/*
   Copyright (c) 2008-2012, 2016 Red Hat, Inc. <http://www.redhat.com>
   This file is part of GlusterFS.

   This file is licensed to you under your choice of the GNU Lesser
   General Public License, version 3 or any later version (LGPLv3 or
   later), or the GNU General Public License, version 2 (GPLv2), in all
   cases as published by the Free Software Foundation.
*/
#include "xlator.h"
#include "defaults.h"
#include "read-only-common.h"
#include "read-only-mem-types.h"
#include "read-only.h"
#include "syncop.h"
#include "worm-helper.h"


int32_t
mem_acct_init (xlator_t *this)
{
        int     ret = -1;

        ret = xlator_mem_acct_init (this, gf_read_only_mt_end + 1);
        if (ret)
                gf_log (this->name, GF_LOG_ERROR, "Memory accounting "
                        "initialization failed.");

        return ret;
}


static int32_t
worm_open (call_frame_t *frame, xlator_t *this, loc_t *loc, int32_t flags,
           fd_t *fd, dict_t *xdata)
{
        if (is_readonly_or_worm_enabled (this) &&
            (flags & (O_WRONLY | O_RDWR | O_APPEND))) {
                STACK_UNWIND_STRICT (open, frame, -1, EROFS, NULL, NULL);
                return 0;
        }

        STACK_WIND_TAIL (frame, FIRST_CHILD(this),
                    FIRST_CHILD(this)->fops->open, loc, flags, fd, xdata);
        return 0;
}


static int32_t
worm_link (call_frame_t *frame, xlator_t *this, loc_t *oldloc, loc_t *newloc,
           dict_t *xdata)
{
        int op_errno                =       EROFS;
        read_only_priv_t *priv      =       NULL;

        priv = this->private;
        GF_ASSERT (priv);
        if (is_readonly_or_worm_enabled (this))
                goto out;
        if (!priv->worm_file) {
                op_errno = 0;
                goto out;
        }

        gf_uuid_copy (oldloc->gfid, oldloc->inode->gfid);
        if (is_wormfile (this, _gf_false, oldloc)) {
                op_errno = 0;
                goto out;
        }
        op_errno = gf_worm_state_transition (this, _gf_false, oldloc,
                                             GF_FOP_LINK);

out:
        if (op_errno)
                STACK_UNWIND_STRICT (link, frame, -1, op_errno, NULL, NULL,
                                     NULL, NULL, NULL);
        else
                STACK_WIND_TAIL (frame, FIRST_CHILD(this),
                                 FIRST_CHILD(this)->fops->link,
                                 oldloc, newloc, xdata);
        return 0;
}


static int32_t
worm_unlink (call_frame_t *frame, xlator_t *this, loc_t *loc, int32_t flags,
             dict_t *xdata)
{
        int op_errno                =       EROFS;
        read_only_priv_t *priv      =       NULL;

        priv = this->private;
        GF_ASSERT (priv);
        if (is_readonly_or_worm_enabled (this)) {
                goto out;
        }
        if (!priv->worm_file) {
                op_errno = 0;
                goto out;
        }

        gf_uuid_copy (loc->gfid, loc->inode->gfid);
        if (is_wormfile (this, _gf_false, loc)) {
                op_errno = 0;
                goto out;
        }
        op_errno = gf_worm_state_transition (this, _gf_false, loc,
                                             GF_FOP_UNLINK);
out:
        if (op_errno)
                STACK_UNWIND_STRICT (unlink, frame, -1, op_errno, NULL, NULL,
                                     NULL);
        else
                STACK_WIND_TAIL (frame, FIRST_CHILD(this),
                                 FIRST_CHILD(this)->fops->unlink,
                                 loc, flags, xdata);
        return 0;
}


static int32_t
worm_rename (call_frame_t *frame, xlator_t *this,
             loc_t *oldloc, loc_t *newloc, dict_t *xdata)
{
        int op_errno                =       EROFS;
        read_only_priv_t *priv      =       NULL;

        priv = this->private;
        GF_ASSERT (priv);
        if (is_readonly_or_worm_enabled (this))
                goto out;
        if (!priv->worm_file) {
                op_errno = 0;
                goto out;
        }

        gf_uuid_copy (oldloc->gfid, oldloc->inode->gfid);
        if (is_wormfile (this, _gf_false, oldloc)) {
                op_errno = 0;
                goto out;
        }
        op_errno = gf_worm_state_transition (this, _gf_false, oldloc,
                                           GF_FOP_RENAME);

out:
        if (op_errno)
                STACK_UNWIND_STRICT (rename, frame, -1, op_errno, NULL,
                                     NULL, NULL, NULL, NULL, NULL);
        else
                STACK_WIND_TAIL (frame, FIRST_CHILD (this),
                                 FIRST_CHILD (this)->fops->rename,
                                 oldloc, newloc, xdata);
        return 0;
}


static int32_t
worm_truncate (call_frame_t *frame, xlator_t *this, loc_t *loc, off_t offset,
               dict_t *xdata)
{
        int op_errno                =       EROFS;
        read_only_priv_t *priv      =       NULL;

        priv = this->private;
        GF_ASSERT (priv);
        if (is_readonly_or_worm_enabled (this))
                goto out;
        if (!priv->worm_file) {
                op_errno = 0;
                goto out;
        }

        if (is_wormfile (this, _gf_false, loc)) {
                op_errno = 0;
                goto out;
        }
        op_errno = gf_worm_state_transition (this, _gf_false, loc,
                                           GF_FOP_TRUNCATE);

out:
        if (op_errno)
                STACK_UNWIND_STRICT (truncate, frame, -1, op_errno, NULL, NULL,
                                     NULL);
        else
                STACK_WIND_TAIL (frame, FIRST_CHILD (this),
                                 FIRST_CHILD (this)->fops->truncate,
                                 loc, offset, xdata);
        return 0;
}


static int32_t
worm_setattr (call_frame_t *frame, xlator_t *this, loc_t *loc,
              struct iatt *stbuf, int32_t valid, dict_t *xdata)
{
        gf_boolean_t rd_only            =       _gf_false;
        worm_reten_state_t reten_state  =       {0,};
        struct iatt stpre               =       {0,};
        read_only_priv_t *priv          =       NULL;
        int op_errno                    =       EROFS;
        int ret                         =       -1;

        priv = this->private;
        GF_ASSERT (priv);
        if (!priv->worm_file) {
                op_errno = 0;
                goto out;
        }

        if (is_wormfile (this, _gf_false, loc)) {
                op_errno = 0;
                goto out;
        }
        if (valid & GF_SET_ATTR_MODE) {
                rd_only = gf_worm_write_disabled (stbuf);
                if (!rd_only) {
                        op_errno = 0;
                        goto out;
                }

                ret = worm_set_state (this, _gf_false, loc,
                                           &reten_state, stbuf);
                if (ret) {
                        gf_log (this->name, GF_LOG_ERROR,
                                "Error setting worm state");
                        goto out;
                }
        } else if (valid & GF_SET_ATTR_ATIME) {
                ret = worm_get_state (this, _gf_false, loc, &reten_state);
                if (ret) {
                        op_errno = 0;
                        goto out;
                }
                if (reten_state.retain) {
                        ret = syncop_stat (this, loc, &stpre, NULL, NULL);
                        if (ret)
                                goto out;
                        if (reten_state.ret_mode == 0) {
                                if (stbuf->ia_atime < stpre.ia_mtime) {
                                        gf_log (this->name, GF_LOG_ERROR,
                                                "Cannot set atime less than "
                                                "the mtime for a WORM-Retained "
                                                "file");
                                        goto out;
                                }
                        } else {
                                if (stbuf->ia_atime < stpre.ia_atime) {
                                        gf_log (this->name, GF_LOG_ERROR,
                                                "Cannot decrease the atime of a"
                                                " WORM-Retained file in "
                                                "Enterprise mode");
                                        goto out;
                                }
                        }
                        stbuf->ia_mtime = stpre.ia_mtime;
                }
        }
        op_errno = 0;

out:
        if (op_errno)
                STACK_UNWIND_STRICT (setattr, frame, -1, EROFS, NULL, NULL,
                                     NULL);
        else
                STACK_WIND_TAIL (frame, FIRST_CHILD (this),
                                 FIRST_CHILD (this)->fops->setattr,
                                 loc, stbuf, valid, xdata);
        return 0;
}


static int32_t
worm_fsetattr (call_frame_t *frame, xlator_t *this, fd_t *fd,
               struct iatt *stbuf, int32_t valid, dict_t *xdata)
{
        gf_boolean_t rd_only            =       _gf_false;
        worm_reten_state_t reten_state  =       {0,};
        struct iatt stpre               =       {0,};
        read_only_priv_t *priv          =       NULL;
        int op_errno                    =       EROFS;
        int ret                         =       -1;

        priv = this->private;
        GF_ASSERT (priv);
        if (!priv->worm_file) {
                op_errno = 0;
                goto out;
        }

        if (is_wormfile (this, _gf_true, fd)) {
                op_errno = 0;
                goto out;
        }
        if (valid & GF_SET_ATTR_MODE) {
                rd_only = gf_worm_write_disabled (stbuf);
                if (!rd_only) {
                        op_errno = 0;
                        goto out;
                }

                ret = worm_set_state (this, _gf_true, fd,
                                      &reten_state, stbuf);
                if (ret) {
                        gf_log (this->name, GF_LOG_ERROR,
                                "Error setting worm state");
                        goto out;
                }
        } else if (valid & GF_SET_ATTR_ATIME) {
                ret = worm_get_state (this, _gf_true, fd, &reten_state);
                if (ret) {
                        op_errno = 0;
                        goto out;
                }
                if (reten_state.retain) {
                        ret = syncop_fstat (this, fd, &stpre, NULL, NULL);
                        if (ret)
                                goto out;
                        if (reten_state.ret_mode == 0) {
                                if (stbuf->ia_atime < stpre.ia_mtime) {
                                        gf_log (this->name, GF_LOG_ERROR,
                                                "Cannot set atime less than "
                                                "the mtime for a WORM-Retained "
                                                "file");
                                        goto out;
                                }
                        } else {
                                if (stbuf->ia_atime < stpre.ia_atime) {
                                        gf_log (this->name, GF_LOG_ERROR,
                                                "Cannot decrease the atime of a"
                                                " WORM-Retained file in "
                                                "Enterprise mode");
                                        goto out;
                                }
                        }
                        stbuf->ia_mtime = stpre.ia_mtime;
                }
        }
        op_errno = 0;

out:
        if (op_errno)
                STACK_UNWIND_STRICT (fsetattr, frame, -1, op_errno, NULL, NULL,
                                     NULL);
        else
                STACK_WIND_TAIL (frame, FIRST_CHILD (this),
                                 FIRST_CHILD (this)->fops->fsetattr,
                                 fd, stbuf, valid, xdata);
        return 0;
}


static int32_t
worm_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)
{
        worm_reten_state_t reten_state    =       {0,};
        read_only_priv_t *priv            =       NULL;
        int op_errno                      =       EROFS;
        int ret                           =       -1;

        priv = this->private;
        GF_ASSERT (priv);
        if (!priv->worm_file) {
                op_errno = 0;
                goto out;
        }
        if (is_wormfile (this, _gf_true, fd)) {
                op_errno = 0;
                goto out;
        }
        ret = worm_get_state (this, _gf_true, fd, &reten_state);
        if (ret) {
                if (ret == -1)
                        op_errno = 0;
                goto out;
        }
        if (!reten_state.worm)
                op_errno = 0;

out:
        if (op_errno)
                STACK_UNWIND_STRICT (writev, frame, -1, op_errno, NULL, NULL,
                                     NULL);
        else
                STACK_WIND_TAIL (frame, FIRST_CHILD (this),
                                 FIRST_CHILD (this)->fops->writev,
                                 fd, vector, count, offset, flags, iobref,
                                 xdata);
        return 0;
}

static int32_t
worm_create_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 int32_t op_ret, int32_t op_errno, fd_t *fd,
                 inode_t *inode, struct iatt *buf,
                 struct iatt *preparent, struct iatt *postparent,
                 dict_t *xdata)
{
        int ret                   =       0;
        read_only_priv_t *priv    =       NULL;
        dict_t *dict              =       NULL;

        priv = this->private;
        GF_ASSERT (priv);
        if (priv->worm_file) {
                dict = dict_new ();
                if (!dict) {
                        gf_log (this->name, GF_LOG_ERROR, "Error creating the "
                                "dict");
                        goto out;
                }
                ret = dict_set_int8 (dict, "trusted.worm_file", 1);
                if (ret) {
                        gf_log (this->name, GF_LOG_ERROR, "Error in setting "
                                "the dict");
                        goto out;
                }
                ret = syncop_fsetxattr (this, fd, dict, 0, NULL, NULL);
                if (ret) {
                        gf_log (this->name, GF_LOG_ERROR,
                                "Error setting xattr");
                        goto out;
                }
                ret = worm_init_state (this, _gf_true, fd);
                if (ret) {
                        gf_log (this->name, GF_LOG_ERROR,
                                "Error initializing state");
                }
        }

out:
        STACK_UNWIND_STRICT (create, frame, op_ret, op_errno, fd, inode, buf,
                             preparent, postparent, xdata);
        if (dict)
                dict_unref (dict);
        return ret;
}


static int32_t
worm_create (call_frame_t *frame, xlator_t *this, loc_t *loc, int32_t flags,
             mode_t mode, mode_t umask, fd_t *fd, dict_t *xdata)
{
        STACK_WIND (frame, worm_create_cbk,  FIRST_CHILD (this),
                    FIRST_CHILD(this)->fops->create, loc, flags,
                    mode, umask, fd, xdata);
        return 0;
}


int32_t
init (xlator_t *this)
{
        int                    ret      = -1;
        read_only_priv_t       *priv    = NULL;

        if (!this->children || this->children->next) {
                gf_log (this->name, GF_LOG_ERROR,
                        "translator not configured with exactly one child");
                return -1;
        }

        if (!this->parents) {
                gf_log (this->name, GF_LOG_WARNING,
                        "dangling volume. check volfile ");
        }

        this->local_pool = mem_pool_new (read_only_priv_t, 64);
        if (!this->local_pool) {
                ret = -1;
                gf_log (this->name, GF_LOG_ERROR,
                        "failed to create read_only_priv_t's memory pool");
                goto out;
        }

        priv = mem_get0 (this->local_pool);
        if (!priv) {
                gf_log (this->name, GF_LOG_ERROR, "Error allocating priv");
                goto out;
        }

        GF_OPTION_INIT ("worm", priv->readonly_or_worm_enabled,
                        bool, out);
        GF_OPTION_INIT ("worm-file-level", priv->worm_file, bool, out);
        GF_OPTION_INIT ("default-retention-period", priv->reten_period,
                        uint64, out);
        GF_OPTION_INIT ("auto-commit-period", priv->com_period, uint64, out);
        GF_OPTION_INIT ("retention-mode", priv->reten_mode, str, out);

        this->private = priv;
        ret = 0;
out:
        return ret;
}


int
reconfigure (xlator_t *this, dict_t *options)
{
        read_only_priv_t   *priv                    = NULL;
        int                ret                      = -1;

        priv = this->private;
        GF_ASSERT (priv);

        GF_OPTION_RECONF ("worm", priv->readonly_or_worm_enabled,
                          options, bool, out);
        GF_OPTION_RECONF ("worm-file-level", priv->worm_file, options, bool,
                          out);
        GF_OPTION_RECONF ("default-retention-period", priv->reten_period,
                          options, uint64, out);
        GF_OPTION_RECONF ("retention-mode", priv->reten_mode, options, str,
                          out);
        GF_OPTION_RECONF ("auto-commit-period", priv->com_period, options,
                          uint64, out);
        ret = 0;
out:
        gf_log (this->name, GF_LOG_DEBUG, "returning %d", ret);
        return ret;
}


void
fini (xlator_t *this)
{
        read_only_priv_t         *priv    = NULL;

        priv = this->private;
        if (!priv)
                goto out;
        mem_put (priv);
        this->private = NULL;
        mem_pool_destroy (this->local_pool);
out:
        return;
}


struct xlator_fops fops = {
        .open        = worm_open,
        .writev      = worm_writev,
        .setattr     = worm_setattr,
        .fsetattr    = worm_fsetattr,
        .rename      = worm_rename,
        .link        = worm_link,
        .unlink      = worm_unlink,
        .truncate    = worm_truncate,
        .create      = worm_create,

        .rmdir       = ro_rmdir,
        .removexattr = ro_removexattr,
        .fsyncdir    = ro_fsyncdir,
        .xattrop     = ro_xattrop,
        .inodelk     = ro_inodelk,
        .finodelk    = ro_finodelk,
        .entrylk     = ro_entrylk,
        .fentrylk    = ro_fentrylk,
        .lk          = ro_lk,
};


struct xlator_cbks cbks;


struct volume_options options[] = {
        { .key  = {"worm"},
          .type = GF_OPTION_TYPE_BOOL,
          .default_value = "off",
          .description = "When \"on\", makes a volume get write once read many "
                         " feature. It is turned \"off\" by default."
        },
        { .key = {"worm-file-level"},
          .type = GF_OPTION_TYPE_BOOL,
          .default_value = "off",
          .description = "When \"on\", activates the file level worm. "
                         "It is turned \"off\" by default."
        },
        { .key = {"default-retention-period"},
          .type = GF_OPTION_TYPE_TIME,
          .default_value = "120",
          .description = "The default retention period for the files."
        },
        { .key = {"retention-mode"},
          .type = GF_OPTION_TYPE_STR,
          .default_value = "relax",
          .description = "The mode of retention (relax/enterprise). "
                         "It is relax by default."
        },
        { .key = {"auto-commit-period"},
          .type = GF_OPTION_TYPE_TIME,
          .default_value = "180",
          .description = "Auto commit period for the files."
        },
};