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-rw-r--r--fs/iomap.c780
1 files changed, 717 insertions, 63 deletions
diff --git a/fs/iomap.c b/fs/iomap.c
index 0d0bd8845586..009071e73bc0 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -1,6 +1,6 @@
/*
* Copyright (C) 2010 Red Hat, Inc.
- * Copyright (c) 2016 Christoph Hellwig.
+ * Copyright (c) 2016-2018 Christoph Hellwig.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
@@ -17,7 +17,9 @@
#include <linux/iomap.h>
#include <linux/uaccess.h>
#include <linux/gfp.h>
+#include <linux/migrate.h>
#include <linux/mm.h>
+#include <linux/mm_inline.h>
#include <linux/swap.h>
#include <linux/pagemap.h>
#include <linux/pagevec.h>
@@ -103,6 +105,467 @@ iomap_sector(struct iomap *iomap, loff_t pos)
return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT;
}
+static struct iomap_page *
+iomap_page_create(struct inode *inode, struct page *page)
+{
+ struct iomap_page *iop = to_iomap_page(page);
+
+ if (iop || i_blocksize(inode) == PAGE_SIZE)
+ return iop;
+
+ iop = kmalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL);
+ atomic_set(&iop->read_count, 0);
+ atomic_set(&iop->write_count, 0);
+ bitmap_zero(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);
+ set_page_private(page, (unsigned long)iop);
+ SetPagePrivate(page);
+ return iop;
+}
+
+static void
+iomap_page_release(struct page *page)
+{
+ struct iomap_page *iop = to_iomap_page(page);
+
+ if (!iop)
+ return;
+ WARN_ON_ONCE(atomic_read(&iop->read_count));
+ WARN_ON_ONCE(atomic_read(&iop->write_count));
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ kfree(iop);
+}
+
+/*
+ * Calculate the range inside the page that we actually need to read.
+ */
+static void
+iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop,
+ loff_t *pos, loff_t length, unsigned *offp, unsigned *lenp)
+{
+ unsigned block_bits = inode->i_blkbits;
+ unsigned block_size = (1 << block_bits);
+ unsigned poff = offset_in_page(*pos);
+ unsigned plen = min_t(loff_t, PAGE_SIZE - poff, length);
+ unsigned first = poff >> block_bits;
+ unsigned last = (poff + plen - 1) >> block_bits;
+ unsigned end = offset_in_page(i_size_read(inode)) >> block_bits;
+
+ /*
+ * If the block size is smaller than the page size we need to check the
+ * per-block uptodate status and adjust the offset and length if needed
+ * to avoid reading in already uptodate ranges.
+ */
+ if (iop) {
+ unsigned int i;
+
+ /* move forward for each leading block marked uptodate */
+ for (i = first; i <= last; i++) {
+ if (!test_bit(i, iop->uptodate))
+ break;
+ *pos += block_size;
+ poff += block_size;
+ plen -= block_size;
+ first++;
+ }
+
+ /* truncate len if we find any trailing uptodate block(s) */
+ for ( ; i <= last; i++) {
+ if (test_bit(i, iop->uptodate)) {
+ plen -= (last - i + 1) * block_size;
+ last = i - 1;
+ break;
+ }
+ }
+ }
+
+ /*
+ * If the extent spans the block that contains the i_size we need to
+ * handle both halves separately so that we properly zero data in the
+ * page cache for blocks that are entirely outside of i_size.
+ */
+ if (first <= end && last > end)
+ plen -= (last - end) * block_size;
+
+ *offp = poff;
+ *lenp = plen;
+}
+
+static void
+iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len)
+{
+ struct iomap_page *iop = to_iomap_page(page);
+ struct inode *inode = page->mapping->host;
+ unsigned first = off >> inode->i_blkbits;
+ unsigned last = (off + len - 1) >> inode->i_blkbits;
+ unsigned int i;
+ bool uptodate = true;
+
+ if (iop) {
+ for (i = 0; i < PAGE_SIZE / i_blocksize(inode); i++) {
+ if (i >= first && i <= last)
+ set_bit(i, iop->uptodate);
+ else if (!test_bit(i, iop->uptodate))
+ uptodate = false;
+ }
+ }
+
+ if (uptodate && !PageError(page))
+ SetPageUptodate(page);
+}
+
+static void
+iomap_read_finish(struct iomap_page *iop, struct page *page)
+{
+ if (!iop || atomic_dec_and_test(&iop->read_count))
+ unlock_page(page);
+}
+
+static void
+iomap_read_page_end_io(struct bio_vec *bvec, int error)
+{
+ struct page *page = bvec->bv_page;
+ struct iomap_page *iop = to_iomap_page(page);
+
+ if (unlikely(error)) {
+ ClearPageUptodate(page);
+ SetPageError(page);
+ } else {
+ iomap_set_range_uptodate(page, bvec->bv_offset, bvec->bv_len);
+ }
+
+ iomap_read_finish(iop, page);
+}
+
+static void
+iomap_read_inline_data(struct inode *inode, struct page *page,
+ struct iomap *iomap)
+{
+ size_t size = i_size_read(inode);
+ void *addr;
+
+ if (PageUptodate(page))
+ return;
+
+ BUG_ON(page->index);
+ BUG_ON(size > PAGE_SIZE - offset_in_page(iomap->inline_data));
+
+ addr = kmap_atomic(page);
+ memcpy(addr, iomap->inline_data, size);
+ memset(addr + size, 0, PAGE_SIZE - size);
+ kunmap_atomic(addr);
+ SetPageUptodate(page);
+}
+
+static void
+iomap_read_end_io(struct bio *bio)
+{
+ int error = blk_status_to_errno(bio->bi_status);
+ struct bio_vec *bvec;
+ int i;
+
+ bio_for_each_segment_all(bvec, bio, i)
+ iomap_read_page_end_io(bvec, error);
+ bio_put(bio);
+}
+
+struct iomap_readpage_ctx {
+ struct page *cur_page;
+ bool cur_page_in_bio;
+ bool is_readahead;
+ struct bio *bio;
+ struct list_head *pages;
+};
+
+static loff_t
+iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
+ struct iomap *iomap)
+{
+ struct iomap_readpage_ctx *ctx = data;
+ struct page *page = ctx->cur_page;
+ struct iomap_page *iop = iomap_page_create(inode, page);
+ bool is_contig = false;
+ loff_t orig_pos = pos;
+ unsigned poff, plen;
+ sector_t sector;
+
+ if (iomap->type == IOMAP_INLINE) {
+ WARN_ON_ONCE(poff);
+ iomap_read_inline_data(inode, page, iomap);
+ return PAGE_SIZE;
+ }
+
+ /* zero post-eof blocks as the page may be mapped */
+ iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen);
+ if (plen == 0)
+ goto done;
+
+ if (iomap->type != IOMAP_MAPPED || pos >= i_size_read(inode)) {
+ zero_user(page, poff, plen);
+ iomap_set_range_uptodate(page, poff, plen);
+ goto done;
+ }
+
+ ctx->cur_page_in_bio = true;
+
+ /*
+ * Try to merge into a previous segment if we can.
+ */
+ sector = iomap_sector(iomap, pos);
+ if (ctx->bio && bio_end_sector(ctx->bio) == sector) {
+ if (__bio_try_merge_page(ctx->bio, page, plen, poff))
+ goto done;
+ is_contig = true;
+ }
+
+ /*
+ * If we start a new segment we need to increase the read count, and we
+ * need to do so before submitting any previous full bio to make sure
+ * that we don't prematurely unlock the page.
+ */
+ if (iop)
+ atomic_inc(&iop->read_count);
+
+ if (!ctx->bio || !is_contig || bio_full(ctx->bio)) {
+ gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
+ int nr_vecs = (length + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+ if (ctx->bio)
+ submit_bio(ctx->bio);
+
+ if (ctx->is_readahead) /* same as readahead_gfp_mask */
+ gfp |= __GFP_NORETRY | __GFP_NOWARN;
+ ctx->bio = bio_alloc(gfp, min(BIO_MAX_PAGES, nr_vecs));
+ ctx->bio->bi_opf = REQ_OP_READ;
+ if (ctx->is_readahead)
+ ctx->bio->bi_opf |= REQ_RAHEAD;
+ ctx->bio->bi_iter.bi_sector = sector;
+ bio_set_dev(ctx->bio, iomap->bdev);
+ ctx->bio->bi_end_io = iomap_read_end_io;
+ }
+
+ __bio_add_page(ctx->bio, page, plen, poff);
+done:
+ /*
+ * Move the caller beyond our range so that it keeps making progress.
+ * For that we have to include any leading non-uptodate ranges, but
+ * we can skip trailing ones as they will be handled in the next
+ * iteration.
+ */
+ return pos - orig_pos + plen;
+}
+
+int
+iomap_readpage(struct page *page, const struct iomap_ops *ops)
+{
+ struct iomap_readpage_ctx ctx = { .cur_page = page };
+ struct inode *inode = page->mapping->host;
+ unsigned poff;
+ loff_t ret;
+
+ for (poff = 0; poff < PAGE_SIZE; poff += ret) {
+ ret = iomap_apply(inode, page_offset(page) + poff,
+ PAGE_SIZE - poff, 0, ops, &ctx,
+ iomap_readpage_actor);
+ if (ret <= 0) {
+ WARN_ON_ONCE(ret == 0);
+ SetPageError(page);
+ break;
+ }
+ }
+
+ if (ctx.bio) {
+ submit_bio(ctx.bio);
+ WARN_ON_ONCE(!ctx.cur_page_in_bio);
+ } else {
+ WARN_ON_ONCE(ctx.cur_page_in_bio);
+ unlock_page(page);
+ }
+
+ /*
+ * Just like mpage_readpages and block_read_full_page we always
+ * return 0 and just mark the page as PageError on errors. This
+ * should be cleaned up all through the stack eventually.
+ */
+ return 0;
+}
+EXPORT_SYMBOL_GPL(iomap_readpage);
+
+static struct page *
+iomap_next_page(struct inode *inode, struct list_head *pages, loff_t pos,
+ loff_t length, loff_t *done)
+{
+ while (!list_empty(pages)) {
+ struct page *page = lru_to_page(pages);
+
+ if (page_offset(page) >= (u64)pos + length)
+ break;
+
+ list_del(&page->lru);
+ if (!add_to_page_cache_lru(page, inode->i_mapping, page->index,
+ GFP_NOFS))
+ return page;
+
+ /*
+ * If we already have a page in the page cache at index we are
+ * done. Upper layers don't care if it is uptodate after the
+ * readpages call itself as every page gets checked again once
+ * actually needed.
+ */
+ *done += PAGE_SIZE;
+ put_page(page);
+ }
+
+ return NULL;
+}
+
+static loff_t
+iomap_readpages_actor(struct inode *inode, loff_t pos, loff_t length,
+ void *data, struct iomap *iomap)
+{
+ struct iomap_readpage_ctx *ctx = data;
+ loff_t done, ret;
+
+ for (done = 0; done < length; done += ret) {
+ if (ctx->cur_page && offset_in_page(pos + done) == 0) {
+ if (!ctx->cur_page_in_bio)
+ unlock_page(ctx->cur_page);
+ put_page(ctx->cur_page);
+ ctx->cur_page = NULL;
+ }
+ if (!ctx->cur_page) {
+ ctx->cur_page = iomap_next_page(inode, ctx->pages,
+ pos, length, &done);
+ if (!ctx->cur_page)
+ break;
+ ctx->cur_page_in_bio = false;
+ }
+ ret = iomap_readpage_actor(inode, pos + done, length - done,
+ ctx, iomap);
+ }
+
+ return done;
+}
+
+int
+iomap_readpages(struct address_space *mapping, struct list_head *pages,
+ unsigned nr_pages, const struct iomap_ops *ops)
+{
+ struct iomap_readpage_ctx ctx = {
+ .pages = pages,
+ .is_readahead = true,
+ };
+ loff_t pos = page_offset(list_entry(pages->prev, struct page, lru));
+ loff_t last = page_offset(list_entry(pages->next, struct page, lru));
+ loff_t length = last - pos + PAGE_SIZE, ret = 0;
+
+ while (length > 0) {
+ ret = iomap_apply(mapping->host, pos, length, 0, ops,
+ &ctx, iomap_readpages_actor);
+ if (ret <= 0) {
+ WARN_ON_ONCE(ret == 0);
+ goto done;
+ }
+ pos += ret;
+ length -= ret;
+ }
+ ret = 0;
+done:
+ if (ctx.bio)
+ submit_bio(ctx.bio);
+ if (ctx.cur_page) {
+ if (!ctx.cur_page_in_bio)
+ unlock_page(ctx.cur_page);
+ put_page(ctx.cur_page);
+ }
+
+ /*
+ * Check that we didn't lose a page due to the arcance calling
+ * conventions..
+ */
+ WARN_ON_ONCE(!ret && !list_empty(ctx.pages));
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iomap_readpages);
+
+int
+iomap_is_partially_uptodate(struct page *page, unsigned long from,
+ unsigned long count)
+{
+ struct iomap_page *iop = to_iomap_page(page);
+ struct inode *inode = page->mapping->host;
+ unsigned first = from >> inode->i_blkbits;
+ unsigned last = (from + count - 1) >> inode->i_blkbits;
+ unsigned i;
+
+ if (iop) {
+ for (i = first; i <= last; i++)
+ if (!test_bit(i, iop->uptodate))
+ return 0;
+ return 1;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(iomap_is_partially_uptodate);
+
+int
+iomap_releasepage(struct page *page, gfp_t gfp_mask)
+{
+ /*
+ * mm accommodates an old ext3 case where clean pages might not have had
+ * the dirty bit cleared. Thus, it can send actual dirty pages to
+ * ->releasepage() via shrink_active_list(), skip those here.
+ */
+ if (PageDirty(page) || PageWriteback(page))
+ return 0;
+ iomap_page_release(page);
+ return 1;
+}
+EXPORT_SYMBOL_GPL(iomap_releasepage);
+
+void
+iomap_invalidatepage(struct page *page, unsigned int offset, unsigned int len)
+{
+ /*
+ * If we are invalidating the entire page, clear the dirty state from it
+ * and release it to avoid unnecessary buildup of the LRU.
+ */
+ if (offset == 0 && len == PAGE_SIZE) {
+ WARN_ON_ONCE(PageWriteback(page));
+ cancel_dirty_page(page);
+ iomap_page_release(page);
+ }
+}
+EXPORT_SYMBOL_GPL(iomap_invalidatepage);
+
+#ifdef CONFIG_MIGRATION
+int
+iomap_migrate_page(struct address_space *mapping, struct page *newpage,
+ struct page *page, enum migrate_mode mode)
+{
+ int ret;
+
+ ret = migrate_page_move_mapping(mapping, newpage, page, NULL, mode, 0);
+ if (ret != MIGRATEPAGE_SUCCESS)
+ return ret;
+
+ if (page_has_private(page)) {
+ ClearPagePrivate(page);
+ set_page_private(newpage, page_private(page));
+ set_page_private(page, 0);
+ SetPagePrivate(newpage);
+ }
+
+ if (mode != MIGRATE_SYNC_NO_COPY)
+ migrate_page_copy(newpage, page);
+ else
+ migrate_page_states(newpage, page);
+ return MIGRATEPAGE_SUCCESS;
+}
+EXPORT_SYMBOL_GPL(iomap_migrate_page);
+#endif /* CONFIG_MIGRATION */
+
static void
iomap_write_failed(struct inode *inode, loff_t pos, unsigned len)
{
@@ -117,6 +580,61 @@ iomap_write_failed(struct inode *inode, loff_t pos, unsigned len)
}
static int
+iomap_read_page_sync(struct inode *inode, loff_t block_start, struct page *page,
+ unsigned poff, unsigned plen, unsigned from, unsigned to,
+ struct iomap *iomap)
+{
+ struct bio_vec bvec;
+ struct bio bio;
+
+ if (iomap->type != IOMAP_MAPPED || block_start >= i_size_read(inode)) {
+ zero_user_segments(page, poff, from, to, poff + plen);
+ iomap_set_range_uptodate(page, poff, plen);
+ return 0;
+ }
+
+ bio_init(&bio, &bvec, 1);
+ bio.bi_opf = REQ_OP_READ;
+ bio.bi_iter.bi_sector = iomap_sector(iomap, block_start);
+ bio_set_dev(&bio, iomap->bdev);
+ __bio_add_page(&bio, page, plen, poff);
+ return submit_bio_wait(&bio);
+}
+
+static int
+__iomap_write_begin(struct inode *inode, loff_t pos, unsigned len,
+ struct page *page, struct iomap *iomap)
+{
+ struct iomap_page *iop = iomap_page_create(inode, page);
+ loff_t block_size = i_blocksize(inode);
+ loff_t block_start = pos & ~(block_size - 1);
+ loff_t block_end = (pos + len + block_size - 1) & ~(block_size - 1);
+ unsigned from = offset_in_page(pos), to = from + len, poff, plen;
+ int status = 0;
+
+ if (PageUptodate(page))
+ return 0;
+
+ do {
+ iomap_adjust_read_range(inode, iop, &block_start,
+ block_end - block_start, &poff, &plen);
+ if (plen == 0)
+ break;
+
+ if ((from > poff && from < poff + plen) ||
+ (to > poff && to < poff + plen)) {
+ status = iomap_read_page_sync(inode, block_start, page,
+ poff, plen, from, to, iomap);
+ if (status)
+ break;
+ }
+
+ } while ((block_start += plen) < block_end);
+
+ return status;
+}
+
+static int
iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
struct page **pagep, struct iomap *iomap)
{
@@ -133,7 +651,12 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
if (!page)
return -ENOMEM;
- status = __block_write_begin_int(page, pos, len, NULL, iomap);
+ if (iomap->type == IOMAP_INLINE)
+ iomap_read_inline_data(inode, page, iomap);
+ else if (iomap->flags & IOMAP_F_BUFFER_HEAD)
+ 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);
@@ -146,14 +669,93 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
return status;
}
+int
+iomap_set_page_dirty(struct page *page)
+{
+ struct address_space *mapping = page_mapping(page);
+ int newly_dirty;
+
+ if (unlikely(!mapping))
+ return !TestSetPageDirty(page);
+
+ /*
+ * Lock out page->mem_cgroup migration to keep PageDirty
+ * synchronized with per-memcg dirty page counters.
+ */
+ lock_page_memcg(page);
+ newly_dirty = !TestSetPageDirty(page);
+ if (newly_dirty)
+ __set_page_dirty(page, mapping, 0);
+ unlock_page_memcg(page);
+
+ if (newly_dirty)
+ __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
+ return newly_dirty;
+}
+EXPORT_SYMBOL_GPL(iomap_set_page_dirty);
+
+static int
+__iomap_write_end(struct inode *inode, loff_t pos, unsigned len,
+ unsigned copied, struct page *page, struct iomap *iomap)
+{
+ flush_dcache_page(page);
+
+ /*
+ * The blocks that were entirely written will now be uptodate, so we
+ * don't have to worry about a readpage reading them and overwriting a
+ * partial write. However if we have encountered a short write and only
+ * partially written into a block, it will not be marked uptodate, so a
+ * readpage might come in and destroy our partial write.
+ *
+ * Do the simplest thing, and just treat any short write to a non
+ * uptodate page as a zero-length write, and force the caller to redo
+ * the whole thing.
+ */
+ if (unlikely(copied < len && !PageUptodate(page))) {
+ copied = 0;
+ } else {
+ iomap_set_range_uptodate(page, offset_in_page(pos), len);
+ iomap_set_page_dirty(page);
+ }
+ return __generic_write_end(inode, pos, copied, page);
+}
+
+static int
+iomap_write_end_inline(struct inode *inode, struct page *page,
+ struct iomap *iomap, loff_t pos, unsigned copied)
+{
+ void *addr;
+
+ WARN_ON_ONCE(!PageUptodate(page));
+ BUG_ON(pos + copied > PAGE_SIZE - offset_in_page(iomap->inline_data));
+
+ addr = kmap_atomic(page);
+ memcpy(iomap->inline_data + pos, addr + pos, copied);
+ kunmap_atomic(addr);
+
+ mark_inode_dirty(inode);
+ __generic_write_end(inode, pos, copied, page);
+ return copied;
+}
+
static int
iomap_write_end(struct inode *inode, loff_t pos, unsigned len,
- unsigned copied, struct page *page)
+ unsigned copied, struct page *page, struct iomap *iomap)
{
int ret;
- ret = generic_write_end(NULL, inode->i_mapping, pos, len,
- copied, page, NULL);
+ if (iomap->type == IOMAP_INLINE) {
+ ret = iomap_write_end_inline(inode, page, iomap, pos, copied);
+ } else if (iomap->flags & IOMAP_F_BUFFER_HEAD) {
+ ret = generic_write_end(NULL, inode->i_mapping, pos, len,
+ copied, page, NULL);
+ } else {
+ ret = __iomap_write_end(inode, pos, len, copied, page, iomap);
+ }
+
+ if (iomap->page_done)
+ iomap->page_done(inode, pos, copied, page, iomap);
+
if (ret < len)
iomap_write_failed(inode, pos, len);
return ret;
@@ -174,7 +776,7 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
unsigned long bytes; /* Bytes to write to page */
size_t copied; /* Bytes copied from user */
- offset = (pos & (PAGE_SIZE - 1));
+ offset = offset_in_page(pos);
bytes = min_t(unsigned long, PAGE_SIZE - offset,
iov_iter_count(i));
again:
@@ -208,7 +810,8 @@ again:
flush_dcache_page(page);
- status = iomap_write_end(inode, pos, bytes, copied, page);
+ status = iomap_write_end(inode, pos, bytes, copied, page,
+ iomap);
if (unlikely(status < 0))
break;
copied = status;
@@ -287,7 +890,7 @@ iomap_dirty_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
unsigned long offset; /* Offset into pagecache page */
unsigned long bytes; /* Bytes to write to page */
- offset = (pos & (PAGE_SIZE - 1));
+ offset = offset_in_page(pos);
bytes = min_t(loff_t, PAGE_SIZE - offset, length);
rpage = __iomap_read_page(inode, pos);
@@ -302,7 +905,7 @@ iomap_dirty_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
WARN_ON_ONCE(!PageUptodate(page));
- status = iomap_write_end(inode, pos, bytes, bytes, page);
+ status = iomap_write_end(inode, pos, bytes, bytes, page, iomap);
if (unlikely(status <= 0)) {
if (WARN_ON_ONCE(status == 0))
return -EIO;
@@ -354,7 +957,7 @@ static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
zero_user(page, offset, bytes);
mark_page_accessed(page);
- return iomap_write_end(inode, pos, bytes, bytes, page);
+ return iomap_write_end(inode, pos, bytes, bytes, page, iomap);
}
static int iomap_dax_zero(loff_t pos, unsigned offset, unsigned bytes,
@@ -379,7 +982,7 @@ iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,
do {
unsigned offset, bytes;
- offset = pos & (PAGE_SIZE - 1); /* Within page */
+ offset = offset_in_page(pos);
bytes = min_t(loff_t, PAGE_SIZE - offset, count);
if (IS_DAX(inode))
@@ -440,11 +1043,16 @@ iomap_page_mkwrite_actor(struct inode *inode, loff_t pos, loff_t length,
struct page *page = data;
int ret;
- ret = __block_write_begin_int(page, pos, length, NULL, iomap);
- if (ret)
- return ret;
+ if (iomap->flags & IOMAP_F_BUFFER_HEAD) {
+ ret = __block_write_begin_int(page, pos, length, NULL, iomap);
+ if (ret)
+ return ret;
+ block_commit_write(page, 0, length);
+ } else {
+ WARN_ON_ONCE(!PageUptodate(page));
+ iomap_page_create(inode, page);
+ }
- block_commit_write(page, 0, length);
return length;
}
@@ -467,7 +1075,7 @@ int iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops)
/* page is wholly or partially inside EOF */
if (((page->index + 1) << PAGE_SHIFT) > size)
- length = size & ~PAGE_MASK;
+ length = offset_in_page(size);
else
length = PAGE_SIZE;
@@ -630,7 +1238,7 @@ page_seek_hole_data(struct inode *inode, struct page *page, loff_t *lastoff,
goto out_unlock_not_found;
for (off = 0; off < PAGE_SIZE; off += bsize) {
- if ((*lastoff & ~PAGE_MASK) >= off + bsize)
+ if (offset_in_page(*lastoff) >= off + bsize)
continue;
if (ops->is_partially_uptodate(page, off, bsize) == seek_data) {
unlock_page(page);
@@ -811,6 +1419,7 @@ struct iomap_dio {
atomic_t ref;
unsigned flags;
int error;
+ bool wait_for_completion;
union {
/* used during submission and for synchronous completion: */
@@ -914,9 +1523,8 @@ static void iomap_dio_bio_end_io(struct bio *bio)
iomap_dio_set_error(dio, blk_status_to_errno(bio->bi_status));
if (atomic_dec_and_test(&dio->ref)) {
- if (is_sync_kiocb(dio->iocb)) {
+ if (dio->wait_for_completion) {
struct task_struct *waiter = dio->submit.waiter;
-
WRITE_ONCE(dio->submit.waiter, NULL);
wake_up_process(waiter);
} else if (dio->flags & IOMAP_DIO_WRITE) {
@@ -963,10 +1571,9 @@ iomap_dio_zero(struct iomap_dio *dio, struct iomap *iomap, loff_t pos,
}
static loff_t
-iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
- void *data, struct iomap *iomap)
+iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
+ struct iomap_dio *dio, struct iomap *iomap)
{
- struct iomap_dio *dio = data;
unsigned int blkbits = blksize_bits(bdev_logical_block_size(iomap->bdev));
unsigned int fs_block_size = i_blocksize(inode), pad;
unsigned int align = iov_iter_alignment(dio->submit.iter);
@@ -980,41 +1587,27 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
if ((pos | length | align) & ((1 << blkbits) - 1))
return -EINVAL;
- switch (iomap->type) {
- case IOMAP_HOLE:
- if (WARN_ON_ONCE(dio->flags & IOMAP_DIO_WRITE))
- return -EIO;
- /*FALLTHRU*/
- case IOMAP_UNWRITTEN:
- if (!(dio->flags & IOMAP_DIO_WRITE)) {
- length = iov_iter_zero(length, dio->submit.iter);
- dio->size += length;
- return length;
- }
+ if (iomap->type == IOMAP_UNWRITTEN) {
dio->flags |= IOMAP_DIO_UNWRITTEN;
need_zeroout = true;
- break;
- case IOMAP_MAPPED:
- if (iomap->flags & IOMAP_F_SHARED)
- dio->flags |= IOMAP_DIO_COW;
- if (iomap->flags & IOMAP_F_NEW) {
- need_zeroout = true;
- } else {
- /*
- * Use a FUA write if we need datasync semantics, this
- * is a pure data IO that doesn't require any metadata
- * updates and the underlying device supports FUA. This
- * allows us to avoid cache flushes on IO completion.
- */
- if (!(iomap->flags & (IOMAP_F_SHARED|IOMAP_F_DIRTY)) &&
- (dio->flags & IOMAP_DIO_WRITE_FUA) &&
- blk_queue_fua(bdev_get_queue(iomap->bdev)))
- use_fua = true;
- }
- break;
- default:
- WARN_ON_ONCE(1);
- return -EIO;
+ }
+
+ if (iomap->flags & IOMAP_F_SHARED)
+ dio->flags |= IOMAP_DIO_COW;
+
+ if (iomap->flags & IOMAP_F_NEW) {
+ need_zeroout = true;
+ } else {
+ /*
+ * Use a FUA write if we need datasync semantics, this
+ * is a pure data IO that doesn't require any metadata
+ * updates and the underlying device supports FUA. This
+ * allows us to avoid cache flushes on IO completion.
+ */
+ if (!(iomap->flags & (IOMAP_F_SHARED|IOMAP_F_DIRTY)) &&
+ (dio->flags & IOMAP_DIO_WRITE_FUA) &&
+ blk_queue_fua(bdev_get_queue(iomap->bdev)))
+ use_fua = true;
}
/*
@@ -1093,6 +1686,66 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
return copied;
}
+static loff_t
+iomap_dio_hole_actor(loff_t length, struct iomap_dio *dio)
+{
+ length = iov_iter_zero(length, dio->submit.iter);
+ dio->size += length;
+ return length;
+}
+
+static loff_t
+iomap_dio_inline_actor(struct inode *inode, loff_t pos, loff_t length,
+ struct iomap_dio *dio, struct iomap *iomap)
+{
+ struct iov_iter *iter = dio->submit.iter;
+ size_t copied;
+
+ BUG_ON(pos + length > PAGE_SIZE - offset_in_page(iomap->inline_data));
+
+ if (dio->flags & IOMAP_DIO_WRITE) {
+ loff_t size = inode->i_size;
+
+ if (pos > size)
+ memset(iomap->inline_data + size, 0, pos - size);
+ copied = copy_from_iter(iomap->inline_data + pos, length, iter);
+ if (copied) {
+ if (pos + copied > size)
+ i_size_write(inode, pos + copied);
+ mark_inode_dirty(inode);
+ }
+ } else {
+ copied = copy_to_iter(iomap->inline_data + pos, length, iter);
+ }
+ dio->size += copied;
+ return copied;
+}
+
+static loff_t
+iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
+ void *data, struct iomap *iomap)
+{
+ struct iomap_dio *dio = data;
+
+ switch (iomap->type) {
+ case IOMAP_HOLE:
+ if (WARN_ON_ONCE(dio->flags & IOMAP_DIO_WRITE))
+ return -EIO;
+ return iomap_dio_hole_actor(length, dio);
+ case IOMAP_UNWRITTEN:
+ if (!(dio->flags & IOMAP_DIO_WRITE))
+ return iomap_dio_hole_actor(length, dio);
+ return iomap_dio_bio_actor(inode, pos, length, dio, iomap);
+ case IOMAP_MAPPED:
+ return iomap_dio_bio_actor(inode, pos, length, dio, iomap);
+ case IOMAP_INLINE:
+ return iomap_dio_inline_actor(inode, pos, length, dio, iomap);
+ default:
+ WARN_ON_ONCE(1);
+ return -EIO;
+ }
+}
+
/*
* iomap_dio_rw() always completes O_[D]SYNC writes regardless of whether the IO
* is being issued as AIO or not. This allows us to optimise pure data writes
@@ -1131,13 +1784,12 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
dio->end_io = end_io;
dio->error = 0;
dio->flags = 0;
+ dio->wait_for_completion = is_sync_kiocb(iocb);
dio->submit.iter = iter;
- if (is_sync_kiocb(iocb)) {
- dio->submit.waiter = current;
- dio->submit.cookie = BLK_QC_T_NONE;
- dio->submit.last_queue = NULL;
- }
+ dio->submit.waiter = current;
+ dio->submit.cookie = BLK_QC_T_NONE;
+ dio->submit.last_queue = NULL;
if (iov_iter_rw(iter) == READ) {
if (pos >= dio->i_size)
@@ -1187,7 +1839,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
dio_warn_stale_pagecache(iocb->ki_filp);
ret = 0;
- if (iov_iter_rw(iter) == WRITE && !is_sync_kiocb(iocb) &&
+ if (iov_iter_rw(iter) == WRITE && !dio->wait_for_completion &&
!inode->i_sb->s_dio_done_wq) {
ret = sb_init_dio_done_wq(inode->i_sb);
if (ret < 0)
@@ -1202,8 +1854,10 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
iomap_dio_actor);
if (ret <= 0) {
/* magic error code to fall back to buffered I/O */
- if (ret == -ENOTBLK)
+ if (ret == -ENOTBLK) {
+ dio->wait_for_completion = true;
ret = 0;
+ }
break;
}
pos += ret;
@@ -1224,7 +1878,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
dio->flags &= ~IOMAP_DIO_NEED_SYNC;
if (!atomic_dec_and_test(&dio->ref)) {
- if (!is_sync_kiocb(iocb))
+ if (!dio->wait_for_completion)
return -EIOCBQUEUED;
for (;;) {