From 38e714da98d6c22d18f2571f2198da7e39b86294 Mon Sep 17 00:00:00 2001 From: Germano Percossi Date: Fri, 7 Apr 2017 12:29:38 +0100 Subject: [PATCH] CIFS: store results of cifs_reopen_file to avoid infinite wait BugLink: http://bugs.launchpad.net/bugs/1687045 commit 1fa839b4986d648b907d117275869a0e46c324b9 upstream. This fixes Continuous Availability when errors during file reopen are encountered. cifs_user_readv and cifs_user_writev would wait for ever if results of cifs_reopen_file are not stored and for later inspection. In fact, results are checked and, in case of errors, a chain of function calls leading to reads and writes to be scheduled in a separate thread is skipped. These threads will wake up the corresponding waiters once reads and writes are done. However, given the return value is not stored, when rc is checked for errors a previous one (always zero) is inspected instead. This leads to pending reads/writes added to the list, making cifs_user_readv and cifs_user_writev wait for ever. Signed-off-by: Germano Percossi Reviewed-by: Pavel Shilovsky Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman Signed-off-by: Stefan Bader Signed-off-by: Thadeu Lima de Souza Cascardo --- fs/cifs/file.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 98dc842e7245..f48109941d6b 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2597,7 +2597,7 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, wdata->credits = credits; if (!wdata->cfile->invalidHandle || - !cifs_reopen_file(wdata->cfile, false)) + !(rc = cifs_reopen_file(wdata->cfile, false))) rc = server->ops->async_writev(wdata, cifs_uncached_writedata_release); if (rc) { @@ -3022,7 +3022,7 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, rdata->credits = credits; if (!rdata->cfile->invalidHandle || - !cifs_reopen_file(rdata->cfile, true)) + !(rc = cifs_reopen_file(rdata->cfile, true))) rc = server->ops->async_readv(rdata); error: if (rc) { @@ -3617,7 +3617,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, } if (!rdata->cfile->invalidHandle || - !cifs_reopen_file(rdata->cfile, true)) + !(rc = cifs_reopen_file(rdata->cfile, true))) rc = server->ops->async_readv(rdata); if (rc) { add_credits_and_wake_if(server, rdata->credits, 0); -- 2.39.5