On Wed, 28 Nov 2012 18:23:45 +0400 Pavel Shilovsky <[email protected]> wrote:
> If we have a read oplock and set a read lock in it, we can't write to the > locked area - so, filemap_fdatawrite may fail with a no information for a > userspace application even if we request a write to non-locked area. Fix > this by checking for brlocks, populating the page cache without marking > affected pages dirty and directly writing to the server. > > Also remove CONFIG_CIFS_SMB2 ifdefs because it's suitable for both CIFS > and SMB2 protocols. > > Signed-off-by: Pavel Shilovsky <[email protected]> > --- > fs/cifs/file.c | 63 > +++++++++++++++++++++++++++++--------------------------- > 1 file changed, 33 insertions(+), 30 deletions(-) > > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > index e7fc39c..5cfed9c 100644 > --- a/fs/cifs/file.c > +++ b/fs/cifs/file.c > @@ -2109,7 +2109,14 @@ static int cifs_write_end(struct file *file, struct > address_space *mapping, > } else { > rc = copied; > pos += copied; > - set_page_dirty(page); > + /* > + * If we don't have write oplock and use the strict cache mode, > + * we can leave pages clean - cifs_strict_writev will send a > + * data to the server itself. > + */ > + if (CIFS_I(inode)->clientCanCacheAll || > + !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)) > + set_page_dirty(page); > } > > if (rc > 0) { > @@ -2460,8 +2467,8 @@ ssize_t cifs_user_writev(struct kiocb *iocb, const > struct iovec *iov, > } > > static ssize_t > -cifs_writev(struct kiocb *iocb, const struct iovec *iov, > - unsigned long nr_segs, loff_t pos) > +cifs_pagecache_writev(struct kiocb *iocb, const struct iovec *iov, > + unsigned long nr_segs, loff_t pos) > { > struct file *file = iocb->ki_filp; > struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data; > @@ -2511,25 +2518,26 @@ cifs_strict_writev(struct kiocb *iocb, const struct > iovec *iov, > struct cifsFileInfo *cfile = (struct cifsFileInfo *) > iocb->ki_filp->private_data; > struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); > + ssize_t written; > > -#ifdef CONFIG_CIFS_SMB2 > - /* > - * If we have an oplock for read and want to write a data to the file > - * we need to store it in the page cache and then push it to the server > - * to be sure the next read will get a valid data. > - */ > - if (!cinode->clientCanCacheAll && cinode->clientCanCacheRead) { > - ssize_t written; > - int rc; > - > - written = generic_file_aio_write(iocb, iov, nr_segs, pos); > - rc = filemap_fdatawrite(inode->i_mapping); > - if (rc) > - return (ssize_t)rc; > - > - return written; > + /* we have a read oplock - need to store a data in the page cache */ > + if (cinode->clientCanCacheRead) { > + if (cap_unix(tcon->ses) && > + ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0) && > + (CIFS_UNIX_FCNTL_CAP & le64_to_cpu( > + tcon->fsUnixInfo.Capability))) > + written = generic_file_aio_write(iocb, iov, nr_segs, > + pos); > + else > + written = cifs_pagecache_writev(iocb, iov, nr_segs, > + pos); > + /* > + * Errors occured during writing or we have read+write oplock - > + * no need to flush to the server. > + */ > + if (written < 0 || cinode->clientCanCacheAll) > + return written; > } > -#endif > > /* > * For non-oplocked files in strict cache mode we need to write the data > @@ -2537,16 +2545,11 @@ cifs_strict_writev(struct kiocb *iocb, const struct > iovec *iov, > * affected pages because it may cause a error with mandatory locks on > * these pages but not on the region from pos to ppos+len-1. > */ > - > - if (!cinode->clientCanCacheAll) > - return cifs_user_writev(iocb, iov, nr_segs, pos); > - > - if (cap_unix(tcon->ses) && > - (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) && > - ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) > - return generic_file_aio_write(iocb, iov, nr_segs, pos); > - > - return cifs_writev(iocb, iov, nr_segs, pos); > + written = cifs_user_writev(iocb, iov, nr_segs, pos); > + /* need to restore pos if errors occured */ > + if (written < 0) > + iocb->ki_pos = pos; > + return written; > } > > static struct cifs_readdata * Looks reasonable... Acked-by: Jeff Layton <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
