* GPL HEADER END
*/
/*
- * Copyright 2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*/
/*
#include "cmm_internal.h"
#include "mdc_internal.h"
+/**
+ * \addtogroup split
+ * @{
+ */
enum {
CMM_SPLIT_SIZE = 128 * 1024
};
-/*
- * This function checks if passed @name come to correct server (local MDT). If
- * not - return -ERESTART and let client know that dir was split and client
- * needs to chose correct stripe.
+/**
+ * This function checks if passed \a name come to correct server (local MDT).
+ *
+ * \param mp Parent directory
+ * \param name Name to lookup
+ * \retval -ERESTART Let client know that dir was split and client needs to
+ * chose correct stripe.
*/
int cmm_split_check(const struct lu_env *env, struct md_object *mp,
const char *name)
if (ma->ma_lmv->mea_count != 0) {
int idx;
- /*
- * Get stripe by name to check the name belongs to master dir,
- * otherwise return the -ERESTART
+ /**
+ * This gets stripe by name to check the name belongs to master
+ * dir, otherwise return the -ERESTART
*/
idx = mea_name2idx(ma->ma_lmv, name, strlen(name));
- /*
- * Check if name came to correct MDT server. We suppose that if
- * client does not know about split, it sends create operation
- * to master MDT. And this is master job to say it that dir got
- * split and client should orward request to correct MDT. This
+ /**
+ * When client does not know about split, it sends create() to
+ * the master MDT and master replay back if directory is split.
+ * So client should orward request to correct MDT. This
* is why we check here if stripe zero or not. Zero stripe means
* master stripe. If stripe calculated from name is not zero -
* return -ERESTART.
return rc;
}
-/*
- * Return preferable access mode to caller taking into account possible split
- * and the fact of existing not splittable dirs in principle.
+/**
+ * Return preferable access mode to the caller taking into account the split
+ * case and the fact of existing not splittable dirs.
*/
int cmm_split_access(const struct lu_env *env, struct md_object *mo,
mdl_mode_t lm)
RETURN(MDL_MINMODE);
}
-/* Check if split is expected for current thread. */
+/**
+ * Check if split is expected for current thread.
+ *
+ * \param mo Directory to split.
+ * \param ma md attributes.
+ * \param split Flag to save split information.
+ */
int cmm_split_expect(const struct lu_env *env, struct md_object *mo,
struct md_attr *ma, int *split)
{
lu_object_put(env, &o->cmo_obj.mo_lu);
}
-/*
- * Allocate new on passed @mc for slave object which is going to create there
- * soon.
+/**
+ * Allocate new FID on passed \a mc for slave object which is going to
+ * create there soon.
*/
static int cmm_split_fid_alloc(const struct lu_env *env,
struct cmm_device *cmm,
cfs_down(&mc->mc_fid_sem);
- /* Alloc new fid on @mc. */
+ /* Alloc new fid on \a mc. */
rc = obd_fid_alloc(mc->mc_desc.cl_exp, fid, NULL);
if (rc > 0)
rc = 0;
RETURN(rc);
}
-/* Allocate new slave object on passed @mc */
+/**
+ * Allocate new slave object on passed \a mc.
+ */
static int cmm_split_slave_create(const struct lu_env *env,
struct cmm_device *cmm,
struct mdc_device *mc,
RETURN(rc);
}
-/*
- * Create so many slaves as number of stripes. This is called in split time
- * before sending pages to slaves.
+/**
+ * Create so many slaves as number of stripes.
+ * This is called in split time before sending pages to slaves.
*/
static int cmm_split_slaves_create(const struct lu_env *env,
struct md_object *mo,
return 0;
}
+/**
+ * Convert string to the lu_name structure.
+ */
static inline struct lu_name *cmm_name(const struct lu_env *env,
char *name, int buflen)
{
return lname;
}
-/*
- * Remove one entry from local MDT. Do not corrupt byte order in page, it will
- * be sent to remote MDT.
+/**
+ * Helper for cmm_split_remove_page(). It removes one entry from local MDT.
+ * Do not corrupt byte order in page, it will be sent to remote MDT.
*/
static int cmm_split_remove_entry(const struct lu_env *env,
struct md_object *mo,
if (lu_object_exists(&obj->cmo_obj.mo_lu) > 0)
is_dir = S_ISDIR(lu_object_attr(&obj->cmo_obj.mo_lu));
else
- /*
- * XXX: These days only cross-ref dirs are possible, so for the
+ /**
+ * \note These days only cross-ref dirs are possible, so for the
* sake of simplicity, in split, we suppose that all cross-ref
* names point to directory and do not do additional getattr to
* remote MDT.
memcpy(name, ent->lde_name, le16_to_cpu(ent->lde_namelen));
lname = cmm_name(env, name, le16_to_cpu(ent->lde_namelen) + 1);
- /*
- * When split, no need update parent's ctime,
+ /**
+ * \note When split, no need update parent's ctime,
* and no permission check for name_remove.
*/
ma->ma_attr.la_ctime = 0;
if (rc)
GOTO(cleanup, rc);
- /*
- * This @ent will be transferred to slave MDS and insert there, so in
- * the slave MDS, we should know whether this object is dir or not, so
- * use the highest bit of the hash to indicate that (because we do not
- * use highest bit of hash).
+ /**
+ * \note For each entry transferred to the slave MDS we should know
+ * whether this object is dir or not. Therefore the highest bit of the
+ * hash is used to indicate that (it is unused for hash purposes anyway).
*/
if (is_dir) {
ent->lde_hash = le64_to_cpu(ent->lde_hash);
return rc;
}
-/*
- * Remove all entries from passed page. These entries are going to remote MDT
- * and thus should be removed locally.
+/**
+ * Remove all entries from passed page.
+ * These entries are going to remote MDT and thus should be removed locally.
*/
static int cmm_split_remove_page(const struct lu_env *env,
struct md_object *mo,
return rc;
}
-/* Send one page to remote MDT for creating entries there. */
+/**
+ * Send one page of entries to the slave MDT.
+ * This page contains entries to be created there.
+ */
static int cmm_split_send_page(const struct lu_env *env,
struct md_object *mo,
struct lu_rdpg *rdpg,
RETURN(rc);
}
-/* Read one page of entries from local MDT. */
+/** Read one page of entries from local MDT. */
static int cmm_split_read_page(const struct lu_env *env,
struct md_object *mo,
struct lu_rdpg *rdpg)
RETURN(rc);
}
-/*
- * This function performs migration of all pages with entries which fit into one
- * stripe and one hash segment.
+/**
+ * This function performs migration of each directory stripe to its MDS.
*/
static int cmm_split_process_stripe(const struct lu_env *env,
struct md_object *mo,
struct lu_dirpage *ldp;
__u32 len = 0;
- /* Read one page from local MDT. */
+ /** - Read one page of entries from local MDT. */
rc = cmm_split_read_page(env, mo, rdpg);
if (rc) {
CERROR("Error in readpage: %d\n", rc);
RETURN(rc);
}
- /* Remove local entries which are going to remite MDT. */
+ /** - Remove local entries which are going to remite MDT. */
rc = cmm_split_remove_page(env, mo, rdpg, end, &len);
if (rc) {
CERROR("Error in remove stripe entries: %d\n", rc);
RETURN(rc);
}
- /* Send entries page to slave MDT. */
+ /**
+ * - Send entries page to slave MDT and repeat while there are
+ * more pages.
+ */
if (len > 0) {
rc = cmm_split_send_page(env, mo, rdpg, lf, len);
if (rc) {
RETURN(rc);
}
+/**
+ * Directory scanner for split operation.
+ *
+ * It calculates hashes for names and organizes files to stripes.
+ */
static int cmm_split_process_dir(const struct lu_env *env,
struct md_object *mo,
struct md_attr *ma)
}
hash_segment = MAX_HASH_SIZE;
+ /** Whole hash range is divided on segments by number of MDS-es. */
do_div(hash_segment, cmm->cmm_tgt_count + 1);
+ /**
+ * For each segment the cmm_split_process_stripe() is called to move
+ * entries on new server.
+ */
for (i = 1; i < cmm->cmm_tgt_count + 1; i++) {
struct lu_fid *lf;
__u64 hash_end;
cleanup:
for (i = 0; i < rdpg->rp_npages; i++)
if (rdpg->rp_pages[i] != NULL)
- __cfs_free_page(rdpg->rp_pages[i]);
+ cfs_free_page(rdpg->rp_pages[i]);
return rc;
}
+/**
+ * Directory splitting.
+ *
+ * Big directory can be split eventually.
+ */
int cmm_split_dir(const struct lu_env *env, struct md_object *mo)
{
struct cmm_device *cmm = cmm_obj2dev(md2cmm_obj(mo));
LASSERT(S_ISDIR(lu_object_attr(&mo->mo_lu)));
memset(ma, 0, sizeof(*ma));
- /* Step1: Checking whether the dir needs to be split. */
+ /** - Step1: Checking whether the dir needs to be split. */
rc = cmm_split_expect(env, mo, ma, &split);
if (rc)
GOTO(out, rc);
CWARN("Dir "DFID" is going to split (size: "LPU64")\n",
PFID(lu_object_fid(&mo->mo_lu)), ma->ma_attr.la_size);
- /*
- * Disable transacrions for split, since there will be so many trans in
+ /**
+ * /note Disable transactions for split, since there will be so many trans in
* this one ops, conflict with current recovery design.
*/
rc = cmm_upcall(env, &cmm->cmm_md_dev, MD_NO_TRANS, NULL);
GOTO(out, rc);
}
- /* Step2: Prepare the md memory */
+ /** - Step2: Prepare the md memory */
ma->ma_lmv_size = CMM_MD_SIZE(cmm->cmm_tgt_count + 1);
OBD_ALLOC(ma->ma_lmv, ma->ma_lmv_size);
if (ma->ma_lmv == NULL)
GOTO(out, rc = -ENOMEM);
- /* Step3: Create slave objects and fill the ma->ma_lmv */
+ /** - Step3: Create slave objects and fill the ma->ma_lmv */
rc = cmm_split_slaves_create(env, mo, ma);
if (rc) {
CERROR("Can't create slaves for split, rc %d\n", rc);
GOTO(cleanup, rc);
}
- /* Step4: Scan and split the object. */
+ /** - Step4: Scan and split the object. */
rc = cmm_split_process_dir(env, mo, ma);
if (rc) {
CERROR("Can't scan and split, rc %d\n", rc);
GOTO(cleanup, rc);
}
- /* Step5: Set mea to the master object. */
+ /** - Step5: Set mea to the master object. */
buf = cmm_buf_get(env, ma->ma_lmv, ma->ma_lmv_size);
rc = mo_xattr_set(env, md_object_next(mo), buf,
MDS_LMV_MD_NAME, 0);
/* set flag in cmm_object */
md2cml_obj(mo)->clo_split = CMM_SPLIT_DONE;
- /*
- * Finally, split succeed, tell client to repeat opetartion on correct
+ /**
+ * - Finally, split succeed, tell client to repeat opetartion on correct
* MDT.
*/
CWARN("Dir "DFID" has been split\n", PFID(lu_object_fid(&mo->mo_lu)));
cmm_lprocfs_time_end(env, cmm, LPROC_CMM_SPLIT);
return rc;
}
+/** @} */
git://git.whamcloud.com / fs / lustre-release.git / blobdiff