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author | Darrick J. Wong <darrick.wong@oracle.com> | 2019-07-15 17:51:00 +0200 |
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committer | Darrick J. Wong <darrick.wong@oracle.com> | 2019-07-17 16:20:43 +0200 |
commit | cb7181ff4b1ca1e4a9dbea8a3982142ce4ed73fd (patch) | |
tree | da6484b487f636f0eefd781f10b522a5652dd2c8 /fs/iomap.c | |
parent | iomap: move the buffered IO code into a separate file (diff) | |
download | linux-cb7181ff4b1ca1e4a9dbea8a3982142ce4ed73fd.tar.xz linux-cb7181ff4b1ca1e4a9dbea8a3982142ce4ed73fd.zip |
iomap: move the main iteration code into a separate file
Move the main iteration code into a separate file so that we can group
related functions in a single file instead of having a single enormous
source file.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/iomap.c')
-rw-r--r-- | fs/iomap.c | 91 |
1 files changed, 0 insertions, 91 deletions
diff --git a/fs/iomap.c b/fs/iomap.c deleted file mode 100644 index 88a3144351a9..000000000000 --- a/fs/iomap.c +++ /dev/null @@ -1,91 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Copyright (C) 2010 Red Hat, Inc. - * Copyright (c) 2016-2018 Christoph Hellwig. - */ -#include <linux/module.h> -#include <linux/compiler.h> -#include <linux/fs.h> -#include <linux/iomap.h> -#include <linux/uaccess.h> -#include <linux/gfp.h> -#include <linux/migrate.h> -#include <linux/mm.h> -#include <linux/mm_inline.h> -#include <linux/swap.h> -#include <linux/pagemap.h> -#include <linux/pagevec.h> -#include <linux/file.h> -#include <linux/uio.h> -#include <linux/backing-dev.h> -#include <linux/buffer_head.h> -#include <linux/task_io_accounting_ops.h> -#include <linux/dax.h> -#include <linux/sched/signal.h> - -#include "internal.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 = { 0 }; - loff_t written = 0, ret; - - /* - * 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); - if (ret) - return ret; - if (WARN_ON(iomap.offset > pos)) - return -EIO; - if (WARN_ON(iomap.length == 0)) - return -EIO; - - /* - * 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. - */ - if (iomap.offset + iomap.length < pos + length) - length = iomap.offset + iomap.length - 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. - */ - written = actor(inode, pos, length, data, &iomap); - - /* - * 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; -} |