From: wang di <di.wang@xxxxxxxxx> All the code needed to implement read_page. This will eventually replace lmv_readpage. Signed-off-by: wang di <di.wang@xxxxxxxxx> Reviewed-on: http://review.whamcloud.com/10761 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4906 Reviewed-by: John L. Hammond <john.hammond@xxxxxxxxx> Reviewed-by: Andreas Dilger <andreas.dilger@xxxxxxxxx> Reviewed-by: Oleg Drokin <oleg.drokin@xxxxxxxxx> Signed-off-by: James Simmons <jsimmons@xxxxxxxxxxxxx> --- drivers/staging/lustre/lustre/lmv/lmv_obd.c | 329 +++++++++++++++++++++++++++ 1 files changed, 329 insertions(+), 0 deletions(-) diff --git a/drivers/staging/lustre/lustre/lmv/lmv_obd.c b/drivers/staging/lustre/lustre/lmv/lmv_obd.c index 3e41f49..1f01be4 100644 --- a/drivers/staging/lustre/lustre/lmv/lmv_obd.c +++ b/drivers/staging/lustre/lustre/lmv/lmv_obd.c @@ -2369,6 +2369,334 @@ static int lmv_readpage(struct obd_export *exp, struct md_op_data *op_data, } /** + * Get current minimum entry from striped directory + * + * This function will search the dir entry, whose hash value is the + * closest(>=) to @hash_offset, from all of sub-stripes, and it is + * only being called for striped directory. + * + * \param[in] exp export of LMV + * \param[in] op_data parameters transferred beween client MD stack + * stripe_information will be included in this + * parameter + * \param[in] cb_op ldlm callback being used in enqueue in + * mdc_read_page + * \param[in] hash_offset the hash value, which is used to locate + * minum(closet) dir entry + * \param[in|out] stripe_offset the caller use this to indicate the stripe + * index of last entry, so to avoid hash conflict + * between stripes. It will also be used to + * return the stripe index of current dir entry. + * \param[in|out] entp the minum entry and it also is being used + * to input the last dir entry to resolve the + * hash conflict + * + * \param[out] ppage the page which holds the minum entry + * + * \retval = 0 get the entry successfully + * negative errno (< 0) does not get the entry + */ +static int lmv_get_min_striped_entry(struct obd_export *exp, + struct md_op_data *op_data, + struct md_callback *cb_op, + __u64 hash_offset, int *stripe_offset, + struct lu_dirent **entp, + struct page **ppage) +{ + struct lmv_stripe_md *lsm = op_data->op_mea1; + struct obd_device *obd = exp->exp_obd; + struct lmv_obd *lmv = &obd->u.lmv; + struct lu_dirent *min_ent = NULL; + struct page *min_page = NULL; + struct lmv_tgt_desc *tgt; + int stripe_count; + int min_idx = 0; + int rc = 0; + int i; + + stripe_count = lsm->lsm_md_stripe_count; + for (i = 0; i < stripe_count; i++) { + __u64 stripe_hash = hash_offset; + struct lu_dirent *ent = NULL; + struct page *page = NULL; + struct lu_dirpage *dp; + + tgt = lmv_get_target(lmv, lsm->lsm_md_oinfo[i].lmo_mds, NULL); + if (IS_ERR(tgt)) { + rc = PTR_ERR(tgt); + goto out; + } + + /* + * op_data will be shared by each stripe, so we need + * reset these value for each stripe + */ + op_data->op_fid1 = lsm->lsm_md_oinfo[i].lmo_fid; + op_data->op_fid2 = lsm->lsm_md_oinfo[i].lmo_fid; + op_data->op_data = lsm->lsm_md_oinfo[i].lmo_root; +next: + rc = md_read_page(tgt->ltd_exp, op_data, cb_op, stripe_hash, + &page); + if (rc) + goto out; + + dp = page_address(page); + for (ent = lu_dirent_start(dp); ent; + ent = lu_dirent_next(ent)) { + /* Skip dummy entry */ + if (!le16_to_cpu(ent->lde_namelen)) + continue; + + if (le64_to_cpu(ent->lde_hash) < hash_offset) + continue; + + if (le64_to_cpu(ent->lde_hash) == hash_offset && + (*entp == ent || i < *stripe_offset)) + continue; + + /* skip . and .. for other stripes */ + if (i && (!strncmp(ent->lde_name, ".", + le16_to_cpu(ent->lde_namelen)) || + !strncmp(ent->lde_name, "..", + le16_to_cpu(ent->lde_namelen)))) + continue; + break; + } + + if (!ent) { + stripe_hash = le64_to_cpu(dp->ldp_hash_end); + + kunmap(page); + put_page(page); + page = NULL; + + /* + * reach the end of current stripe, go to next stripe + */ + if (stripe_hash == MDS_DIR_END_OFF) + continue; + else + goto next; + } + + if (min_ent) { + if (le64_to_cpu(min_ent->lde_hash) > + le64_to_cpu(ent->lde_hash)) { + min_ent = ent; + kunmap(min_page); + put_page(min_page); + min_idx = i; + min_page = page; + } else { + kunmap(page); + put_page(page); + page = NULL; + } + } else { + min_ent = ent; + min_page = page; + min_idx = i; + } + } + +out: + if (*ppage) { + kunmap(*ppage); + put_page(*ppage); + } + *stripe_offset = min_idx; + *entp = min_ent; + *ppage = min_page; + return rc; +} + +/** + * Build dir entry page from a striped directory + * + * This function gets one entry by @offset from a striped directory. It will + * read entries from all of stripes, and choose one closest to the required + * offset(&offset). A few notes + * 1. skip . and .. for non-zero stripes, because there can only have one . + * and .. in a directory. + * 2. op_data will be shared by all of stripes, instead of allocating new + * one, so need to restore before reusing. + * 3. release the entry page if that is not being chosen. + * + * \param[in] exp obd export refer to LMV + * \param[in] op_data hold those MD parameters of read_entry + * \param[in] cb_op ldlm callback being used in enqueue in mdc_read_entry + * \param[out] ldp the entry being read + * \param[out] ppage the page holding the entry. Note: because the entry + * will be accessed in upper layer, so we need hold the + * page until the usages of entry is finished, see + * ll_dir_entry_next. + * + * retval =0 if get entry successfully + * <0 cannot get entry + */ +static int lmv_read_striped_page(struct obd_export *exp, + struct md_op_data *op_data, + struct md_callback *cb_op, + __u64 offset, struct page **ppage) +{ + struct inode *master_inode = op_data->op_data; + struct lu_fid master_fid = op_data->op_fid1; + struct obd_device *obd = exp->exp_obd; + __u64 hash_offset = offset; + struct page *min_ent_page = NULL; + struct page *ent_page = NULL; + struct lu_dirent *min_ent = NULL; + struct lu_dirent *last_ent; + struct lu_dirent *ent; + struct lu_dirpage *dp; + size_t left_bytes; + int ent_idx = 0; + void *area; + int rc; + + rc = lmv_check_connect(obd); + if (rc) + return rc; + + /* + * Allocate a page and read entries from all of stripes and fill + * the page by hash order + */ + ent_page = alloc_page(GFP_KERNEL); + if (!ent_page) + return -ENOMEM; + + /* Initialize the entry page */ + dp = kmap(ent_page); + memset(dp, 0, sizeof(*dp)); + dp->ldp_hash_start = cpu_to_le64(offset); + dp->ldp_flags |= LDF_COLLIDE; + + area = dp + 1; + left_bytes = PAGE_SIZE - sizeof(*dp); + ent = area; + last_ent = ent; + do { + __u16 ent_size; + + /* Find the minum entry from all sub-stripes */ + rc = lmv_get_min_striped_entry(exp, op_data, cb_op, hash_offset, + &ent_idx, &min_ent, + &min_ent_page); + if (rc) + goto out; + + /* + * If it can not get minum entry, it means it already reaches + * the end of this directory + */ + if (!min_ent) { + last_ent->lde_reclen = 0; + hash_offset = MDS_DIR_END_OFF; + goto out; + } + + ent_size = le16_to_cpu(min_ent->lde_reclen); + + /* + * the last entry lde_reclen is 0, but it might not + * the end of this entry of this temporay entry + */ + if (!ent_size) + ent_size = lu_dirent_calc_size( + le16_to_cpu(min_ent->lde_namelen), + le32_to_cpu(min_ent->lde_attrs)); + if (ent_size > left_bytes) { + last_ent->lde_reclen = cpu_to_le16(0); + hash_offset = le64_to_cpu(min_ent->lde_hash); + goto out; + } + + memcpy(ent, min_ent, ent_size); + + /* + * Replace . with master FID and Replace .. with the parent FID + * of master object + */ + if (!strncmp(ent->lde_name, ".", + le16_to_cpu(ent->lde_namelen)) && + le16_to_cpu(ent->lde_namelen) == 1) + fid_cpu_to_le(&ent->lde_fid, &master_fid); + else if (!strncmp(ent->lde_name, "..", + le16_to_cpu(ent->lde_namelen)) && + le16_to_cpu(ent->lde_namelen) == 2) + fid_cpu_to_le(&ent->lde_fid, &op_data->op_fid3); + + left_bytes -= ent_size; + ent->lde_reclen = cpu_to_le16(ent_size); + last_ent = ent; + ent = (void *)ent + ent_size; + hash_offset = le64_to_cpu(min_ent->lde_hash); + if (hash_offset == MDS_DIR_END_OFF) { + last_ent->lde_reclen = 0; + break; + } + } while (1); +out: + if (min_ent_page) { + kunmap(min_ent_page); + put_page(min_ent_page); + } + + if (unlikely(rc)) { + __free_page(ent_page); + ent_page = NULL; + } else { + if (ent == area) + dp->ldp_flags |= LDF_EMPTY; + dp->ldp_flags = cpu_to_le32(dp->ldp_flags); + dp->ldp_hash_end = cpu_to_le64(hash_offset); + } + + /* + * We do not want to allocate md_op_data during each + * dir entry reading, so op_data will be shared by every stripe, + * then we need to restore it back to original value before + * return to the upper layer + */ + op_data->op_fid1 = master_fid; + op_data->op_fid2 = master_fid; + op_data->op_data = master_inode; + + *ppage = ent_page; + + return rc; +} + +int lmv_read_page(struct obd_export *exp, struct md_op_data *op_data, + struct md_callback *cb_op, __u64 offset, + struct page **ppage) +{ + struct lmv_stripe_md *lsm = op_data->op_mea1; + struct obd_device *obd = exp->exp_obd; + struct lmv_obd *lmv = &obd->u.lmv; + struct lmv_tgt_desc *tgt; + int rc; + + rc = lmv_check_connect(obd); + if (rc) + return rc; + + if (unlikely(lsm)) { + rc = lmv_read_striped_page(exp, op_data, cb_op, offset, ppage); + return rc; + } + + tgt = lmv_find_target(lmv, &op_data->op_fid1); + if (IS_ERR(tgt)) + return PTR_ERR(tgt); + + rc = md_read_page(tgt->ltd_exp, op_data, cb_op, offset, ppage); + + return rc; +} + +/** * Unlink a file/directory * * Unlink a file or directory under the parent dir. The unlink request @@ -3268,6 +3596,7 @@ static struct md_ops lmv_md_ops = { .setxattr = lmv_setxattr, .sync = lmv_sync, .readpage = lmv_readpage, + .read_page = lmv_read_page, .unlink = lmv_unlink, .init_ea_size = lmv_init_ea_size, .cancel_unused = lmv_cancel_unused, -- 1.7.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
