| Message ID | 20190429163239.4874-3-agruenba@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v6,1/4] iomap: Clean up __generic_write_end calling | expand |
> +static int gfs2_iomap_page_prepare(struct inode *inode, loff_t pos, > + unsigned len, struct iomap *iomap) > +{ > + return 0; > +} Now that we check for each callback there is no need to add a dummy one in this patch. But given that that won't change the end result: Reviewed-by: Christoph Hellwig <hch@lst.de>
On Mon 29-04-19 18:32:38, Andreas Gruenbacher wrote: > Move the page_done callback into a separate iomap_page_ops structure and > add a page_prepare calback to be called before the next page is written > to. In gfs2, we'll want to start a transaction in page_prepare and end > it in page_done. Other filesystems that implement data journaling will > require the same kind of mechanism. > > Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Looks good to me. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/gfs2/bmap.c | 22 +++++++++++++++++----- > fs/iomap.c | 36 ++++++++++++++++++++++++++---------- > include/linux/iomap.h | 22 +++++++++++++++++----- > 3 files changed, 60 insertions(+), 20 deletions(-) > > diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c > index 5da4ca9041c0..6b980703bae7 100644 > --- a/fs/gfs2/bmap.c > +++ b/fs/gfs2/bmap.c > @@ -991,15 +991,27 @@ static void gfs2_write_unlock(struct inode *inode) > gfs2_glock_dq_uninit(&ip->i_gh); > } > > -static void gfs2_iomap_journaled_page_done(struct inode *inode, loff_t pos, > - unsigned copied, struct page *page, > - struct iomap *iomap) > +static int gfs2_iomap_page_prepare(struct inode *inode, loff_t pos, > + unsigned len, struct iomap *iomap) > +{ > + return 0; > +} > + > +static void gfs2_iomap_page_done(struct inode *inode, loff_t pos, > + unsigned copied, struct page *page, > + struct iomap *iomap) > { > struct gfs2_inode *ip = GFS2_I(inode); > > - gfs2_page_add_databufs(ip, page, offset_in_page(pos), copied); > + if (page) > + gfs2_page_add_databufs(ip, page, offset_in_page(pos), copied); > } > > +static const struct iomap_page_ops gfs2_iomap_page_ops = { > + .page_prepare = gfs2_iomap_page_prepare, > + .page_done = gfs2_iomap_page_done, > +}; > + > static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, > loff_t length, unsigned flags, > struct iomap *iomap, > @@ -1077,7 +1089,7 @@ static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, > } > } > if (!gfs2_is_stuffed(ip) && gfs2_is_jdata(ip)) > - iomap->page_done = gfs2_iomap_journaled_page_done; > + iomap->page_ops = &gfs2_iomap_page_ops; > return 0; > > out_trans_end: > diff --git a/fs/iomap.c b/fs/iomap.c > index b01ed5a28d2c..ee9ce7a06244 100644 > --- a/fs/iomap.c > +++ b/fs/iomap.c > @@ -665,6 +665,7 @@ static int > iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, > struct page **pagep, struct iomap *iomap) > { > + const struct iomap_page_ops *page_ops = iomap->page_ops; > pgoff_t index = pos >> PAGE_SHIFT; > struct page *page; > int status = 0; > @@ -674,9 +675,17 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, > if (fatal_signal_pending(current)) > return -EINTR; > > + if (page_ops && page_ops->page_prepare) { > + status = page_ops->page_prepare(inode, pos, len, iomap); > + if (status) > + return status; > + } > + > page = grab_cache_page_write_begin(inode->i_mapping, index, flags); > - if (!page) > - return -ENOMEM; > + if (!page) { > + status = -ENOMEM; > + goto out_no_page; > + } > > if (iomap->type == IOMAP_INLINE) > iomap_read_inline_data(inode, page, iomap); > @@ -684,15 +693,21 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, > status = __block_write_begin_int(page, pos, len, NULL, iomap); > else > status = __iomap_write_begin(inode, pos, len, page, iomap); > - if (unlikely(status)) { > - unlock_page(page); > - put_page(page); > - page = NULL; > > - iomap_write_failed(inode, pos, len); > - } > + if (unlikely(status)) > + goto out_unlock; > > *pagep = page; > + return 0; > + > +out_unlock: > + unlock_page(page); > + put_page(page); > + iomap_write_failed(inode, pos, len); > + > +out_no_page: > + if (page_ops && page_ops->page_done) > + page_ops->page_done(inode, pos, 0, NULL, iomap); > return status; > } > > @@ -766,6 +781,7 @@ static int > iomap_write_end(struct inode *inode, loff_t pos, unsigned len, > unsigned copied, struct page *page, struct iomap *iomap) > { > + const struct iomap_page_ops *page_ops = iomap->page_ops; > int ret; > > if (iomap->type == IOMAP_INLINE) { > @@ -778,8 +794,8 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, > } > > ret = __generic_write_end(inode, pos, ret, page); > - if (iomap->page_done) > - iomap->page_done(inode, pos, copied, page, iomap); > + if (page_ops) > + page_ops->page_done(inode, pos, copied, page, iomap); > put_page(page); > > if (ret < len) > diff --git a/include/linux/iomap.h b/include/linux/iomap.h > index 0fefb5455bda..2103b94cb1bf 100644 > --- a/include/linux/iomap.h > +++ b/include/linux/iomap.h > @@ -53,6 +53,8 @@ struct vm_fault; > */ > #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ > > +struct iomap_page_ops; > + > struct iomap { > u64 addr; /* disk offset of mapping, bytes */ > loff_t offset; /* file offset of mapping, bytes */ > @@ -63,12 +65,22 @@ struct iomap { > struct dax_device *dax_dev; /* dax_dev for dax operations */ > void *inline_data; > void *private; /* filesystem private */ > + const struct iomap_page_ops *page_ops; > +}; > > - /* > - * Called when finished processing a page in the mapping returned in > - * this iomap. At least for now this is only supported in the buffered > - * write path. > - */ > +/* > + * When a filesystem sets page_ops in an iomap mapping it returns, page_prepare > + * and page_done will be called for each page written to. This only applies to > + * buffered writes as unbuffered writes will not typically have pages > + * associated with them. > + * > + * When page_prepare succeeds, page_done will always be called to do any > + * cleanup work necessary. In that page_done call, @page will be NULL if the > + * associated page could not be obtained. > + */ > +struct iomap_page_ops { > + int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len, > + struct iomap *iomap); > void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, > struct page *page, struct iomap *iomap); > }; > -- > 2.20.1 >
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 5da4ca9041c0..6b980703bae7 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -991,15 +991,27 @@ static void gfs2_write_unlock(struct inode *inode) gfs2_glock_dq_uninit(&ip->i_gh); } -static void gfs2_iomap_journaled_page_done(struct inode *inode, loff_t pos, - unsigned copied, struct page *page, - struct iomap *iomap) +static int gfs2_iomap_page_prepare(struct inode *inode, loff_t pos, + unsigned len, struct iomap *iomap) +{ + return 0; +} + +static void gfs2_iomap_page_done(struct inode *inode, loff_t pos, + unsigned copied, struct page *page, + struct iomap *iomap) { struct gfs2_inode *ip = GFS2_I(inode); - gfs2_page_add_databufs(ip, page, offset_in_page(pos), copied); + if (page) + gfs2_page_add_databufs(ip, page, offset_in_page(pos), copied); } +static const struct iomap_page_ops gfs2_iomap_page_ops = { + .page_prepare = gfs2_iomap_page_prepare, + .page_done = gfs2_iomap_page_done, +}; + static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, loff_t length, unsigned flags, struct iomap *iomap, @@ -1077,7 +1089,7 @@ static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, } } if (!gfs2_is_stuffed(ip) && gfs2_is_jdata(ip)) - iomap->page_done = gfs2_iomap_journaled_page_done; + iomap->page_ops = &gfs2_iomap_page_ops; return 0; out_trans_end: diff --git a/fs/iomap.c b/fs/iomap.c index b01ed5a28d2c..ee9ce7a06244 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -665,6 +665,7 @@ static int iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, struct page **pagep, struct iomap *iomap) { + const struct iomap_page_ops *page_ops = iomap->page_ops; pgoff_t index = pos >> PAGE_SHIFT; struct page *page; int status = 0; @@ -674,9 +675,17 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, if (fatal_signal_pending(current)) return -EINTR; + if (page_ops && page_ops->page_prepare) { + status = page_ops->page_prepare(inode, pos, len, iomap); + if (status) + return status; + } + page = grab_cache_page_write_begin(inode->i_mapping, index, flags); - if (!page) - return -ENOMEM; + if (!page) { + status = -ENOMEM; + goto out_no_page; + } if (iomap->type == IOMAP_INLINE) iomap_read_inline_data(inode, page, iomap); @@ -684,15 +693,21 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, status = __block_write_begin_int(page, pos, len, NULL, iomap); else status = __iomap_write_begin(inode, pos, len, page, iomap); - if (unlikely(status)) { - unlock_page(page); - put_page(page); - page = NULL; - iomap_write_failed(inode, pos, len); - } + if (unlikely(status)) + goto out_unlock; *pagep = page; + return 0; + +out_unlock: + unlock_page(page); + put_page(page); + iomap_write_failed(inode, pos, len); + +out_no_page: + if (page_ops && page_ops->page_done) + page_ops->page_done(inode, pos, 0, NULL, iomap); return status; } @@ -766,6 +781,7 @@ static int iomap_write_end(struct inode *inode, loff_t pos, unsigned len, unsigned copied, struct page *page, struct iomap *iomap) { + const struct iomap_page_ops *page_ops = iomap->page_ops; int ret; if (iomap->type == IOMAP_INLINE) { @@ -778,8 +794,8 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, } ret = __generic_write_end(inode, pos, ret, page); - if (iomap->page_done) - iomap->page_done(inode, pos, copied, page, iomap); + if (page_ops) + page_ops->page_done(inode, pos, copied, page, iomap); put_page(page); if (ret < len) diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 0fefb5455bda..2103b94cb1bf 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -53,6 +53,8 @@ struct vm_fault; */ #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ +struct iomap_page_ops; + struct iomap { u64 addr; /* disk offset of mapping, bytes */ loff_t offset; /* file offset of mapping, bytes */ @@ -63,12 +65,22 @@ struct iomap { struct dax_device *dax_dev; /* dax_dev for dax operations */ void *inline_data; void *private; /* filesystem private */ + const struct iomap_page_ops *page_ops; +}; - /* - * Called when finished processing a page in the mapping returned in - * this iomap. At least for now this is only supported in the buffered - * write path. - */ +/* + * When a filesystem sets page_ops in an iomap mapping it returns, page_prepare + * and page_done will be called for each page written to. This only applies to + * buffered writes as unbuffered writes will not typically have pages + * associated with them. + * + * When page_prepare succeeds, page_done will always be called to do any + * cleanup work necessary. In that page_done call, @page will be NULL if the + * associated page could not be obtained. + */ +struct iomap_page_ops { + int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len, + struct iomap *iomap); void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, struct page *page, struct iomap *iomap); };
Move the page_done callback into a separate iomap_page_ops structure and add a page_prepare calback to be called before the next page is written to. In gfs2, we'll want to start a transaction in page_prepare and end it in page_done. Other filesystems that implement data journaling will require the same kind of mechanism. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> --- fs/gfs2/bmap.c | 22 +++++++++++++++++----- fs/iomap.c | 36 ++++++++++++++++++++++++++---------- include/linux/iomap.h | 22 +++++++++++++++++----- 3 files changed, 60 insertions(+), 20 deletions(-)