From 8be9f564d25e7adc582f9f3689040ce5aa6f1f5b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 21 Jun 2016 09:38:45 +1000 Subject: [PATCH] fs: iomap based fiemap implementation Add a simple fiemap implementation based on iomap_ops, partially based on a previous implementation from Bob Peterson . Signed-off-by: Christoph Hellwig Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/iomap.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/iomap.h | 3 ++ 2 files changed, 93 insertions(+) diff --git a/fs/iomap.c b/fs/iomap.c index 477817c..48141b8 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -405,3 +405,93 @@ out_unlock: return ret; } EXPORT_SYMBOL_GPL(iomap_page_mkwrite); + +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_UNWRITTEN: + flags |= FIEMAP_EXTENT_UNWRITTEN; + break; + case IOMAP_MAPPED: + break; + } + + return fiemap_fill_next_extent(fi, iomap->offset, + iomap->blkno != IOMAP_NULL_BLOCK ? iomap->blkno << 9: 0, + iomap->length, flags | FIEMAP_EXTENT_MERGED); + +} + +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, 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; + + ret = filemap_write_and_wait(inode->i_mapping); + if (ret) + return ret; + + while (len > 0) { + ret = iomap_apply(inode, start, len, 0, ops, &ctx, + iomap_fiemap_actor); + 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); diff --git a/include/linux/iomap.h b/include/linux/iomap.h index d2f469a..3267df4 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -3,6 +3,7 @@ #include +struct fiemap_extent_info; struct inode; struct iov_iter; struct kiocb; @@ -63,5 +64,7 @@ int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, struct iomap_ops *ops); int iomap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, struct iomap_ops *ops); +int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, + loff_t start, loff_t len, struct iomap_ops *ops); #endif /* LINUX_IOMAP_H */ -- 2.7.4