45dd052e67
By moving FIEMAP_FLAG_SYNC handling to fiemap_prep we ensure it is handled once instead of duplicated, but can still be done under fs locks, like xfs/iomap intended with its duplicate handling. Also make sure the error value of filemap_write_and_wait is propagated to user space. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Link: https://lore.kernel.org/r/20200523073016.2944131-8-hch@lst.de Signed-off-by: Theodore Ts'o <tytso@mit.edu>
141 lines
2.9 KiB
C
141 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2016-2018 Christoph Hellwig.
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*/
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#include <linux/module.h>
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#include <linux/compiler.h>
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#include <linux/fs.h>
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#include <linux/iomap.h>
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#include <linux/fiemap.h>
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struct fiemap_ctx {
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struct fiemap_extent_info *fi;
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struct iomap prev;
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};
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static int iomap_to_fiemap(struct fiemap_extent_info *fi,
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struct iomap *iomap, u32 flags)
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{
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switch (iomap->type) {
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case IOMAP_HOLE:
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/* skip holes */
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return 0;
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case IOMAP_DELALLOC:
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flags |= FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN;
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break;
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case IOMAP_MAPPED:
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break;
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case IOMAP_UNWRITTEN:
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flags |= FIEMAP_EXTENT_UNWRITTEN;
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break;
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case IOMAP_INLINE:
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flags |= FIEMAP_EXTENT_DATA_INLINE;
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break;
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}
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if (iomap->flags & IOMAP_F_MERGED)
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flags |= FIEMAP_EXTENT_MERGED;
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if (iomap->flags & IOMAP_F_SHARED)
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flags |= FIEMAP_EXTENT_SHARED;
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return fiemap_fill_next_extent(fi, iomap->offset,
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iomap->addr != IOMAP_NULL_ADDR ? iomap->addr : 0,
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iomap->length, flags);
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}
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static loff_t
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iomap_fiemap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
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struct iomap *iomap, struct iomap *srcmap)
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{
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struct fiemap_ctx *ctx = data;
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loff_t ret = length;
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if (iomap->type == IOMAP_HOLE)
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return length;
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ret = iomap_to_fiemap(ctx->fi, &ctx->prev, 0);
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ctx->prev = *iomap;
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switch (ret) {
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case 0: /* success */
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return length;
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case 1: /* extent array full */
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return 0;
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default:
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return ret;
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}
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}
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int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
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u64 start, u64 len, const struct iomap_ops *ops)
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{
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struct fiemap_ctx ctx;
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loff_t ret;
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memset(&ctx, 0, sizeof(ctx));
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ctx.fi = fi;
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ctx.prev.type = IOMAP_HOLE;
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ret = fiemap_prep(inode, fi, start, &len, 0);
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if (ret)
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return ret;
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while (len > 0) {
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ret = iomap_apply(inode, start, len, IOMAP_REPORT, ops, &ctx,
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iomap_fiemap_actor);
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/* inode with no (attribute) mapping will give ENOENT */
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if (ret == -ENOENT)
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break;
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if (ret < 0)
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return ret;
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if (ret == 0)
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break;
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start += ret;
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len -= ret;
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}
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if (ctx.prev.type != IOMAP_HOLE) {
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ret = iomap_to_fiemap(fi, &ctx.prev, FIEMAP_EXTENT_LAST);
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if (ret < 0)
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return ret;
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(iomap_fiemap);
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static loff_t
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iomap_bmap_actor(struct inode *inode, loff_t pos, loff_t length,
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void *data, struct iomap *iomap, struct iomap *srcmap)
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{
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sector_t *bno = data, addr;
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if (iomap->type == IOMAP_MAPPED) {
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addr = (pos - iomap->offset + iomap->addr) >> inode->i_blkbits;
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*bno = addr;
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}
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return 0;
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}
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/* legacy ->bmap interface. 0 is the error return (!) */
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sector_t
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iomap_bmap(struct address_space *mapping, sector_t bno,
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const struct iomap_ops *ops)
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{
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struct inode *inode = mapping->host;
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loff_t pos = bno << inode->i_blkbits;
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unsigned blocksize = i_blocksize(inode);
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int ret;
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if (filemap_write_and_wait(mapping))
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return 0;
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bno = 0;
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ret = iomap_apply(inode, pos, blocksize, 0, ops, &bno,
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iomap_bmap_actor);
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if (ret)
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return 0;
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return bno;
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}
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EXPORT_SYMBOL_GPL(iomap_bmap);
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