performance/read-ahead: throwaway read-ahead cache of all fds on writes on any fd

This is to make sure applications that read and write on different fds
of the same file work.

This patch also fixes two other issues:
1. while iterating over the list of open fds on an inode, initialize
tmp_file to 0 for each iteration before fd_ctx_get to make sure we
don't carry over the history from previous iterations.
2. remove flushing of cache in flush and fsync as by themselves, they
don't modify the data

Change-Id: Ib9959eb73702a3ebbf90badccaa16b2608050eff
Signed-off-by: Raghavendra G <rgowdapp@redhat.com>
Updates: bz#1512691

1 files changed, 32 insertions, 28 deletions

diff --git a/xlators/performance/read-ahead/src/read-ahead.c b/xlators/performance/read-ahead/src/read-ahead.c
index d001784797a..1185c6e4183 100644
--- a/xlators/performance/read-ahead/src/read-ahead.c
+++ b/xlators/performance/read-ahead/src/read-ahead.c
@@ -583,21 +583,12 @@ ra_fsync_cbk (call_frame_t *frame, void *cookie, xlator_t *this, int32_t op_ret,
 int
 ra_flush (call_frame_t *frame, xlator_t *this, fd_t *fd, dict_t *xdata)
 {
-        ra_file_t *file     = NULL;
-        uint64_t   tmp_file = 0;
         int32_t    op_errno = EINVAL;
 
         GF_ASSERT (frame);
         GF_VALIDATE_OR_GOTO (frame->this->name, this, unwind);
         GF_VALIDATE_OR_GOTO (frame->this->name, fd, unwind);
 
-        fd_ctx_get (fd, this, &tmp_file);
-
-        file = (ra_file_t *)(long)tmp_file;
-        if (file) {
-                flush_region (frame, file, 0, file->pages.prev->offset+1, 0);
-        }
-
         STACK_WIND (frame, ra_flush_cbk, FIRST_CHILD (this),
                     FIRST_CHILD (this)->fops->flush, fd, xdata);
         return 0;
@@ -612,21 +603,12 @@ int
 ra_fsync (call_frame_t *frame, xlator_t *this, fd_t *fd, int32_t datasync,
           dict_t *xdata)
 {
-        ra_file_t *file     = NULL;
-        uint64_t   tmp_file = 0;
         int32_t    op_errno = EINVAL;
 
         GF_ASSERT (frame);
         GF_VALIDATE_OR_GOTO (frame->this->name, this, unwind);
         GF_VALIDATE_OR_GOTO (frame->this->name, fd, unwind);
 
-        fd_ctx_get (fd, this, &tmp_file);
-
-        file = (ra_file_t *)(long)tmp_file;
-        if (file) {
-                flush_region (frame, file, 0, file->pages.prev->offset+1, 0);
-        }
-
         STACK_WIND (frame, ra_fsync_cbk, FIRST_CHILD (this),
                     FIRST_CHILD (this)->fops->fsync, fd, datasync, xdata);
         return 0;
@@ -664,22 +646,39 @@ ra_writev (call_frame_t *frame, xlator_t *this, fd_t *fd, struct iovec *vector,
            int32_t count, off_t offset, uint32_t flags, struct iobref *iobref,
            dict_t *xdata)
 {
-        ra_file_t *file    = NULL;
-        uint64_t  tmp_file = 0;
-        int32_t   op_errno = EINVAL;
+        ra_file_t *file     = NULL;
+        uint64_t   tmp_file = 0;
+        int32_t    op_errno = EINVAL;
+        inode_t   *inode    = NULL;
+        fd_t      *iter_fd  = NULL;
 
         GF_ASSERT (frame);
         GF_VALIDATE_OR_GOTO (frame->this->name, this, unwind);
         GF_VALIDATE_OR_GOTO (frame->this->name, fd, unwind);
 
-        fd_ctx_get (fd, this, &tmp_file);
-        file = (ra_file_t *)(long)tmp_file;
-        if (file) {
-                flush_region (frame, file, 0, file->pages.prev->offset+1, 1);
-                frame->local = file;
-                /* reset the read-ahead counters too */
-                file->expected = file->page_count = 0;
+        inode = fd->inode;
+
+        LOCK (&inode->lock);
+        {
+                list_for_each_entry (iter_fd, &inode->fd_list, inode_list) {
+                        tmp_file = 0;
+                        fd_ctx_get (iter_fd, this, &tmp_file);
+                        file = (ra_file_t *)(long)tmp_file;
+
+                        if (!file)
+                                continue;
+
+                        if (iter_fd == fd)
+                                frame->local = file;
+
+                        flush_region (frame, file, 0,
+                                      file->pages.prev->offset + 1, 1);
+
+                        /* reset the read-ahead counters too */
+                        file->expected = file->page_count = 0;
+                }
         }
+        UNLOCK (&inode->lock);
 
         STACK_WIND (frame, ra_writev_cbk,
                     FIRST_CHILD(this),
@@ -737,6 +736,7 @@ ra_truncate (call_frame_t *frame, xlator_t *this, loc_t *loc, off_t offset,
         LOCK (&inode->lock);
         {
                 list_for_each_entry (iter_fd, &inode->fd_list, inode_list) {
+                        tmp_file = 0;
                         fd_ctx_get (iter_fd, this, &tmp_file);
                         file = (ra_file_t *)(long)tmp_file;
 
@@ -877,6 +877,7 @@ ra_fstat (call_frame_t *frame, xlator_t *this, fd_t *fd, dict_t *xdata)
         LOCK (&inode->lock);
         {
                 list_for_each_entry (iter_fd, &inode->fd_list, inode_list) {
+                        tmp_file = 0;
                         fd_ctx_get (iter_fd, this, &tmp_file);
                         file = (ra_file_t *)(long)tmp_file;
 
@@ -917,6 +918,7 @@ ra_ftruncate (call_frame_t *frame, xlator_t *this, fd_t *fd, off_t offset,
         LOCK (&inode->lock);
         {
                 list_for_each_entry (iter_fd, &inode->fd_list, inode_list) {
+                        tmp_file = 0;
                         fd_ctx_get (iter_fd, this, &tmp_file);
                         file = (ra_file_t *)(long)tmp_file;
                         if (!file)
@@ -975,6 +977,7 @@ ra_discard(call_frame_t *frame, xlator_t *this, fd_t *fd, off_t offset,
         LOCK (&inode->lock);
         {
                 list_for_each_entry (iter_fd, &inode->fd_list, inode_list) {
+                        tmp_file = 0;
                         fd_ctx_get (iter_fd, this, &tmp_file);
                         file = (ra_file_t *)(long)tmp_file;
                         if (!file)
@@ -1025,6 +1028,7 @@ ra_zerofill(call_frame_t *frame, xlator_t *this, fd_t *fd, off_t offset,
         LOCK (&inode->lock);
         {
                 list_for_each_entry (iter_fd, &inode->fd_list, inode_list) {
+                        tmp_file = 0;
                         fd_ctx_get (iter_fd, this, &tmp_file);
                         file = (ra_file_t *)(long)tmp_file;
                         if (!file)