iomap: remove iomap_apply

iomap_apply is unused now, so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[djwong: rebase this patch to preserve git history of iomap loop control]
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
This commit is contained in:
Christoph Hellwig 2021-08-10 18:33:13 -07:00 committed by Darrick J. Wong
parent ca289e0b95
commit 57320a01fe
3 changed files with 0 additions and 141 deletions

View File

@ -3,101 +3,10 @@
* Copyright (C) 2010 Red Hat, Inc.
* Copyright (c) 2016-2021 Christoph Hellwig.
*/
#include <linux/module.h>
#include <linux/compiler.h>
#include <linux/fs.h>
#include <linux/iomap.h>
#include "trace.h"
/*
* Execute a iomap write on a segment of the mapping that spans a
* contiguous range of pages that have identical block mapping state.
*
* This avoids the need to map pages individually, do individual allocations
* for each page and most importantly avoid the need for filesystem specific
* locking per page. Instead, all the operations are amortised over the entire
* range of pages. It is assumed that the filesystems will lock whatever
* resources they require in the iomap_begin call, and release them in the
* iomap_end call.
*/
loff_t
iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags,
const struct iomap_ops *ops, void *data, iomap_actor_t actor)
{
struct iomap iomap = { .type = IOMAP_HOLE };
struct iomap srcmap = { .type = IOMAP_HOLE };
loff_t written = 0, ret;
u64 end;
trace_iomap_apply(inode, pos, length, flags, ops, actor, _RET_IP_);
/*
* Need to map a range from start position for length bytes. This can
* span multiple pages - it is only guaranteed to return a range of a
* single type of pages (e.g. all into a hole, all mapped or all
* unwritten). Failure at this point has nothing to undo.
*
* If allocation is required for this range, reserve the space now so
* that the allocation is guaranteed to succeed later on. Once we copy
* the data into the page cache pages, then we cannot fail otherwise we
* expose transient stale data. If the reserve fails, we can safely
* back out at this point as there is nothing to undo.
*/
ret = ops->iomap_begin(inode, pos, length, flags, &iomap, &srcmap);
if (ret)
return ret;
if (WARN_ON(iomap.offset > pos)) {
written = -EIO;
goto out;
}
if (WARN_ON(iomap.length == 0)) {
written = -EIO;
goto out;
}
trace_iomap_apply_dstmap(inode, &iomap);
if (srcmap.type != IOMAP_HOLE)
trace_iomap_apply_srcmap(inode, &srcmap);
/*
* Cut down the length to the one actually provided by the filesystem,
* as it might not be able to give us the whole size that we requested.
*/
end = iomap.offset + iomap.length;
if (srcmap.type != IOMAP_HOLE)
end = min(end, srcmap.offset + srcmap.length);
if (pos + length > end)
length = end - pos;
/*
* Now that we have guaranteed that the space allocation will succeed,
* we can do the copy-in page by page without having to worry about
* failures exposing transient data.
*
* To support COW operations, we read in data for partially blocks from
* the srcmap if the file system filled it in. In that case we the
* length needs to be limited to the earlier of the ends of the iomaps.
* If the file system did not provide a srcmap we pass in the normal
* iomap into the actors so that they don't need to have special
* handling for the two cases.
*/
written = actor(inode, pos, length, data, &iomap,
srcmap.type != IOMAP_HOLE ? &srcmap : &iomap);
out:
/*
* Now the data has been copied, commit the range we've copied. This
* should not fail unless the filesystem has had a fatal error.
*/
if (ops->iomap_end) {
ret = ops->iomap_end(inode, pos, length,
written > 0 ? written : 0,
flags, &iomap);
}
return written ? written : ret;
}
static inline int iomap_iter_advance(struct iomap_iter *iter)
{
/* handle the previous iteration (if any) */

View File

@ -138,49 +138,9 @@ DECLARE_EVENT_CLASS(iomap_class,
DEFINE_EVENT(iomap_class, name, \
TP_PROTO(struct inode *inode, struct iomap *iomap), \
TP_ARGS(inode, iomap))
DEFINE_IOMAP_EVENT(iomap_apply_dstmap);
DEFINE_IOMAP_EVENT(iomap_apply_srcmap);
DEFINE_IOMAP_EVENT(iomap_iter_dstmap);
DEFINE_IOMAP_EVENT(iomap_iter_srcmap);
TRACE_EVENT(iomap_apply,
TP_PROTO(struct inode *inode, loff_t pos, loff_t length,
unsigned int flags, const void *ops, void *actor,
unsigned long caller),
TP_ARGS(inode, pos, length, flags, ops, actor, caller),
TP_STRUCT__entry(
__field(dev_t, dev)
__field(u64, ino)
__field(loff_t, pos)
__field(loff_t, length)
__field(unsigned int, flags)
__field(const void *, ops)
__field(void *, actor)
__field(unsigned long, caller)
),
TP_fast_assign(
__entry->dev = inode->i_sb->s_dev;
__entry->ino = inode->i_ino;
__entry->pos = pos;
__entry->length = length;
__entry->flags = flags;
__entry->ops = ops;
__entry->actor = actor;
__entry->caller = caller;
),
TP_printk("dev %d:%d ino 0x%llx pos %lld length %lld flags %s (0x%x) "
"ops %ps caller %pS actor %ps",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->ino,
__entry->pos,
__entry->length,
__print_flags(__entry->flags, "|", IOMAP_FLAGS_STRINGS),
__entry->flags,
__entry->ops,
(void *)__entry->caller,
__entry->actor)
);
TRACE_EVENT(iomap_iter,
TP_PROTO(struct iomap_iter *iter, const void *ops,
unsigned long caller),

View File

@ -217,16 +217,6 @@ static inline struct iomap *iomap_iter_srcmap(struct iomap_iter *i)
return &i->iomap;
}
/*
* Main iomap iterator function.
*/
typedef loff_t (*iomap_actor_t)(struct inode *inode, loff_t pos, loff_t len,
void *data, struct iomap *iomap, struct iomap *srcmap);
loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length,
unsigned flags, const struct iomap_ops *ops, void *data,
iomap_actor_t actor);
ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
const struct iomap_ops *ops);
int iomap_readpage(struct page *page, const struct iomap_ops *ops);