| Message ID | 3761685e05d2803c5ba1891f9d9004692254da95.1491415908.git-series.germano.percossi@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
2017-04-07 4:29 GMT-07:00 Germano Percossi <germano.percossi@citrix.com>: > 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 <germano.percossi@citrix.com> > --- > 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 aa3debb..21d4045 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); > -- > git-series 0.9.1 > -- > To unsubscribe from this list: send the line "unsubscribe linux-cifs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html Nice catch! This one should probably go to stable. Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> -- Best regards, Pavel Shilovsky -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index aa3debb..21d4045 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);
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 <germano.percossi@citrix.com> --- fs/cifs/file.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)