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-rw-r--r--fs/iomap/fiemap.c144
1 files changed, 144 insertions, 0 deletions
diff --git a/fs/iomap/fiemap.c b/fs/iomap/fiemap.c
new file mode 100644
index 000000000000..f26fdd36e383
--- /dev/null
+++ b/fs/iomap/fiemap.c
@@ -0,0 +1,144 @@
+// 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>
+
+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 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,
+ loff_t start, loff_t 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_check_flags(fi, FIEMAP_FLAG_SYNC);
+ if (ret)
+ return ret;
+
+ if (fi->fi_flags & FIEMAP_FLAG_SYNC) {
+ ret = filemap_write_and_wait(inode->i_mapping);
+ 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)
+{
+ sector_t *bno = data, addr;
+
+ if (iomap->type == IOMAP_MAPPED) {
+ addr = (pos - iomap->offset + iomap->addr) >> inode->i_blkbits;
+ if (addr > INT_MAX)
+ WARN(1, "would truncate bmap result\n");
+ else
+ *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);
+
+ if (filemap_write_and_wait(mapping))
+ return 0;
+
+ bno = 0;
+ iomap_apply(inode, pos, blocksize, 0, ops, &bno, iomap_bmap_actor);
+ return bno;
+}
+EXPORT_SYMBOL_GPL(iomap_bmap);