@@ -17793,6 +17793,16 @@ L: linux-kernel@vger.kernel.org
S: Maintained
F: arch/x86/kernel/cpu/zhaoxin.c
+ZONEFS FILESYSTEM
+M: Damien Le Moal <damien.lemoal@wdc.com>
+M: Naohiro Aota <naohiro.aota@wdc.com>
+R: Johannes Thumshirn <jth@kernel.org>
+L: linux-fsdevel@vger.kernel.org
+T: git git@github.com:damien-lemoal/zonefs.git
+S: Maintained
+F: Documentation/filesystems/zonefs.txt
+F: fs/zonefs/
+
ZPOOL COMPRESSED PAGE STORAGE API
M: Dan Streetman <ddstreet@ieee.org>
L: linux-mm@kvack.org
@@ -40,6 +40,7 @@ source "fs/ocfs2/Kconfig"
source "fs/btrfs/Kconfig"
source "fs/nilfs2/Kconfig"
source "fs/f2fs/Kconfig"
+source "fs/zonefs/Kconfig"
config FS_DAX
bool "Direct Access (DAX) support"
@@ -130,3 +130,4 @@ obj-$(CONFIG_F2FS_FS) += f2fs/
obj-$(CONFIG_CEPH_FS) += ceph/
obj-$(CONFIG_PSTORE) += pstore/
obj-$(CONFIG_EFIVAR_FS) += efivarfs/
+obj-$(CONFIG_ZONEFS_FS) += zonefs/
new file mode 100644
@@ -0,0 +1,9 @@
+config ZONEFS_FS
+ tristate "zonefs filesystem support"
+ depends on BLOCK
+ depends on BLK_DEV_ZONED
+ help
+ zonefs is a simple File System which exposes zones of a zoned block
+ device as files.
+
+ If unsure, say N.
new file mode 100644
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_ZONEFS_FS) += zonefs.o
+
+zonefs-y := super.o
new file mode 100644
@@ -0,0 +1,1097 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Simple zone file system for zoned block devices.
+ *
+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
+ */
+#include <linux/module.h>
+#include <linux/fs.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/parser.h>
+#include <linux/uio.h>
+#include <linux/mman.h>
+#include <linux/sched/mm.h>
+#include <linux/crc32.h>
+
+#include "zonefs.h"
+
+static int zonefs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
+ unsigned int flags, struct iomap *iomap)
+{
+ struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);
+ struct zonefs_inode_info *zi = ZONEFS_I(inode);
+ loff_t max_isize = zonefs_file_max_size(inode);
+ loff_t isize;
+
+ /*
+ * For sequential zones, enforce direct IO writes. This is already
+ * checked when writes are issued, so warn about this here if we
+ * get buffered write to a sequential file inode.
+ */
+ if (WARN_ON_ONCE(zonefs_file_is_seq(inode) && (flags & IOMAP_WRITE) &&
+ !(flags & IOMAP_DIRECT)))
+ return -EIO;
+
+ /* An IO cannot exceed the zone size */
+ if (offset >= max_isize)
+ return -EFBIG;
+
+ /* All blocks are always mapped */
+ mutex_lock(&zi->i_truncate_mutex);
+ isize = i_size_read(inode);
+ if (offset >= isize) {
+ length = min(length, max_isize - offset);
+ iomap->type = IOMAP_UNWRITTEN;
+ } else {
+ length = min(length, isize - offset);
+ iomap->type = IOMAP_MAPPED;
+ }
+ mutex_unlock(&zi->i_truncate_mutex);
+
+ iomap->offset = offset & (~sbi->s_blocksize_mask);
+ iomap->length = ((offset + length + sbi->s_blocksize_mask) &
+ (~sbi->s_blocksize_mask)) - iomap->offset;
+ iomap->bdev = inode->i_sb->s_bdev;
+ iomap->addr = (zonefs_file_start_sector(inode) << SECTOR_SHIFT)
+ + iomap->offset;
+
+ return 0;
+}
+
+static const struct iomap_ops zonefs_iomap_ops = {
+ .iomap_begin = zonefs_iomap_begin,
+};
+
+static int zonefs_readpage(struct file *unused, struct page *page)
+{
+ return iomap_readpage(page, &zonefs_iomap_ops);
+}
+
+static int zonefs_readpages(struct file *unused, struct address_space *mapping,
+ struct list_head *pages, unsigned int nr_pages)
+{
+ return iomap_readpages(mapping, pages, nr_pages, &zonefs_iomap_ops);
+}
+
+static int zonefs_map_blocks(struct iomap_writepage_ctx *wpc,
+ struct inode *inode, loff_t offset)
+{
+ if (offset >= wpc->iomap.offset &&
+ offset < wpc->iomap.offset + wpc->iomap.length)
+ return 0;
+
+ memset(&wpc->iomap, 0, sizeof(wpc->iomap));
+ return zonefs_iomap_begin(inode, offset, zonefs_file_max_size(inode),
+ 0, &wpc->iomap);
+}
+
+static const struct iomap_writeback_ops zonefs_writeback_ops = {
+ .map_blocks = zonefs_map_blocks,
+};
+
+static int zonefs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ struct iomap_writepage_ctx wpc = { };
+
+ return iomap_writepage(page, wbc, &wpc, &zonefs_writeback_ops);
+}
+
+static int zonefs_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct iomap_writepage_ctx wpc = { };
+
+ return iomap_writepages(mapping, wbc, &wpc, &zonefs_writeback_ops);
+}
+
+static const struct address_space_operations zonefs_file_aops = {
+ .readpage = zonefs_readpage,
+ .readpages = zonefs_readpages,
+ .writepage = zonefs_writepage,
+ .writepages = zonefs_writepages,
+ .set_page_dirty = iomap_set_page_dirty,
+ .releasepage = iomap_releasepage,
+ .invalidatepage = iomap_invalidatepage,
+ .migratepage = iomap_migrate_page,
+ .is_partially_uptodate = iomap_is_partially_uptodate,
+ .error_remove_page = generic_error_remove_page,
+ .direct_IO = noop_direct_IO,
+};
+
+static int zonefs_seq_file_truncate(struct inode *inode)
+{
+ struct zonefs_inode_info *zi = ZONEFS_I(inode);
+ int ret;
+
+ inode_dio_wait(inode);
+
+ /* Serialize against page faults */
+ down_write(&zi->i_mmap_sem);
+
+ /* Serialize against zonefs_iomap_begin() */
+ mutex_lock(&zi->i_truncate_mutex);
+
+ ret = blkdev_reset_zones(inode->i_sb->s_bdev,
+ zonefs_file_start_sector(inode),
+ zonefs_file_max_size(inode) >> SECTOR_SHIFT,
+ GFP_NOFS);
+ if (ret) {
+ zonefs_err(inode->i_sb,
+ "Reset zone at %llu failed %d",
+ zonefs_file_start_sector(inode),
+ ret);
+ } else {
+ truncate_setsize(inode, 0);
+ zi->i_wpoffset = 0;
+ }
+
+ mutex_unlock(&zi->i_truncate_mutex);
+ up_write(&zi->i_mmap_sem);
+
+ return ret;
+}
+
+static int zonefs_inode_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+ struct inode *inode = d_inode(dentry);
+ int ret;
+
+ ret = setattr_prepare(dentry, iattr);
+ if (ret)
+ return ret;
+
+ 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(inode, iattr);
+ if (ret)
+ return ret;
+ }
+
+ if (iattr->ia_valid & ATTR_SIZE) {
+ /* The size of conventional zone files cannot be changed */
+ if (zonefs_file_is_conv(inode))
+ return -EPERM;
+
+ /*
+ * For sequential zone files, we can only allow truncating to
+ * 0 size which is equivalent to a zone reset.
+ */
+ if (iattr->ia_size != 0)
+ return -EPERM;
+
+ ret = zonefs_seq_file_truncate(inode);
+ if (ret)
+ return ret;
+ }
+
+ setattr_copy(inode, iattr);
+
+ return 0;
+}
+
+static const struct inode_operations zonefs_file_inode_operations = {
+ .setattr = zonefs_inode_setattr,
+};
+
+static int zonefs_conv_file_write_and_wait(struct file *file, loff_t start,
+ loff_t end)
+{
+ int ret;
+
+ ret = file_write_and_wait_range(file, start, end);
+ if (ret)
+ return ret;
+
+ return file_check_and_advance_wb_err(file);
+}
+
+static int zonefs_file_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync)
+{
+ struct inode *inode = file_inode(file);
+ int ret = 0;
+
+ /*
+ * Since only direct writes are allowed in sequential files, page cache
+ * flush is needed only for conventional zone files.
+ */
+ if (zonefs_file_is_conv(inode))
+ ret = zonefs_conv_file_write_and_wait(file, start, end);
+
+ if (ret == 0)
+ ret = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+
+ return ret;
+}
+
+static vm_fault_t zonefs_filemap_fault(struct vm_fault *vmf)
+{
+ struct zonefs_inode_info *zi = ZONEFS_I(file_inode(vmf->vma->vm_file));
+ vm_fault_t ret;
+
+ down_read(&zi->i_mmap_sem);
+ ret = filemap_fault(vmf);
+ up_read(&zi->i_mmap_sem);
+
+ return ret;
+}
+
+static vm_fault_t zonefs_filemap_page_mkwrite(struct vm_fault *vmf)
+{
+ struct inode *inode = file_inode(vmf->vma->vm_file);
+ struct zonefs_inode_info *zi = ZONEFS_I(inode);
+ vm_fault_t ret;
+
+ sb_start_pagefault(inode->i_sb);
+ file_update_time(vmf->vma->vm_file);
+
+ /* Serialize against truncates */
+ down_read(&zi->i_mmap_sem);
+ ret = iomap_page_mkwrite(vmf, &zonefs_iomap_ops);
+ up_read(&zi->i_mmap_sem);
+
+ sb_end_pagefault(inode->i_sb);
+ return ret;
+}
+
+static const struct vm_operations_struct zonefs_file_vm_ops = {
+ .fault = zonefs_filemap_fault,
+ .map_pages = filemap_map_pages,
+ .page_mkwrite = zonefs_filemap_page_mkwrite,
+};
+
+static int zonefs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ /*
+ * Conventional zone files can be mmap-ed READ/WRITE.
+ * For sequential zone files, only readonly mappings are possible.
+ */
+ if (zonefs_file_is_seq(file_inode(file)) &&
+ (vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
+ return -EINVAL;
+
+ file_accessed(file);
+ vma->vm_ops = &zonefs_file_vm_ops;
+
+ return 0;
+}
+
+static loff_t zonefs_file_llseek(struct file *file, loff_t offset, int whence)
+{
+ loff_t isize = i_size_read(file_inode(file));
+
+ /*
+ * Seeks are limited to below the zone size for conventional zones
+ * and below the zone write pointer for sequential zones. In both
+ * cases, this limit is the inode size.
+ */
+ return generic_file_llseek_size(file, offset, whence, isize, isize);
+}
+
+static ssize_t zonefs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct zonefs_inode_info *zi = ZONEFS_I(inode);
+ struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);
+ loff_t max_pos;
+ size_t count;
+ ssize_t ret;
+
+ if (iocb->ki_pos >= zonefs_file_max_size(inode))
+ return 0;
+
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (!inode_trylock_shared(inode))
+ return -EAGAIN;
+ } else {
+ inode_lock_shared(inode);
+ }
+
+ mutex_lock(&zi->i_truncate_mutex);
+
+ /*
+ * Limit read operations to written data.
+ */
+ max_pos = i_size_read(inode);
+ if (iocb->ki_pos >= max_pos) {
+ mutex_unlock(&zi->i_truncate_mutex);
+ ret = 0;
+ goto out;
+ }
+
+ iov_iter_truncate(to, max_pos - iocb->ki_pos);
+
+ mutex_unlock(&zi->i_truncate_mutex);
+
+ count = iov_iter_count(to);
+
+ if (iocb->ki_flags & IOCB_DIRECT) {
+ /*
+ * Direct IO reads must be aligned to device physical sector
+ * size.
+ */
+ if ((iocb->ki_pos | count) & sbi->s_blocksize_mask) {
+ ret = -EINVAL;
+ } else {
+ file_accessed(iocb->ki_filp);
+ ret = iomap_dio_rw(iocb, to, &zonefs_iomap_ops, NULL);
+ }
+ } else {
+ ret = generic_file_read_iter(iocb, to);
+ }
+
+out:
+ inode_unlock_shared(inode);
+
+ return ret;
+}
+
+/*
+ * When a write error occurs in a sequential zone, the zone write pointer
+ * position must be refreshed to correct the file size and zonefs inode
+ * write pointer offset.
+ */
+static int zonefs_seq_file_write_failed(struct inode *inode, int error)
+{
+ struct super_block *sb = inode->i_sb;
+ struct zonefs_inode_info *zi = ZONEFS_I(inode);
+ sector_t sector = zi->i_zsector;
+ unsigned int nofs_flag;
+ struct blk_zone zone;
+ int n = 1, ret;
+ loff_t pos;
+
+ zonefs_warn(sb, "Updating inode zone %llu info\n", sector);
+
+ /*
+ * blkdev_report_zones() uses GFP_KERNEL by default. Force execution as
+ * if GFP_NOFS was specified to no end up recusrsing into the FS on
+ * memory allocation.
+ */
+ nofs_flag = memalloc_nofs_save();
+ ret = blkdev_report_zones(sb->s_bdev, sector, &zone, &n);
+ memalloc_nofs_restore(nofs_flag);
+
+ if (ret || !n) {
+ if (!n)
+ ret = -EIO;
+ zonefs_err(sb, "Get zone %llu report failed %d\n",
+ sector, ret);
+ return ret;
+ }
+
+ pos = (zone.wp - zone.start) << SECTOR_SHIFT;
+ zi->i_wpoffset = pos;
+ if (i_size_read(inode) != pos)
+ i_size_write(inode, pos);
+
+ return error;
+}
+
+static int zonefs_file_dio_write_end(struct kiocb *iocb, ssize_t size, int ret,
+ unsigned int flags)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct zonefs_inode_info *zi = ZONEFS_I(inode);
+
+ if (ret)
+ return ret;
+
+ /*
+ * Conventional zone file size is fixed to the zone size so there
+ * is no need to do anything.
+ */
+ if (zonefs_file_is_conv(inode))
+ return 0;
+
+ mutex_lock(&zi->i_truncate_mutex);
+
+ if (size < 0) {
+ ret = zonefs_seq_file_write_failed(inode, size);
+ } else {
+ /* Update seq file size */
+ if (i_size_read(inode) < iocb->ki_pos + size)
+ i_size_write(inode, iocb->ki_pos + size);
+ }
+
+ mutex_unlock(&zi->i_truncate_mutex);
+
+ return ret;
+}
+
+static const struct iomap_dio_ops zonefs_dio_ops = {
+ .end_io = zonefs_file_dio_write_end,
+};
+
+static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct zonefs_inode_info *zi = ZONEFS_I(inode);
+ struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);
+ size_t count;
+ ssize_t ret;
+
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (!inode_trylock(inode))
+ return -EAGAIN;
+ } else {
+ inode_lock(inode);
+ }
+
+ ret = generic_write_checks(iocb, from);
+ if (ret <= 0)
+ goto out;
+
+ iov_iter_truncate(from, zonefs_file_max_size(inode) - iocb->ki_pos);
+ count = iov_iter_count(from);
+
+ /*
+ * Direct writes must be aligned to the block size, that is, the device
+ * physical sector size, to avoid errors when writing sequential zones
+ * on 512e devices (512B logical sector, 4KB physical sectors).
+ */
+ if ((iocb->ki_pos | count) & sbi->s_blocksize_mask) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /*
+ * Enforce sequential writes (append only) in sequential zones.
+ */
+ mutex_lock(&zi->i_truncate_mutex);
+ if (zonefs_file_is_seq(inode) &&
+ iocb->ki_pos != zi->i_wpoffset) {
+ zonefs_err(inode->i_sb,
+ "Unaligned write at %llu + %zu (wp %llu)\n",
+ iocb->ki_pos, count,
+ zi->i_wpoffset);
+ mutex_unlock(&zi->i_truncate_mutex);
+ ret = -EINVAL;
+ goto out;
+ }
+ mutex_unlock(&zi->i_truncate_mutex);
+
+ ret = iomap_dio_rw(iocb, from, &zonefs_iomap_ops, &zonefs_dio_ops);
+ if (zonefs_file_is_seq(inode) &&
+ (ret > 0 || ret == -EIOCBQUEUED)) {
+ if (ret > 0)
+ count = ret;
+ mutex_lock(&zi->i_truncate_mutex);
+ zi->i_wpoffset += count;
+ mutex_unlock(&zi->i_truncate_mutex);
+ }
+
+out:
+ inode_unlock(inode);
+
+ return ret;
+}
+
+static ssize_t zonefs_file_buffered_write(struct kiocb *iocb,
+ struct iov_iter *from)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ size_t count;
+ ssize_t ret;
+
+ /*
+ * Direct IO writes are mandatory for sequential zones so that the
+ * write IO order is preserved.
+ */
+ if (zonefs_file_is_seq(inode))
+ return -EIO;
+
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (!inode_trylock(inode))
+ return -EAGAIN;
+ } else {
+ inode_lock(inode);
+ }
+
+ ret = generic_write_checks(iocb, from);
+ if (ret <= 0)
+ goto out;
+
+ iov_iter_truncate(from, zonefs_file_max_size(inode) - iocb->ki_pos);
+ count = iov_iter_count(from);
+
+ ret = iomap_file_buffered_write(iocb, from, &zonefs_iomap_ops);
+ if (ret > 0)
+ iocb->ki_pos += ret;
+
+out:
+ inode_unlock(inode);
+
+ if (ret > 0)
+ ret = generic_write_sync(iocb, ret);
+
+ return ret;
+}
+
+static ssize_t zonefs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+
+ /*
+ * Check that the write operation does not go beyond the zone size.
+ */
+ if (iocb->ki_pos >= zonefs_file_max_size(inode))
+ return -EFBIG;
+
+ if (iocb->ki_flags & IOCB_DIRECT)
+ return zonefs_file_dio_write(iocb, from);
+
+ return zonefs_file_buffered_write(iocb, from);
+}
+
+static const struct file_operations zonefs_file_operations = {
+ .open = generic_file_open,
+ .fsync = zonefs_file_fsync,
+ .mmap = zonefs_file_mmap,
+ .llseek = zonefs_file_llseek,
+ .read_iter = zonefs_file_read_iter,
+ .write_iter = zonefs_file_write_iter,
+ .splice_read = generic_file_splice_read,
+ .splice_write = iter_file_splice_write,
+ .iopoll = iomap_dio_iopoll,
+};
+
+
+static struct kmem_cache *zonefs_inode_cachep;
+
+static struct inode *zonefs_alloc_inode(struct super_block *sb)
+{
+ struct zonefs_inode_info *zi;
+
+ zi = kmem_cache_alloc(zonefs_inode_cachep, GFP_KERNEL);
+ if (!zi)
+ return NULL;
+
+ mutex_init(&zi->i_truncate_mutex);
+ init_rwsem(&zi->i_mmap_sem);
+ inode_init_once(&zi->i_vnode);
+
+ return &zi->i_vnode;
+}
+
+static void zonefs_free_inode(struct inode *inode)
+{
+ kmem_cache_free(zonefs_inode_cachep, ZONEFS_I(inode));
+}
+
+static struct dentry *zonefs_create_inode(struct dentry *parent,
+ const char *name,
+ struct blk_zone *zone)
+{
+ struct zonefs_sb_info *sbi = ZONEFS_SB(parent->d_sb);
+ struct inode *dir = d_inode(parent);
+ struct dentry *dentry;
+ struct inode *inode;
+
+ dentry = d_alloc_name(parent, name);
+ if (!dentry)
+ return NULL;
+
+ inode = new_inode(parent->d_sb);
+ if (!inode)
+ goto out_dput;
+
+ inode->i_ino = get_next_ino();
+ if (zone) {
+ struct zonefs_inode_info *zi = ZONEFS_I(inode);
+
+ /*
+ * Zone file: for read-only zones, do not allow writes.
+ * For offline zones, disable all accesses and set the file
+ * size to 0.
+ */
+ inode->i_mode = S_IFREG;
+ switch (zone->cond) {
+ case BLK_ZONE_COND_READONLY:
+ inode->i_mode |= sbi->s_perm & ~(0222); /* S_IWUGO */
+ case BLK_ZONE_COND_OFFLINE:
+ break;
+ default:
+ inode->i_mode |= sbi->s_perm;
+ }
+ inode->i_uid = sbi->s_uid;
+ inode->i_gid = sbi->s_gid;
+ zi->i_ztype = zonefs_zone_type(zone);
+ zi->i_zsector = zone->start;
+ zi->i_max_size = zone->len << SECTOR_SHIFT;
+
+ if (zone->cond == BLK_ZONE_COND_OFFLINE)
+ zi->i_wpoffset = 0;
+ else if (zonefs_file_is_conv(inode))
+ zi->i_wpoffset = zi->i_max_size;
+ else
+ zi->i_wpoffset =
+ (zone->wp - zone->start) << SECTOR_SHIFT;
+
+ inode->i_size = zi->i_wpoffset;
+ inode->i_blocks = zone->len;
+ inode->i_fop = &zonefs_file_operations;
+ inode->i_op = &zonefs_file_inode_operations;
+ inode->i_mapping->a_ops = &zonefs_file_aops;
+ } else {
+ /* Zone group directory */
+ inode_init_owner(inode, dir, S_IFDIR | 0555);
+ inode->i_fop = &simple_dir_operations;
+ inode->i_op = &simple_dir_inode_operations;
+ set_nlink(inode, 2);
+ inc_nlink(dir);
+ }
+ inode->i_ctime = inode->i_mtime = inode->i_atime = dir->i_ctime;
+
+ d_add(dentry, inode);
+ d_inode(parent)->i_size += sizeof(struct dentry);
+
+ return dentry;
+
+out_dput:
+ dput(dentry);
+ return NULL;
+}
+
+/*
+ * 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);
+ sector_t nr_sectors = sb->s_bdev->bd_part->nr_sects;
+ enum zonefs_ztype t;
+ u64 fsid;
+
+ buf->f_type = ZONEFS_MAGIC;
+ buf->f_bsize = dentry->d_sb->s_blocksize;
+ buf->f_namelen = ZONEFS_NAME_MAX;
+
+ buf->f_blocks = nr_sectors >> (sb->s_blocksize_bits - SECTOR_SHIFT);
+ buf->f_bfree = 0;
+ buf->f_bavail = 0;
+
+ buf->f_files = blkdev_nr_zones(sb->s_bdev);
+ for (t = 0 ; t < ZONEFS_ZTYPE_MAX; t++) {
+ if (sbi->s_nr_zones[t])
+ buf->f_files++;
+ }
+ buf->f_ffree = 0;
+
+ fsid = le64_to_cpup((void *)sbi->s_uuid.b) ^
+ le64_to_cpup((void *)sbi->s_uuid.b + sizeof(u64));
+ buf->f_fsid.val[0] = (u32)fsid;
+ buf->f_fsid.val[1] = (u32)(fsid >> 32);
+
+ return 0;
+}
+
+static const struct super_operations zonefs_sops = {
+ .alloc_inode = zonefs_alloc_inode,
+ .free_inode = zonefs_free_inode,
+ .statfs = zonefs_statfs,
+};
+
+static char *zgroups_name[ZONEFS_ZTYPE_MAX] = {
+ "cnv",
+ "seq"
+};
+
+/*
+ * Create a zone group and populate it with zone files.
+ */
+static int zonefs_create_zgroup(struct super_block *sb, struct blk_zone *zones,
+ enum zonefs_ztype type)
+{
+ struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
+ struct blk_zone *zone, *next, *end;
+ char name[ZONEFS_NAME_MAX];
+ unsigned int nr_files = 0;
+ struct dentry *dir;
+
+ /* If the group is empty, nothing to do */
+ if (!sbi->s_nr_zones[type])
+ return 0;
+
+ dir = zonefs_create_inode(sb->s_root, zgroups_name[type], NULL);
+ if (!dir)
+ return -ENOMEM;
+
+ /*
+ * Note: The first zone contains the super block: skip it.
+ */
+ end = zones + blkdev_nr_zones(sb->s_bdev);
+ for (zone = &zones[1]; zone < end; zone = next) {
+
+ next = zone + 1;
+ if (zonefs_zone_type(zone) != type)
+ continue;
+
+ /*
+ * 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.
+ * Only zones with the same condition can be agreggated so that
+ * offline zones are excluded and readonly zones are aggregated
+ * together into a read only file.
+ */
+ if (type == ZONEFS_ZTYPE_CNV &&
+ zonefs_has_feature(sbi, ZONEFS_F_AGRCNV)) {
+ for (; next < end; next++) {
+ if (zonefs_zone_type(next) != type ||
+ next->cond != zone->cond)
+ break;
+ zone->len += next->len;
+ }
+ }
+
+ if (zonefs_has_feature(sbi, ZONEFS_F_STARTSECT_NAME))
+ /* Use zone start sector as file names */
+ snprintf(name, ZONEFS_NAME_MAX - 1, "%llu",
+ zone->start);
+ else
+ /* Use file number as file names */
+ snprintf(name, ZONEFS_NAME_MAX - 1, "%u", nr_files);
+ nr_files++;
+
+ if (!zonefs_create_inode(dir, name, zone))
+ return -ENOMEM;
+ }
+
+ zonefs_info(sb, "Zone group %d (%s), %u zones -> %u file%s\n",
+ type, zgroups_name[type], sbi->s_nr_zones[type],
+ nr_files, nr_files > 1 ? "s" : "");
+
+ return 0;
+}
+
+static struct blk_zone *zonefs_get_zone_info(struct super_block *sb)
+{
+ struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
+ struct block_device *bdev = sb->s_bdev;
+ sector_t nr_sectors = bdev->bd_part->nr_sects;
+ unsigned int i, n, nr_zones = 0;
+ struct blk_zone *zones, *zone;
+ sector_t sector = 0;
+ int ret;
+
+ zones = kvcalloc(blkdev_nr_zones(bdev),
+ sizeof(struct blk_zone), GFP_KERNEL);
+ if (!zones)
+ return ERR_PTR(-ENOMEM);
+
+ /* Get zones information */
+ zone = zones;
+ while (nr_zones < blkdev_nr_zones(bdev) &&
+ sector < nr_sectors) {
+
+ n = blkdev_nr_zones(bdev) - nr_zones;
+ ret = blkdev_report_zones(bdev, sector, zone, &n);
+ if (ret) {
+ zonefs_err(sb, "Zone report failed %d\n", ret);
+ goto err;
+ }
+ if (!n) {
+ zonefs_err(sb, "No zones reported\n");
+ ret = -EIO;
+ goto err;
+ }
+
+ for (i = 0; i < n; i++) {
+ switch (zone->type) {
+ case BLK_ZONE_TYPE_CONVENTIONAL:
+ zone->wp = zone->start + zone->len;
+ if (zone > zones)
+ sbi->s_nr_zones[ZONEFS_ZTYPE_CNV]++;
+ break;
+ case BLK_ZONE_TYPE_SEQWRITE_REQ:
+ case BLK_ZONE_TYPE_SEQWRITE_PREF:
+ if (zone > zones)
+ sbi->s_nr_zones[ZONEFS_ZTYPE_SEQ]++;
+ break;
+ default:
+ zonefs_err(sb, "Unsupported zone type 0x%x\n",
+ zone->type);
+ ret = -EIO;
+ goto err;
+ }
+ sector += zone->len;
+ zone++;
+ }
+
+ nr_zones += n;
+ }
+
+ if (sector < nr_sectors ||
+ nr_zones != blkdev_nr_zones(bdev)) {
+ zonefs_err(sb, "Invalid zone report\n");
+ ret = -EIO;
+ goto err;
+ }
+
+ return zones;
+
+err:
+ kvfree(zones);
+ return ERR_PTR(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;
+ struct bio bio;
+ struct bio_vec bio_vec;
+ struct page *page;
+ u32 crc, stored_crc;
+ int ret;
+
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ bio_init(&bio, &bio_vec, 1);
+ bio.bi_iter.bi_sector = 0;
+ bio_set_dev(&bio, sb->s_bdev);
+ bio_set_op_attrs(&bio, REQ_OP_READ, 0);
+ bio_add_page(&bio, page, PAGE_SIZE, 0);
+
+ ret = submit_bio_wait(&bio);
+ if (ret)
+ goto out;
+
+ super = page_address(page);
+
+ stored_crc = super->s_crc;
+ super->s_crc = 0;
+ crc = crc32_le(ZONEFS_MAGIC, (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);
+ ret = -EIO;
+ goto out;
+ }
+
+ ret = -EINVAL;
+ if (le32_to_cpu(super->s_magic) != ZONEFS_MAGIC)
+ goto out;
+
+ 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 out;
+ }
+
+
+ if (zonefs_has_feature(sbi, 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 out;
+ }
+ }
+ if (zonefs_has_feature(sbi, 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 out;
+ }
+ }
+
+ if (zonefs_has_feature(sbi, 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 out;
+ }
+
+ uuid_copy(&sbi->s_uuid, &super->s_uuid);
+ ret = 0;
+
+out:
+ __free_page(page);
+
+ return ret;
+}
+
+/*
+ * 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.
+ */
+static int zonefs_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct zonefs_sb_info *sbi;
+ struct blk_zone *zones;
+ struct inode *inode;
+ enum zonefs_ztype t;
+ int ret;
+
+ /* Check device type */
+ if (!bdev_is_zoned(sb->s_bdev)) {
+ zonefs_err(sb, "Not a zoned block device\n");
+ return -EINVAL;
+ }
+
+ /* Initialize super block information */
+ sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+ if (!sbi)
+ return -ENOMEM;
+
+ sb->s_fs_info = sbi;
+ sb->s_magic = ZONEFS_MAGIC;
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_op = &zonefs_sops;
+ sb->s_time_gran = 1;
+
+ /*
+ * The block size is always equal to the device physical sector size to
+ * ensure that writes on 512e disks (512B logical block and 4KB
+ * physical block) are always aligned.
+ */
+ sb_set_blocksize(sb, bdev_physical_block_size(sb->s_bdev));
+ sbi->s_blocksize_mask = sb->s_blocksize - 1;
+
+ sbi->s_uid = GLOBAL_ROOT_UID;
+ sbi->s_gid = GLOBAL_ROOT_GID;
+ sbi->s_perm = 0640; /* S_IRUSR | S_IWUSR | S_IRGRP */
+
+ ret = zonefs_read_super(sb);
+ if (ret)
+ return ret;
+
+ zones = zonefs_get_zone_info(sb);
+ if (IS_ERR(zones))
+ return PTR_ERR(zones);
+
+ pr_info("zonefs: Mounting %s, %u zones",
+ sb->s_id, blkdev_nr_zones(sb->s_bdev));
+
+ /* Create root directory inode */
+ ret = -ENOMEM;
+ inode = new_inode(sb);
+ if (!inode)
+ goto out;
+
+ inode->i_ino = get_next_ino();
+ inode->i_mode = S_IFDIR | 0755;
+ inode->i_ctime = inode->i_mtime = inode->i_atime = current_time(inode);
+ inode->i_op = &simple_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ inode->i_size = sizeof(struct dentry) * 2;
+ set_nlink(inode, 2);
+
+ sb->s_root = d_make_root(inode);
+ if (!sb->s_root)
+ goto out;
+
+ /* Create and populate zone groups */
+ for (t = ZONEFS_ZTYPE_CNV; t < ZONEFS_ZTYPE_MAX; t++) {
+ ret = zonefs_create_zgroup(sb, zones, t);
+ if (ret)
+ break;
+ }
+
+out:
+ kvfree(zones);
+
+ return ret;
+}
+
+static struct dentry *zonefs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_bdev(fs_type, flags, dev_name, data, zonefs_fill_super);
+}
+
+static void zonefs_kill_super(struct super_block *sb)
+{
+ struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
+
+ kfree(sbi);
+ if (sb->s_root)
+ d_genocide(sb->s_root);
+ kill_block_super(sb);
+}
+
+/*
+ * File system definition and registration.
+ */
+static struct file_system_type zonefs_type = {
+ .owner = THIS_MODULE,
+ .name = "zonefs",
+ .mount = zonefs_mount,
+ .kill_sb = zonefs_kill_super,
+ .fs_flags = FS_REQUIRES_DEV,
+};
+
+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_MEM_SPREAD | 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 = register_filesystem(&zonefs_type);
+ if (ret) {
+ zonefs_destroy_inodecache();
+ return ret;
+ }
+
+ return 0;
+}
+
+static void __exit zonefs_exit(void)
+{
+ zonefs_destroy_inodecache();
+ unregister_filesystem(&zonefs_type);
+}
+
+MODULE_AUTHOR("Damien Le Moal");
+MODULE_DESCRIPTION("Zone file system for zoned block devices");
+MODULE_LICENSE("GPL");
+module_init(zonefs_init);
+module_exit(zonefs_exit);
new file mode 100644
@@ -0,0 +1,185 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Simple zone file system for zoned block devices.
+ *
+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
+ */
+#ifndef __ZONEFS_H__
+#define __ZONEFS_H__
+
+#include <linux/fs.h>
+#include <linux/magic.h>
+#include <linux/uuid.h>
+#include <linux/mutex.h>
+#include <linux/rwsem.h>
+
+/*
+ * Maximum length of file names: this only needs to be large enough to fit
+ * the zone group directory names and a decimal value of the start sector of
+ * the zones for file names. 16 characters is plenty.
+ */
+#define ZONEFS_NAME_MAX 16
+
+/*
+ * Zone types: ZONEFS_ZTYPE_SEQ is used for all sequential zone types
+ * defined in linux/blkzoned.h, that is, BLK_ZONE_TYPE_SEQWRITE_REQ and
+ * BLK_ZONE_TYPE_SEQWRITE_PREF.
+ */
+enum zonefs_ztype {
+ ZONEFS_ZTYPE_CNV,
+ ZONEFS_ZTYPE_SEQ,
+ ZONEFS_ZTYPE_MAX,
+};
+
+static inline enum zonefs_ztype zonefs_zone_type(struct blk_zone *zone)
+{
+ if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
+ return ZONEFS_ZTYPE_CNV;
+ return ZONEFS_ZTYPE_SEQ;
+}
+
+/*
+ * Inode private data.
+ */
+struct zonefs_inode_info {
+ struct inode i_vnode;
+ enum zonefs_ztype i_ztype;
+ sector_t i_zsector;
+ loff_t i_wpoffset;
+ loff_t i_max_size;
+ struct mutex i_truncate_mutex;
+ struct rw_semaphore i_mmap_sem;
+};
+
+static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode)
+{
+ return container_of(inode, struct zonefs_inode_info, i_vnode);
+}
+
+static inline bool zonefs_file_is_conv(struct inode *inode)
+{
+ return ZONEFS_I(inode)->i_ztype == ZONEFS_ZTYPE_CNV;
+}
+
+static inline bool zonefs_file_is_seq(struct inode *inode)
+{
+ return ZONEFS_I(inode)->i_ztype == ZONEFS_ZTYPE_SEQ;
+}
+
+/*
+ * Start sector on disk of a file zone.
+ */
+static inline loff_t zonefs_file_start_sector(struct inode *inode)
+{
+ return ZONEFS_I(inode)->i_zsector;
+}
+
+/*
+ * Maximum possible size of a file (i.e. the zone size).
+ */
+static inline loff_t zonefs_file_max_size(struct inode *inode)
+{
+ return ZONEFS_I(inode)->i_max_size;
+}
+
+/*
+ * On-disk super block (block 0).
+ */
+#define ZONEFS_SUPER_SIZE 4096
+struct zonefs_super {
+
+ /* Magic number */
+ __le32 s_magic;
+
+ /* Checksum */
+ __le32 s_crc;
+
+ /* Features */
+ __le64 s_features;
+
+ /* 128-bit uuid */
+ uuid_t s_uuid;
+
+ /* UID/GID to use for files */
+ __le32 s_uid;
+ __le32 s_gid;
+
+ /* File permissions */
+ __le32 s_perm;
+
+ /* Padding to ZONEFS_SUPER_SIZE bytes */
+ __u8 s_reserved[4052];
+
+} __packed;
+
+/*
+ * Feature flags: used on disk in the s_features field of struct zonefs_super
+ * and in-memory in the s_feartures field of struct zonefs_sb_info.
+ */
+enum zonefs_features {
+ /*
+ * Use a zone start sector value as file name.
+ */
+ __ZONEFS_F_STARTSECT_NAME,
+ /*
+ * Aggregate contiguous conventional zones into a single file.
+ */
+ __ZONEFS_F_AGRCNV,
+ /*
+ * Use super block specified UID for files instead of default.
+ */
+ __ZONEFS_F_UID,
+ /*
+ * Use super block specified GID for files instead of default.
+ */
+ __ZONEFS_F_GID,
+ /*
+ * Use super block specified file permissions instead of default 640.
+ */
+ __ZONEFS_F_PERM,
+};
+
+#define ZONEFS_F_STARTSECT_NAME (1ULL << __ZONEFS_F_STARTSECT_NAME)
+#define ZONEFS_F_AGRCNV (1ULL << __ZONEFS_F_AGRCNV)
+#define ZONEFS_F_UID (1ULL << __ZONEFS_F_UID)
+#define ZONEFS_F_GID (1ULL << __ZONEFS_F_GID)
+#define ZONEFS_F_PERM (1ULL << __ZONEFS_F_PERM)
+
+#define ZONEFS_F_DEFINED_FEATURES \
+ (ZONEFS_F_STARTSECT_NAME | ZONEFS_F_AGRCNV | \
+ ZONEFS_F_UID | ZONEFS_F_GID | ZONEFS_F_PERM)
+
+/*
+ * In-memory Super block information.
+ */
+struct zonefs_sb_info {
+
+ unsigned long long s_features;
+ kuid_t s_uid; /* File owner UID */
+ kgid_t s_gid; /* File owner GID */
+ umode_t s_perm; /* File permissions */
+ uuid_t s_uuid;
+
+ loff_t s_blocksize_mask;
+ unsigned int s_nr_zones[ZONEFS_ZTYPE_MAX];
+};
+
+static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb)
+{
+ return sb->s_fs_info;
+}
+
+static inline bool zonefs_has_feature(struct zonefs_sb_info *sbi,
+ enum zonefs_features f)
+{
+ return sbi->s_features & f;
+}
+
+#define zonefs_info(sb, format, args...) \
+ pr_info("zonefs (%s): " format, sb->s_id, ## args)
+#define zonefs_err(sb, format, args...) \
+ pr_err("zonefs (%s) ERROR: " format, sb->s_id, ## args)
+#define zonefs_warn(sb, format, args...) \
+ pr_warn("zonefs (%s) WARN: " format, sb->s_id, ## args)
+
+#endif
@@ -86,6 +86,7 @@
#define NSFS_MAGIC 0x6e736673
#define BPF_FS_MAGIC 0xcafe4a11
#define AAFS_MAGIC 0x5a3c69f0
+#define ZONEFS_MAGIC 0x5a4f4653
/* Since UDF 2.01 is ISO 13346 based... */
#define UDF_SUPER_MAGIC 0x15013346