![Sage Weil](/assets/img/avatar_default.png)
We used to use i_head_snapc to keep track of which snapc the current epoch of dirty data was dirtied under. It is used by queue_cap_snap to set up the cap_snap. However, since we queue cap snaps for any dirty caps, not just for dirty file data, we need to keep a valid i_head_snapc anytime we have dirty|flushing caps. This fixes a NULL pointer deref in queue_cap_snap when writing back dirty caps without data (e.g., snaptest-authwb.sh). Signed-off-by: Sage Weil <sage@newdream.net>
1181 lines
32 KiB
C
1181 lines
32 KiB
C
#include "ceph_debug.h"
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#include <linux/backing-dev.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/writeback.h> /* generic_writepages */
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#include <linux/slab.h>
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#include <linux/pagevec.h>
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#include <linux/task_io_accounting_ops.h>
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#include "super.h"
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#include "osd_client.h"
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/*
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* Ceph address space ops.
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*
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* There are a few funny things going on here.
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*
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* The page->private field is used to reference a struct
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* ceph_snap_context for _every_ dirty page. This indicates which
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* snapshot the page was logically dirtied in, and thus which snap
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* context needs to be associated with the osd write during writeback.
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*
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* Similarly, struct ceph_inode_info maintains a set of counters to
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* count dirty pages on the inode. In the absense of snapshots,
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* i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
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*
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* When a snapshot is taken (that is, when the client receives
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* notification that a snapshot was taken), each inode with caps and
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* with dirty pages (dirty pages implies there is a cap) gets a new
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* ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
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* order, new snaps go to the tail). The i_wrbuffer_ref_head count is
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* moved to capsnap->dirty. (Unless a sync write is currently in
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* progress. In that case, the capsnap is said to be "pending", new
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* writes cannot start, and the capsnap isn't "finalized" until the
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* write completes (or fails) and a final size/mtime for the inode for
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* that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0.
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*
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* On writeback, we must submit writes to the osd IN SNAP ORDER. So,
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* we look for the first capsnap in i_cap_snaps and write out pages in
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* that snap context _only_. Then we move on to the next capsnap,
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* eventually reaching the "live" or "head" context (i.e., pages that
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* are not yet snapped) and are writing the most recently dirtied
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* pages.
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*
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* Invalidate and so forth must take care to ensure the dirty page
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* accounting is preserved.
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*/
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#define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
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#define CONGESTION_OFF_THRESH(congestion_kb) \
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(CONGESTION_ON_THRESH(congestion_kb) - \
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(CONGESTION_ON_THRESH(congestion_kb) >> 2))
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/*
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* Dirty a page. Optimistically adjust accounting, on the assumption
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* that we won't race with invalidate. If we do, readjust.
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*/
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static int ceph_set_page_dirty(struct page *page)
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{
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struct address_space *mapping = page->mapping;
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struct inode *inode;
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struct ceph_inode_info *ci;
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int undo = 0;
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struct ceph_snap_context *snapc;
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if (unlikely(!mapping))
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return !TestSetPageDirty(page);
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if (TestSetPageDirty(page)) {
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dout("%p set_page_dirty %p idx %lu -- already dirty\n",
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mapping->host, page, page->index);
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return 0;
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}
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inode = mapping->host;
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ci = ceph_inode(inode);
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/*
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* Note that we're grabbing a snapc ref here without holding
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* any locks!
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*/
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snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context);
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/* dirty the head */
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spin_lock(&inode->i_lock);
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if (ci->i_head_snapc == NULL)
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ci->i_head_snapc = ceph_get_snap_context(snapc);
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++ci->i_wrbuffer_ref_head;
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if (ci->i_wrbuffer_ref == 0)
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igrab(inode);
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++ci->i_wrbuffer_ref;
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dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
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"snapc %p seq %lld (%d snaps)\n",
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mapping->host, page, page->index,
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ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1,
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ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
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snapc, snapc->seq, snapc->num_snaps);
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spin_unlock(&inode->i_lock);
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/* now adjust page */
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spin_lock_irq(&mapping->tree_lock);
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if (page->mapping) { /* Race with truncate? */
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WARN_ON_ONCE(!PageUptodate(page));
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account_page_dirtied(page, page->mapping);
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radix_tree_tag_set(&mapping->page_tree,
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page_index(page), PAGECACHE_TAG_DIRTY);
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/*
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* Reference snap context in page->private. Also set
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* PagePrivate so that we get invalidatepage callback.
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*/
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page->private = (unsigned long)snapc;
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SetPagePrivate(page);
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} else {
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dout("ANON set_page_dirty %p (raced truncate?)\n", page);
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undo = 1;
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}
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spin_unlock_irq(&mapping->tree_lock);
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if (undo)
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/* whoops, we failed to dirty the page */
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ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
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__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
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BUG_ON(!PageDirty(page));
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return 1;
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}
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/*
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* If we are truncating the full page (i.e. offset == 0), adjust the
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* dirty page counters appropriately. Only called if there is private
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* data on the page.
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*/
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static void ceph_invalidatepage(struct page *page, unsigned long offset)
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{
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struct inode *inode;
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struct ceph_inode_info *ci;
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struct ceph_snap_context *snapc = (void *)page->private;
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BUG_ON(!PageLocked(page));
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BUG_ON(!page->private);
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BUG_ON(!PagePrivate(page));
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BUG_ON(!page->mapping);
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inode = page->mapping->host;
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/*
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* We can get non-dirty pages here due to races between
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* set_page_dirty and truncate_complete_page; just spit out a
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* warning, in case we end up with accounting problems later.
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*/
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if (!PageDirty(page))
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pr_err("%p invalidatepage %p page not dirty\n", inode, page);
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if (offset == 0)
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ClearPageChecked(page);
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ci = ceph_inode(inode);
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if (offset == 0) {
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dout("%p invalidatepage %p idx %lu full dirty page %lu\n",
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inode, page, page->index, offset);
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ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
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ceph_put_snap_context(snapc);
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page->private = 0;
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ClearPagePrivate(page);
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} else {
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dout("%p invalidatepage %p idx %lu partial dirty page\n",
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inode, page, page->index);
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}
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}
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/* just a sanity check */
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static int ceph_releasepage(struct page *page, gfp_t g)
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{
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struct inode *inode = page->mapping ? page->mapping->host : NULL;
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dout("%p releasepage %p idx %lu\n", inode, page, page->index);
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WARN_ON(PageDirty(page));
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WARN_ON(page->private);
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WARN_ON(PagePrivate(page));
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return 0;
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}
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/*
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* read a single page, without unlocking it.
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*/
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static int readpage_nounlock(struct file *filp, struct page *page)
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{
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struct inode *inode = filp->f_dentry->d_inode;
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struct ceph_inode_info *ci = ceph_inode(inode);
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struct ceph_osd_client *osdc = &ceph_inode_to_client(inode)->osdc;
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int err = 0;
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u64 len = PAGE_CACHE_SIZE;
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dout("readpage inode %p file %p page %p index %lu\n",
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inode, filp, page, page->index);
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err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
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page->index << PAGE_CACHE_SHIFT, &len,
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ci->i_truncate_seq, ci->i_truncate_size,
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&page, 1);
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if (err == -ENOENT)
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err = 0;
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if (err < 0) {
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SetPageError(page);
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goto out;
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} else if (err < PAGE_CACHE_SIZE) {
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/* zero fill remainder of page */
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zero_user_segment(page, err, PAGE_CACHE_SIZE);
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}
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SetPageUptodate(page);
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out:
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return err < 0 ? err : 0;
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}
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static int ceph_readpage(struct file *filp, struct page *page)
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{
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int r = readpage_nounlock(filp, page);
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unlock_page(page);
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return r;
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}
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/*
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* Build a vector of contiguous pages from the provided page list.
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*/
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static struct page **page_vector_from_list(struct list_head *page_list,
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unsigned *nr_pages)
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{
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struct page **pages;
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struct page *page;
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int next_index, contig_pages = 0;
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/* build page vector */
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pages = kmalloc(sizeof(*pages) * *nr_pages, GFP_NOFS);
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if (!pages)
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return ERR_PTR(-ENOMEM);
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BUG_ON(list_empty(page_list));
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next_index = list_entry(page_list->prev, struct page, lru)->index;
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list_for_each_entry_reverse(page, page_list, lru) {
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if (page->index == next_index) {
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dout("readpages page %d %p\n", contig_pages, page);
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pages[contig_pages] = page;
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contig_pages++;
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next_index++;
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} else {
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break;
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}
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}
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*nr_pages = contig_pages;
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return pages;
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}
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/*
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* Read multiple pages. Leave pages we don't read + unlock in page_list;
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* the caller (VM) cleans them up.
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*/
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static int ceph_readpages(struct file *file, struct address_space *mapping,
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struct list_head *page_list, unsigned nr_pages)
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{
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struct inode *inode = file->f_dentry->d_inode;
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struct ceph_inode_info *ci = ceph_inode(inode);
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struct ceph_osd_client *osdc = &ceph_inode_to_client(inode)->osdc;
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int rc = 0;
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struct page **pages;
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loff_t offset;
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u64 len;
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dout("readpages %p file %p nr_pages %d\n",
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inode, file, nr_pages);
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pages = page_vector_from_list(page_list, &nr_pages);
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if (IS_ERR(pages))
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return PTR_ERR(pages);
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/* guess read extent */
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offset = pages[0]->index << PAGE_CACHE_SHIFT;
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len = nr_pages << PAGE_CACHE_SHIFT;
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rc = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
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offset, &len,
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ci->i_truncate_seq, ci->i_truncate_size,
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pages, nr_pages);
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if (rc == -ENOENT)
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rc = 0;
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if (rc < 0)
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goto out;
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for (; !list_empty(page_list) && len > 0;
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rc -= PAGE_CACHE_SIZE, len -= PAGE_CACHE_SIZE) {
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struct page *page =
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list_entry(page_list->prev, struct page, lru);
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list_del(&page->lru);
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if (rc < (int)PAGE_CACHE_SIZE) {
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/* zero (remainder of) page */
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int s = rc < 0 ? 0 : rc;
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zero_user_segment(page, s, PAGE_CACHE_SIZE);
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}
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if (add_to_page_cache_lru(page, mapping, page->index,
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GFP_NOFS)) {
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page_cache_release(page);
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dout("readpages %p add_to_page_cache failed %p\n",
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inode, page);
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continue;
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}
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dout("readpages %p adding %p idx %lu\n", inode, page,
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page->index);
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flush_dcache_page(page);
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SetPageUptodate(page);
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unlock_page(page);
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page_cache_release(page);
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}
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rc = 0;
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out:
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kfree(pages);
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return rc;
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}
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/*
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* Get ref for the oldest snapc for an inode with dirty data... that is, the
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* only snap context we are allowed to write back.
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*/
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static struct ceph_snap_context *get_oldest_context(struct inode *inode,
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u64 *snap_size)
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{
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struct ceph_inode_info *ci = ceph_inode(inode);
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struct ceph_snap_context *snapc = NULL;
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struct ceph_cap_snap *capsnap = NULL;
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spin_lock(&inode->i_lock);
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list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
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dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
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capsnap->context, capsnap->dirty_pages);
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if (capsnap->dirty_pages) {
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snapc = ceph_get_snap_context(capsnap->context);
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if (snap_size)
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*snap_size = capsnap->size;
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break;
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}
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}
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if (!snapc && ci->i_wrbuffer_ref_head) {
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snapc = ceph_get_snap_context(ci->i_head_snapc);
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dout(" head snapc %p has %d dirty pages\n",
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snapc, ci->i_wrbuffer_ref_head);
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}
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spin_unlock(&inode->i_lock);
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return snapc;
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}
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/*
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* Write a single page, but leave the page locked.
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*
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* If we get a write error, set the page error bit, but still adjust the
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* dirty page accounting (i.e., page is no longer dirty).
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*/
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static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
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{
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struct inode *inode;
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struct ceph_inode_info *ci;
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struct ceph_client *client;
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struct ceph_osd_client *osdc;
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loff_t page_off = page->index << PAGE_CACHE_SHIFT;
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int len = PAGE_CACHE_SIZE;
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loff_t i_size;
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int err = 0;
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struct ceph_snap_context *snapc, *oldest;
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u64 snap_size = 0;
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long writeback_stat;
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dout("writepage %p idx %lu\n", page, page->index);
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if (!page->mapping || !page->mapping->host) {
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dout("writepage %p - no mapping\n", page);
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return -EFAULT;
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}
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inode = page->mapping->host;
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ci = ceph_inode(inode);
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client = ceph_inode_to_client(inode);
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osdc = &client->osdc;
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/* verify this is a writeable snap context */
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snapc = (void *)page->private;
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if (snapc == NULL) {
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dout("writepage %p page %p not dirty?\n", inode, page);
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goto out;
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}
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oldest = get_oldest_context(inode, &snap_size);
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if (snapc->seq > oldest->seq) {
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dout("writepage %p page %p snapc %p not writeable - noop\n",
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inode, page, (void *)page->private);
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/* we should only noop if called by kswapd */
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WARN_ON((current->flags & PF_MEMALLOC) == 0);
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ceph_put_snap_context(oldest);
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goto out;
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}
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ceph_put_snap_context(oldest);
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/* is this a partial page at end of file? */
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if (snap_size)
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i_size = snap_size;
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else
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i_size = i_size_read(inode);
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if (i_size < page_off + len)
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len = i_size - page_off;
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dout("writepage %p page %p index %lu on %llu~%u\n",
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inode, page, page->index, page_off, len);
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writeback_stat = atomic_long_inc_return(&client->writeback_count);
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if (writeback_stat >
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CONGESTION_ON_THRESH(client->mount_args->congestion_kb))
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set_bdi_congested(&client->backing_dev_info, BLK_RW_ASYNC);
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set_page_writeback(page);
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err = ceph_osdc_writepages(osdc, ceph_vino(inode),
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&ci->i_layout, snapc,
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page_off, len,
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ci->i_truncate_seq, ci->i_truncate_size,
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&inode->i_mtime,
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&page, 1, 0, 0, true);
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if (err < 0) {
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dout("writepage setting page/mapping error %d %p\n", err, page);
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SetPageError(page);
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mapping_set_error(&inode->i_data, err);
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if (wbc)
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wbc->pages_skipped++;
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} else {
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dout("writepage cleaned page %p\n", page);
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err = 0; /* vfs expects us to return 0 */
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}
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page->private = 0;
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ClearPagePrivate(page);
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end_page_writeback(page);
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ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
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ceph_put_snap_context(snapc); /* page's reference */
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out:
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return err;
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}
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static int ceph_writepage(struct page *page, struct writeback_control *wbc)
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{
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int err;
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struct inode *inode = page->mapping->host;
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BUG_ON(!inode);
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igrab(inode);
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err = writepage_nounlock(page, wbc);
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unlock_page(page);
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iput(inode);
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return err;
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}
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/*
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* lame release_pages helper. release_pages() isn't exported to
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* modules.
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*/
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static void ceph_release_pages(struct page **pages, int num)
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{
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struct pagevec pvec;
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int i;
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pagevec_init(&pvec, 0);
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for (i = 0; i < num; i++) {
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if (pagevec_add(&pvec, pages[i]) == 0)
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pagevec_release(&pvec);
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}
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pagevec_release(&pvec);
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}
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/*
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* async writeback completion handler.
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*
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* If we get an error, set the mapping error bit, but not the individual
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* page error bits.
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|
*/
|
|
static void writepages_finish(struct ceph_osd_request *req,
|
|
struct ceph_msg *msg)
|
|
{
|
|
struct inode *inode = req->r_inode;
|
|
struct ceph_osd_reply_head *replyhead;
|
|
struct ceph_osd_op *op;
|
|
struct ceph_inode_info *ci = ceph_inode(inode);
|
|
unsigned wrote;
|
|
struct page *page;
|
|
int i;
|
|
struct ceph_snap_context *snapc = req->r_snapc;
|
|
struct address_space *mapping = inode->i_mapping;
|
|
__s32 rc = -EIO;
|
|
u64 bytes = 0;
|
|
struct ceph_client *client = ceph_inode_to_client(inode);
|
|
long writeback_stat;
|
|
unsigned issued = ceph_caps_issued(ci);
|
|
|
|
/* parse reply */
|
|
replyhead = msg->front.iov_base;
|
|
WARN_ON(le32_to_cpu(replyhead->num_ops) == 0);
|
|
op = (void *)(replyhead + 1);
|
|
rc = le32_to_cpu(replyhead->result);
|
|
bytes = le64_to_cpu(op->extent.length);
|
|
|
|
if (rc >= 0) {
|
|
/*
|
|
* Assume we wrote the pages we originally sent. The
|
|
* osd might reply with fewer pages if our writeback
|
|
* raced with a truncation and was adjusted at the osd,
|
|
* so don't believe the reply.
|
|
*/
|
|
wrote = req->r_num_pages;
|
|
} else {
|
|
wrote = 0;
|
|
mapping_set_error(mapping, rc);
|
|
}
|
|
dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
|
|
inode, rc, bytes, wrote);
|
|
|
|
/* clean all pages */
|
|
for (i = 0; i < req->r_num_pages; i++) {
|
|
page = req->r_pages[i];
|
|
BUG_ON(!page);
|
|
WARN_ON(!PageUptodate(page));
|
|
|
|
writeback_stat =
|
|
atomic_long_dec_return(&client->writeback_count);
|
|
if (writeback_stat <
|
|
CONGESTION_OFF_THRESH(client->mount_args->congestion_kb))
|
|
clear_bdi_congested(&client->backing_dev_info,
|
|
BLK_RW_ASYNC);
|
|
|
|
ceph_put_snap_context((void *)page->private);
|
|
page->private = 0;
|
|
ClearPagePrivate(page);
|
|
dout("unlocking %d %p\n", i, page);
|
|
end_page_writeback(page);
|
|
|
|
/*
|
|
* We lost the cache cap, need to truncate the page before
|
|
* it is unlocked, otherwise we'd truncate it later in the
|
|
* page truncation thread, possibly losing some data that
|
|
* raced its way in
|
|
*/
|
|
if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
|
|
generic_error_remove_page(inode->i_mapping, page);
|
|
|
|
unlock_page(page);
|
|
}
|
|
dout("%p wrote+cleaned %d pages\n", inode, wrote);
|
|
ceph_put_wrbuffer_cap_refs(ci, req->r_num_pages, snapc);
|
|
|
|
ceph_release_pages(req->r_pages, req->r_num_pages);
|
|
if (req->r_pages_from_pool)
|
|
mempool_free(req->r_pages,
|
|
ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool);
|
|
else
|
|
kfree(req->r_pages);
|
|
ceph_osdc_put_request(req);
|
|
}
|
|
|
|
/*
|
|
* allocate a page vec, either directly, or if necessary, via a the
|
|
* mempool. we avoid the mempool if we can because req->r_num_pages
|
|
* may be less than the maximum write size.
|
|
*/
|
|
static void alloc_page_vec(struct ceph_client *client,
|
|
struct ceph_osd_request *req)
|
|
{
|
|
req->r_pages = kmalloc(sizeof(struct page *) * req->r_num_pages,
|
|
GFP_NOFS);
|
|
if (!req->r_pages) {
|
|
req->r_pages = mempool_alloc(client->wb_pagevec_pool, GFP_NOFS);
|
|
req->r_pages_from_pool = 1;
|
|
WARN_ON(!req->r_pages);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* initiate async writeback
|
|
*/
|
|
static int ceph_writepages_start(struct address_space *mapping,
|
|
struct writeback_control *wbc)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
struct backing_dev_info *bdi = mapping->backing_dev_info;
|
|
struct ceph_inode_info *ci = ceph_inode(inode);
|
|
struct ceph_client *client;
|
|
pgoff_t index, start, end;
|
|
int range_whole = 0;
|
|
int should_loop = 1;
|
|
pgoff_t max_pages = 0, max_pages_ever = 0;
|
|
struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc;
|
|
struct pagevec pvec;
|
|
int done = 0;
|
|
int rc = 0;
|
|
unsigned wsize = 1 << inode->i_blkbits;
|
|
struct ceph_osd_request *req = NULL;
|
|
int do_sync;
|
|
u64 snap_size = 0;
|
|
|
|
/*
|
|
* Include a 'sync' in the OSD request if this is a data
|
|
* integrity write (e.g., O_SYNC write or fsync()), or if our
|
|
* cap is being revoked.
|
|
*/
|
|
do_sync = wbc->sync_mode == WB_SYNC_ALL;
|
|
if (ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER))
|
|
do_sync = 1;
|
|
dout("writepages_start %p dosync=%d (mode=%s)\n",
|
|
inode, do_sync,
|
|
wbc->sync_mode == WB_SYNC_NONE ? "NONE" :
|
|
(wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD"));
|
|
|
|
client = ceph_inode_to_client(inode);
|
|
if (client->mount_state == CEPH_MOUNT_SHUTDOWN) {
|
|
pr_warning("writepage_start %p on forced umount\n", inode);
|
|
return -EIO; /* we're in a forced umount, don't write! */
|
|
}
|
|
if (client->mount_args->wsize && client->mount_args->wsize < wsize)
|
|
wsize = client->mount_args->wsize;
|
|
if (wsize < PAGE_CACHE_SIZE)
|
|
wsize = PAGE_CACHE_SIZE;
|
|
max_pages_ever = wsize >> PAGE_CACHE_SHIFT;
|
|
|
|
pagevec_init(&pvec, 0);
|
|
|
|
/* ?? */
|
|
if (wbc->nonblocking && bdi_write_congested(bdi)) {
|
|
dout(" writepages congested\n");
|
|
wbc->encountered_congestion = 1;
|
|
goto out_final;
|
|
}
|
|
|
|
/* where to start/end? */
|
|
if (wbc->range_cyclic) {
|
|
start = mapping->writeback_index; /* Start from prev offset */
|
|
end = -1;
|
|
dout(" cyclic, start at %lu\n", start);
|
|
} else {
|
|
start = wbc->range_start >> PAGE_CACHE_SHIFT;
|
|
end = wbc->range_end >> PAGE_CACHE_SHIFT;
|
|
if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
|
|
range_whole = 1;
|
|
should_loop = 0;
|
|
dout(" not cyclic, %lu to %lu\n", start, end);
|
|
}
|
|
index = start;
|
|
|
|
retry:
|
|
/* find oldest snap context with dirty data */
|
|
ceph_put_snap_context(snapc);
|
|
snapc = get_oldest_context(inode, &snap_size);
|
|
if (!snapc) {
|
|
/* hmm, why does writepages get called when there
|
|
is no dirty data? */
|
|
dout(" no snap context with dirty data?\n");
|
|
goto out;
|
|
}
|
|
dout(" oldest snapc is %p seq %lld (%d snaps)\n",
|
|
snapc, snapc->seq, snapc->num_snaps);
|
|
if (last_snapc && snapc != last_snapc) {
|
|
/* if we switched to a newer snapc, restart our scan at the
|
|
* start of the original file range. */
|
|
dout(" snapc differs from last pass, restarting at %lu\n",
|
|
index);
|
|
index = start;
|
|
}
|
|
last_snapc = snapc;
|
|
|
|
while (!done && index <= end) {
|
|
unsigned i;
|
|
int first;
|
|
pgoff_t next;
|
|
int pvec_pages, locked_pages;
|
|
struct page *page;
|
|
int want;
|
|
u64 offset, len;
|
|
struct ceph_osd_request_head *reqhead;
|
|
struct ceph_osd_op *op;
|
|
long writeback_stat;
|
|
|
|
next = 0;
|
|
locked_pages = 0;
|
|
max_pages = max_pages_ever;
|
|
|
|
get_more_pages:
|
|
first = -1;
|
|
want = min(end - index,
|
|
min((pgoff_t)PAGEVEC_SIZE,
|
|
max_pages - (pgoff_t)locked_pages) - 1)
|
|
+ 1;
|
|
pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index,
|
|
PAGECACHE_TAG_DIRTY,
|
|
want);
|
|
dout("pagevec_lookup_tag got %d\n", pvec_pages);
|
|
if (!pvec_pages && !locked_pages)
|
|
break;
|
|
for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
|
|
page = pvec.pages[i];
|
|
dout("? %p idx %lu\n", page, page->index);
|
|
if (locked_pages == 0)
|
|
lock_page(page); /* first page */
|
|
else if (!trylock_page(page))
|
|
break;
|
|
|
|
/* only dirty pages, or our accounting breaks */
|
|
if (unlikely(!PageDirty(page)) ||
|
|
unlikely(page->mapping != mapping)) {
|
|
dout("!dirty or !mapping %p\n", page);
|
|
unlock_page(page);
|
|
break;
|
|
}
|
|
if (!wbc->range_cyclic && page->index > end) {
|
|
dout("end of range %p\n", page);
|
|
done = 1;
|
|
unlock_page(page);
|
|
break;
|
|
}
|
|
if (next && (page->index != next)) {
|
|
dout("not consecutive %p\n", page);
|
|
unlock_page(page);
|
|
break;
|
|
}
|
|
if (wbc->sync_mode != WB_SYNC_NONE) {
|
|
dout("waiting on writeback %p\n", page);
|
|
wait_on_page_writeback(page);
|
|
}
|
|
if ((snap_size && page_offset(page) > snap_size) ||
|
|
(!snap_size &&
|
|
page_offset(page) > i_size_read(inode))) {
|
|
dout("%p page eof %llu\n", page, snap_size ?
|
|
snap_size : i_size_read(inode));
|
|
done = 1;
|
|
unlock_page(page);
|
|
break;
|
|
}
|
|
if (PageWriteback(page)) {
|
|
dout("%p under writeback\n", page);
|
|
unlock_page(page);
|
|
break;
|
|
}
|
|
|
|
/* only if matching snap context */
|
|
pgsnapc = (void *)page->private;
|
|
if (pgsnapc->seq > snapc->seq) {
|
|
dout("page snapc %p %lld > oldest %p %lld\n",
|
|
pgsnapc, pgsnapc->seq, snapc, snapc->seq);
|
|
unlock_page(page);
|
|
if (!locked_pages)
|
|
continue; /* keep looking for snap */
|
|
break;
|
|
}
|
|
|
|
if (!clear_page_dirty_for_io(page)) {
|
|
dout("%p !clear_page_dirty_for_io\n", page);
|
|
unlock_page(page);
|
|
break;
|
|
}
|
|
|
|
/* ok */
|
|
if (locked_pages == 0) {
|
|
/* prepare async write request */
|
|
offset = page->index << PAGE_CACHE_SHIFT;
|
|
len = wsize;
|
|
req = ceph_osdc_new_request(&client->osdc,
|
|
&ci->i_layout,
|
|
ceph_vino(inode),
|
|
offset, &len,
|
|
CEPH_OSD_OP_WRITE,
|
|
CEPH_OSD_FLAG_WRITE |
|
|
CEPH_OSD_FLAG_ONDISK,
|
|
snapc, do_sync,
|
|
ci->i_truncate_seq,
|
|
ci->i_truncate_size,
|
|
&inode->i_mtime, true, 1);
|
|
max_pages = req->r_num_pages;
|
|
|
|
alloc_page_vec(client, req);
|
|
req->r_callback = writepages_finish;
|
|
req->r_inode = inode;
|
|
}
|
|
|
|
/* note position of first page in pvec */
|
|
if (first < 0)
|
|
first = i;
|
|
dout("%p will write page %p idx %lu\n",
|
|
inode, page, page->index);
|
|
|
|
writeback_stat =
|
|
atomic_long_inc_return(&client->writeback_count);
|
|
if (writeback_stat > CONGESTION_ON_THRESH(
|
|
client->mount_args->congestion_kb)) {
|
|
set_bdi_congested(&client->backing_dev_info,
|
|
BLK_RW_ASYNC);
|
|
}
|
|
|
|
set_page_writeback(page);
|
|
req->r_pages[locked_pages] = page;
|
|
locked_pages++;
|
|
next = page->index + 1;
|
|
}
|
|
|
|
/* did we get anything? */
|
|
if (!locked_pages)
|
|
goto release_pvec_pages;
|
|
if (i) {
|
|
int j;
|
|
BUG_ON(!locked_pages || first < 0);
|
|
|
|
if (pvec_pages && i == pvec_pages &&
|
|
locked_pages < max_pages) {
|
|
dout("reached end pvec, trying for more\n");
|
|
pagevec_reinit(&pvec);
|
|
goto get_more_pages;
|
|
}
|
|
|
|
/* shift unused pages over in the pvec... we
|
|
* will need to release them below. */
|
|
for (j = i; j < pvec_pages; j++) {
|
|
dout(" pvec leftover page %p\n",
|
|
pvec.pages[j]);
|
|
pvec.pages[j-i+first] = pvec.pages[j];
|
|
}
|
|
pvec.nr -= i-first;
|
|
}
|
|
|
|
/* submit the write */
|
|
offset = req->r_pages[0]->index << PAGE_CACHE_SHIFT;
|
|
len = min((snap_size ? snap_size : i_size_read(inode)) - offset,
|
|
(u64)locked_pages << PAGE_CACHE_SHIFT);
|
|
dout("writepages got %d pages at %llu~%llu\n",
|
|
locked_pages, offset, len);
|
|
|
|
/* revise final length, page count */
|
|
req->r_num_pages = locked_pages;
|
|
reqhead = req->r_request->front.iov_base;
|
|
op = (void *)(reqhead + 1);
|
|
op->extent.length = cpu_to_le64(len);
|
|
op->payload_len = cpu_to_le32(len);
|
|
req->r_request->hdr.data_len = cpu_to_le32(len);
|
|
|
|
ceph_osdc_start_request(&client->osdc, req, true);
|
|
req = NULL;
|
|
|
|
/* continue? */
|
|
index = next;
|
|
wbc->nr_to_write -= locked_pages;
|
|
if (wbc->nr_to_write <= 0)
|
|
done = 1;
|
|
|
|
release_pvec_pages:
|
|
dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
|
|
pvec.nr ? pvec.pages[0] : NULL);
|
|
pagevec_release(&pvec);
|
|
|
|
if (locked_pages && !done)
|
|
goto retry;
|
|
}
|
|
|
|
if (should_loop && !done) {
|
|
/* more to do; loop back to beginning of file */
|
|
dout("writepages looping back to beginning of file\n");
|
|
should_loop = 0;
|
|
index = 0;
|
|
goto retry;
|
|
}
|
|
|
|
if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
|
|
mapping->writeback_index = index;
|
|
|
|
out:
|
|
if (req)
|
|
ceph_osdc_put_request(req);
|
|
if (rc > 0)
|
|
rc = 0; /* vfs expects us to return 0 */
|
|
ceph_put_snap_context(snapc);
|
|
dout("writepages done, rc = %d\n", rc);
|
|
out_final:
|
|
return rc;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* See if a given @snapc is either writeable, or already written.
|
|
*/
|
|
static int context_is_writeable_or_written(struct inode *inode,
|
|
struct ceph_snap_context *snapc)
|
|
{
|
|
struct ceph_snap_context *oldest = get_oldest_context(inode, NULL);
|
|
int ret = !oldest || snapc->seq <= oldest->seq;
|
|
|
|
ceph_put_snap_context(oldest);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* We are only allowed to write into/dirty the page if the page is
|
|
* clean, or already dirty within the same snap context.
|
|
*
|
|
* called with page locked.
|
|
* return success with page locked,
|
|
* or any failure (incl -EAGAIN) with page unlocked.
|
|
*/
|
|
static int ceph_update_writeable_page(struct file *file,
|
|
loff_t pos, unsigned len,
|
|
struct page *page)
|
|
{
|
|
struct inode *inode = file->f_dentry->d_inode;
|
|
struct ceph_inode_info *ci = ceph_inode(inode);
|
|
struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
|
|
loff_t page_off = pos & PAGE_CACHE_MASK;
|
|
int pos_in_page = pos & ~PAGE_CACHE_MASK;
|
|
int end_in_page = pos_in_page + len;
|
|
loff_t i_size;
|
|
int r;
|
|
struct ceph_snap_context *snapc, *oldest;
|
|
|
|
retry_locked:
|
|
/* writepages currently holds page lock, but if we change that later, */
|
|
wait_on_page_writeback(page);
|
|
|
|
/* check snap context */
|
|
BUG_ON(!ci->i_snap_realm);
|
|
down_read(&mdsc->snap_rwsem);
|
|
BUG_ON(!ci->i_snap_realm->cached_context);
|
|
snapc = (void *)page->private;
|
|
if (snapc && snapc != ci->i_head_snapc) {
|
|
/*
|
|
* this page is already dirty in another (older) snap
|
|
* context! is it writeable now?
|
|
*/
|
|
oldest = get_oldest_context(inode, NULL);
|
|
up_read(&mdsc->snap_rwsem);
|
|
|
|
if (snapc->seq > oldest->seq) {
|
|
ceph_put_snap_context(oldest);
|
|
dout(" page %p snapc %p not current or oldest\n",
|
|
page, snapc);
|
|
/*
|
|
* queue for writeback, and wait for snapc to
|
|
* be writeable or written
|
|
*/
|
|
snapc = ceph_get_snap_context(snapc);
|
|
unlock_page(page);
|
|
ceph_queue_writeback(inode);
|
|
r = wait_event_interruptible(ci->i_cap_wq,
|
|
context_is_writeable_or_written(inode, snapc));
|
|
ceph_put_snap_context(snapc);
|
|
if (r == -ERESTARTSYS)
|
|
return r;
|
|
return -EAGAIN;
|
|
}
|
|
ceph_put_snap_context(oldest);
|
|
|
|
/* yay, writeable, do it now (without dropping page lock) */
|
|
dout(" page %p snapc %p not current, but oldest\n",
|
|
page, snapc);
|
|
if (!clear_page_dirty_for_io(page))
|
|
goto retry_locked;
|
|
r = writepage_nounlock(page, NULL);
|
|
if (r < 0)
|
|
goto fail_nosnap;
|
|
goto retry_locked;
|
|
}
|
|
|
|
if (PageUptodate(page)) {
|
|
dout(" page %p already uptodate\n", page);
|
|
return 0;
|
|
}
|
|
|
|
/* full page? */
|
|
if (pos_in_page == 0 && len == PAGE_CACHE_SIZE)
|
|
return 0;
|
|
|
|
/* past end of file? */
|
|
i_size = inode->i_size; /* caller holds i_mutex */
|
|
|
|
if (i_size + len > inode->i_sb->s_maxbytes) {
|
|
/* file is too big */
|
|
r = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
if (page_off >= i_size ||
|
|
(pos_in_page == 0 && (pos+len) >= i_size &&
|
|
end_in_page - pos_in_page != PAGE_CACHE_SIZE)) {
|
|
dout(" zeroing %p 0 - %d and %d - %d\n",
|
|
page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE);
|
|
zero_user_segments(page,
|
|
0, pos_in_page,
|
|
end_in_page, PAGE_CACHE_SIZE);
|
|
return 0;
|
|
}
|
|
|
|
/* we need to read it. */
|
|
up_read(&mdsc->snap_rwsem);
|
|
r = readpage_nounlock(file, page);
|
|
if (r < 0)
|
|
goto fail_nosnap;
|
|
goto retry_locked;
|
|
|
|
fail:
|
|
up_read(&mdsc->snap_rwsem);
|
|
fail_nosnap:
|
|
unlock_page(page);
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* We are only allowed to write into/dirty the page if the page is
|
|
* clean, or already dirty within the same snap context.
|
|
*/
|
|
static int ceph_write_begin(struct file *file, struct address_space *mapping,
|
|
loff_t pos, unsigned len, unsigned flags,
|
|
struct page **pagep, void **fsdata)
|
|
{
|
|
struct inode *inode = file->f_dentry->d_inode;
|
|
struct page *page;
|
|
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
|
|
int r;
|
|
|
|
do {
|
|
/* get a page */
|
|
page = grab_cache_page_write_begin(mapping, index, 0);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
*pagep = page;
|
|
|
|
dout("write_begin file %p inode %p page %p %d~%d\n", file,
|
|
inode, page, (int)pos, (int)len);
|
|
|
|
r = ceph_update_writeable_page(file, pos, len, page);
|
|
} while (r == -EAGAIN);
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* we don't do anything in here that simple_write_end doesn't do
|
|
* except adjust dirty page accounting and drop read lock on
|
|
* mdsc->snap_rwsem.
|
|
*/
|
|
static int ceph_write_end(struct file *file, struct address_space *mapping,
|
|
loff_t pos, unsigned len, unsigned copied,
|
|
struct page *page, void *fsdata)
|
|
{
|
|
struct inode *inode = file->f_dentry->d_inode;
|
|
struct ceph_client *client = ceph_inode_to_client(inode);
|
|
struct ceph_mds_client *mdsc = &client->mdsc;
|
|
unsigned from = pos & (PAGE_CACHE_SIZE - 1);
|
|
int check_cap = 0;
|
|
|
|
dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
|
|
inode, page, (int)pos, (int)copied, (int)len);
|
|
|
|
/* zero the stale part of the page if we did a short copy */
|
|
if (copied < len)
|
|
zero_user_segment(page, from+copied, len);
|
|
|
|
/* did file size increase? */
|
|
/* (no need for i_size_read(); we caller holds i_mutex */
|
|
if (pos+copied > inode->i_size)
|
|
check_cap = ceph_inode_set_size(inode, pos+copied);
|
|
|
|
if (!PageUptodate(page))
|
|
SetPageUptodate(page);
|
|
|
|
set_page_dirty(page);
|
|
|
|
unlock_page(page);
|
|
up_read(&mdsc->snap_rwsem);
|
|
page_cache_release(page);
|
|
|
|
if (check_cap)
|
|
ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
|
|
|
|
return copied;
|
|
}
|
|
|
|
/*
|
|
* we set .direct_IO to indicate direct io is supported, but since we
|
|
* intercept O_DIRECT reads and writes early, this function should
|
|
* never get called.
|
|
*/
|
|
static ssize_t ceph_direct_io(int rw, struct kiocb *iocb,
|
|
const struct iovec *iov,
|
|
loff_t pos, unsigned long nr_segs)
|
|
{
|
|
WARN_ON(1);
|
|
return -EINVAL;
|
|
}
|
|
|
|
const struct address_space_operations ceph_aops = {
|
|
.readpage = ceph_readpage,
|
|
.readpages = ceph_readpages,
|
|
.writepage = ceph_writepage,
|
|
.writepages = ceph_writepages_start,
|
|
.write_begin = ceph_write_begin,
|
|
.write_end = ceph_write_end,
|
|
.set_page_dirty = ceph_set_page_dirty,
|
|
.invalidatepage = ceph_invalidatepage,
|
|
.releasepage = ceph_releasepage,
|
|
.direct_IO = ceph_direct_io,
|
|
};
|
|
|
|
|
|
/*
|
|
* vm ops
|
|
*/
|
|
|
|
/*
|
|
* Reuse write_begin here for simplicity.
|
|
*/
|
|
static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
|
|
{
|
|
struct inode *inode = vma->vm_file->f_dentry->d_inode;
|
|
struct page *page = vmf->page;
|
|
struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
|
|
loff_t off = page->index << PAGE_CACHE_SHIFT;
|
|
loff_t size, len;
|
|
int ret;
|
|
|
|
size = i_size_read(inode);
|
|
if (off + PAGE_CACHE_SIZE <= size)
|
|
len = PAGE_CACHE_SIZE;
|
|
else
|
|
len = size & ~PAGE_CACHE_MASK;
|
|
|
|
dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode,
|
|
off, len, page, page->index);
|
|
|
|
lock_page(page);
|
|
|
|
ret = VM_FAULT_NOPAGE;
|
|
if ((off > size) ||
|
|
(page->mapping != inode->i_mapping))
|
|
goto out;
|
|
|
|
ret = ceph_update_writeable_page(vma->vm_file, off, len, page);
|
|
if (ret == 0) {
|
|
/* success. we'll keep the page locked. */
|
|
set_page_dirty(page);
|
|
up_read(&mdsc->snap_rwsem);
|
|
ret = VM_FAULT_LOCKED;
|
|
} else {
|
|
if (ret == -ENOMEM)
|
|
ret = VM_FAULT_OOM;
|
|
else
|
|
ret = VM_FAULT_SIGBUS;
|
|
}
|
|
out:
|
|
dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret);
|
|
if (ret != VM_FAULT_LOCKED)
|
|
unlock_page(page);
|
|
return ret;
|
|
}
|
|
|
|
static struct vm_operations_struct ceph_vmops = {
|
|
.fault = filemap_fault,
|
|
.page_mkwrite = ceph_page_mkwrite,
|
|
};
|
|
|
|
int ceph_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
struct address_space *mapping = file->f_mapping;
|
|
|
|
if (!mapping->a_ops->readpage)
|
|
return -ENOEXEC;
|
|
file_accessed(file);
|
|
vma->vm_ops = &ceph_vmops;
|
|
vma->vm_flags |= VM_CAN_NONLINEAR;
|
|
return 0;
|
|
}
|