Posix: structs re-aligned and manual padding added

All the structs present inside xlators/storage/posix have been re-aligned
into memory efficient way. Manual padding has been added to remove
compile time padding. This manual padding is for development and
debugging benefits. It lets to use -Wpadded option and raise warnings
from the remaining structs where compile time padding happens.

Change-Id: Ie72c02810803eae29fca435c71aa131a1315b8a8
Updates: bz#1754448
Signed-off-by: Purna Pavan Chandra Aekkaladevi <paekkala@redhat.com>

2 files changed, 52 insertions, 44 deletions

diff --git a/xlators/storage/posix/src/posix-metadata.h b/xlators/storage/posix/src/posix-metadata.h
index 63e8771d3b1..d37014af93e 100644
--- a/xlators/storage/posix/src/posix-metadata.h
+++ b/xlators/storage/posix/src/posix-metadata.h
@@ -15,13 +15,15 @@
 
 /* In memory representation posix metadata xattr */
 typedef struct {
-    /* version of structure, bumped up if any new member is added */
-    uint8_t version;
     /* flags indicates valid fields in the structure */
     uint64_t flags;
     struct timespec ctime;
     struct timespec mtime;
     struct timespec atime;
+    /* version of structure, bumped up if any new member is added */
+    uint8_t version;
+
+    char _pad[7]; /* manual padding */
 } posix_mdata_t;
 
 typedef struct {
diff --git a/xlators/storage/posix/src/posix.h b/xlators/storage/posix/src/posix.h
index 7893a9b3e35..359b838f34b 100644
--- a/xlators/storage/posix/src/posix.h
+++ b/xlators/storage/posix/src/posix.h
@@ -119,12 +119,14 @@
  */
 
 struct posix_fd {
-    int fd;        /* fd returned by the kernel */
-    int32_t flags; /* flags for open/creat      */
-    DIR *dir;      /* handle returned by the kernel */
-    off_t dir_eof; /* offset at dir EOF */
-    int odirect;
+    int fd;                /* fd returned by the kernel */
+    int32_t flags;         /* flags for open/creat      */
+    DIR *dir;              /* handle returned by the kernel */
+    off_t dir_eof;         /* offset at dir EOF */
     struct list_head list; /* to add to the janitor list */
+    int odirect;
+
+    char _pad[4]; /* manual padding */
 };
 
 struct posix_private {
@@ -141,30 +143,9 @@ struct posix_private {
     struct timeval init_time;
 
     time_t last_landfill_check;
-    int32_t janitor_sleep_duration;
 
     gf_atomic_t read_value;  /* Total read, from init */
     gf_atomic_t write_value; /* Total write, from init */
-    /*
-       In some cases, two exported volumes may reside on the same
-       partition on the server. Sending statvfs info for both
-       the volumes will lead to erroneous df output at the client,
-       since free space on the partition will be counted twice.
-
-       In such cases, user can disable exporting statvfs info
-       on one of the volumes by setting this option.
-    */
-    gf_boolean_t export_statfs;
-
-    gf_boolean_t o_direct; /* always open files in O_DIRECT mode */
-
-    /*
-       decide whether posix_unlink does open (file), unlink (file), close (fd)
-       instead of just unlink (file). with the former approach there is no
-       lockout of access to parent directory during removal of very large files
-       for the entire duration of freeing of data blocks.
-    */
-    gf_boolean_t background_unlink;
 
     /* janitor task which cleans up /.trash (created by replicate) */
     struct gf_tw_timer_list *janitor;
@@ -178,17 +159,11 @@ struct posix_private {
     /* uuid of glusterd that swapned the brick process */
     uuid_t glusterd_uuid;
 
-    gf_boolean_t aio_configured;
-    gf_boolean_t aio_init_done;
-    gf_boolean_t aio_capable;
 #ifdef HAVE_LIBAIO
     io_context_t ctxp;
     pthread_t aiothread;
 #endif
 
-    /* node-uuid in pathinfo xattr */
-    gf_boolean_t node_uuid_pathinfo;
-
     pthread_t fsyncer;
     struct list_head fsyncs;
     pthread_mutex_t fsync_mutex;
@@ -196,6 +171,7 @@ struct posix_private {
     pthread_mutex_t janitor_mutex;
     pthread_cond_t janitor_cond;
     int fsync_queue_count;
+    int32_t janitor_sleep_duration;
 
     enum {
         BATCH_NONE = 0,
@@ -206,8 +182,6 @@ struct posix_private {
     } batch_fsync_mode;
 
     uint32_t batch_fsync_delay_usec;
-    gf_boolean_t update_pgfid_nlinks;
-    gf_boolean_t gfid2path;
     char gfid2path_sep[8];
 
     /* seconds to sleep between health checks */
@@ -215,13 +189,10 @@ struct posix_private {
     /* seconds to sleep to wait for aio write finish for health checks */
     uint32_t health_check_timeout;
     pthread_t health_check;
-    gf_boolean_t health_check_active;
 
     double disk_reserve;
-    char disk_unit;
-    uint32_t disk_space_full;
     pthread_t disk_space_check;
-    gf_boolean_t disk_space_check_active;
+    uint32_t disk_space_full;
 
 #ifdef GF_DARWIN_HOST_OS
     enum {
@@ -236,9 +207,6 @@ struct posix_private {
        same backend. Very much usable in brick-splitting feature. */
     int32_t shared_brick_count;
 
-    /* This option is used for either to call a landfill_purge or not */
-    gf_boolean_t disable_landfill_purge;
-
     /*Option to set mode bit permission that will always be set on
       file/directory. */
     mode_t force_create_mode;
@@ -247,9 +215,45 @@ struct posix_private {
     mode_t create_directory_mask;
     uint32_t max_hardlinks;
 
+    /* This option is used for either to call a landfill_purge or not */
+    gf_boolean_t disable_landfill_purge;
+
     gf_boolean_t fips_mode_rchecksum;
     gf_boolean_t ctime;
     gf_boolean_t janitor_task_stop;
+
+    gf_boolean_t disk_space_check_active;
+    char disk_unit;
+    gf_boolean_t health_check_active;
+    gf_boolean_t update_pgfid_nlinks;
+    gf_boolean_t gfid2path;
+    /* node-uuid in pathinfo xattr */
+    gf_boolean_t node_uuid_pathinfo;
+    /*
+       In some cases, two exported volumes may reside on the same
+       partition on the server. Sending statvfs info for both
+       the volumes will lead to erroneous df output at the client,
+       since free space on the partition will be counted twice.
+
+       In such cases, user can disable exporting statvfs info
+       on one of the volumes by setting this option.
+    */
+    gf_boolean_t export_statfs;
+
+    gf_boolean_t o_direct; /* always open files in O_DIRECT mode */
+
+    /*
+       decide whether posix_unlink does open (file), unlink (file), close (fd)
+       instead of just unlink (file). with the former approach there is no
+       lockout of access to parent directory during removal of very large files
+       for the entire duration of freeing of data blocks.
+    */
+    gf_boolean_t background_unlink;
+    gf_boolean_t aio_configured;
+    gf_boolean_t aio_init_done;
+    gf_boolean_t aio_capable;
+
+    char _pad[4]; /* manual padding */
 };
 
 typedef struct {
@@ -263,9 +267,11 @@ typedef struct {
     fd_t *fd;
     int fdnum;
     int flags;
-    int32_t op_errno;
     char *list;
     size_t list_size;
+    int32_t op_errno;
+
+    char _pad[4]; /* manual padding */
 } posix_xattr_filler_t;
 
 typedef struct {