cluster/ec: Fix reopen flags to avoid misbehavior

Problem:
when a file needs to be re-opened O_APPEND and O_EXCL
flags are not filtered in EC.

- O_APPEND should be filtered because EC doesn't send O_APPEND below EC for
open to make sure writes happen on the individual fragments instead of at the
end of the file.

- O_EXCL should be filtered because shd could have created the file so even
when file exists open should succeed

- O_CREAT should be filtered because open happens with gfid as parameter. So
open fop will create just the gfid which will lead to problems.

Fix:
Filter out these two flags in reopen.

Change-Id: Ia280470fcb5188a09caa07bf665a2a94bce23bc4
Fixes: bz#1739450
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>

2 files changed, 8 insertions, 3 deletions

diff --git a/xlators/cluster/ec/src/ec-common.c b/xlators/cluster/ec/src/ec-common.c
index 28b31c913c9..5fb4610e1d7 100644
--- a/xlators/cluster/ec/src/ec-common.c
+++ b/xlators/cluster/ec/src/ec-common.c
@@ -101,6 +101,7 @@ ec_fix_open(ec_fop_data_t *fop, uintptr_t mask)
 {
     uintptr_t need_open = 0;
     int ret = 0;
+    int32_t flags = 0;
     loc_t loc = {
         0,
     };
@@ -121,6 +122,7 @@ ec_fix_open(ec_fop_data_t *fop, uintptr_t mask)
         goto out;
     }
 
+    flags = fop->fd->flags & (~(O_TRUNC | O_APPEND | O_CREAT | O_EXCL));
     if (IA_IFDIR == fop->fd->inode->ia_type) {
         ec_opendir(fop->frame, fop->xl, need_open,
                    EC_MINIMUM_ONE | EC_FOP_NO_PROPAGATE_ERROR, NULL, NULL,
@@ -128,7 +130,7 @@ ec_fix_open(ec_fop_data_t *fop, uintptr_t mask)
     } else {
         ec_open(fop->frame, fop->xl, need_open,
                 EC_MINIMUM_ONE | EC_FOP_NO_PROPAGATE_ERROR, NULL, NULL, &loc,
-                fop->fd->flags & (~O_TRUNC), fop->fd, NULL);
+                flags, fop->fd, NULL);
     }
 
 out:
diff --git a/xlators/cluster/ec/src/ec-inode-write.c b/xlators/cluster/ec/src/ec-inode-write.c
index 4f35b6d7bd2..2f28e11637c 100644
--- a/xlators/cluster/ec/src/ec-inode-write.c
+++ b/xlators/cluster/ec/src/ec-inode-write.c
@@ -1985,10 +1985,13 @@ ec_get_lock_good_mask(inode_t *inode, xlator_t *xl)
     LOCK(&inode->lock);
     {
         ictx = __ec_inode_get(inode, xl);
-        lock = ictx->inode_lock;
+        if (ictx)
+            lock = ictx->inode_lock;
     }
     UNLOCK(&inode->lock);
-    return lock->good_mask;
+    if (lock)
+        return lock->good_mask;
+    return 0;
 }
 
 void