diff options
Diffstat (limited to 'drivers/staging/lustre/lustre/obdclass/linkea.c')
| -rw-r--r-- | drivers/staging/lustre/lustre/obdclass/linkea.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/obdclass/linkea.c b/drivers/staging/lustre/lustre/obdclass/linkea.c new file mode 100644 index 000000000000..b5c19ac1470f --- /dev/null +++ b/drivers/staging/lustre/lustre/obdclass/linkea.c @@ -0,0 +1,194 @@ +/* + * GPL HEADER START + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 only, + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 for more details (a copy is included + * in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU General Public License + * version 2 along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA + * + * GPL HEADER END + */ +/* + * Copyright (c) 2013, Intel Corporation. + * Use is subject to license terms. + * + * Author: Di Wang <di.wang@intel.com> + */ + +#include <lustre/lustre_idl.h> +#include <obd.h> +#include <lustre_linkea.h> + +int linkea_data_new(struct linkea_data *ldata, struct lu_buf *buf) +{ + ldata->ld_buf = lu_buf_check_and_alloc(buf, PAGE_CACHE_SIZE); + if (ldata->ld_buf->lb_buf == NULL) + return -ENOMEM; + ldata->ld_leh = ldata->ld_buf->lb_buf; + ldata->ld_leh->leh_magic = LINK_EA_MAGIC; + ldata->ld_leh->leh_len = sizeof(struct link_ea_header); + ldata->ld_leh->leh_reccount = 0; + return 0; +} +EXPORT_SYMBOL(linkea_data_new); + +int linkea_init(struct linkea_data *ldata) +{ + struct link_ea_header *leh; + + LASSERT(ldata->ld_buf != NULL); + leh = ldata->ld_buf->lb_buf; + if (leh->leh_magic == __swab32(LINK_EA_MAGIC)) { + leh->leh_magic = LINK_EA_MAGIC; + leh->leh_reccount = __swab32(leh->leh_reccount); + leh->leh_len = __swab64(leh->leh_len); + /* entries are swabbed by linkea_entry_unpack */ + } + if (leh->leh_magic != LINK_EA_MAGIC) + return -EINVAL; + if (leh->leh_reccount == 0) + return -ENODATA; + + ldata->ld_leh = leh; + return 0; +} +EXPORT_SYMBOL(linkea_init); + +/** + * Pack a link_ea_entry. + * All elements are stored as chars to avoid alignment issues. + * Numbers are always big-endian + * \retval record length + */ +static int linkea_entry_pack(struct link_ea_entry *lee, + const struct lu_name *lname, + const struct lu_fid *pfid) +{ + struct lu_fid tmpfid; + int reclen; + + fid_cpu_to_be(&tmpfid, pfid); + if (OBD_FAIL_CHECK(OBD_FAIL_LFSCK_LINKEA_CRASH)) + tmpfid.f_ver = ~0; + memcpy(&lee->lee_parent_fid, &tmpfid, sizeof(tmpfid)); + memcpy(lee->lee_name, lname->ln_name, lname->ln_namelen); + reclen = sizeof(struct link_ea_entry) + lname->ln_namelen; + + lee->lee_reclen[0] = (reclen >> 8) & 0xff; + lee->lee_reclen[1] = reclen & 0xff; + return reclen; +} + +void linkea_entry_unpack(const struct link_ea_entry *lee, int *reclen, + struct lu_name *lname, struct lu_fid *pfid) +{ + *reclen = (lee->lee_reclen[0] << 8) | lee->lee_reclen[1]; + memcpy(pfid, &lee->lee_parent_fid, sizeof(*pfid)); + fid_be_to_cpu(pfid, pfid); + lname->ln_name = lee->lee_name; + lname->ln_namelen = *reclen - sizeof(struct link_ea_entry); +} +EXPORT_SYMBOL(linkea_entry_unpack); + +/** + * Add a record to the end of link ea buf + **/ +int linkea_add_buf(struct linkea_data *ldata, const struct lu_name *lname, + const struct lu_fid *pfid) +{ + LASSERT(ldata->ld_leh != NULL); + + if (lname == NULL || pfid == NULL) + return -EINVAL; + + ldata->ld_reclen = lname->ln_namelen + sizeof(struct link_ea_entry); + if (ldata->ld_leh->leh_len + ldata->ld_reclen > + ldata->ld_buf->lb_len) { + if (lu_buf_check_and_grow(ldata->ld_buf, + ldata->ld_leh->leh_len + + ldata->ld_reclen) < 0) + return -ENOMEM; + } + + ldata->ld_leh = ldata->ld_buf->lb_buf; + ldata->ld_lee = ldata->ld_buf->lb_buf + ldata->ld_leh->leh_len; + ldata->ld_reclen = linkea_entry_pack(ldata->ld_lee, lname, pfid); + ldata->ld_leh->leh_len += ldata->ld_reclen; + ldata->ld_leh->leh_reccount++; + CDEBUG(D_INODE, "New link_ea name '%.*s' is added\n", + lname->ln_namelen, lname->ln_name); + return 0; +} +EXPORT_SYMBOL(linkea_add_buf); + +/** Del the current record from the link ea buf */ +void linkea_del_buf(struct linkea_data *ldata, const struct lu_name *lname) +{ + LASSERT(ldata->ld_leh != NULL && ldata->ld_lee != NULL); + + ldata->ld_leh->leh_reccount--; + ldata->ld_leh->leh_len -= ldata->ld_reclen; + memmove(ldata->ld_lee, (char *)ldata->ld_lee + ldata->ld_reclen, + (char *)ldata->ld_leh + ldata->ld_leh->leh_len - + (char *)ldata->ld_lee); + CDEBUG(D_INODE, "Old link_ea name '%.*s' is removed\n", + lname->ln_namelen, lname->ln_name); +} +EXPORT_SYMBOL(linkea_del_buf); + +/** + * Check if such a link exists in linkEA. + * + * \param ldata link data the search to be done on + * \param lname name in the parent's directory entry pointing to this object + * \param pfid parent fid the link to be found for + * + * \retval 0 success + * \retval -ENOENT link does not exist + * \retval -ve on error + */ +int linkea_links_find(struct linkea_data *ldata, const struct lu_name *lname, + const struct lu_fid *pfid) +{ + struct lu_name tmpname; + struct lu_fid tmpfid; + int count; + + LASSERT(ldata->ld_leh != NULL); + + /* link #0 */ + ldata->ld_lee = (struct link_ea_entry *)(ldata->ld_leh + 1); + + for (count = 0; count < ldata->ld_leh->leh_reccount; count++) { + linkea_entry_unpack(ldata->ld_lee, &ldata->ld_reclen, + &tmpname, &tmpfid); + if (tmpname.ln_namelen == lname->ln_namelen && + lu_fid_eq(&tmpfid, pfid) && + (strncmp(tmpname.ln_name, lname->ln_name, + tmpname.ln_namelen) == 0)) + break; + ldata->ld_lee = (struct link_ea_entry *)((char *)ldata->ld_lee + + ldata->ld_reclen); + } + + if (count == ldata->ld_leh->leh_reccount) { + CDEBUG(D_INODE, "Old link_ea name '%.*s' not found\n", + lname->ln_namelen, lname->ln_name); + ldata->ld_lee = NULL; + return -ENOENT; + } + return 0; +} +EXPORT_SYMBOL(linkea_links_find); |