forked from Minki/linux
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
|
|
/*
|
|
* Copyright (c) 2016-2018 Christoph Hellwig.
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/compiler.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/iomap.h>
|
|
#include <linux/fiemap.h>
|
|
|
|
struct fiemap_ctx {
|
|
struct fiemap_extent_info *fi;
|
|
struct iomap prev;
|
|
};
|
|
|
|
static int iomap_to_fiemap(struct fiemap_extent_info *fi,
|
|
struct iomap *iomap, u32 flags)
|
|
{
|
|
switch (iomap->type) {
|
|
case IOMAP_HOLE:
|
|
/* skip holes */
|
|
return 0;
|
|
case IOMAP_DELALLOC:
|
|
flags |= FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN;
|
|
break;
|
|
case IOMAP_MAPPED:
|
|
break;
|
|
case IOMAP_UNWRITTEN:
|
|
flags |= FIEMAP_EXTENT_UNWRITTEN;
|
|
break;
|
|
case IOMAP_INLINE:
|
|
flags |= FIEMAP_EXTENT_DATA_INLINE;
|
|
break;
|
|
}
|
|
|
|
if (iomap->flags & IOMAP_F_MERGED)
|
|
flags |= FIEMAP_EXTENT_MERGED;
|
|
if (iomap->flags & IOMAP_F_SHARED)
|
|
flags |= FIEMAP_EXTENT_SHARED;
|
|
|
|
return fiemap_fill_next_extent(fi, iomap->offset,
|
|
iomap->addr != IOMAP_NULL_ADDR ? iomap->addr : 0,
|
|
iomap->length, flags);
|
|
}
|
|
|
|
static loff_t
|
|
iomap_fiemap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
|
|
struct iomap *iomap, struct iomap *srcmap)
|
|
{
|
|
struct fiemap_ctx *ctx = data;
|
|
loff_t ret = length;
|
|
|
|
if (iomap->type == IOMAP_HOLE)
|
|
return length;
|
|
|
|
ret = iomap_to_fiemap(ctx->fi, &ctx->prev, 0);
|
|
ctx->prev = *iomap;
|
|
switch (ret) {
|
|
case 0: /* success */
|
|
return length;
|
|
case 1: /* extent array full */
|
|
return 0;
|
|
default:
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
|
|
u64 start, u64 len, const struct iomap_ops *ops)
|
|
{
|
|
struct fiemap_ctx ctx;
|
|
loff_t ret;
|
|
|
|
memset(&ctx, 0, sizeof(ctx));
|
|
ctx.fi = fi;
|
|
ctx.prev.type = IOMAP_HOLE;
|
|
|
|
ret = fiemap_prep(inode, fi, start, &len, 0);
|
|
if (ret)
|
|
return ret;
|
|
|
|
while (len > 0) {
|
|
ret = iomap_apply(inode, start, len, IOMAP_REPORT, ops, &ctx,
|
|
iomap_fiemap_actor);
|
|
/* inode with no (attribute) mapping will give ENOENT */
|
|
if (ret == -ENOENT)
|
|
break;
|
|
if (ret < 0)
|
|
return ret;
|
|
if (ret == 0)
|
|
break;
|
|
|
|
start += ret;
|
|
len -= ret;
|
|
}
|
|
|
|
if (ctx.prev.type != IOMAP_HOLE) {
|
|
ret = iomap_to_fiemap(fi, &ctx.prev, FIEMAP_EXTENT_LAST);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_fiemap);
|
|
|
|
static loff_t
|
|
iomap_bmap_actor(struct inode *inode, loff_t pos, loff_t length,
|
|
void *data, struct iomap *iomap, struct iomap *srcmap)
|
|
{
|
|
sector_t *bno = data, addr;
|
|
|
|
if (iomap->type == IOMAP_MAPPED) {
|
|
addr = (pos - iomap->offset + iomap->addr) >> inode->i_blkbits;
|
|
*bno = addr;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* legacy ->bmap interface. 0 is the error return (!) */
|
|
sector_t
|
|
iomap_bmap(struct address_space *mapping, sector_t bno,
|
|
const struct iomap_ops *ops)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
loff_t pos = bno << inode->i_blkbits;
|
|
unsigned blocksize = i_blocksize(inode);
|
|
int ret;
|
|
|
|
if (filemap_write_and_wait(mapping))
|
|
return 0;
|
|
|
|
bno = 0;
|
|
ret = iomap_apply(inode, pos, blocksize, 0, ops, &bno,
|
|
iomap_bmap_actor);
|
|
if (ret)
|
|
return 0;
|
|
return bno;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_bmap);
|