[PATCH 03/29] staging: lustre: llite: restart short read/write for normal IO

From: James Simmons
Date: Thu Oct 27 2016 - 18:12:33 EST


From: Bobi Jam <bobijam.xu@xxxxxxxxx>

If normal IO got short read/write, we'd restart the IO from where
we've accomplished until we meet EOF or error happens.

Signed-off-by: Bobi Jam <bobijam.xu@xxxxxxxxx>
Signed-off-by: Jinshan Xiong <jinshan.xiong@xxxxxxxxx>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6389
Reviewed-on: http://review.whamcloud.com/14123
Reviewed-by: Andreas Dilger <andreas.dilger@xxxxxxxxx>
Reviewed-by: Oleg Drokin <oleg.drokin@xxxxxxxxx>
Signed-off-by: James Simmons <jsimmons@xxxxxxxxxxxxx>
---
drivers/staging/lustre/lnet/libcfs/fail.c | 1 +
.../staging/lustre/lustre/include/obd_support.h | 2 +
drivers/staging/lustre/lustre/llite/file.c | 41 ++++++++++++--------
drivers/staging/lustre/lustre/llite/vvp_io.c | 19 ++++++++-
4 files changed, 45 insertions(+), 18 deletions(-)

diff --git a/drivers/staging/lustre/lnet/libcfs/fail.c b/drivers/staging/lustre/lnet/libcfs/fail.c
index e4b1a0a..3a9c8dd 100644
--- a/drivers/staging/lustre/lnet/libcfs/fail.c
+++ b/drivers/staging/lustre/lnet/libcfs/fail.c
@@ -113,6 +113,7 @@ int __cfs_fail_check_set(__u32 id, __u32 value, int set)
break;
case CFS_FAIL_LOC_RESET:
cfs_fail_loc = value;
+ atomic_set(&cfs_fail_count, 0);
break;
default:
LASSERTF(0, "called with bad set %u\n", set);
diff --git a/drivers/staging/lustre/lustre/include/obd_support.h b/drivers/staging/lustre/lustre/include/obd_support.h
index 1233c34..7f3f8cd 100644
--- a/drivers/staging/lustre/lustre/include/obd_support.h
+++ b/drivers/staging/lustre/lustre/include/obd_support.h
@@ -458,6 +458,8 @@
#define OBD_FAIL_LOV_INIT 0x1403
#define OBD_FAIL_GLIMPSE_DELAY 0x1404
#define OBD_FAIL_LLITE_XATTR_ENOMEM 0x1405
+#define OBD_FAIL_MAKE_LOVEA_HOLE 0x1406
+#define OBD_FAIL_LLITE_LOST_LAYOUT 0x1407
#define OBD_FAIL_GETATTR_DELAY 0x1409

#define OBD_FAIL_FID_INDIR 0x1501
diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c
index 0accf28..2c8df43 100644
--- a/drivers/staging/lustre/lustre/llite/file.c
+++ b/drivers/staging/lustre/lustre/llite/file.c
@@ -972,9 +972,11 @@ void ll_io_init(struct cl_io *io, const struct file *file, int write)
{
struct ll_inode_info *lli = ll_i2info(file_inode(file));
struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+ struct vvp_io *vio = vvp_env_io(env);
struct range_lock range;
struct cl_io *io;
- ssize_t result;
+ ssize_t result = 0;
+ int rc = 0;

CDEBUG(D_VFSTRACE, "file: %pD, type: %d ppos: %llu, count: %zu\n",
file, iot, *ppos, count);
@@ -1006,16 +1008,15 @@ void ll_io_init(struct cl_io *io, const struct file *file, int write)
CDEBUG(D_VFSTRACE, "Range lock [%llu, %llu]\n",
range.rl_node.in_extent.start,
range.rl_node.in_extent.end);
- result = range_lock(&lli->lli_write_tree,
- &range);
- if (result < 0)
+ rc = range_lock(&lli->lli_write_tree, &range);
+ if (rc < 0)
goto out;

range_locked = true;
}
down_read(&lli->lli_trunc_sem);
ll_cl_add(file, env, io);
- result = cl_io_loop(env, io);
+ rc = cl_io_loop(env, io);
ll_cl_remove(file, env);
up_read(&lli->lli_trunc_sem);
if (range_locked) {
@@ -1026,24 +1027,26 @@ void ll_io_init(struct cl_io *io, const struct file *file, int write)
}
} else {
/* cl_io_rw_init() handled IO */
- result = io->ci_result;
+ rc = io->ci_result;
}

if (io->ci_nob > 0) {
result = io->ci_nob;
+ count -= io->ci_nob;
*ppos = io->u.ci_wr.wr.crw_pos;
+
+ /* prepare IO restart */
+ if (count > 0)
+ args->u.normal.via_iter = vio->vui_iter;
}
- goto out;
out:
cl_io_fini(env, io);
- /* If any bit been read/written (result != 0), we just return
- * short read/write instead of restart io.
- */
- if ((result == 0 || result == -ENODATA) && io->ci_need_restart) {
- CDEBUG(D_VFSTRACE, "Restart %s on %pD from %lld, count:%zu\n",
+
+ if ((!rc || rc == -ENODATA) && count > 0 && io->ci_need_restart) {
+ CDEBUG(D_VFSTRACE, "%s: restart %s from %lld, count:%zu, result: %zd\n",
+ file_dentry(file)->d_name.name,
iot == CIT_READ ? "read" : "write",
- file, *ppos, count);
- LASSERTF(io->ci_nob == 0, "%zd\n", io->ci_nob);
+ *ppos, count, result);
goto restart;
}

@@ -1056,13 +1059,19 @@ void ll_io_init(struct cl_io *io, const struct file *file, int write)
ll_stats_ops_tally(ll_i2sbi(file_inode(file)),
LPROC_LL_WRITE_BYTES, result);
fd->fd_write_failed = false;
- } else if (result != -ERESTARTSYS) {
+ } else if (!result && !rc) {
+ rc = io->ci_result;
+ if (rc < 0)
+ fd->fd_write_failed = true;
+ else
+ fd->fd_write_failed = false;
+ } else if (rc != -ERESTARTSYS) {
fd->fd_write_failed = true;
}
}
CDEBUG(D_VFSTRACE, "iot: %d, result: %zd\n", iot, result);

- return result;
+ return result > 0 ? result : rc;
}

static ssize_t ll_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
diff --git a/drivers/staging/lustre/lustre/llite/vvp_io.c b/drivers/staging/lustre/lustre/llite/vvp_io.c
index 87fdab2..3d327b4 100644
--- a/drivers/staging/lustre/lustre/llite/vvp_io.c
+++ b/drivers/staging/lustre/lustre/llite/vvp_io.c
@@ -72,9 +72,10 @@ static bool can_populate_pages(const struct lu_env *env, struct cl_io *io,
/* don't need lock here to check lli_layout_gen as we have held
* extent lock and GROUP lock has to hold to swap layout
*/
- if (ll_layout_version_get(lli) != vio->vui_layout_gen) {
+ if (ll_layout_version_get(lli) != vio->vui_layout_gen ||
+ OBD_FAIL_CHECK_RESET(OBD_FAIL_LLITE_LOST_LAYOUT, 0)) {
io->ci_need_restart = 1;
- /* this will return application a short read/write */
+ /* this will cause a short read/write */
io->ci_continue = 0;
rc = false;
}
@@ -924,6 +925,20 @@ static int vvp_io_write_start(const struct lu_env *env,

CDEBUG(D_VFSTRACE, "write: [%lli, %lli)\n", pos, pos + (long long)cnt);

+ /*
+ * The maximum Lustre file size is variable, based on the OST maximum
+ * object size and number of stripes. This needs another check in
+ * addition to the VFS checks earlier.
+ */
+ if (pos + cnt > ll_file_maxbytes(inode)) {
+ CDEBUG(D_INODE,
+ "%s: file " DFID " offset %llu > maxbytes %llu\n",
+ ll_get_fsname(inode->i_sb, NULL, 0),
+ PFID(ll_inode2fid(inode)), pos + cnt,
+ ll_file_maxbytes(inode));
+ return -EFBIG;
+ }
+
if (!vio->vui_iter) {
/* from a temp io in ll_cl_init(). */
result = 0;
--
1.7.1