linux/fs/zonefs/file.c
Linus Torvalds 6016fc9162 New code for 6.6:
* Make large writes to the page cache fill sparse parts of the cache
    with large folios, then use large memcpy calls for the large folio.
  * Track the per-block dirty state of each large folio so that a
    buffered write to a single byte on a large folio does not result in a
    (potentially) multi-megabyte writeback IO.
  * Allow some directio completions to be performed in the initiating
    task's context instead of punting through a workqueue.  This will
    reduce latency for some io_uring requests.
 
 Signed-off-by: Darrick J. Wong <djwong@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQQ2qTKExjcn+O1o2YRKO3ySh0YRpgUCZM0Z1AAKCRBKO3ySh0YR
 pp7BAQCzkKejCM0185tNIH/faHjzidSisNQkJ5HoB4Opq9U66AEA6IPuAdlPlM/J
 FPW1oPq33Yn7AV4wXjUNFfDLzVb/Fgg=
 =dFBU
 -----END PGP SIGNATURE-----

Merge tag 'iomap-6.6-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull iomap updates from Darrick Wong:
 "We've got some big changes for this release -- I'm very happy to be
  landing willy's work to enable large folios for the page cache for
  general read and write IOs when the fs can make contiguous space
  allocations, and Ritesh's work to track sub-folio dirty state to
  eliminate the write amplification problems inherent in using large
  folios.

  As a bonus, io_uring can now process write completions in the caller's
  context instead of bouncing through a workqueue, which should reduce
  io latency dramatically. IOWs, XFS should see a nice performance bump
  for both IO paths.

  Summary:

   - Make large writes to the page cache fill sparse parts of the cache
     with large folios, then use large memcpy calls for the large folio.

   - Track the per-block dirty state of each large folio so that a
     buffered write to a single byte on a large folio does not result in
     a (potentially) multi-megabyte writeback IO.

   - Allow some directio completions to be performed in the initiating
     task's context instead of punting through a workqueue. This will
     reduce latency for some io_uring requests"

* tag 'iomap-6.6-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (26 commits)
  iomap: support IOCB_DIO_CALLER_COMP
  io_uring/rw: add write support for IOCB_DIO_CALLER_COMP
  fs: add IOCB flags related to passing back dio completions
  iomap: add IOMAP_DIO_INLINE_COMP
  iomap: only set iocb->private for polled bio
  iomap: treat a write through cache the same as FUA
  iomap: use an unsigned type for IOMAP_DIO_* defines
  iomap: cleanup up iomap_dio_bio_end_io()
  iomap: Add per-block dirty state tracking to improve performance
  iomap: Allocate ifs in ->write_begin() early
  iomap: Refactor iomap_write_delalloc_punch() function out
  iomap: Use iomap_punch_t typedef
  iomap: Fix possible overflow condition in iomap_write_delalloc_scan
  iomap: Add some uptodate state handling helpers for ifs state bitmap
  iomap: Drop ifs argument from iomap_set_range_uptodate()
  iomap: Rename iomap_page to iomap_folio_state and others
  iomap: Copy larger chunks from userspace
  iomap: Create large folios in the buffered write path
  filemap: Allow __filemap_get_folio to allocate large folios
  filemap: Add fgf_t typedef
  ...
2023-08-28 11:59:52 -07:00

848 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)
{
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_page = generic_error_remove_page,
.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) {
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;
}
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;
if (zonefs_zone_is_seq(z) &&
(ret > 0 || ret == -EIOCBQUEUED)) {
if (ret > 0)
count = ret;
/*
* Update the zone write pointer offset assuming the write
* operation succeeded. If it did not, the error recovery path
* will correct it. Also do active seq file accounting.
*/
mutex_lock(&zi->i_truncate_mutex);
z->z_wpoffset += count;
zonefs_inode_account_active(inode);
mutex_unlock(&zi->i_truncate_mutex);
}
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,
};