BD Backend: Open,read and related calls support for LV

BUG: 805138
Change-Id: I811c179d4244342537dbedb8a24fd2ec628942ed
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Reviewed-on: http://review.gluster.org/3552
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

4 files changed, 296 insertions, 0 deletions

diff --git a/xlators/storage/bd_map/src/bd_map.c b/xlators/storage/bd_map/src/bd_map.c
index e7a684c55..29de9fc1d 100644
--- a/xlators/storage/bd_map/src/bd_map.c
+++ b/xlators/storage/bd_map/src/bd_map.c
@@ -34,6 +34,183 @@
 
 /* Regular fops */
 
+int
+bd_access (call_frame_t *frame, xlator_t *this,
+                loc_t *loc, int32_t mask, dict_t *xdict)
+{
+        int32_t   op_ret         = -1;
+        int32_t   op_errno       = 0;
+        char      path[PATH_MAX] = {0, };
+
+        VALIDATE_OR_GOTO (frame, out);
+        VALIDATE_OR_GOTO (this, out);
+        VALIDATE_OR_GOTO (loc, out);
+
+        sprintf (path, "/dev/mapper/%s", loc->path);
+        op_ret = access (path, mask & 07);
+        if (op_ret == -1) {
+                op_errno = errno;
+                gf_log (this->name, GF_LOG_ERROR, "access failed on %s: %s",
+                                loc->path, strerror (op_errno));
+                goto out;
+        }
+        op_ret = 0;
+out:
+        STACK_UNWIND_STRICT (access, frame, op_ret, op_errno, NULL);
+
+        return 0;
+}
+
+int32_t
+bd_open (call_frame_t *frame, xlator_t *this,
+                loc_t *loc, int32_t flags, fd_t *fd, dict_t *xdata)
+{
+        int32_t         op_ret          = -1;
+        int32_t         op_errno        = 0;
+        int32_t         _fd             = -1;
+        bd_fd_t         *bd_fd          = NULL;
+        bd_entry_t      *lventry        = NULL;
+        bd_priv_t       *priv           = NULL;
+        char            *devpath        = NULL;
+
+        VALIDATE_OR_GOTO (frame, out);
+        VALIDATE_OR_GOTO (this, out);
+        VALIDATE_OR_GOTO (this->private, out);
+        VALIDATE_OR_GOTO (loc, out);
+        VALIDATE_OR_GOTO (fd, out);
+
+        priv = this->private;
+        VALIDATE_OR_GOTO (priv, out);
+
+        BD_ENTRY (priv, lventry, loc->path);
+        if (!lventry) {
+                op_errno = ENOENT;
+                goto out;
+        }
+
+        gf_asprintf (&devpath, "/dev/%s/%s", lventry->parent->name,
+                      lventry->name);
+        _fd = open (devpath, flags, 0);
+        if (_fd == -1) {
+                op_errno = errno;
+                gf_log (this->name, GF_LOG_ERROR,
+                                "open on %s: %s", devpath, strerror (op_errno));
+                goto out;
+        }
+
+        bd_fd = GF_CALLOC (1, sizeof(*bd_fd), gf_bd_fd);
+        if (!bd_fd) {
+                op_errno = errno;
+                goto out;
+        }
+        bd_fd->entry = lventry;
+        bd_fd->fd = _fd;
+
+        op_ret = fd_ctx_set (fd, this, (uint64_t)(long)bd_fd);
+        if (op_ret) {
+                gf_log (this->name, GF_LOG_WARNING,
+                                "failed to set the fd context path=%s fd=%p",
+                                loc->name, fd);
+                goto out;
+        }
+
+        op_ret = 0;
+out:
+        if (op_ret == -1) {
+                if (_fd != -1)
+                        close (_fd);
+                /* FIXME: Should we call fd_ctx_set with NULL? */
+                if (bd_fd)
+                        GF_FREE (bd_fd);
+                if (lventry)
+                        BD_PUT_ENTRY (priv, lventry);
+        }
+        if (devpath)
+                GF_FREE (devpath);
+
+        STACK_UNWIND_STRICT (open, frame, op_ret, op_errno, fd, NULL);
+
+        return 0;
+}
+
+int
+bd_readv (call_frame_t *frame, xlator_t *this, fd_t *fd, size_t size,
+                off_t offset, uint32_t flags, dict_t *xdata)
+{
+        uint64_t        tmp_bd_fd  = 0;
+        int32_t         op_ret     = -1;
+        int32_t         op_errno   = 0;
+        int             _fd        = -1;
+        bd_priv_t       *priv      = NULL;
+        struct iobuf    *iobuf     = NULL;
+        struct iobref   *iobref    = NULL;
+        struct iovec    vec        = {0, };
+        bd_fd_t         *bd_fd     = NULL;
+        int             ret        = -1;
+        struct iatt     stbuf      = {0, };
+
+        VALIDATE_OR_GOTO (frame, out);
+        VALIDATE_OR_GOTO (this, out);
+        VALIDATE_OR_GOTO (fd, out);
+        VALIDATE_OR_GOTO (this->private, out);
+
+        priv = this->private;
+        VALIDATE_OR_GOTO (priv, out);
+
+        ret = fd_ctx_get (fd, this, &tmp_bd_fd);
+        if (ret < 0) {
+                op_errno = -EINVAL;
+                gf_log (this->name, GF_LOG_WARNING,
+                                "bd_fd is NULL from fd=%p", fd);
+                goto out;
+        }
+        bd_fd = (bd_fd_t *)(long)tmp_bd_fd;
+        if (!size) {
+                op_errno = EINVAL;
+                gf_log (this->name, GF_LOG_WARNING, "size=%"GF_PRI_SIZET, size);
+                goto out;
+        }
+        iobuf = iobuf_get2 (this->ctx->iobuf_pool, size);
+        if (!iobuf) {
+                op_errno = ENOMEM;
+                goto out;
+        }
+        _fd = bd_fd->fd;
+        op_ret = pread (_fd, iobuf->ptr, size, offset);
+        if (op_ret == -1) {
+                op_errno = errno;
+                gf_log (this->name, GF_LOG_ERROR,
+                                "read failed on fd=%p: %s", fd,
+                                strerror (op_errno));
+                goto out;
+        }
+
+        vec.iov_base = iobuf->ptr;
+        vec.iov_len = op_ret;
+
+        iobref = iobref_new ();
+        iobref_add (iobref, iobuf);
+        BD_ENTRY_UPDATE_ATIME (bd_fd->entry);
+
+        memcpy (&stbuf, bd_fd->entry->attr, sizeof(stbuf));
+
+        /* Hack to notify higher layers of EOF. */
+        if (bd_fd->entry->size == 0)
+                op_errno = ENOENT;
+        else if ((offset + vec.iov_len) >= bd_fd->entry->size)
+                op_errno = ENOENT;
+        op_ret = vec.iov_len;
+out:
+        STACK_UNWIND_STRICT (readv, frame, op_ret, op_errno,
+                        &vec, 1, &stbuf, iobref, NULL);
+
+        if (iobref)
+                iobref_unref (iobref);
+        if (iobuf)
+                iobuf_unref (iobuf);
+        return 0;
+}
+
 int32_t
 bd_lookup (call_frame_t *frame, xlator_t *this, loc_t *loc, dict_t *xattr_req)
 {
@@ -135,6 +312,39 @@ out:
 }
 
 int32_t
+bd_fstat (call_frame_t *frame, xlator_t *this, fd_t *fd, dict_t *xdata)
+{
+        int            ret         = -1;
+        int32_t        op_ret      = -1;
+        int32_t        op_errno    = 0;
+        uint64_t       tmp_bd_fd   = 0;
+        struct iatt    buf         = {0, };
+        bd_fd_t        *bd_fd      = NULL;
+        int            _fd         = -1;
+
+        VALIDATE_OR_GOTO (frame, out);
+        VALIDATE_OR_GOTO (this, out);
+        VALIDATE_OR_GOTO (fd, out);
+
+        ret = fd_ctx_get (fd, this, &tmp_bd_fd);
+        if (ret < 0) {
+                gf_log (this->name, GF_LOG_WARNING,
+                                "bd_fd is NULL, fd=%p", fd);
+                op_errno = -EINVAL;
+                goto out;
+        }
+        bd_fd = (bd_fd_t *)(long)tmp_bd_fd;
+        _fd = bd_fd->fd;
+
+        memcpy (&buf, bd_fd->entry->attr, sizeof(buf));
+        op_ret = 0;
+
+out:
+        STACK_UNWIND_STRICT (stat, frame, op_ret, op_errno, &buf, NULL);
+        return 0;
+}
+
+int32_t
 bd_opendir (call_frame_t *frame, xlator_t *this,
                loc_t *loc, fd_t *fd, dict_t *xdata)
 {
@@ -290,6 +500,61 @@ out:
         return 0;
 }
 
+int32_t
+bd_release (xlator_t *this, fd_t *fd)
+{
+        bd_fd_t      *bd_fd    = NULL;
+        int          ret       = -1;
+        uint64_t     tmp_bd_fd = 0;
+        bd_priv_t    *priv     = NULL;
+
+        VALIDATE_OR_GOTO (this, out);
+        VALIDATE_OR_GOTO (fd, out);
+
+        priv = this->private;
+        VALIDATE_OR_GOTO (priv, out);
+
+        ret = fd_ctx_get (fd, this, &tmp_bd_fd);
+        if (ret < 0) {
+                gf_log (this->name, GF_LOG_WARNING, "bd_fd is NULL from fd=%p",
+                                fd);
+                goto out;
+        }
+        bd_fd = (bd_fd_t *) (long)tmp_bd_fd;
+        close (bd_fd->fd);
+        BD_PUT_ENTRY (priv, bd_fd->entry);
+
+        GF_FREE (bd_fd);
+out:
+        return 0;
+}
+
+int32_t
+bd_flush (call_frame_t *frame, xlator_t *this, fd_t *fd, dict_t *xdict)
+{
+        int32_t     op_ret    = -1;
+        int32_t     op_errno  = 0;
+        int         ret       = -1;
+        uint64_t    tmp_bd_fd = 0;
+
+        VALIDATE_OR_GOTO (frame, out);
+        VALIDATE_OR_GOTO (this, out);
+        VALIDATE_OR_GOTO (fd, out);
+
+        ret = fd_ctx_get (fd, this, &tmp_bd_fd);
+        if (ret < 0) {
+                op_errno = -EINVAL;
+                gf_log (this->name, GF_LOG_WARNING,
+                                "bd_fd is NULL on fd=%p", fd);
+                goto out;
+        }
+        op_ret = 0;
+out:
+        STACK_UNWIND_STRICT (flush, frame, op_ret, op_errno, NULL);
+
+        return 0;
+}
+
 int
 __bd_fill_readdir (pthread_rwlock_t *bd_lock, bd_fd_t *bd_fd, off_t off,
                 size_t size, gf_dirent_t *entries)
@@ -881,10 +1146,16 @@ struct xlator_fops fops = {
         .readdirp    = bd_readdirp,
         .stat        = bd_stat,
         .statfs      = bd_statfs,
+        .open        = bd_open,
+        .access      = bd_access,
+        .flush       = bd_flush,
+        .readv       = bd_readv,
+        .fstat       = bd_fstat,
 };
 
 struct xlator_cbks cbks = {
         .releasedir  = bd_releasedir,
+        .release     = bd_release,
 };
 
 struct volume_options options[] = {
diff --git a/xlators/storage/bd_map/src/bd_map.h b/xlators/storage/bd_map/src/bd_map.h
index 974ec9288..936defbbb 100644
--- a/xlators/storage/bd_map/src/bd_map.h
+++ b/xlators/storage/bd_map/src/bd_map.h
@@ -64,6 +64,7 @@ typedef struct bd_entry {
 typedef struct bd_fd {
         bd_entry_t      *entry;
         bd_entry_t      *p_entry; /* Parent entry */
+        int             fd;
 } bd_fd_t;
 
 typedef struct bd_priv {
diff --git a/xlators/storage/bd_map/src/bd_map_help.c b/xlators/storage/bd_map/src/bd_map_help.c
index 2b5c321f6..3576d7056 100644
--- a/xlators/storage/bd_map/src/bd_map_help.c
+++ b/xlators/storage/bd_map/src/bd_map_help.c
@@ -47,6 +47,25 @@ static void bd_entry_get_ino (uint64_t *inode)
         UNLOCK (&inode_lk);
 }
 
+void bd_update_time (bd_entry_t *entry, int type)
+{
+        struct timespec ts;
+
+        clock_gettime (CLOCK_REALTIME, &ts);
+        if (type == 0) {
+                entry->attr->ia_mtime = ts.tv_sec;
+                entry->attr->ia_mtime_nsec = ts.tv_nsec;
+                entry->attr->ia_atime = ts.tv_sec;
+                entry->attr->ia_atime_nsec = ts.tv_nsec;
+        } else if (type == 1) {
+                entry->attr->ia_mtime = ts.tv_sec;
+                entry->attr->ia_mtime_nsec = ts.tv_nsec;
+        } else {
+                entry->attr->ia_atime = ts.tv_sec;
+                entry->attr->ia_atime_nsec = ts.tv_nsec;
+        }
+}
+
 static bd_entry_t *bd_entry_init (const char *name)
 {
         bd_entry_t *bdentry;
diff --git a/xlators/storage/bd_map/src/bd_map_help.h b/xlators/storage/bd_map/src/bd_map_help.h
index 997b8b716..46862f328 100644
--- a/xlators/storage/bd_map/src/bd_map_help.h
+++ b/xlators/storage/bd_map/src/bd_map_help.h
@@ -47,6 +47,10 @@
                 BD_UNLOCK (&priv->lock);        \
         } while (0)
 
+#define BD_ENTRY_UPDATE_TIME(bdentry)  bd_update_time (bdentry, 0)
+#define BD_ENTRY_UPDATE_ATIME(bdentry) bd_update_time (bdentry, 2)
+#define BD_ENTRY_UPDATE_MTIME(bdentry) bd_update_time (bdentry, 1)
+
 extern bd_entry_t *bd_rootp;
 extern gf_lock_t inode_lk;
 
@@ -59,5 +63,6 @@ bd_entry_t *bd_entry_get (const char *name);
 void bd_entry_put (bd_entry_t *entry);
 int bd_build_lv_list (bd_priv_t *priv, char *vg);
 int bd_entry_cleanup (void);
+void bd_update_time (bd_entry_t *entry, int type);
 
 #endif