From 055b24a8f23090043b2ce0c30f03e12c5f2c9e72 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 2 Sep 2019 13:02:57 -0400 Subject: nfsd: Don't garbage collect files that might contain write errors If a file may contain unstable writes that can error out, then we want to avoid garbage collecting the struct nfsd_file that may be tracking those errors. So in the garbage collector, we try to avoid collecting files that aren't clean. Furthermore, we avoid immediately kicking off the garbage collector in the case where the reference drops to zero for the case where there is a write error that is being tracked. If the file is unhashed while an error is pending, then declare a reboot, to ensure the client resends any unstable writes. Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields --- fs/nfsd/filecache.c | 43 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) (limited to 'fs/nfsd') diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index da9e790a055e..ef55e9b1cd4e 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -215,6 +215,36 @@ nfsd_file_free(struct nfsd_file *nf) return flush; } +static bool +nfsd_file_check_writeback(struct nfsd_file *nf) +{ + struct file *file = nf->nf_file; + struct address_space *mapping; + + if (!file || !(file->f_mode & FMODE_WRITE)) + return false; + mapping = file->f_mapping; + return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) || + mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK); +} + +static int +nfsd_file_check_write_error(struct nfsd_file *nf) +{ + struct file *file = nf->nf_file; + + if (!file || !(file->f_mode & FMODE_WRITE)) + return 0; + return filemap_check_wb_err(file->f_mapping, READ_ONCE(file->f_wb_err)); +} + +static bool +nfsd_file_in_use(struct nfsd_file *nf) +{ + return nfsd_file_check_writeback(nf) || + nfsd_file_check_write_error(nf); +} + static void nfsd_file_do_unhash(struct nfsd_file *nf) { @@ -222,6 +252,8 @@ nfsd_file_do_unhash(struct nfsd_file *nf) trace_nfsd_file_unhash(nf); + if (nfsd_file_check_write_error(nf)) + nfsd_reset_boot_verifier(net_generic(nf->nf_net, nfsd_net_id)); --nfsd_file_hashtbl[nf->nf_hashval].nfb_count; hlist_del_rcu(&nf->nf_node); if (!list_empty(&nf->nf_lru)) @@ -276,9 +308,10 @@ void nfsd_file_put(struct nfsd_file *nf) { bool is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0; + bool unused = !nfsd_file_in_use(nf); set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); - if (nfsd_file_put_noref(nf) == 1 && is_hashed) + if (nfsd_file_put_noref(nf) == 1 && is_hashed && unused) nfsd_file_schedule_laundrette(NFSD_FILE_LAUNDRETTE_MAY_FLUSH); } @@ -344,6 +377,14 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, */ if (atomic_read(&nf->nf_ref) > 1) goto out_skip; + + /* + * Don't throw out files that are still undergoing I/O or + * that have uncleared errors pending. + */ + if (nfsd_file_check_writeback(nf)) + goto out_skip; + if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) goto out_rescan; -- cgit v1.2.3-59-g8ed1b