change the zone state to "closed", that is, the zone
* will remain active. Since this can then cause failure of explicit
* open operation on other zones if the drive active zone resources
* are exceeded, make sure that the zone does not remain active by
* resetting it.
*/
if (op == REQ_OP_ZONE_CLOSE && !z->z_wpoffset)
op = REQ_OP_ZONE_RESET;
trace_zonefs_zone_mgmt(sb, z, op);
ret = blkdev_zone_mgmt(sb->s_bdev, op, z->z_sector,
z->z_size >> SECTOR_SHIFT);
if (ret) {
zonefs_err(sb,
"Zone management operation %s at %llu failed %d\n",
blk_op_str(op), z->z_sector, ret);
return ret;
}
return 0;
}
int zonefs_inode_zone_mgmt(struct inode *inode, enum req_op op)
{
lockdep_assert_held(&ZONEFS_I(inode)->i_truncate_mutex);
return zonefs_zone_mgmt(inode->i_sb, zonefs_inode_zone(inode), op);
}
void zonefs_i_size_write(struct inode *inode, loff_t isize)
{
struct zonefs_zone *z = zonefs_inode_zone(inode);
i_size_write(inode, isize);
/*
* A full zone is no longer open/active and does not need
* explicit closing.
*/
if (isize >= z->z_capacity) {
struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);
if (z->z_flags & ZONEFS_ZONE_ACTIVE)
atomic_dec(&sbi->s_active_seq_files);
z->z_flags &= ~(ZONEFS_ZONE_OPEN | ZONEFS_ZONE_ACTIVE);
}
}
void zonefs_update_stats(struct inode *inode, loff_t new_isize)
{
struct super_block *sb = inode->i_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
loff_t old_isize = i_size_read(inode);
loff_t nr_blocks;
if (new_isize == old_isize)
return;
spin_lock(&sbi->s_lock);
/*
* This may be called for an update after an IO error.
* So beware of the values seen.
*/
if (new_isize < old_isize) {
nr_blocks = (old_isize - new_isize) >> sb->s_blocksize_bits;
if (sbi->s_used_blocks > nr_blocks)
sbi->s_used_blocks -= nr_blocks;
else
sbi->s_used_blocks = 0;
} else {
sbi->s_used_blocks +=
(new_isize - old_isize) >> sb->s_blocksize_bits;
if (sbi->s_used_blocks > sbi->s_blocks)
sbi->s_used_blocks = sbi->s_blocks;
}
spin_unlock(&sbi->s_lock);
}
/*
* Check a zone condition. Return the amount of written (and still readable)
* data in the zone.
*/
static loff_t zonefs_check_zone_condition(struct super_block *sb,
struct zonefs_zone *z,
struct blk_zone *zone)
{
switch (zone->cond) {
case BLK_ZONE_COND_OFFLINE:
zonefs_warn(sb, "Zone %llu: offline zone\n",
z->z_sector);
z->z_flags |= ZONEFS_ZONE_OFFLINE;
return 0;
case BLK_ZONE_COND_READONLY:
/*
* The write pointer of read-only zones is invalid, so we cannot
* determine the zone wpoffset (inode size). We thus keep the
* zone wpoffset as is, which leads to an empty file
* (wpoffset == 0) on mount. For a runtime error, this keeps
* the inode size as it was when last updated so that the user
* can recover data.
*/
zonefs_warn(sb, "Zone %llu: read-only zone\n",
z->z_sector);
z->z_flags |= ZONEFS_ZONE_READONLY;
if (zonefs_zone_is_cnv(z))
return z->z_capacity;
return z->z_wpoffset;
case BLK_ZONE_COND_FULL:
/* The write pointer of full zones is invalid. */
return z->z_capacity;
default:
if (zonefs_zone_is_cnv(z))
return z->z_capacity;
return (zone->wp - zone->start) << SECTOR_SHIFT;
}
}
/*
* Check a zone condition and adjust its inode access permissions for
* offline and readonly zones.
*/
static void zonefs_inode_update_mode(struct inode *inode)
{
struct zonefs_zone *z = zonefs_inode_zone(inode);
if (z->z_flags & ZONEFS_ZONE_OFFLINE) {
/* Offline zones cannot be read nor written */
inode->i_flags |= S_IMMUTABLE;
inode->i_mode &= ~0777;
} else if (z->z_flags & ZONEFS_ZONE_READONLY) {
/* Readonly zones cannot be written */
inode->i_flags |= S_IMMUTABLE;
if (z->z_flags & ZONEFS_ZONE_INIT_MODE)
inode->i_mode &= ~0777;
else
inode->i_mode &= ~0222;
}
z->z_flags &= ~ZONEFS_ZONE_INIT_MODE;
z->z_mode = inode->i_mode;
}
static int zonefs_io_error_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
struct blk_zone *z = data;
*z = *zone;
return 0;
}
static void zonefs_handle_io_error(struct inode *inode, struct blk_zone *zone,
bool write)
{
struct zonefs_zone *z = zonefs_inode_zone(inode);
struct super_block *sb = inode->i_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
loff_t isize, data_size;
/*
* Check the zone condition: if the zone is not "bad" (offline or
* read-only), read errors are simply signaled to the IO issuer as long
* as there is no inconsistency between the inode size and the amount of
* data writen in the zone (data_size).
*/
data_size = zonefs_check_zone_condition(sb, z, zone);
isize = i_size_read(inode);
if (!(z->z_flags & (ZONEFS_ZONE_READONLY | ZONEFS_ZONE_OFFLINE)) &&
!write && isize == data_size)
return;
/*
* At this point, we detected either a bad zone or an inconsistency
* between the inode size and the amount of data written in the zone.
* For the latter case, the cause may be a write IO error or an external
* action on the device. Two error patterns exist:
* 1) The inode size is lower than the amount of data in the zone:
* a write operation partially failed and data was writen at the end
* of the file. This can happen in the case of a large direct IO
* needing several BIOs and/or write requests to be processed.
* 2) The inode size is larger than the amount of data in the zone:
* this can happen with a deferred write error with the use of the
* device side write cache after getting successful write IO
* completions. Other possibilities are (a) an external corruption,
* e.g. an application reset the zone directly, or (b) the device
* has a serious problem (e.g. firmware bug).
*
* In all cases, warn about inode size inconsistency and handle the
* IO error according to the zone condition and to the mount options.
*/
if (isize != data_size)
zonefs_warn(sb,
"inode %lu: invalid size %lld (should be %lld)\n",
inode->i_ino, isize, data_size);
/*
* First handle bad zones signaled by hardware. The mount options
* errors=zone-ro and errors=zone-offline result in changing the
* zone condition to read-only and offline respectively, as if the
* condition was signaled by the hardware.
*/
if ((z->z_flags & ZONEFS_ZONE_OFFLINE) ||
(sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL)) {
zonefs_warn(sb, "inode %lu: read/write access disabled\n",
inode->i_ino);
if (!(z->z_flags & ZONEFS_ZONE_OFFLINE))
z->z_flags |= ZONEFS_ZONE_OFFLINE;
zonefs_inode_update_mode(inode);
data_size = 0;
} else if ((z->z_flags & ZONEFS_ZONE_READONLY) ||
(sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO)) {
zonefs_warn(sb, "inode %lu: write access disabled\n",
inode->i_ino);
if (!(z->z_flags & ZONEFS_ZONE_READONLY))
z->z_flags |= ZONEFS_ZONE_READONLY;
zonefs_inode_update_mode(inode);
data_size = isize;
} else if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO &&
data_size > isize) {
/* Do not expose garbage data */
data_size = isize;
}
/*
* If the filesystem is mounted with the explicit-open mount option, we
* need to clear the ZONEFS_ZONE_OPEN flag if the zone transitioned to
* the read-only or offline condition, to avoid attempting an explicit
* close of the zone when the inode file is closed.
*/
if ((sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) &&
(z->z_flags & (ZONEFS_ZONE_READONLY | ZONEFS_ZONE_OFFLINE)))
z->z_flags &= ~ZONEFS_ZONE_OPEN;
/*
* If error=remount-ro was specified, any error result in remounting
* the volume as read-only.
*/
if ((sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO) && !sb_rdonly(sb)) {
zonefs_warn(sb, "remounting filesystem read-only\n");
sb->s_flags |= SB_RDONLY;
}
/*
* Update block usage stats and the inode size to prevent access to
* invalid data.
*/
zonefs_update_stats(inode, data_size);
zonefs_i_size_write(inode, data_size);
z->z_wpoffset = data_size;
zonefs_inode_account_active(inode);
}
/*
* When an file IO error occurs, check the file zone to see if there is a change
* in the zone condition (e.g. offline or read-only). For a failed write to a
* sequential zone, the zone write pointer position must also be checked to
* eventually correct the file size and zonefs inode write pointer offset
* (which can be out of sync with the drive due to partial write failures).
*/
void __zonefs_io_error(struct inode *inode, bool write)
{
struct zonefs_zone *z = zonefs_inode_zone(inode);
struct super_block *sb = inode->i_sb;
unsigned int noio_flag;
struct blk_zone zone;
int ret;
/*
* Conventional zone have no write pointer and cannot become read-only
* or offline. So simply fake a report for a single or aggregated zone
* and let zonefs_handle_io_error() correct the zone inode information
* according to the mount options.
*/
if (!zonefs_zone_is_seq(z)) {
zone.start = z->z_sector;
zone.len = z->z_size >> SECTOR_SHIFT;
zone.wp = zone.start + zone.len;
zone.type = BLK_ZONE_TYPE_CONVENTIONAL;
zone.cond = BLK_ZONE_COND_NOT_WP;
zone.capacity = zone.len;
goto handle_io_error;
}
/*
* Memory allocations in blkdev_report_zones() can trigger a memory
* reclaim which may in turn cause a recursion into zonefs as well as
* struct request allocations for the same device. The former case may
* end up in a deadlock on the inode truncate mutex, while the latter
* may prevent IO forward progress. Executing the report zones under
* the GFP_NOIO context avoids both problems.
*/
noio_flag = memalloc_noio_save();
ret = blkdev_report_zones(sb->s_bdev, z->z_sector, 1,
zonefs_io_error_cb, &zone);
memalloc_noio_restore(noio_flag);
if (ret != 1) {
zonefs_err(sb, "Get inode %lu zone information failed %d\n",
inode->i_ino, ret);
zonefs_warn(sb, "remounting filesystem read-only\n");
sb->s_flags |= SB_RDONLY;
return;
}
handle_io_error:
zonefs_handle_io_error(inode, &zone, write);
}
static struct kmem_cache *zonefs_inode_cachep;
static struct inode *zonefs_alloc_inode(struct super_block *sb)
{
struct zonefs_inode_info *zi;
zi = alloc_inode_sb(sb, zonefs_inode_cachep, GFP_KERNEL);
if (!zi)
return NULL;
inode_init_once(&zi->i_vnode);
mutex_init(&zi->i_truncate_mutex);
zi->i_wr_refcnt = 0;
return &zi->i_vnode;
}
static void zonefs_free_inode(struct inode *inode)
{
kmem_cache_free(zonefs_inode_cachep, ZONEFS_I(inode));
}
/*
* File system stat.
*/
static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
enum zonefs_ztype t;
buf->f_type = ZONEFS_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_namelen = ZONEFS_NAME_MAX;
spin_lock(&sbi->s_lock);
buf->f_blocks = sbi->s_blocks;
if (WARN_ON(sbi->s_used_blocks > sbi->s_blocks))
buf->f_bfree = 0;
else
buf->f_bfree = buf->f_blocks - sbi->s_used_blocks;
buf->f_bavail = buf->f_bfree;
for (t = 0; t < ZONEFS_ZTYPE_MAX; t++) {
if (sbi->s_zgroup[t].g_nr_zones)
buf->f_files += sbi->s_zgroup[t].g_nr_zones + 1;
}
buf->f_ffree = 0;
spin_unlock(&sbi->s_lock);
buf->f_fsid = uuid_to_fsid(sbi->s_uuid.b);
return 0;
}
enum {
Opt_errors, Opt_explicit_open,
};
struct zonefs_context {
unsigned long s_mount_opts;
};
static const struct constant_table zonefs_param_errors[] = {
{"remount-ro", ZONEFS_MNTOPT_ERRORS_RO},
{"zone-ro", ZONEFS_MNTOPT_ERRORS_ZRO},
{"zone-offline", ZONEFS_MNTOPT_ERRORS_ZOL},
{"repair", ZONEFS_MNTOPT_ERRORS_REPAIR},
{}
};
static const struct fs_parameter_spec zonefs_param_spec[] = {
fsparam_enum ("errors", Opt_errors, zonefs_param_errors),
fsparam_flag ("explicit-open", Opt_explicit_open),
{}
};
static int zonefs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
struct zonefs_context *ctx = fc->fs_private;
struct fs_parse_result result;
int opt;
opt = fs_parse(fc, zonefs_param_spec, param, &result);
if (opt < 0)
return opt;
switch (opt) {
case Opt_errors:
ctx->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
ctx->s_mount_opts |= result.uint_32;
break;
case Opt_explicit_open:
ctx->s_mount_opts |= ZONEFS_MNTOPT_EXPLICIT_OPEN;
break;
default:
return -EINVAL;
}
return 0;
}
static int zonefs_show_options(struct seq_file *seq, struct dentry *root)
{
struct zonefs_sb_info *sbi = ZONEFS_SB(root->d_sb);
if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO)
seq_puts(seq, ",errors=remount-ro");
if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO)
seq_puts(seq, ",errors=zone-ro");
if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL)
seq_puts(seq, ",errors=zone-offline");
if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_REPAIR)
seq_puts(seq, ",errors=repair");
return 0;
}
static int zonefs_inode_setattr(struct mnt_idmap *idmap,
struct dentry *dentry, struct iattr *iattr)
{
struct inode *inode = d_inode(dentry);
int ret;
if (unlikely(IS_IMMUTABLE(inode)))
return -EPERM;
ret = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
if (ret)
return ret;
/*
* Since files and directories cannot be created nor deleted, do not
* allow setting any write attributes on the sub-directories grouping
* files by zone type.
*/
if ((iattr->ia_valid & ATTR_MODE) && S_ISDIR(inode->i_mode) &&
(iattr->ia_mode & 0222))
return -EPERM;
if (((iattr->ia_valid & ATTR_UID) &&
!uid_eq(iattr->ia_uid, inode->i_uid)) ||
((iattr->ia_valid & ATTR_GID) &&
!gid_eq(iattr->ia_gid, inode->i_gid))) {
ret = dquot_transfer(&nop_mnt_idmap, inode, iattr);
if (ret)
return ret;
}
if (iattr->ia_valid & ATTR_SIZE) {
ret = zonefs_file_truncate(inode, iattr->ia_size);
if (ret)
return ret;
}
setattr_copy(&nop_mnt_idmap, inode, iattr);
if (S_ISREG(inode->i_mode)) {
struct zonefs_zone *z = zonefs_inode_zone(inode);
z->z_mode = inode->i_mode;
z->z_uid = inode->i_uid;
z->z_gid = inode->i_gid;
}
return 0;
}
static const struct inode_operations zonefs_file_inode_operations = {
.setattr = zonefs_inode_setattr,
};
static long zonefs_fname_to_fno(const struct qstr *fname)
{
const char *name = fname->name;
unsigned int len = fname->len;
long fno = 0, shift = 1;
const char *rname;
char c = *name;
unsigned int i;
/*
* File names are always a base-10 number string without any
* leading 0s.
*/
if (!isdigit(c))
return -ENOENT;
if (len > 1 && c == '0')
return -ENOENT;
if (len == 1)
return c - '0';
for (i = 0, rname = name + len - 1; i < len; i++, rname--) {
c = *rname;
if (!isdigit(c))
return -ENOENT;
fno += (c - '0') * shift;
shift *= 10;
}
return fno;
}
static struct inode *zonefs_get_file_inode(struct inode *dir,
struct dentry *dentry)
{
struct zonefs_zone_group *zgroup = dir->i_private;
struct super_block *sb = dir->i_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
struct zonefs_zone *z;
struct inode *inode;
ino_t ino;
long fno;
/* Get the file number from the file name */
fno = zonefs_fname_to_fno(&dentry->d_name);
if (fno < 0)
return ERR_PTR(fno);
if (!zgroup->g_nr_zones || fno >= zgroup->g_nr_zones)
return ERR_PTR(-ENOENT);
z = &zgroup->g_zones[fno];
ino = z->z_sector >> sbi->s_zone_sectors_shift;
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode->i_state & I_NEW)) {
WARN_ON_ONCE(inode->i_private != z);
return inode;
}
inode->i_ino = ino;
inode->i_mode = z->z_mode;
inode_set_mtime_to_ts(inode,
inode_set_atime_to_ts(inode, inode_set_ctime_to_ts(inode, inode_get_ctime(dir))));
inode->i_uid = z->z_uid;
inode->i_gid = z->z_gid;
inode->i_size = z->z_wpoffset;
inode->i_blocks = z->z_capacity >> SECTOR_SHIFT;
inode->i_private = z;
inode->i_op = &zonefs_file_inode_operations;
inode->i_fop = &zonefs_file_operations;
inode->i_mapping->a_ops = &zonefs_file_aops;
mapping_set_large_folios(inode->i_mapping);
/* Update the inode access rights depending on the zone condition */
zonefs_inode_update_mode(inode);
unlock_new_inode(inode);
return inode;
}
static struct inode *zonefs_get_zgroup_inode(struct super_block *sb,
enum zonefs_ztype ztype)
{
struct inode *root = d_inode(sb->s_root);
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
struct inode *inode;
ino_t ino = bdev_nr_zones(sb->s_bdev) + ztype + 1;
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode->i_state & I_NEW))
return inode;
inode->i_ino = ino;
inode_init_owner(&nop_mnt_idmap, inode, root, S_IFDIR | 0555);
inode->i_size = sbi->s_zgroup[ztype].g_nr_zones;
inode_set_mtime_to_ts(inode,
inode_set_atime_to_ts(inode, inode_set_ctime_to_ts(inode, inode_get_ctime(root))));
inode->i_private = &sbi->s_zgroup[ztype];
set_nlink(inode, 2);
inode->i_op = &zonefs_dir_inode_operations;
inode->i_fop = &zonefs_dir_operations;
unlock_new_inode(inode);
return inode;
}
static struct inode *zonefs_get_dir_inode(struct inode *dir,
struct dentry *dentry)
{
struct super_block *sb = dir->i_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
const char *name = dentry->d_name.name;
enum zonefs_ztype ztype;
/*
* We only need to check for the "seq" directory and
* the "cnv" directory if we have conventional zones.
*/
if (dentry->d_name.len != 3)
return ERR_PTR(-ENOENT);
for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
if (sbi->s_zgroup[ztype].g_nr_zones &&
memcmp(name, zonefs_zgroup_name(ztype), 3) == 0)
break;
}
if (ztype == ZONEFS_ZTYPE_MAX)
return ERR_PTR(-ENOENT);
return zonefs_get_zgroup_inode(sb, ztype);
}
static struct dentry *zonefs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode;
if (dentry->d_name.len > ZONEFS_NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
if (dir == d_inode(dir->i_sb->s_root))
inode = zonefs_get_dir_inode(dir, dentry);
else
inode = zonefs_get_file_inode(dir, dentry);
return d_splice_alias(inode, dentry);
}
static int zonefs_readdir_root(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct super_block *sb = inode->i_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
enum zonefs_ztype ztype = ZONEFS_ZTYPE_CNV;
ino_t base_ino = bdev_nr_zones(sb->s_bdev) + 1;
if (ctx->pos >= inode->i_size)
return 0;
if (!dir_emit_dots(file, ctx))
return 0;
if (ctx->pos == 2) {
if (!sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones)
ztype = ZONEFS_ZTYPE_SEQ;
if (!dir_emit(ctx, zonefs_zgroup_name(ztype), 3,
base_ino + ztype, DT_DIR))
return 0;
ctx->pos++;
}
if (ctx->pos == 3 && ztype != ZONEFS_ZTYPE_SEQ) {
ztype = ZONEFS_ZTYPE_SEQ;
if (!dir_emit(ctx, zonefs_zgroup_name(ztype), 3,
base_ino + ztype, DT_DIR))
return 0;
ctx->pos++;
}
return 0;
}
static int zonefs_readdir_zgroup(struct file *file,
struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct zonefs_zone_group *zgroup = inode->i_private;
struct super_block *sb = inode->i_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
struct zonefs_zone *z;
int fname_len;
char *fname;
ino_t ino;
int f;
/*
* The size of zone group directories is equal to the number
* of zone files in the group and does note include the "." and
* ".." entries. Hence the "+ 2" here.
*/
if (ctx->pos >= inode->i_size + 2)
return 0;
if (!dir_emit_dots(file, ctx))
return 0;
fname = kmalloc(ZONEFS_NAME_MAX, GFP_KERNEL);
if (!fname)
return -ENOMEM;
for (f = ctx->pos - 2; f < zgroup->g_nr_zones; f++) {
z = &zgroup->g_zones[f];
ino = z->z_sector >> sbi->s_zone_sectors_shift;
fname_len = snprintf(fname, ZONEFS_NAME_MAX - 1, "%u", f);
if (!dir_emit(ctx, fname, fname_len, ino, DT_REG))
break;
ctx->pos++;
}
kfree(fname);
return 0;
}
static int zonefs_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
if (inode == d_inode(inode->i_sb->s_root))
return zonefs_readdir_root(file, ctx);
return zonefs_readdir_zgroup(file, ctx);
}
const struct inode_operations zonefs_dir_inode_operations = {
.lookup = zonefs_lookup,
.setattr = zonefs_inode_setattr,
};
const struct file_operations zonefs_dir_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate_shared = zonefs_readdir,
};
struct zonefs_zone_data {
struct super_block *sb;
unsigned int nr_zones[ZONEFS_ZTYPE_MAX];
sector_t cnv_zone_start;
struct blk_zone *zones;
};
static int zonefs_get_zone_info_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
struct zonefs_zone_data *zd = data;
struct super_block *sb = zd->sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
/*
* We do not care about the first zone: it contains the super block
* and not exposed as a file.
*/
if (!idx)
return 0;
/*
* Count the number of zones that will be exposed as files.
* For sequential zones, we always have as many files as zones.
* FOr conventional zones, the number of files depends on if we have
* conventional zones aggregation enabled.
*/
switch (zone->type) {
case BLK_ZONE_TYPE_CONVENTIONAL:
if (sbi->s_features & ZONEFS_F_AGGRCNV) {
/* One file per set of contiguous conventional zones */
if (!(sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones) ||
zone->start != zd->cnv_zone_start)
sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones++;
zd->cnv_zone_start = zone->start + zone->len;
} else {
/* One file per zone */
sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones++;
}
break;
case BLK_ZONE_TYPE_SEQWRITE_REQ:
case BLK_ZONE_TYPE_SEQWRITE_PREF:
sbi->s_zgroup[ZONEFS_ZTYPE_SEQ].g_nr_zones++;
break;
default:
zonefs_err(zd->sb, "Unsupported zone type 0x%x\n",
zone->type);
return -EIO;
}
memcpy(&zd->zones[idx], zone, sizeof(struct blk_zone));
return 0;
}
static int zonefs_get_zone_info(struct zonefs_zone_data *zd)
{
struct block_device *bdev = zd->sb->s_bdev;
int ret;
zd->zones = kvcalloc(bdev_nr_zones(bdev), sizeof(struct blk_zone),
GFP_KERNEL);
if (!zd->zones)
return -ENOMEM;
/* Get zones information from the device */
ret = blkdev_report_zones(bdev, 0, BLK_ALL_ZONES,
zonefs_get_zone_info_cb, zd);
if (ret < 0) {
zonefs_err(zd->sb, "Zone report failed %d\n", ret);
return ret;
}
if (ret != bdev_nr_zones(bdev)) {
zonefs_err(zd->sb, "Invalid zone report (%d/%u zones)\n",
ret, bdev_nr_zones(bdev));
return -EIO;
}
return 0;
}
static inline void zonefs_free_zone_info(struct zonefs_zone_data *zd)
{
kvfree(zd->zones);
}
/*
* Create a zone group and populate it with zone files.
*/
static int zonefs_init_zgroup(struct super_block *sb,
struct zonefs_zone_data *zd,
enum zonefs_ztype ztype)
{
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
struct zonefs_zone_group *zgroup = &sbi->s_zgroup[ztype];
struct blk_zone *zone, *next, *end;
struct zonefs_zone *z;
unsigned int n = 0;
int ret;
/* Allocate the zone group. If it is empty, we have nothing to do. */
if (!zgroup->g_nr_zones)
return 0;
zgroup->g_zones = kvcalloc(zgroup->g_nr_zones,
sizeof(struct zonefs_zone), GFP_KERNEL);
if (!zgroup->g_zones)
return -ENOMEM;
/*
* Initialize the zone groups using the device zone information.
* We always skip the first zone as it contains the super block
* and is not use to back a file.
*/
end = zd->zones + bdev_nr_zones(sb->s_bdev);
for (zone = &zd->zones[1]; zone < end; zone = next) {
next = zone + 1;
if (zonefs_zone_type(zone) != ztype)
continue;
if (WARN_ON_ONCE(n >= zgroup->g_nr_zones))
return -EINVAL;
/*
* For conventional zones, contiguous zones can be aggregated
* together to form larger files. Note that this overwrites the
* length of the first zone of the set of contiguous zones
* aggregated together. If one offline or read-only zone is
* found, assume that all zones aggregated have the same
* condition.
*/
if (ztype == ZONEFS_ZTYPE_CNV &&
(sbi->s_features & ZONEFS_F_AGGRCNV)) {
for (; next < end; next++) {
if (zonefs_zone_type(next) != ztype)
break;
zone->len += next->len;
zone->capacity += next->capacity;
if (next->cond == BLK_ZONE_COND_READONLY &&
zone->cond != BLK_ZONE_COND_OFFLINE)
zone->cond = BLK_ZONE_COND_READONLY;
else if (next->cond == BLK_ZONE_COND_OFFLINE)
zone->cond = BLK_ZONE_COND_OFFLINE;
}
}
z = &zgroup->g_zones[n];
if (ztype == ZONEFS_ZTYPE_CNV)
z->z_flags |= ZONEFS_ZONE_CNV;
z->z_sector = zone->start;
z->z_size = zone->len << SECTOR_SHIFT;
if (z->z_size > bdev_zone_sectors(sb->s_bdev) << SECTOR_SHIFT &&
!(sbi->s_features & ZONEFS_F_AGGRCNV)) {
zonefs_err(sb,
"Invalid zone size %llu (device zone sectors %llu)\n",
z->z_size,
bdev_zone_sectors(sb->s_bdev) << SECTOR_SHIFT);
return -EINVAL;
}
z->z_capacity = min_t(loff_t, MAX_LFS_FILESIZE,
zone->capacity << SECTOR_SHIFT);
z->z_wpoffset = zonefs_check_zone_condition(sb, z, zone);
z->z_mode = S_IFREG | sbi->s_perm;
z->z_uid = sbi->s_uid;
z->z_gid = sbi->s_gid;
/*
* Let zonefs_inode_update_mode() know that we will need
* special initialization of the inode mode the first time
* it is accessed.
*/
z->z_flags |= ZONEFS_ZONE_INIT_MODE;
sb->s_maxbytes = max(z->z_capacity, sb->s_maxbytes);
sbi->s_blocks += z->z_capacity >> sb->s_blocksize_bits;
sbi->s_used_blocks += z->z_wpoffset >> sb->s_blocksize_bits;
/*
* For sequential zones, make sure that any open zone is closed
* first to ensure that the initial number of open zones is 0,
* in sync with the open zone accounting done when the mount
* option ZONEFS_MNTOPT_EXPLICIT_OPEN is used.
*/
if (ztype == ZONEFS_ZTYPE_SEQ &&
(zone->cond == BLK_ZONE_COND_IMP_OPEN ||
zone->cond == BLK_ZONE_COND_EXP_OPEN)) {
ret = zonefs_zone_mgmt(sb, z, REQ_OP_ZONE_CLOSE);
if (ret)
return ret;
}
zonefs_account_active(sb, z);
n++;
}
if (WARN_ON_ONCE(n != zgroup->g_nr_zones))
return -EINVAL;
zonefs_info(sb, "Zone group \"%s\" has %u file%s\n",
zonefs_zgroup_name(ztype),
zgroup->g_nr_zones,
str_plural(zgroup->g_nr_zones));
return 0;
}
static void zonefs_free_zgroups(struct super_block *sb)
{
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
enum zonefs_ztype ztype;
if (!sbi)
return;
for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
kvfree(sbi->s_zgroup[ztype].g_zones);
sbi->s_zgroup[ztype].g_zones = NULL;
}
}
/*
* Create a zone group and populate it with zone files.
*/
static int zonefs_init_zgroups(struct super_block *sb)
{
struct zonefs_zone_data zd;
enum zonefs_ztype ztype;
int ret;
/* First get the device zone information */
memset(&zd, 0, sizeof(struct zonefs_zone_data));
zd.sb = sb;
ret = zonefs_get_zone_info(&zd);
if (ret)
goto cleanup;
/* Allocate and initialize the zone groups */
for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
ret = zonefs_init_zgroup(sb, &zd, ztype);
if (ret) {
zonefs_info(sb,
"Zone group \"%s\" initialization failed\n",
zonefs_zgroup_name(ztype));
break;
}
}
cleanup:
zonefs_free_zone_info(&zd);
if (ret)
zonefs_free_zgroups(sb);
return ret;
}
/*
* Read super block information from the device.
*/
static int zonefs_read_super(struct super_block *sb)
{
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
struct zonefs_super *super;
u32 crc, stored_crc;
struct page *page;
struct bio_vec bio_vec;
struct bio bio;
int ret;
page = alloc_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
bio_init(&bio, sb->s_bdev, &bio_vec, 1, REQ_OP_READ);
bio.bi_iter.bi_sector = 0;
__bio_add_page(&bio, page, PAGE_SIZE, 0);
ret = submit_bio_wait(&bio);
if (ret)
goto free_page;
super = page_address(page);
ret = -EINVAL;
if (le32_to_cpu(super->s_magic) != ZONEFS_MAGIC)
goto free_page;
stored_crc = le32_to_cpu(super->s_crc);
super->s_crc = 0;
crc = crc32(~0U, (unsigned char *)super, sizeof(struct zonefs_super));
if (crc != stored_crc) {
zonefs_err(sb, "Invalid checksum (Expected 0x%08x, got 0x%08x)",
crc, stored_crc);
goto free_page;
}
sbi->s_features = le64_to_cpu(super->s_features);
if (sbi->s_features & ~ZONEFS_F_DEFINED_FEATURES) {
zonefs_err(sb, "Unknown features set 0x%llx\n",
sbi->s_features);
goto free_page;
}
if (sbi->s_features & ZONEFS_F_UID) {
sbi->s_uid = make_kuid(current_user_ns(),
le32_to_cpu(super->s_uid));
if (!uid_valid(sbi->s_uid)) {
zonefs_err(sb, "Invalid UID feature\n");
goto free_page;
}
}
if (sbi->s_features & ZONEFS_F_GID) {
sbi->s_gid = make_kgid(current_user_ns(),
le32_to_cpu(super->s_gid));
if (!gid_valid(sbi->s_gid)) {
zonefs_err(sb, "Invalid GID feature\n");
goto free_page;
}
}
if (sbi->s_features & ZONEFS_F_PERM)
sbi->s_perm = le32_to_cpu(super->s_perm);
if (memchr_inv(super->s_reserved, 0, sizeof(super->s_reserved))) {
zonefs_err(sb, "Reserved area is being used\n");
goto free_page;
}
import_uuid(&sbi->s_uuid, super->s_uuid);
ret = 0;
free_page:
__free_page(page);
return ret;
}
static const struct super_operations zonefs_sops = {
.alloc_inode = zonefs_alloc_inode,
.free_inode = zonefs_free_inode,
.statfs = zonefs_statfs,
.show_options = zonefs_show_options,
};
static int zonefs_get_zgroup_inodes(struct super_block *sb)
{
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
struct inode *dir_inode;
enum zonefs_ztype ztype;
for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
if (!sbi->s_zgroup[ztype].g_nr_zones)
continue;
dir_inode = zonefs_get_zgroup_inode(sb, ztype);
if (IS_ERR(dir_inode))
return PTR_ERR(dir_inode);
sbi->s_zgroup[ztype].g_inode = dir_inode;
}
return 0;
}
static void zonefs_release_zgroup_inodes(struct super_block *sb)
{
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
enum zonefs_ztype ztype;
if (!sbi)
return;
for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
if (sbi->s_zgroup[ztype].g_inode) {
iput(sbi->s_zgroup[ztype].g_inode);
sbi->s_zgroup[ztype].g_inode = NULL;
}
}
}
/*
* Check that the device is zoned. If it is, get the list of zones and create
* sub-directories and files according to the device zone configuration and
* format options.
*/
static int zonefs_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct zonefs_sb_info *sbi;
struct zonefs_context *ctx = fc->fs_private;
struct inode *inode;
enum zonefs_ztype ztype;
int ret;
if (!bdev_is_zoned(sb->s_bdev)) {
zonefs_err(sb, "Not a zoned block device\n");
return -EINVAL;
}
/*
* Initialize super block information: the maximum file size is updated
* when the zone files are created so that the format option
* ZONEFS_F_AGGRCNV which increases the maximum file size of a file
* beyond the zone size is taken into account.
*/
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi)
return -ENOMEM;
spin_lock_init(&sbi->s_lock);
sb->s_fs_info = sbi;
sb->s_magic = ZONEFS_MAGIC;
sb->s_maxbytes = 0;
sb->s_op = &zonefs_sops;
sb->s_time_gran = 1;
/*
* The block size is set to the device zone write granularity to ensure
* that write operations are always aligned according to the device
* interface constraints.
*/
sb_set_blocksize(sb, bdev_zone_write_granularity(sb->s_bdev));
sbi->s_zone_sectors_shift = ilog2(bdev_zone_sectors(sb->s_bdev));
sbi->s_uid = GLOBAL_ROOT_UID;
sbi->s_gid = GLOBAL_ROOT_GID;
sbi->s_perm = 0640;
sbi->s_mount_opts = ctx->s_mount_opts;
atomic_set(&sbi->s_wro_seq_files, 0);
sbi->s_max_wro_seq_files = bdev_max_open_zones(sb->s_bdev);
atomic_set(&sbi->s_active_seq_files, 0);
sbi->s_max_active_seq_files = bdev_max_active_zones(sb->s_bdev);
ret = zonefs_read_super(sb);
if (ret)
return ret;
zonefs_info(sb, "Mounting %u zones", bdev_nr_zones(sb->s_bdev));
if (!sbi->s_max_wro_seq_files &&
!sbi->s_max_active_seq_files &&
sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) {
zonefs_info(sb,
"No open and active zone limits. Ignoring explicit_open mount option\n");
sbi->s_mount_opts &= ~ZONEFS_MNTOPT_EXPLICIT_OPEN;
}
/* Initialize the zone groups */
ret = zonefs_init_zgroups(sb);
if (ret)
goto cleanup;
/* Create the root directory inode */
ret = -ENOMEM;
inode = new_inode(sb);
if (!inode)
goto cleanup;
inode->i_ino = bdev_nr_zones(sb->s_bdev);
inode->i_mode = S_IFDIR | 0555;
simple_inode_init_ts(inode);
inode->i_op = &zonefs_dir_inode_operations;
inode->i_fop = &zonefs_dir_operations;
inode->i_size = 2;
set_nlink(inode, 2);
for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
if (sbi->s_zgroup[ztype].g_nr_zones) {
inc_nlink(inode);
inode->i_size++;
}
}
sb->s_root = d_make_root(inode);
if (!sb->s_root)
goto cleanup;
/*
* Take a reference on the zone groups directory inodes
* to keep them in the inode cache.
*/
ret = zonefs_get_zgroup_inodes(sb);
if (ret)
goto cleanup;
ret = zonefs_sysfs_register(sb);
if (ret)
goto cleanup;
return 0;
cleanup:
zonefs_release_zgroup_inodes(sb);
zonefs_free_zgroups(sb);
return ret;
}
static void zonefs_kill_super(struct super_block *sb)
{
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
/* Release the reference on the zone group directory inodes */
zonefs_release_zgroup_inodes(sb);
kill_block_super(sb);
zonefs_sysfs_unregister(sb);
zonefs_free_zgroups(sb);
kfree(sbi);
}
static void zonefs_free_fc(struct fs_context *fc)
{
struct zonefs_context *ctx = fc->fs_private;
kfree(ctx);
}
static int zonefs_get_tree(struct fs_context *fc)
{
return get_tree_bdev(fc, zonefs_fill_super);
}
static int zonefs_reconfigure(struct fs_context *fc)
{
struct zonefs_context *ctx = fc->fs_private;
struct super_block *sb = fc->root->d_sb;
struct zonefs_sb_info *sbi = sb->s_fs_info;
sync_filesystem(fc->root->d_sb);
/* Copy new options from ctx into sbi. */
sbi->s_mount_opts = ctx->s_mount_opts;
return 0;
}
static const struct fs_context_operations zonefs_context_ops = {
.parse_param = zonefs_parse_param,
.get_tree = zonefs_get_tree,
.reconfigure = zonefs_reconfigure,
.free = zonefs_free_fc,
};
/*
* Set up the filesystem mount context.
*/
static int zonefs_init_fs_context(struct fs_context *fc)
{
struct zonefs_context *ctx;
ctx = kzalloc(sizeof(struct zonefs_context), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->s_mount_opts = ZONEFS_MNTOPT_ERRORS_RO;
fc->ops = &zonefs_context_ops;
fc->fs_private = ctx;
return 0;
}
/*
* File system definition and registration.
*/
static struct file_system_type zonefs_type = {
.owner = THIS_MODULE,
.name = "zonefs",
.kill_sb = zonefs_kill_super,
.fs_flags = FS_REQUIRES_DEV,
.init_fs_context = zonefs_init_fs_context,
.parameters = zonefs_param_spec,
};
static int __init zonefs_init_inodecache(void)
{
zonefs_inode_cachep = kmem_cache_create("zonefs_inode_cache",
sizeof(struct zonefs_inode_info), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
NULL);
if (zonefs_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void zonefs_destroy_inodecache(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy the inode cache.
*/
rcu_barrier();
kmem_cache_destroy(zonefs_inode_cachep);
}
static int __init zonefs_init(void)
{
int ret;
BUILD_BUG_ON(sizeof(struct zonefs_super) != ZONEFS_SUPER_SIZE);
ret = zonefs_init_inodecache();
if (ret)
return ret;
ret = zonefs_sysfs_init();
if (ret)
goto destroy_inodecache;
ret = register_filesystem(&zonefs_type);
if (ret)
goto sysfs_exit;
return 0;
sysfs_exit:
zonefs_sysfs_exit();
destroy_inodecache:
zonefs_destroy_inodecache();
return ret;
}
static void __exit zonefs_exit(void)
{
unregister_filesystem(&zonefs_type);
zonefs_sysfs_exit();
zonefs_destroy_inodecache();
}
MODULE_AUTHOR("Damien Le Moal");
MODULE_DESCRIPTION("Zone file system for zoned block devices");
MODULE_LICENSE("GPL");
MODULE_ALIAS_FS("zonefs");
module_init(zonefs_init);
module_exit(zonefs_exit);
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