original_kernel/fs/zonefs/file.c

861 lines
22 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Simple file system for zoned block devices exposing zones as files.
*
* Copyright (C) 2022 Western Digital Corporation or its affiliates.
*/
#include <linux/module.h>
#include <linux/pagemap.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/task_io_accounting_ops.h>
#include "zonefs.h"
#include "trace.h"
static int zonefs_read_iomap_begin(struct inode *inode, loff_t offset,
loff_t length, unsigned int flags,
struct iomap *iomap, struct iomap *srcmap)
{
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct zonefs_zone *z = zonefs_inode_zone(inode);
struct super_block *sb = inode->i_sb;
loff_t isize;
/*
* All blocks are always mapped below EOF. If reading past EOF,
* act as if there is a hole up to the file maximum size.
*/
mutex_lock(&zi->i_truncate_mutex);
iomap->bdev = inode->i_sb->s_bdev;
iomap->offset = ALIGN_DOWN(offset, sb->s_blocksize);
isize = i_size_read(inode);
if (iomap->offset >= isize) {
iomap->type = IOMAP_HOLE;
iomap->addr = IOMAP_NULL_ADDR;
iomap->length = length;
} else {
iomap->type = IOMAP_MAPPED;
iomap->addr = (z->z_sector << SECTOR_SHIFT) + iomap->offset;
iomap->length = isize - iomap->offset;
}
mutex_unlock(&zi->i_truncate_mutex);
trace_zonefs_iomap_begin(inode, iomap);
return 0;
}
static const struct iomap_ops zonefs_read_iomap_ops = {
.iomap_begin = zonefs_read_iomap_begin,
};
static int zonefs_write_iomap_begin(struct inode *inode, loff_t offset,
loff_t length, unsigned int flags,
struct iomap *iomap, struct iomap *srcmap)
{
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct zonefs_zone *z = zonefs_inode_zone(inode);
struct super_block *sb = inode->i_sb;
loff_t isize;
/* All write I/Os should always be within the file maximum size */
if (WARN_ON_ONCE(offset + length > z->z_capacity))
return -EIO;
/*
* Sequential zones can only accept direct writes. This is already
* checked when writes are issued, so warn if we see a page writeback
* operation.
*/
if (WARN_ON_ONCE(zonefs_zone_is_seq(z) && !(flags & IOMAP_DIRECT)))
return -EIO;
/*
* For conventional zones, all blocks are always mapped. For sequential
* zones, all blocks after always mapped below the inode size (zone
* write pointer) and unwriten beyond.
*/
mutex_lock(&zi->i_truncate_mutex);
iomap->bdev = inode->i_sb->s_bdev;
iomap->offset = ALIGN_DOWN(offset, sb->s_blocksize);
iomap->addr = (z->z_sector << SECTOR_SHIFT) + iomap->offset;
isize = i_size_read(inode);
if (iomap->offset >= isize) {
iomap->type = IOMAP_UNWRITTEN;
iomap->length = z->z_capacity - iomap->offset;
} else {
iomap->type = IOMAP_MAPPED;
iomap->length = isize - iomap->offset;
}
mutex_unlock(&zi->i_truncate_mutex);
trace_zonefs_iomap_begin(inode, iomap);
return 0;
}
static const struct iomap_ops zonefs_write_iomap_ops = {
.iomap_begin = zonefs_write_iomap_begin,
};
static int zonefs_read_folio(struct file *unused, struct folio *folio)
{
return iomap_read_folio(folio, &zonefs_read_iomap_ops);
}
static void zonefs_readahead(struct readahead_control *rac)
{
iomap_readahead(rac, &zonefs_read_iomap_ops);
}
/*
* Map blocks for page writeback. This is used only on conventional zone files,
* which implies that the page range can only be within the fixed inode size.
*/
static int zonefs_write_map_blocks(struct iomap_writepage_ctx *wpc,
struct inode *inode, loff_t offset,
unsigned int len)
{
struct zonefs_zone *z = zonefs_inode_zone(inode);
if (WARN_ON_ONCE(zonefs_zone_is_seq(z)))
return -EIO;
if (WARN_ON_ONCE(offset >= i_size_read(inode)))
return -EIO;
/* If the mapping is already OK, nothing needs to be done */
if (offset >= wpc->iomap.offset &&
offset < wpc->iomap.offset + wpc->iomap.length)
return 0;
return zonefs_write_iomap_begin(inode, offset,
z->z_capacity - offset,
IOMAP_WRITE, &wpc->iomap, NULL);
}
static const struct iomap_writeback_ops zonefs_writeback_ops = {
.map_blocks = zonefs_write_map_blocks,
};
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 int zonefs_swap_activate(struct swap_info_struct *sis,
struct file *swap_file, sector_t *span)
{
struct inode *inode = file_inode(swap_file);
if (zonefs_inode_is_seq(inode)) {
zonefs_err(inode->i_sb,
"swap file: not a conventional zone file\n");
return -EINVAL;
}
return iomap_swapfile_activate(sis, swap_file, span,
&zonefs_read_iomap_ops);
}
const struct address_space_operations zonefs_file_aops = {
.read_folio = zonefs_read_folio,
.readahead = zonefs_readahead,
.writepages = zonefs_writepages,
.dirty_folio = iomap_dirty_folio,
.release_folio = iomap_release_folio,
.invalidate_folio = iomap_invalidate_folio,
.migrate_folio = filemap_migrate_folio,
.is_partially_uptodate = iomap_is_partially_uptodate,
.error_remove_folio = generic_error_remove_folio,
.swap_activate = zonefs_swap_activate,
};
int zonefs_file_truncate(struct inode *inode, loff_t isize)
{
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct zonefs_zone *z = zonefs_inode_zone(inode);
loff_t old_isize;
enum req_op op;
int ret = 0;
/*
* Only sequential zone files can be truncated and truncation is allowed
* only down to a 0 size, which is equivalent to a zone reset, and to
* the maximum file size, which is equivalent to a zone finish.
*/
if (!zonefs_zone_is_seq(z))
return -EPERM;
if (!isize)
op = REQ_OP_ZONE_RESET;
else if (isize == z->z_capacity)
op = REQ_OP_ZONE_FINISH;
else
return -EPERM;
inode_dio_wait(inode);
/* Serialize against page faults */
filemap_invalidate_lock(inode->i_mapping);
/* Serialize against zonefs_iomap_begin() */
mutex_lock(&zi->i_truncate_mutex);
old_isize = i_size_read(inode);
if (isize == old_isize)
goto unlock;
ret = zonefs_inode_zone_mgmt(inode, op);
if (ret)
goto unlock;
/*
* If the mount option ZONEFS_MNTOPT_EXPLICIT_OPEN is set,
* take care of open zones.
*/
if (z->z_flags & ZONEFS_ZONE_OPEN) {
/*
* Truncating a zone to EMPTY or FULL is the equivalent of
* closing the zone. For a truncation to 0, we need to
* re-open the zone to ensure new writes can be processed.
* For a truncation to the maximum file size, the zone is
* closed and writes cannot be accepted anymore, so clear
* the open flag.
*/
if (!isize)
ret = zonefs_inode_zone_mgmt(inode, REQ_OP_ZONE_OPEN);
else
z->z_flags &= ~ZONEFS_ZONE_OPEN;
}
zonefs_update_stats(inode, isize);
truncate_setsize(inode, isize);
z->z_wpoffset = isize;
zonefs_inode_account_active(inode);
unlock:
mutex_unlock(&zi->i_truncate_mutex);
filemap_invalidate_unlock(inode->i_mapping);
return ret;
}
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;
if (unlikely(IS_IMMUTABLE(inode)))
return -EPERM;
/*
* Since only direct writes are allowed in sequential files, page cache
* flush is needed only for conventional zone files.
*/
if (zonefs_inode_is_cnv(inode))
ret = file_write_and_wait_range(file, start, end);
if (!ret)
ret = blkdev_issue_flush(inode->i_sb->s_bdev);
if (ret)
zonefs_io_error(inode, true);
return ret;
}
static vm_fault_t zonefs_filemap_page_mkwrite(struct vm_fault *vmf)
{
struct inode *inode = file_inode(vmf->vma->vm_file);
vm_fault_t ret;
if (unlikely(IS_IMMUTABLE(inode)))
return VM_FAULT_SIGBUS;
/*
* Sanity check: only conventional zone files can have shared
* writeable mappings.
*/
if (zonefs_inode_is_seq(inode))
return VM_FAULT_NOPAGE;
sb_start_pagefault(inode->i_sb);
file_update_time(vmf->vma->vm_file);
/* Serialize against truncates */
filemap_invalidate_lock_shared(inode->i_mapping);
ret = iomap_page_mkwrite(vmf, &zonefs_write_iomap_ops);
filemap_invalidate_unlock_shared(inode->i_mapping);
sb_end_pagefault(inode->i_sb);
return ret;
}
static const struct vm_operations_struct zonefs_file_vm_ops = {
.fault = 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 zones accept random writes, so their files can support
* shared writable mappings. For sequential zone files, only read
* mappings are possible since there are no guarantees for write
* ordering between msync() and page cache writeback.
*/
if (zonefs_inode_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 int zonefs_file_write_dio_end_io(struct kiocb *iocb, ssize_t size,
int error, unsigned int flags)
{
struct inode *inode = file_inode(iocb->ki_filp);
struct zonefs_inode_info *zi = ZONEFS_I(inode);
if (error) {
/*
* For Sync IOs, error recovery is called from
* zonefs_file_dio_write().
*/
if (!is_sync_kiocb(iocb))
zonefs_io_error(inode, true);
return error;
}
if (size && zonefs_inode_is_seq(inode)) {
/*
* Note that we may be seeing completions out of order,
* but that is not a problem since a write completed
* successfully necessarily means that all preceding writes
* were also successful. So we can safely increase the inode
* size to the write end location.
*/
mutex_lock(&zi->i_truncate_mutex);
if (i_size_read(inode) < iocb->ki_pos + size) {
zonefs_update_stats(inode, iocb->ki_pos + size);
zonefs_i_size_write(inode, iocb->ki_pos + size);
}
mutex_unlock(&zi->i_truncate_mutex);
}
return 0;
}
static const struct iomap_dio_ops zonefs_write_dio_ops = {
.end_io = zonefs_file_write_dio_end_io,
};
/*
* Do not exceed the LFS limits nor the file zone size. If pos is under the
* limit it becomes a short access. If it exceeds the limit, return -EFBIG.
*/
static loff_t zonefs_write_check_limits(struct file *file, loff_t pos,
loff_t count)
{
struct inode *inode = file_inode(file);
struct zonefs_zone *z = zonefs_inode_zone(inode);
loff_t limit = rlimit(RLIMIT_FSIZE);
loff_t max_size = z->z_capacity;
if (limit != RLIM_INFINITY) {
if (pos >= limit) {
send_sig(SIGXFSZ, current, 0);
return -EFBIG;
}
count = min(count, limit - pos);
}
if (!(file->f_flags & O_LARGEFILE))
max_size = min_t(loff_t, MAX_NON_LFS, max_size);
if (unlikely(pos >= max_size))
return -EFBIG;
return min(count, max_size - pos);
}
static ssize_t zonefs_write_checks(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct zonefs_zone *z = zonefs_inode_zone(inode);
loff_t count;
if (IS_SWAPFILE(inode))
return -ETXTBSY;
if (!iov_iter_count(from))
return 0;
if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
return -EINVAL;
if (iocb->ki_flags & IOCB_APPEND) {
if (zonefs_zone_is_cnv(z))
return -EINVAL;
mutex_lock(&zi->i_truncate_mutex);
iocb->ki_pos = z->z_wpoffset;
mutex_unlock(&zi->i_truncate_mutex);
}
count = zonefs_write_check_limits(file, iocb->ki_pos,
iov_iter_count(from));
if (count < 0)
return count;
iov_iter_truncate(from, count);
return iov_iter_count(from);
}
/*
* Handle direct writes. For sequential zone files, this is the only possible
* write path. For these files, check that the user is issuing writes
* sequentially from the end of the file. This code assumes that the block layer
* delivers write requests to the device in sequential order. This is always the
* case if a block IO scheduler implementing the ELEVATOR_F_ZBD_SEQ_WRITE
* elevator feature is being used (e.g. mq-deadline). The block layer always
* automatically select such an elevator for zoned block devices during the
* device initialization.
*/
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_zone *z = zonefs_inode_zone(inode);
struct super_block *sb = inode->i_sb;
ssize_t ret, count;
/*
* For async direct IOs to sequential zone files, refuse IOCB_NOWAIT
* as this can cause write reordering (e.g. the first aio gets EAGAIN
* on the inode lock but the second goes through but is now unaligned).
*/
if (zonefs_zone_is_seq(z) && !is_sync_kiocb(iocb) &&
(iocb->ki_flags & IOCB_NOWAIT))
return -EOPNOTSUPP;
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!inode_trylock(inode))
return -EAGAIN;
} else {
inode_lock(inode);
}
count = zonefs_write_checks(iocb, from);
if (count <= 0) {
ret = count;
goto inode_unlock;
}
if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) {
ret = -EINVAL;
goto inode_unlock;
}
/* Enforce sequential writes (append only) in sequential zones */
if (zonefs_zone_is_seq(z)) {
mutex_lock(&zi->i_truncate_mutex);
if (iocb->ki_pos != z->z_wpoffset) {
mutex_unlock(&zi->i_truncate_mutex);
ret = -EINVAL;
goto inode_unlock;
}
/*
* Advance the zone write pointer offset. This assumes that the
* IO will succeed, which is OK to do because we do not allow
* partial writes (IOMAP_DIO_PARTIAL is not set) and if the IO
* fails, the error path will correct the write pointer offset.
*/
z->z_wpoffset += count;
zonefs_inode_account_active(inode);
mutex_unlock(&zi->i_truncate_mutex);
}
/*
* iomap_dio_rw() may return ENOTBLK if there was an issue with
* page invalidation. Overwrite that error code with EBUSY so that
* the user can make sense of the error.
*/
ret = iomap_dio_rw(iocb, from, &zonefs_write_iomap_ops,
&zonefs_write_dio_ops, 0, NULL, 0);
if (ret == -ENOTBLK)
ret = -EBUSY;
/*
* For a failed IO or partial completion, trigger error recovery
* to update the zone write pointer offset to a correct value.
* For asynchronous IOs, zonefs_file_write_dio_end_io() may already
* have executed error recovery if the IO already completed when we
* reach here. However, we cannot know that and execute error recovery
* again (that will not change anything).
*/
if (zonefs_zone_is_seq(z)) {
if (ret > 0 && ret != count)
ret = -EIO;
if (ret < 0 && ret != -EIOCBQUEUED)
zonefs_io_error(inode, true);
}
inode_unlock:
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);
ssize_t ret;
/*
* Direct IO writes are mandatory for sequential zone files so that the
* write IO issuing order is preserved.
*/
if (zonefs_inode_is_seq(inode))
return -EIO;
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!inode_trylock(inode))
return -EAGAIN;
} else {
inode_lock(inode);
}
ret = zonefs_write_checks(iocb, from);
if (ret <= 0)
goto inode_unlock;
ret = iomap_file_buffered_write(iocb, from, &zonefs_write_iomap_ops);
if (ret == -EIO)
zonefs_io_error(inode, true);
inode_unlock:
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);
struct zonefs_zone *z = zonefs_inode_zone(inode);
if (unlikely(IS_IMMUTABLE(inode)))
return -EPERM;
if (sb_rdonly(inode->i_sb))
return -EROFS;
/* Write operations beyond the zone capacity are not allowed */
if (iocb->ki_pos >= z->z_capacity)
return -EFBIG;
if (iocb->ki_flags & IOCB_DIRECT) {
ssize_t ret = zonefs_file_dio_write(iocb, from);
if (ret != -ENOTBLK)
return ret;
}
return zonefs_file_buffered_write(iocb, from);
}
static int zonefs_file_read_dio_end_io(struct kiocb *iocb, ssize_t size,
int error, unsigned int flags)
{
if (error) {
zonefs_io_error(file_inode(iocb->ki_filp), false);
return error;
}
return 0;
}
static const struct iomap_dio_ops zonefs_read_dio_ops = {
.end_io = zonefs_file_read_dio_end_io,
};
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_zone *z = zonefs_inode_zone(inode);
struct super_block *sb = inode->i_sb;
loff_t isize;
ssize_t ret;
/* Offline zones cannot be read */
if (unlikely(IS_IMMUTABLE(inode) && !(inode->i_mode & 0777)))
return -EPERM;
if (iocb->ki_pos >= z->z_capacity)
return 0;
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!inode_trylock_shared(inode))
return -EAGAIN;
} else {
inode_lock_shared(inode);
}
/* Limit read operations to written data */
mutex_lock(&zi->i_truncate_mutex);
isize = i_size_read(inode);
if (iocb->ki_pos >= isize) {
mutex_unlock(&zi->i_truncate_mutex);
ret = 0;
goto inode_unlock;
}
iov_iter_truncate(to, isize - iocb->ki_pos);
mutex_unlock(&zi->i_truncate_mutex);
if (iocb->ki_flags & IOCB_DIRECT) {
size_t count = iov_iter_count(to);
if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) {
ret = -EINVAL;
goto inode_unlock;
}
file_accessed(iocb->ki_filp);
ret = iomap_dio_rw(iocb, to, &zonefs_read_iomap_ops,
&zonefs_read_dio_ops, 0, NULL, 0);
} else {
ret = generic_file_read_iter(iocb, to);
if (ret == -EIO)
zonefs_io_error(inode, false);
}
inode_unlock:
inode_unlock_shared(inode);
return ret;
}
static ssize_t zonefs_file_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe,
size_t len, unsigned int flags)
{
struct inode *inode = file_inode(in);
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct zonefs_zone *z = zonefs_inode_zone(inode);
loff_t isize;
ssize_t ret = 0;
/* Offline zones cannot be read */
if (unlikely(IS_IMMUTABLE(inode) && !(inode->i_mode & 0777)))
return -EPERM;
if (*ppos >= z->z_capacity)
return 0;
inode_lock_shared(inode);
/* Limit read operations to written data */
mutex_lock(&zi->i_truncate_mutex);
isize = i_size_read(inode);
if (*ppos >= isize)
len = 0;
else
len = min_t(loff_t, len, isize - *ppos);
mutex_unlock(&zi->i_truncate_mutex);
if (len > 0) {
ret = filemap_splice_read(in, ppos, pipe, len, flags);
if (ret == -EIO)
zonefs_io_error(inode, false);
}
inode_unlock_shared(inode);
return ret;
}
/*
* Write open accounting is done only for sequential files.
*/
static inline bool zonefs_seq_file_need_wro(struct inode *inode,
struct file *file)
{
if (zonefs_inode_is_cnv(inode))
return false;
if (!(file->f_mode & FMODE_WRITE))
return false;
return true;
}
static int zonefs_seq_file_write_open(struct inode *inode)
{
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct zonefs_zone *z = zonefs_inode_zone(inode);
int ret = 0;
mutex_lock(&zi->i_truncate_mutex);
if (!zi->i_wr_refcnt) {
struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);
unsigned int wro = atomic_inc_return(&sbi->s_wro_seq_files);
if (sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) {
if (sbi->s_max_wro_seq_files
&& wro > sbi->s_max_wro_seq_files) {
atomic_dec(&sbi->s_wro_seq_files);
ret = -EBUSY;
goto unlock;
}
if (i_size_read(inode) < z->z_capacity) {
ret = zonefs_inode_zone_mgmt(inode,
REQ_OP_ZONE_OPEN);
if (ret) {
atomic_dec(&sbi->s_wro_seq_files);
goto unlock;
}
z->z_flags |= ZONEFS_ZONE_OPEN;
zonefs_inode_account_active(inode);
}
}
}
zi->i_wr_refcnt++;
unlock:
mutex_unlock(&zi->i_truncate_mutex);
return ret;
}
static int zonefs_file_open(struct inode *inode, struct file *file)
{
int ret;
file->f_mode |= FMODE_CAN_ODIRECT;
ret = generic_file_open(inode, file);
if (ret)
return ret;
if (zonefs_seq_file_need_wro(inode, file))
return zonefs_seq_file_write_open(inode);
return 0;
}
static void zonefs_seq_file_write_close(struct inode *inode)
{
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct zonefs_zone *z = zonefs_inode_zone(inode);
struct super_block *sb = inode->i_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
int ret = 0;
mutex_lock(&zi->i_truncate_mutex);
zi->i_wr_refcnt--;
if (zi->i_wr_refcnt)
goto unlock;
/*
* The file zone may not be open anymore (e.g. the file was truncated to
* its maximum size or it was fully written). For this case, we only
* need to decrement the write open count.
*/
if (z->z_flags & ZONEFS_ZONE_OPEN) {
ret = zonefs_inode_zone_mgmt(inode, REQ_OP_ZONE_CLOSE);
if (ret) {
__zonefs_io_error(inode, false);
/*
* Leaving zones explicitly open may lead to a state
* where most zones cannot be written (zone resources
* exhausted). So take preventive action by remounting
* read-only.
*/
if (z->z_flags & ZONEFS_ZONE_OPEN &&
!(sb->s_flags & SB_RDONLY)) {
zonefs_warn(sb,
"closing zone at %llu failed %d\n",
z->z_sector, ret);
zonefs_warn(sb,
"remounting filesystem read-only\n");
sb->s_flags |= SB_RDONLY;
}
goto unlock;
}
z->z_flags &= ~ZONEFS_ZONE_OPEN;
zonefs_inode_account_active(inode);
}
atomic_dec(&sbi->s_wro_seq_files);
unlock:
mutex_unlock(&zi->i_truncate_mutex);
}
static int zonefs_file_release(struct inode *inode, struct file *file)
{
/*
* If we explicitly open a zone we must close it again as well, but the
* zone management operation can fail (either due to an IO error or as
* the zone has gone offline or read-only). Make sure we don't fail the
* close(2) for user-space.
*/
if (zonefs_seq_file_need_wro(inode, file))
zonefs_seq_file_write_close(inode);
return 0;
}
const struct file_operations zonefs_file_operations = {
.open = zonefs_file_open,
.release = zonefs_file_release,
.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 = zonefs_file_splice_read,
.splice_write = iter_file_splice_write,
.iopoll = iocb_bio_iopoll,
};