Commit 630f5dda authored by David Howells's avatar David Howells
Browse files

afs: Wait on PG_fscache before modifying/releasing a page 



PG_fscache is going to be used to indicate that a page is being written to
the cache, and that the page should not be modified or released until it's
finished.

Make afs_invalidatepage() and afs_releasepage() wait for it.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Tested-By: default avatarMarc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/158861253957.340223.7465334678444521655.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/159465832417.1377938.3571599385208729791.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/160588536286.3465195.13231895135369807920.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118153708.1232039.3535103645871176749.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161049369.2537118.11591934943429117060.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340412903.1303470.6424701655031380012.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539556890.286939.5873470593519458598.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653812726.2770958.18167145829938766503.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789096241.6155.5907241930823579235.stgit@warthog.procyon.org.uk/ # v6
parent bd80d8a8

fs/afs/file.c

+9 −0
Original line number Diff line number Diff line
@@ -593,6 +593,7 @@ static void afs_invalidatepage(struct page *page, unsigned int offset, 
	if (PagePrivate(page))

		afs_invalidate_dirty(page, offset, length);



	wait_on_page_fscache(page);

	_leave("");

}
@@ -610,6 +611,14 @@ static int afs_releasepage(struct page *page, gfp_t gfp_flags) 


	/* deny if page is being written to the cache and the caller hasn't

	 * elected to wait */

#ifdef CONFIG_AFS_FSCACHE

	if (PageFsCache(page)) {

		if (!(gfp_flags & __GFP_DIRECT_RECLAIM) || !(gfp_flags & __GFP_FS))

			return false;

		wait_on_page_fscache(page);

	}

#endif



	if (PagePrivate(page)) {

		detach_page_private(page);

		trace_afs_page_dirty(vnode, tracepoint_string("rel"), page);

fs/afs/write.c

+10 −0
Original line number Diff line number Diff line
@@ -117,6 +117,10 @@ int afs_write_begin(struct file *file, struct address_space *mapping, 
		SetPageUptodate(page);

	}



#ifdef CONFIG_AFS_FSCACHE

	wait_on_page_fscache(page);

#endif



try_again:

	/* See if this page is already partially written in a way that we can

	 * merge the new write with.
@@ -857,6 +861,11 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf) 
	/* Wait for the page to be written to the cache before we allow it to

	 * be modified.  We then assume the entire page will need writing back.

	 */

#ifdef CONFIG_AFS_FSCACHE

	if (PageFsCache(vmf->page) &&

	    wait_on_page_bit_killable(vmf->page, PG_fscache) < 0)

		return VM_FAULT_RETRY;

#endif



	if (wait_on_page_writeback_killable(vmf->page))

		return VM_FAULT_RETRY;
@@ -947,5 +956,6 @@ int afs_launder_page(struct page *page) 


	detach_page_private(page);

	trace_afs_page_dirty(vnode, tracepoint_string("laundered"), page);

	wait_on_page_fscache(page);

	return ret;

}