From d1665e414297c3a46fd80cb8242ad0c8e82acae7 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Tue, 14 Feb 2006 11:54:42 +0000 Subject: [GFS2] Put back O_DIRECT support This patch adds back O_DIRECT support with various caveats attached: 1. Journaled data can be read via O_DIRECT since its now the same on disk format as normal data files. 2. Journaled data writes with O_DIRECT will be failed sliently back to normal writes (should we really do this I wonder or should we return an error instead?) 3. Stuffed files will be failed back to normal buffered I/O 4. All the usual corner cases (write beyond current end of file, write to an unallocated block) will also revert to normal buffered I/O. The I/O path is slightly odd as reads arrive at the page cache layer with the lock for the file already held, but writes arrive unlocked. Signed-off-by: Steven Whitehouse --- fs/gfs2/ops_file.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) (limited to 'fs/gfs2/ops_file.c') diff --git a/fs/gfs2/ops_file.c b/fs/gfs2/ops_file.c index 56820b39a99..bcde7a0b76f 100644 --- a/fs/gfs2/ops_file.c +++ b/fs/gfs2/ops_file.c @@ -176,16 +176,16 @@ static ssize_t __gfs2_file_aio_read(struct kiocb *iocb, * If any segment has a negative length, or the cumulative * length ever wraps negative then return -EINVAL. */ - count += iv->iov_len; - if (unlikely((ssize_t)(count|iv->iov_len) < 0)) - return -EINVAL; - if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len)) - continue; - if (seg == 0) - return -EFAULT; - nr_segs = seg; - count -= iv->iov_len; /* This segment is no good */ - break; + count += iv->iov_len; + if (unlikely((ssize_t)(count|iv->iov_len) < 0)) + return -EINVAL; + if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len)) + continue; + if (seg == 0) + return -EFAULT; + nr_segs = seg; + count -= iv->iov_len; /* This segment is no good */ + break; } /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */ @@ -204,10 +204,14 @@ static ssize_t __gfs2_file_aio_read(struct kiocb *iocb, retval = gfs2_glock_nq_m_atime(1, &gh); if (retval) goto out; - + if (gfs2_is_stuffed(ip)) { + gfs2_glock_dq_m(1, &gh); + gfs2_holder_uninit(&gh); + goto fallback_to_normal; + } size = i_size_read(inode); if (pos < size) { - retval = gfs2_direct_IO_read(iocb, iov, pos, nr_segs); + retval = gfs2_direct_IO_read(iocb, iov, pos, nr_segs); if (retval > 0 && !is_sync_kiocb(iocb)) retval = -EIOCBQUEUED; if (retval > 0) @@ -219,6 +223,7 @@ static ssize_t __gfs2_file_aio_read(struct kiocb *iocb, goto out; } +fallback_to_normal: retval = 0; if (count) { for (seg = 0; seg < nr_segs; seg++) { -- cgit v1.2.3-18-g5258