From patchwork Sat Jan 7 00:36:12 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 9502529 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7EE8F60459 for ; Sat, 7 Jan 2017 00:36:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6F19E2811E for ; Sat, 7 Jan 2017 00:36:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6394928520; Sat, 7 Jan 2017 00:36:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6A3BB2811E for ; Sat, 7 Jan 2017 00:36:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966394AbdAGAgQ (ORCPT ); Fri, 6 Jan 2017 19:36:16 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:40615 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964977AbdAGAgP (ORCPT ); Fri, 6 Jan 2017 19:36:15 -0500 Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id v070aEk5023034 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Sat, 7 Jan 2017 00:36:14 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id v070aE3h032584 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Sat, 7 Jan 2017 00:36:14 GMT Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id v070aEKC003459 for ; Sat, 7 Jan 2017 00:36:14 GMT Received: from localhost (/24.21.211.40) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 06 Jan 2017 16:36:13 -0800 Subject: [PATCH 04/47] xfs: introduce the XFS_IOC_GETFSMAP ioctl From: "Darrick J. Wong" To: darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org Date: Fri, 06 Jan 2017 16:36:12 -0800 Message-ID: <148374937283.30431.11927442457304013157.stgit@birch.djwong.org> In-Reply-To: <148374934333.30431.11042523766304087227.stgit@birch.djwong.org> References: <148374934333.30431.11042523766304087227.stgit@birch.djwong.org> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Introduce a new ioctl that uses the reverse mapping btree to return information about the physical layout of the filesystem. Signed-off-by: Darrick J. Wong --- fs/xfs/Makefile | 1 fs/xfs/libxfs/xfs_fs.h | 95 +++++++ fs/xfs/xfs_fsmap.c | 698 ++++++++++++++++++++++++++++++++++++++++++++++++ fs/xfs/xfs_fsmap.h | 51 ++++ fs/xfs/xfs_ioctl.c | 104 +++++++ fs/xfs/xfs_ioctl32.c | 1 fs/xfs/xfs_trace.h | 85 ++++++ fs/xfs/xfs_trans.c | 22 ++ fs/xfs/xfs_trans.h | 2 9 files changed, 1059 insertions(+) create mode 100644 fs/xfs/xfs_fsmap.c create mode 100644 fs/xfs/xfs_fsmap.h -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile index 26ef195..5c90f82 100644 --- a/fs/xfs/Makefile +++ b/fs/xfs/Makefile @@ -79,6 +79,7 @@ xfs-y += xfs_aops.o \ xfs_extent_busy.o \ xfs_file.o \ xfs_filestream.o \ + xfs_fsmap.o \ xfs_fsops.o \ xfs_globals.o \ xfs_icache.o \ diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h index b72dc82..e62996f 100644 --- a/fs/xfs/libxfs/xfs_fs.h +++ b/fs/xfs/libxfs/xfs_fs.h @@ -93,6 +93,100 @@ struct getbmapx { #define BMV_OF_SHARED 0x8 /* segment shared with another file */ /* + * Structure for XFS_IOC_GETFSMAP. + * + * The memory layout for this call are the scalar values defined in + * struct fsmap_head, followed by two struct fsmap that describe + * the lower and upper bound of mappings to return, followed by an + * array of struct fsmap mappings. + * + * fmh_iflags control the output of the call, whereas fmh_oflags report + * on the overall record output. fmh_count should be set to the + * length of the fmh_recs array, and fmh_entries will be set to the + * number of entries filled out during each call. If fmh_count is + * zero, the number of reverse mappings will be returned in + * fmh_entries, though no mappings will be returned. fmh_reserved + * must be set to zero. + * + * The two elements in the fmh_keys array are used to constrain the + * output. The first element in the array should represent the + * lowest disk mapping ("low key") that the user wants to learn + * about. If this value is all zeroes, the filesystem will return + * the first entry it knows about. For a subsequent call, the + * contents of fsmap_head.fmh_recs[fsmap_head.fmh_count - 1] should be + * copied into fmh_keys[0] to have the kernel start where it left off. + * + * The second element in the fmh_keys array should represent the + * highest disk mapping ("high key") that the user wants to learn + * about. If this value is all ones, the filesystem will not stop + * until it runs out of mapping to return or runs out of space in + * fmh_recs. + * + * fmr_device can be either a 32-bit cookie representing a device, or + * a 32-bit dev_t if the FMH_OF_DEV_T flag is set. fmr_physical, + * fmr_offset, and fmr_length are expressed in units of bytes. + * fmr_owner is either an inode number, or a special value if + * FMR_OF_SPECIAL_OWNER is set in fmr_flags. + */ +#ifndef HAVE_GETFSMAP +struct fsmap { + __u32 fmr_device; /* device id */ + __u32 fmr_flags; /* mapping flags */ + __u64 fmr_physical; /* device offset of segment */ + __u64 fmr_owner; /* owner id */ + __u64 fmr_offset; /* file offset of segment */ + __u64 fmr_length; /* length of segment */ + __u64 fmr_reserved[3]; /* must be zero */ +}; + +struct fsmap_head { + __u32 fmh_iflags; /* control flags */ + __u32 fmh_oflags; /* output flags */ + __u32 fmh_count; /* # of entries in array incl. input */ + __u32 fmh_entries; /* # of entries filled in (output). */ + __u64 fmh_reserved[6]; /* must be zero */ + + struct fsmap fmh_keys[2]; /* low and high keys for the mapping search */ + struct fsmap fmh_recs[]; /* returned records */ +}; + +/* Size of an fsmap_head with room for nr records. */ +static inline size_t +fsmap_sizeof( + unsigned int nr) +{ + return sizeof(struct fsmap_head) + nr * sizeof(struct fsmap); +} +#endif + +/* fmh_iflags values - set by XFS_IOC_GETFSMAP caller in the header. */ +/* no flags defined yet */ +#define FMH_IF_VALID 0 + +/* fmh_oflags values - returned in the header segment only. */ +#define FMH_OF_DEV_T 0x1 /* fmr_device values will be dev_t */ + +/* fmr_flags values - returned for each non-header segment */ +#define FMR_OF_PREALLOC 0x1 /* segment = unwritten pre-allocation */ +#define FMR_OF_ATTR_FORK 0x2 /* segment = attribute fork */ +#define FMR_OF_EXTENT_MAP 0x4 /* segment = extent map */ +#define FMR_OF_SHARED 0x8 /* segment = shared with another file */ +#define FMR_OF_SPECIAL_OWNER 0x10 /* owner is a special value */ +#define FMR_OF_LAST 0x20 /* segment is the last in the FS */ + +/* fmr_owner special values */ +#define FMR_OWN_FREE (-1ULL) /* free space */ +#define FMR_OWN_UNKNOWN (-2ULL) /* unknown owner */ +#define FMR_OWN_FS (-3ULL) /* static fs metadata */ +#define FMR_OWN_LOG (-4ULL) /* journalling log */ +#define FMR_OWN_AG (-5ULL) /* per-AG metadata */ +#define FMR_OWN_INOBT (-6ULL) /* inode btree blocks */ +#define FMR_OWN_INODES (-7ULL) /* inodes */ +#define FMR_OWN_REFC (-8ULL) /* refcount tree */ +#define FMR_OWN_COW (-9ULL) /* cow staging */ +#define FMR_OWN_DEFECTIVE (-10ULL) /* bad blocks */ + +/* * Structure for XFS_IOC_FSSETDM. * For use by backup and restore programs to set the XFS on-disk inode * fields di_dmevmask and di_dmstate. These must be set to exactly and @@ -502,6 +596,7 @@ typedef struct xfs_swapext #define XFS_IOC_GETBMAPX _IOWR('X', 56, struct getbmap) #define XFS_IOC_ZERO_RANGE _IOW ('X', 57, struct xfs_flock64) #define XFS_IOC_FREE_EOFBLOCKS _IOR ('X', 58, struct xfs_fs_eofblocks) +#define XFS_IOC_GETFSMAP _IOWR('X', 59, struct fsmap_head) /* * ioctl commands that replace IRIX syssgi()'s diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c new file mode 100644 index 0000000..985415b --- /dev/null +++ b/fs/xfs/xfs_fsmap.c @@ -0,0 +1,698 @@ +/* + * Copyright (C) 2017 Oracle. All Rights Reserved. + * + * Author: Darrick J. Wong + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it would 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 for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_log_format.h" +#include "xfs_trans_resv.h" +#include "xfs_sb.h" +#include "xfs_mount.h" +#include "xfs_defer.h" +#include "xfs_inode.h" +#include "xfs_trans.h" +#include "xfs_error.h" +#include "xfs_btree.h" +#include "xfs_rmap_btree.h" +#include "xfs_trace.h" +#include "xfs_log.h" +#include "xfs_rmap.h" +#include "xfs_alloc.h" +#include "xfs_bit.h" +#include "xfs_fsmap.h" + +/* Convert an xfs_fsmap to an fsmap. */ +void +xfs_fsmap_from_internal( + struct fsmap *dest, + struct xfs_fsmap *src) +{ + dest->fmr_device = src->fmr_device; + dest->fmr_flags = src->fmr_flags; + dest->fmr_physical = BBTOB(src->fmr_physical); + dest->fmr_owner = src->fmr_owner; + dest->fmr_offset = BBTOB(src->fmr_offset); + dest->fmr_length = BBTOB(src->fmr_length); + dest->fmr_reserved[0] = 0; + dest->fmr_reserved[1] = 0; + dest->fmr_reserved[2] = 0; +} + +/* Convert an fsmap to an xfs_fsmap. */ +void +xfs_fsmap_to_internal( + struct xfs_fsmap *dest, + struct fsmap *src) +{ + dest->fmr_device = src->fmr_device; + dest->fmr_flags = src->fmr_flags; + dest->fmr_physical = BTOBBT(src->fmr_physical); + dest->fmr_owner = src->fmr_owner; + dest->fmr_offset = BTOBBT(src->fmr_offset); + dest->fmr_length = BTOBBT(src->fmr_length); +} + +/* Convert an fsmap owner into an rmapbt owner. */ +static int +xfs_fsmap_owner_to_rmap( + struct xfs_fsmap *fmr, + struct xfs_rmap_irec *rm) +{ + if (!(fmr->fmr_flags & FMR_OF_SPECIAL_OWNER)) { + if (XFS_RMAP_NON_INODE_OWNER(fmr->fmr_owner)) + return -EINVAL; + rm->rm_owner = fmr->fmr_owner; + return 0; + } + + switch (fmr->fmr_owner) { + case 0: /* "lowest owner id possible" */ + case FMR_OWN_FREE: + case FMR_OWN_UNKNOWN: + case FMR_OWN_FS: + case FMR_OWN_LOG: + case FMR_OWN_AG: + case FMR_OWN_INOBT: + case FMR_OWN_INODES: + case FMR_OWN_REFC: + case FMR_OWN_COW: + rm->rm_owner = fmr->fmr_owner; + return 0; + case FMR_OWN_DEFECTIVE: + /* fall through */ + default: + return -EINVAL; + } +} + +/* Convert an rmapbt owner into an fsmap owner. */ +static int +xfs_fsmap_owner_from_rmap( + struct xfs_rmap_irec *rm, + struct xfs_fsmap *fmr) +{ + fmr->fmr_flags = 0; + if (!XFS_RMAP_NON_INODE_OWNER(rm->rm_owner)) { + fmr->fmr_owner = rm->rm_owner; + return 0; + } + fmr->fmr_flags |= FMR_OF_SPECIAL_OWNER; + + switch (rm->rm_owner) { + case XFS_RMAP_OWN_FS: + case XFS_RMAP_OWN_LOG: + case XFS_RMAP_OWN_AG: + case XFS_RMAP_OWN_INOBT: + case XFS_RMAP_OWN_INODES: + case XFS_RMAP_OWN_REFC: + case XFS_RMAP_OWN_COW: + fmr->fmr_owner = rm->rm_owner; + return 0; + default: + return -EFSCORRUPTED; + } +} + +/* getfsmap query state */ +struct xfs_getfsmap_info { + struct xfs_fsmap_head *head; + struct xfs_fsmap *rkey_low; /* lowest key */ + xfs_fsmap_format_t formatter; /* formatting fn */ + void *format_arg; /* format buffer */ + bool last; /* last extent? */ + xfs_daddr_t next_daddr; /* next daddr we expect */ + u32 dev; /* device id */ + u64 missing_owner; /* owner of holes */ + + xfs_agnumber_t agno; /* AG number, if applicable */ + struct xfs_buf *agf_bp; /* AGF, for refcount queries */ + struct xfs_rmap_irec low; /* low rmap key */ + struct xfs_rmap_irec high; /* high rmap key */ +}; + +/* Associate a device with a getfsmap handler. */ +struct xfs_getfsmap_dev { + u32 dev; + int (*fn)(struct xfs_trans *tp, + struct xfs_fsmap *keys, + struct xfs_getfsmap_info *info); +}; + +/* Compare two getfsmap device handlers. */ +static int +xfs_getfsmap_dev_compare( + const void *p1, + const void *p2) +{ + const struct xfs_getfsmap_dev *d1 = p1; + const struct xfs_getfsmap_dev *d2 = p2; + + return d1->dev - d2->dev; +} + +/* Compare a record against our starting point */ +static bool +xfs_getfsmap_rec_before_low_key( + struct xfs_getfsmap_info *info, + struct xfs_rmap_irec *rec) +{ + uint64_t x, y; + + if (rec->rm_startblock < info->low.rm_startblock) + return true; + if (rec->rm_startblock > info->low.rm_startblock) + return false; + + if (rec->rm_owner < info->low.rm_owner) + return true; + if (rec->rm_owner > info->low.rm_owner) + return false; + + x = xfs_rmap_irec_offset_pack(rec); + y = xfs_rmap_irec_offset_pack(&info->low); + if (x < y) + return true; + return false; +} + +/* + * Format a reverse mapping for getfsmap, having translated rm_startblock + * into the appropriate daddr units. + */ +STATIC int +xfs_getfsmap_helper( + struct xfs_mount *mp, + struct xfs_getfsmap_info *info, + struct xfs_rmap_irec *rec, + xfs_daddr_t rec_daddr) +{ + struct xfs_fsmap fmr; + xfs_daddr_t key_end; + int error; + + /* + * Filter out records that start before our startpoint, if the + * caller requested that. + */ + if (xfs_getfsmap_rec_before_low_key(info, rec)) { + rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount); + if (info->next_daddr < rec_daddr) + info->next_daddr = rec_daddr; + return XFS_BTREE_QUERY_RANGE_CONTINUE; + } + + /* + * If the caller passed in a length with the low record and + * the record represents a file data extent, we incremented + * the offset in the low key by the length in the hopes of + * finding reverse mappings for the physical blocks we just + * saw. We did /not/ increment next_daddr by the length + * because the range query would not be able to find shared + * extents within the same physical block range. + * + * However, the extent we've been fed could have a startblock + * past the passed-in low record. If this is the case, + * advance next_daddr to the end of the passed-in low record + * so we don't report the extent prior to this extent as + * free. + */ + key_end = info->rkey_low->fmr_physical + info->rkey_low->fmr_length; + if (info->dev == info->rkey_low->fmr_device && + info->next_daddr < key_end && rec_daddr >= key_end) + info->next_daddr = key_end; + + /* Are we just counting mappings? */ + if (info->head->fmh_count == 0) { + if (rec_daddr > info->next_daddr) + info->head->fmh_entries++; + + if (info->last) + return XFS_BTREE_QUERY_RANGE_CONTINUE; + + info->head->fmh_entries++; + + rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount); + if (info->next_daddr < rec_daddr) + info->next_daddr = rec_daddr; + return XFS_BTREE_QUERY_RANGE_CONTINUE; + } + + /* + * If the record starts past the last physical block we saw, + * then we've found some free space. Report that too. + */ + if (rec_daddr > info->next_daddr) { + if (info->head->fmh_entries >= info->head->fmh_count) + return XFS_BTREE_QUERY_RANGE_ABORT; + + trace_xfs_fsmap_mapping(mp, info->dev, info->agno, + XFS_DADDR_TO_FSB(mp, info->next_daddr), + XFS_DADDR_TO_FSB(mp, rec_daddr - + info->next_daddr), + info->missing_owner, 0); + + fmr.fmr_device = info->dev; + fmr.fmr_physical = info->next_daddr; + fmr.fmr_owner = info->missing_owner; + fmr.fmr_offset = 0; + fmr.fmr_length = rec_daddr - info->next_daddr; + fmr.fmr_flags = FMR_OF_SPECIAL_OWNER; + error = info->formatter(&fmr, info->format_arg); + if (error) + return error; + info->head->fmh_entries++; + } + + if (info->last) + goto out; + + /* Fill out the extent we found */ + if (info->head->fmh_entries >= info->head->fmh_count) + return XFS_BTREE_QUERY_RANGE_ABORT; + + trace_xfs_fsmap_mapping(mp, info->dev, info->agno, + rec->rm_startblock, rec->rm_blockcount, rec->rm_owner, + rec->rm_offset); + + fmr.fmr_device = info->dev; + fmr.fmr_physical = rec_daddr; + error = xfs_fsmap_owner_from_rmap(rec, &fmr); + if (error) + return error; + fmr.fmr_offset = XFS_FSB_TO_BB(mp, rec->rm_offset); + fmr.fmr_length = XFS_FSB_TO_BB(mp, rec->rm_blockcount); + if (rec->rm_flags & XFS_RMAP_UNWRITTEN) + fmr.fmr_flags |= FMR_OF_PREALLOC; + if (rec->rm_flags & XFS_RMAP_ATTR_FORK) + fmr.fmr_flags |= FMR_OF_ATTR_FORK; + if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK) + fmr.fmr_flags |= FMR_OF_EXTENT_MAP; + error = info->formatter(&fmr, info->format_arg); + if (error) + return error; + info->head->fmh_entries++; + +out: + rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount); + if (info->next_daddr < rec_daddr) + info->next_daddr = rec_daddr; + return XFS_BTREE_QUERY_RANGE_CONTINUE; +} + +/* Transform a rmapbt irec into a fsmap */ +STATIC int +xfs_getfsmap_datadev_helper( + struct xfs_btree_cur *cur, + struct xfs_rmap_irec *rec, + void *priv) +{ + struct xfs_mount *mp = cur->bc_mp; + struct xfs_getfsmap_info *info = priv; + xfs_fsblock_t fsb; + xfs_daddr_t rec_daddr; + + fsb = XFS_AGB_TO_FSB(mp, cur->bc_private.a.agno, rec->rm_startblock); + rec_daddr = XFS_FSB_TO_DADDR(mp, fsb); + + return xfs_getfsmap_helper(mp, info, rec, rec_daddr); +} + +/* Transform a absolute-startblock rmap (rtdev, logdev) into a fsmap */ +STATIC int +xfs_getfsmap_rtdev_helper( + struct xfs_btree_cur *cur, + struct xfs_rmap_irec *rec, + void *priv) +{ + struct xfs_mount *mp = cur->bc_mp; + struct xfs_getfsmap_info *info = priv; + xfs_daddr_t rec_daddr; + + rec_daddr = XFS_FSB_TO_BB(mp, rec->rm_startblock); + + return xfs_getfsmap_helper(mp, info, rec, rec_daddr); +} + +/* Set rmap flags based on the getfsmap flags */ +static void +xfs_getfsmap_set_irec_flags( + struct xfs_rmap_irec *irec, + struct xfs_fsmap *fmr) +{ + irec->rm_flags = 0; + if (fmr->fmr_flags & FMR_OF_ATTR_FORK) + irec->rm_flags |= XFS_RMAP_ATTR_FORK; + if (fmr->fmr_flags & FMR_OF_EXTENT_MAP) + irec->rm_flags |= XFS_RMAP_BMBT_BLOCK; + if (fmr->fmr_flags & FMR_OF_PREALLOC) + irec->rm_flags |= XFS_RMAP_UNWRITTEN; +} + +/* Execute a getfsmap query against the log device. */ +STATIC int +xfs_getfsmap_logdev( + struct xfs_trans *tp, + struct xfs_fsmap *keys, + struct xfs_getfsmap_info *info) +{ + struct xfs_mount *mp = tp->t_mountp; + struct xfs_fsmap *dkey_low = keys; + struct xfs_btree_cur cur; + struct xfs_rmap_irec rmap; + int error; + + /* Set up search keys */ + info->low.rm_startblock = XFS_BB_TO_FSBT(mp, dkey_low->fmr_physical); + info->low.rm_offset = XFS_BB_TO_FSBT(mp, dkey_low->fmr_offset); + error = xfs_fsmap_owner_to_rmap(keys, &info->low); + if (error) + return error; + info->low.rm_blockcount = 0; + xfs_getfsmap_set_irec_flags(&info->low, dkey_low); + + error = xfs_fsmap_owner_to_rmap(keys + 1, &info->high); + if (error) + return error; + info->high.rm_startblock = -1U; + info->high.rm_owner = ULLONG_MAX; + info->high.rm_offset = ULLONG_MAX; + info->high.rm_blockcount = 0; + info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS; + info->missing_owner = FMR_OWN_FREE; + + trace_xfs_fsmap_low_key(mp, info->dev, info->agno, + info->low.rm_startblock, + info->low.rm_blockcount, + info->low.rm_owner, + info->low.rm_offset); + + trace_xfs_fsmap_high_key(mp, info->dev, info->agno, + info->high.rm_startblock, + info->high.rm_blockcount, + info->high.rm_owner, + info->high.rm_offset); + + + if (dkey_low->fmr_physical > 0) + return 0; + + rmap.rm_startblock = 0; + rmap.rm_blockcount = mp->m_sb.sb_logblocks; + rmap.rm_owner = XFS_RMAP_OWN_LOG; + rmap.rm_offset = 0; + rmap.rm_flags = 0; + + cur.bc_mp = mp; + return xfs_getfsmap_rtdev_helper(&cur, &rmap, info); +} + +/* Execute a getfsmap query against the regular data device. */ +STATIC int +xfs_getfsmap_datadev( + struct xfs_trans *tp, + struct xfs_fsmap *keys, + struct xfs_getfsmap_info *info) +{ + struct xfs_mount *mp = tp->t_mountp; + struct xfs_btree_cur *bt_cur = NULL; + struct xfs_fsmap *dkey_low; + struct xfs_fsmap *dkey_high; + xfs_fsblock_t start_fsb; + xfs_fsblock_t end_fsb; + xfs_agnumber_t start_ag; + xfs_agnumber_t end_ag; + xfs_daddr_t eofs; + int error = 0; + + dkey_low = keys; + dkey_high = keys + 1; + eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks); + if (dkey_low->fmr_physical >= eofs) + return 0; + if (dkey_high->fmr_physical >= eofs) + dkey_high->fmr_physical = eofs - 1; + start_fsb = XFS_DADDR_TO_FSB(mp, dkey_low->fmr_physical); + end_fsb = XFS_DADDR_TO_FSB(mp, dkey_high->fmr_physical); + + /* Set up search keys */ + info->low.rm_startblock = XFS_FSB_TO_AGBNO(mp, start_fsb); + info->low.rm_offset = XFS_BB_TO_FSBT(mp, dkey_low->fmr_offset); + error = xfs_fsmap_owner_to_rmap(dkey_low, &info->low); + if (error) + return error; + info->low.rm_blockcount = 0; + xfs_getfsmap_set_irec_flags(&info->low, dkey_low); + + info->high.rm_startblock = -1U; + info->high.rm_owner = ULLONG_MAX; + info->high.rm_offset = ULLONG_MAX; + info->high.rm_blockcount = 0; + info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS; + info->missing_owner = FMR_OWN_FREE; + + start_ag = XFS_FSB_TO_AGNO(mp, start_fsb); + end_ag = XFS_FSB_TO_AGNO(mp, end_fsb); + + /* Query each AG */ + for (info->agno = start_ag; info->agno <= end_ag; info->agno++) { + if (info->agno == end_ag) { + info->high.rm_startblock = XFS_FSB_TO_AGBNO(mp, + end_fsb); + info->high.rm_offset = XFS_BB_TO_FSBT(mp, + dkey_high->fmr_offset); + error = xfs_fsmap_owner_to_rmap(dkey_high, &info->high); + if (error) + goto err; + xfs_getfsmap_set_irec_flags(&info->high, dkey_high); + } + + if (bt_cur) { + xfs_btree_del_cursor(bt_cur, XFS_BTREE_NOERROR); + bt_cur = NULL; + info->agf_bp = NULL; + } + + error = xfs_alloc_read_agf(mp, tp, info->agno, 0, + &info->agf_bp); + if (error) + goto err; + + trace_xfs_fsmap_low_key(mp, info->dev, info->agno, + info->low.rm_startblock, + info->low.rm_blockcount, + info->low.rm_owner, + info->low.rm_offset); + + trace_xfs_fsmap_high_key(mp, info->dev, info->agno, + info->high.rm_startblock, + info->high.rm_blockcount, + info->high.rm_owner, + info->high.rm_offset); + + bt_cur = xfs_rmapbt_init_cursor(mp, tp, info->agf_bp, + info->agno); + error = xfs_rmap_query_range(bt_cur, &info->low, &info->high, + xfs_getfsmap_datadev_helper, info); + if (error) + goto err; + + if (info->agno == start_ag) { + info->low.rm_startblock = 0; + info->low.rm_owner = 0; + info->low.rm_offset = 0; + info->low.rm_flags = 0; + } + } + + /* Report any free space at the end of the AG */ + info->last = true; + error = xfs_getfsmap_datadev_helper(bt_cur, &info->high, info); + if (error) + goto err; + +err: + if (bt_cur) + xfs_btree_del_cursor(bt_cur, error < 0 ? XFS_BTREE_ERROR : + XFS_BTREE_NOERROR); + if (info->agf_bp) + info->agf_bp = NULL; + + return error; +} + +/* Do we recognize the device? */ +STATIC bool +xfs_getfsmap_is_valid_device( + struct xfs_mount *mp, + struct xfs_fsmap *fm) +{ + if (fm->fmr_device == 0 || fm->fmr_device == UINT_MAX || + fm->fmr_device == new_encode_dev(mp->m_ddev_targp->bt_dev)) + return true; + if (mp->m_logdev_targp && + fm->fmr_device == new_encode_dev(mp->m_logdev_targp->bt_dev)) + return true; + return false; +} + +/* Ensure that the low key is less than the high key. */ +STATIC bool +xfs_getfsmap_check_keys( + struct xfs_fsmap *low_key, + struct xfs_fsmap *high_key) +{ + if (low_key->fmr_device > high_key->fmr_device) + return false; + if (low_key->fmr_device < high_key->fmr_device) + return true; + + if (low_key->fmr_physical > high_key->fmr_physical) + return false; + if (low_key->fmr_physical < high_key->fmr_physical) + return true; + + if (low_key->fmr_owner > high_key->fmr_owner) + return false; + if (low_key->fmr_owner < high_key->fmr_owner) + return true; + + if (low_key->fmr_offset > high_key->fmr_offset) + return false; + if (low_key->fmr_offset < high_key->fmr_offset) + return true; + + return false; +} + +#define XFS_GETFSMAP_DEVS 3 +/* + * Get filesystem's extents as described in head, and format for + * output. Calls formatter to fill the user's buffer until all + * extents are mapped, until the passed-in head->fmh_count slots have + * been filled, or until the formatter short-circuits the loop, if it + * is tracking filled-in extents on its own. + */ +int +xfs_getfsmap( + struct xfs_mount *mp, + struct xfs_fsmap_head *head, + xfs_fsmap_format_t formatter, + void *arg) +{ + struct xfs_trans *tp = NULL; + struct xfs_fsmap *rkey_low; /* request keys */ + struct xfs_fsmap *rkey_high; + struct xfs_fsmap dkeys[2]; /* per-dev keys */ + struct xfs_getfsmap_dev handlers[XFS_GETFSMAP_DEVS]; + struct xfs_getfsmap_info info = {0}; + int i; + int error = 0; + + if (!xfs_sb_version_hasrmapbt(&mp->m_sb)) + return -EOPNOTSUPP; + if (head->fmh_iflags & ~FMH_IF_VALID) + return -EINVAL; + rkey_low = head->fmh_keys; + rkey_high = rkey_low + 1; + if (!xfs_getfsmap_is_valid_device(mp, rkey_low) || + !xfs_getfsmap_is_valid_device(mp, rkey_high)) + return -EINVAL; + + head->fmh_entries = 0; + + /* Set up our device handlers. */ + memset(handlers, 0, sizeof(handlers)); + handlers[0].dev = new_encode_dev(mp->m_ddev_targp->bt_dev); + handlers[0].fn = xfs_getfsmap_datadev; + if (mp->m_logdev_targp != mp->m_ddev_targp) { + handlers[1].dev = new_encode_dev(mp->m_logdev_targp->bt_dev); + handlers[1].fn = xfs_getfsmap_logdev; + } + + xfs_sort(handlers, XFS_GETFSMAP_DEVS, sizeof(struct xfs_getfsmap_dev), + xfs_getfsmap_dev_compare); + + /* + * Since we allow the user to copy the last mapping from a previous + * call into the low key slot, we have to advance the low key by + * whatever the reported length is. If the offset field doesn't apply, + * move up the start block to the next extent and start over with the + * lowest owner/offset possible; otherwise it's file data, so move up + * the offset only. + */ + dkeys[0] = *rkey_low; + if (dkeys[0].fmr_flags & (FMR_OF_SPECIAL_OWNER | FMR_OF_EXTENT_MAP)) { + dkeys[0].fmr_physical += dkeys[0].fmr_length; + dkeys[0].fmr_owner = 0; + dkeys[0].fmr_offset = 0; + } else + dkeys[0].fmr_offset += dkeys[0].fmr_length; + memset(&dkeys[1], 0xFF, sizeof(struct xfs_fsmap)); + + if (!xfs_getfsmap_check_keys(dkeys, rkey_high)) + return -EINVAL; + + info.rkey_low = rkey_low; + info.formatter = formatter; + info.format_arg = arg; + info.head = head; + + /* For each device we support... */ + for (i = 0; i < XFS_GETFSMAP_DEVS; i++) { + /* Is this device within the range the user asked for? */ + if (!handlers[i].fn) + continue; + if (rkey_low->fmr_device > handlers[i].dev) + continue; + if (rkey_high->fmr_device < handlers[i].dev) + break; + + /* + * If this device number matches the high key, we have + * to pass the high key to the handler to limit the + * query results. If the device number exceeds the + * low key, zero out the low key so that we get + * everything from the beginning. + */ + if (handlers[i].dev == rkey_high->fmr_device) + dkeys[1] = *rkey_high; + if (handlers[i].dev > rkey_low->fmr_device) + memset(&dkeys[0], 0, sizeof(struct xfs_fsmap)); + + error = xfs_trans_alloc_empty(mp, &tp); + if (error) + break; + + info.next_daddr = dkeys[0].fmr_physical; + info.dev = handlers[i].dev; + info.last = false; + info.agno = NULLAGNUMBER; + error = handlers[i].fn(tp, dkeys, &info); + if (error) + break; + xfs_trans_cancel(tp); + tp = NULL; + } + + if (tp) + xfs_trans_cancel(tp); + head->fmh_oflags = FMH_OF_DEV_T; + return error; +} diff --git a/fs/xfs/xfs_fsmap.h b/fs/xfs/xfs_fsmap.h new file mode 100644 index 0000000..1943047 --- /dev/null +++ b/fs/xfs/xfs_fsmap.h @@ -0,0 +1,51 @@ +/* + * Copyright (C) 2017 Oracle. All Rights Reserved. + * + * Author: Darrick J. Wong + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it would 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 for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#ifndef __XFS_FSMAP_H__ +#define __XFS_FSMAP_H__ + +/* internal fsmap representation */ +struct xfs_fsmap { + dev_t fmr_device; /* device id */ + uint32_t fmr_flags; /* mapping flags */ + uint64_t fmr_physical; /* device offset of segment */ + uint64_t fmr_owner; /* owner id */ + xfs_fileoff_t fmr_offset; /* file offset of segment */ + xfs_filblks_t fmr_length; /* length of segment, blocks */ +}; + +struct xfs_fsmap_head { + uint32_t fmh_iflags; /* control flags */ + uint32_t fmh_oflags; /* output flags */ + unsigned int fmh_count; /* # of entries in array incl. input */ + unsigned int fmh_entries; /* # of entries filled in (output). */ + + struct xfs_fsmap fmh_keys[2]; /* low and high keys */ +}; + +void xfs_fsmap_from_internal(struct fsmap *dest, struct xfs_fsmap *src); +void xfs_fsmap_to_internal(struct xfs_fsmap *dest, struct fsmap *src); + +/* fsmap to userspace formatter - copy to user & advance pointer */ +typedef int (*xfs_fsmap_format_t)(struct xfs_fsmap *, void *); + +int xfs_getfsmap(struct xfs_mount *mp, struct xfs_fsmap_head *head, + xfs_fsmap_format_t formatter, void *arg); + +#endif /* __XFS_FSMAP_H__ */ diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index c67cfb4..d39da5d 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -41,6 +41,8 @@ #include "xfs_trans.h" #include "xfs_pnfs.h" #include "xfs_acl.h" +#include "xfs_btree.h" +#include "xfs_fsmap.h" #include #include @@ -1607,6 +1609,103 @@ xfs_ioc_getbmapx( return 0; } +struct getfsmap_info { + struct xfs_mount *mp; + struct fsmap __user *data; + __u32 last_flags; +}; + +STATIC int +xfs_getfsmap_format(struct xfs_fsmap *xfm, void *priv) +{ + struct getfsmap_info *info = priv; + struct fsmap fm; + + trace_xfs_getfsmap_mapping(info->mp, xfm->fmr_device, xfm->fmr_physical, + xfm->fmr_length, xfm->fmr_owner, xfm->fmr_offset, + xfm->fmr_flags); + + info->last_flags = xfm->fmr_flags; + xfs_fsmap_from_internal(&fm, xfm); + if (copy_to_user(info->data, &fm, sizeof(struct fsmap))) + return -EFAULT; + + info->data++; + return 0; +} + +STATIC int +xfs_ioc_getfsmap( + struct xfs_inode *ip, + void __user *arg) +{ + struct getfsmap_info info; + struct xfs_fsmap_head xhead = {0}; + struct fsmap_head head; + bool aborted = false; + int error; + + if (copy_from_user(&head, arg, sizeof(struct fsmap_head))) + return -EFAULT; + if (head.fmh_reserved[0] || head.fmh_reserved[1] || + head.fmh_reserved[2] || head.fmh_reserved[3] || + head.fmh_reserved[4] || head.fmh_reserved[5] || + head.fmh_keys[0].fmr_reserved[0] || + head.fmh_keys[0].fmr_reserved[1] || + head.fmh_keys[0].fmr_reserved[2] || + head.fmh_keys[1].fmr_reserved[0] || + head.fmh_keys[1].fmr_reserved[1] || + head.fmh_keys[1].fmr_reserved[2]) + return -EINVAL; + + xhead.fmh_iflags = head.fmh_iflags; + xhead.fmh_count = head.fmh_count; + xfs_fsmap_to_internal(&xhead.fmh_keys[0], &head.fmh_keys[0]); + xfs_fsmap_to_internal(&xhead.fmh_keys[1], &head.fmh_keys[1]); + + trace_xfs_getfsmap_low_key(ip->i_mount, + xhead.fmh_keys[0].fmr_device, + xhead.fmh_keys[0].fmr_physical, + xhead.fmh_keys[0].fmr_length, + xhead.fmh_keys[0].fmr_owner, + xhead.fmh_keys[0].fmr_offset, + xhead.fmh_keys[0].fmr_flags); + + trace_xfs_getfsmap_high_key(ip->i_mount, + xhead.fmh_keys[1].fmr_device, + xhead.fmh_keys[1].fmr_physical, + xhead.fmh_keys[1].fmr_length, + xhead.fmh_keys[1].fmr_owner, + xhead.fmh_keys[1].fmr_offset, + xhead.fmh_keys[1].fmr_flags); + + info.mp = ip->i_mount; + info.data = ((__force struct fsmap_head *)arg)->fmh_recs; + error = xfs_getfsmap(ip->i_mount, &xhead, xfs_getfsmap_format, &info); + if (error == XFS_BTREE_QUERY_RANGE_ABORT) { + error = 0; + aborted = true; + } else if (error) + return error; + + /* If we didn't abort, set the "last" flag in the last fmx */ + if (!aborted && xhead.fmh_entries) { + info.data--; + info.last_flags |= FMR_OF_LAST; + if (copy_to_user(&info.data->fmr_flags, &info.last_flags, + sizeof(info.last_flags))) + return -EFAULT; + } + + /* copy back header */ + head.fmh_entries = xhead.fmh_entries; + head.fmh_oflags = xhead.fmh_oflags; + if (copy_to_user(arg, &head, sizeof(struct fsmap_head))) + return -EFAULT; + + return 0; +} + int xfs_ioc_swapext( xfs_swapext_t *sxp) @@ -1787,6 +1886,11 @@ xfs_file_ioctl( case XFS_IOC_GETBMAPX: return xfs_ioc_getbmapx(ip, arg); + case XFS_IOC_GETFSMAP: + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + return xfs_ioc_getfsmap(ip, arg); + case XFS_IOC_FD_TO_HANDLE: case XFS_IOC_PATH_TO_HANDLE: case XFS_IOC_PATH_TO_FSHANDLE: { diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c index 7c49938..5ba41b7 100644 --- a/fs/xfs/xfs_ioctl32.c +++ b/fs/xfs/xfs_ioctl32.c @@ -554,6 +554,7 @@ xfs_file_compat_ioctl( case XFS_IOC_GOINGDOWN: case XFS_IOC_ERROR_INJECTION: case XFS_IOC_ERROR_CLEARALL: + case XFS_IOC_GETFSMAP: return xfs_file_ioctl(filp, cmd, p); #ifndef BROKEN_X86_ALIGNMENT /* These are handled fine if no alignment issues */ diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index 69c5bcd..09f4755 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -3266,6 +3266,91 @@ DEFINE_INODE_IREC_EVENT(xfs_swap_extent_rmap_remap); DEFINE_INODE_IREC_EVENT(xfs_swap_extent_rmap_remap_piece); DEFINE_INODE_ERROR_EVENT(xfs_swap_extent_rmap_error); +/* fsmap traces */ +DECLARE_EVENT_CLASS(xfs_fsmap_class, + TP_PROTO(struct xfs_mount *mp, u32 keydev, xfs_agnumber_t agno, + xfs_fsblock_t bno, xfs_filblks_t len, __uint64_t owner, + __uint64_t offset), + TP_ARGS(mp, keydev, agno, bno, len, owner, offset), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(dev_t, keydev) + __field(xfs_agnumber_t, agno) + __field(xfs_fsblock_t, bno) + __field(xfs_filblks_t, len) + __field(__uint64_t, owner) + __field(__uint64_t, offset) + ), + TP_fast_assign( + __entry->dev = mp->m_super->s_dev; + __entry->keydev = new_decode_dev(keydev); + __entry->agno = agno; + __entry->bno = bno; + __entry->len = len; + __entry->owner = owner; + __entry->offset = offset; + ), + TP_printk("dev %d:%d keydev %d:%d agno %u bno %llu len %llu owner %lld offset 0x%llx\n", + MAJOR(__entry->dev), MINOR(__entry->dev), + MAJOR(__entry->keydev), MINOR(__entry->keydev), + __entry->agno, + __entry->bno, + __entry->len, + __entry->owner, + __entry->offset) +) +#define DEFINE_FSMAP_EVENT(name) \ +DEFINE_EVENT(xfs_fsmap_class, name, \ + TP_PROTO(struct xfs_mount *mp, u32 keydev, xfs_agnumber_t agno, \ + xfs_fsblock_t bno, xfs_filblks_t len, __uint64_t owner, \ + __uint64_t offset), \ + TP_ARGS(mp, keydev, agno, bno, len, owner, offset)) +DEFINE_FSMAP_EVENT(xfs_fsmap_low_key); +DEFINE_FSMAP_EVENT(xfs_fsmap_high_key); +DEFINE_FSMAP_EVENT(xfs_fsmap_mapping); + +DECLARE_EVENT_CLASS(xfs_getfsmap_class, + TP_PROTO(struct xfs_mount *mp, u32 keydev, xfs_daddr_t block, + xfs_daddr_t len, __uint64_t owner, __uint64_t offset, + __uint64_t flags), + TP_ARGS(mp, keydev, block, len, owner, offset, flags), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(dev_t, keydev) + __field(xfs_daddr_t, block) + __field(xfs_daddr_t, len) + __field(__uint64_t, owner) + __field(__uint64_t, offset) + __field(__uint64_t, flags) + ), + TP_fast_assign( + __entry->dev = mp->m_super->s_dev; + __entry->keydev = new_decode_dev(keydev); + __entry->block = block; + __entry->len = len; + __entry->owner = owner; + __entry->offset = offset; + __entry->flags = flags; + ), + TP_printk("dev %d:%d keydev %d:%d block %llu len %llu owner %lld offset %llu flags 0x%llx\n", + MAJOR(__entry->dev), MINOR(__entry->dev), + MAJOR(__entry->keydev), MINOR(__entry->keydev), + __entry->block, + __entry->len, + __entry->owner, + __entry->offset, + __entry->flags) +) +#define DEFINE_GETFSMAP_EVENT(name) \ +DEFINE_EVENT(xfs_getfsmap_class, name, \ + TP_PROTO(struct xfs_mount *mp, u32 keydev, xfs_daddr_t block, \ + xfs_daddr_t len, __uint64_t owner, __uint64_t offset, \ + __uint64_t flags), \ + TP_ARGS(mp, keydev, block, len, owner, offset, flags)) +DEFINE_GETFSMAP_EVENT(xfs_getfsmap_low_key); +DEFINE_GETFSMAP_EVENT(xfs_getfsmap_high_key); +DEFINE_GETFSMAP_EVENT(xfs_getfsmap_mapping); + #endif /* _TRACE_XFS_H */ #undef TRACE_INCLUDE_PATH diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index 70f42ea..a280e12 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -263,6 +263,28 @@ xfs_trans_alloc( } /* + * Create an empty transaction with no reservation. This is a defensive + * mechanism for routines that query metadata without actually modifying + * them -- if the metadata being queried is somehow cross-linked (think a + * btree block pointer that points higher in the tree), we risk deadlock. + * However, blocks grabbed as part of a transaction can be re-grabbed. + * The verifiers will notice the corrupt block and the operation will fail + * back to userspace without deadlocking. + * + * Note the zero-length reservation; this transaction MUST be cancelled + * without any dirty data. + */ +int +xfs_trans_alloc_empty( + struct xfs_mount *mp, + struct xfs_trans **tpp) +{ + struct xfs_trans_res resv = {0}; + + return xfs_trans_alloc(mp, &resv, 0, 0, XFS_TRANS_NO_WRITECOUNT, tpp); +} + +/* * Record the indicated change to the given field for application * to the file system's superblock when the transaction commits. * For now, just store the change in the transaction structure. diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h index 61b7fbd..98024cb 100644 --- a/fs/xfs/xfs_trans.h +++ b/fs/xfs/xfs_trans.h @@ -159,6 +159,8 @@ typedef struct xfs_trans { int xfs_trans_alloc(struct xfs_mount *mp, struct xfs_trans_res *resp, uint blocks, uint rtextents, uint flags, struct xfs_trans **tpp); +int xfs_trans_alloc_empty(struct xfs_mount *mp, + struct xfs_trans **tpp); void xfs_trans_mod_sb(xfs_trans_t *, uint, int64_t); struct xfs_buf *xfs_trans_get_buf_map(struct xfs_trans *tp,