iomap: remove iomap_apply (57320a01) · Commits · EulixOS / Software / Kernel

fs/iomap/apply.c

+0 −91

Original line number	Diff line number	Diff line
		@@ -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) */

fs/iomap/trace.h

+0 −40

Original line number	Diff line number	Diff line
		@@ -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),

include/linux/iomap.h

+0 −10

Original line number	Diff line number	Diff line
		@@ -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);