| Message ID | 1462783638-4968-10-git-send-email-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
----- Original Message -----
| Add a simple fiemap implementation based on iomap_ops, partially based
| on a previous implementation from Bob Peterson <rpeterso@redhat.com>.
|
| Signed-off-by: Christoph Hellwig <hch@lst.de>
| ---
| 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 f84c6eb..7e639bf 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 854766f..b3deee1 100644
| --- a/include/linux/iomap.h
| +++ b/include/linux/iomap.h
| @@ -3,6 +3,7 @@
|
| #include <linux/types.h>
|
| +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 */
| --
| 2.1.4
|
|
Hi Christoph,
I've been looking at this again. Where are the calls to the fs-specific bits
for fiemap? It looks like iomap_fiemap calls iomap_apply, which calls
iomap_fiemap_actor, but that doesn't call any ops->iomap_get_iomap or similar.
It calls the iomap_begin (which BTW has a comment that says "Execute a iomap
write" which is probably wrong and should be more generic, as for cases like
fiemap) and it calls iomap_end. But it never calls an fs-specific actor
anywhere. Am I missing something? My earlier version passed in the actor
function, as per Dave Chinner's request, but yours doesn't.
Regards,
Bob Peterson
Red Hat File Systems
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On Mon, May 23, 2016 at 04:09:26PM -0400, Bob Peterson wrote: > I've been looking at this again. Where are the calls to the fs-specific bits > for fiemap? In the iomap_ops structure passed to iomap_fiemap. > It looks like iomap_fiemap calls iomap_apply, which calls > iomap_fiemap_actor, but that doesn't call any ops->iomap_get_iomap or similar. > It calls the iomap_begin (which BTW has a comment that says "Execute a iomap > write" which is probably wrong and should be more generic, as for cases like > fiemap) and it calls iomap_end. But it never calls an fs-specific actor > anywhere. Am I missing something? My earlier version passed in the actor > function, as per Dave Chinner's request, but yours doesn't. The iomap_begin callback is where you do the mapping. the iomap_end callback does any required cleanup, which in case of GFS2 probably would be dropping the cluster lock protecting the mapping. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/iomap.c b/fs/iomap.c index f84c6eb..7e639bf 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 854766f..b3deee1 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -3,6 +3,7 @@ #include <linux/types.h> +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 */
Add a simple fiemap implementation based on iomap_ops, partially based on a previous implementation from Bob Peterson <rpeterso@redhat.com>. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/iomap.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/iomap.h | 3 ++ 2 files changed, 93 insertions(+)