[PATCH 21/25] afs: Wait on PG_fscache before modifying/releasing a page
From: David Howells <dhowells@redhat.com>
Date: 2021-01-21 02:18:55
Also in:
ceph-devel, linux-cifs, linux-nfs, lkml
Subsystem:
afs filesystem, filesystems (vfs and infrastructure), the rest · Maintainers:
David Howells, Marc Dionne, Alexander Viro, Christian Brauner, Linus Torvalds
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: David Howells <dhowells@redhat.com> --- fs/afs/file.c | 9 +++++++++ fs/afs/write.c | 10 ++++++++++ 2 files changed, 19 insertions(+)
diff --git a/fs/afs/file.c b/fs/afs/file.c
index f1bab69e99d4..acbc21a8c80e 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c@@ -594,6 +594,7 @@ 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(""); }
@@ -611,6 +612,14 @@ 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);
diff --git a/fs/afs/write.c b/fs/afs/write.c
index dd4dc1c868b5..e1791de90478 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c@@ -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 (PageWriteback(vmf->page) && wait_on_page_bit_killable(vmf->page, PG_writeback) < 0)
@@ -948,5 +957,6 @@ 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; }