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Diffstat (limited to '')
| -rw-r--r-- | fs/xfs/xfs_bmap_util.c | 1856 |
1 files changed, 1856 insertions, 0 deletions
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c new file mode 100644 index 000000000..04d0c2bff --- /dev/null +++ b/fs/xfs/xfs_bmap_util.c @@ -0,0 +1,1856 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2000-2006 Silicon Graphics, Inc. + * Copyright (c) 2012 Red Hat, Inc. + * All Rights Reserved. + */ +#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_bit.h" +#include "xfs_mount.h" +#include "xfs_defer.h" +#include "xfs_inode.h" +#include "xfs_btree.h" +#include "xfs_trans.h" +#include "xfs_alloc.h" +#include "xfs_bmap.h" +#include "xfs_bmap_util.h" +#include "xfs_bmap_btree.h" +#include "xfs_rtalloc.h" +#include "xfs_error.h" +#include "xfs_quota.h" +#include "xfs_trans_space.h" +#include "xfs_trace.h" +#include "xfs_icache.h" +#include "xfs_iomap.h" +#include "xfs_reflink.h" + +/* Kernel only BMAP related definitions and functions */ + +/* + * Convert the given file system block to a disk block. We have to treat it + * differently based on whether the file is a real time file or not, because the + * bmap code does. + */ +xfs_daddr_t +xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb) +{ + if (XFS_IS_REALTIME_INODE(ip)) + return XFS_FSB_TO_BB(ip->i_mount, fsb); + return XFS_FSB_TO_DADDR(ip->i_mount, fsb); +} + +/* + * Routine to zero an extent on disk allocated to the specific inode. + * + * The VFS functions take a linearised filesystem block offset, so we have to + * convert the sparse xfs fsb to the right format first. + * VFS types are real funky, too. + */ +int +xfs_zero_extent( + struct xfs_inode *ip, + xfs_fsblock_t start_fsb, + xfs_off_t count_fsb) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_buftarg *target = xfs_inode_buftarg(ip); + xfs_daddr_t sector = xfs_fsb_to_db(ip, start_fsb); + sector_t block = XFS_BB_TO_FSBT(mp, sector); + + return blkdev_issue_zeroout(target->bt_bdev, + block << (mp->m_super->s_blocksize_bits - 9), + count_fsb << (mp->m_super->s_blocksize_bits - 9), + GFP_NOFS, 0); +} + +#ifdef CONFIG_XFS_RT +int +xfs_bmap_rtalloc( + struct xfs_bmalloca *ap) +{ + struct xfs_mount *mp = ap->ip->i_mount; + xfs_fileoff_t orig_offset = ap->offset; + xfs_rtblock_t rtb; + xfs_extlen_t prod = 0; /* product factor for allocators */ + xfs_extlen_t mod = 0; /* product factor for allocators */ + xfs_extlen_t ralen = 0; /* realtime allocation length */ + xfs_extlen_t align; /* minimum allocation alignment */ + xfs_extlen_t orig_length = ap->length; + xfs_extlen_t minlen = mp->m_sb.sb_rextsize; + xfs_extlen_t raminlen; + bool rtlocked = false; + bool ignore_locality = false; + int error; + + align = xfs_get_extsz_hint(ap->ip); +retry: + prod = align / mp->m_sb.sb_rextsize; + error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev, + align, 1, ap->eof, 0, + ap->conv, &ap->offset, &ap->length); + if (error) + return error; + ASSERT(ap->length); + ASSERT(ap->length % mp->m_sb.sb_rextsize == 0); + + /* + * If we shifted the file offset downward to satisfy an extent size + * hint, increase minlen by that amount so that the allocator won't + * give us an allocation that's too short to cover at least one of the + * blocks that the caller asked for. + */ + if (ap->offset != orig_offset) + minlen += orig_offset - ap->offset; + + /* + * If the offset & length are not perfectly aligned + * then kill prod, it will just get us in trouble. + */ + div_u64_rem(ap->offset, align, &mod); + if (mod || ap->length % align) + prod = 1; + /* + * Set ralen to be the actual requested length in rtextents. + */ + ralen = ap->length / mp->m_sb.sb_rextsize; + /* + * If the old value was close enough to XFS_BMBT_MAX_EXTLEN that + * we rounded up to it, cut it back so it's valid again. + * Note that if it's a really large request (bigger than + * XFS_BMBT_MAX_EXTLEN), we don't hear about that number, and can't + * adjust the starting point to match it. + */ + if (ralen * mp->m_sb.sb_rextsize >= XFS_MAX_BMBT_EXTLEN) + ralen = XFS_MAX_BMBT_EXTLEN / mp->m_sb.sb_rextsize; + + /* + * Lock out modifications to both the RT bitmap and summary inodes + */ + if (!rtlocked) { + xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP); + xfs_trans_ijoin(ap->tp, mp->m_rbmip, XFS_ILOCK_EXCL); + xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM); + xfs_trans_ijoin(ap->tp, mp->m_rsumip, XFS_ILOCK_EXCL); + rtlocked = true; + } + + /* + * If it's an allocation to an empty file at offset 0, + * pick an extent that will space things out in the rt area. + */ + if (ap->eof && ap->offset == 0) { + xfs_rtblock_t rtx; /* realtime extent no */ + + error = xfs_rtpick_extent(mp, ap->tp, ralen, &rtx); + if (error) + return error; + ap->blkno = rtx * mp->m_sb.sb_rextsize; + } else { + ap->blkno = 0; + } + + xfs_bmap_adjacent(ap); + + /* + * Realtime allocation, done through xfs_rtallocate_extent. + */ + if (ignore_locality) + ap->blkno = 0; + else + do_div(ap->blkno, mp->m_sb.sb_rextsize); + rtb = ap->blkno; + ap->length = ralen; + raminlen = max_t(xfs_extlen_t, 1, minlen / mp->m_sb.sb_rextsize); + error = xfs_rtallocate_extent(ap->tp, ap->blkno, raminlen, ap->length, + &ralen, ap->wasdel, prod, &rtb); + if (error) + return error; + + if (rtb != NULLRTBLOCK) { + ap->blkno = rtb * mp->m_sb.sb_rextsize; + ap->length = ralen * mp->m_sb.sb_rextsize; + ap->ip->i_nblocks += ap->length; + xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE); + if (ap->wasdel) + ap->ip->i_delayed_blks -= ap->length; + /* + * Adjust the disk quota also. This was reserved + * earlier. + */ + xfs_trans_mod_dquot_byino(ap->tp, ap->ip, + ap->wasdel ? XFS_TRANS_DQ_DELRTBCOUNT : + XFS_TRANS_DQ_RTBCOUNT, ap->length); + return 0; + } + + if (align > mp->m_sb.sb_rextsize) { + /* + * We previously enlarged the request length to try to satisfy + * an extent size hint. The allocator didn't return anything, + * so reset the parameters to the original values and try again + * without alignment criteria. + */ + ap->offset = orig_offset; + ap->length = orig_length; + minlen = align = mp->m_sb.sb_rextsize; + goto retry; + } + + if (!ignore_locality && ap->blkno != 0) { + /* + * If we can't allocate near a specific rt extent, try again + * without locality criteria. + */ + ignore_locality = true; + goto retry; + } + + ap->blkno = NULLFSBLOCK; + ap->length = 0; + return 0; +} +#endif /* CONFIG_XFS_RT */ + +/* + * Extent tree block counting routines. + */ + +/* + * Count leaf blocks given a range of extent records. Delayed allocation + * extents are not counted towards the totals. + */ +xfs_extnum_t +xfs_bmap_count_leaves( + struct xfs_ifork *ifp, + xfs_filblks_t *count) +{ + struct xfs_iext_cursor icur; + struct xfs_bmbt_irec got; + xfs_extnum_t numrecs = 0; + + for_each_xfs_iext(ifp, &icur, &got) { + if (!isnullstartblock(got.br_startblock)) { + *count += got.br_blockcount; + numrecs++; + } + } + + return numrecs; +} + +/* + * Count fsblocks of the given fork. Delayed allocation extents are + * not counted towards the totals. + */ +int +xfs_bmap_count_blocks( + struct xfs_trans *tp, + struct xfs_inode *ip, + int whichfork, + xfs_extnum_t *nextents, + xfs_filblks_t *count) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork); + struct xfs_btree_cur *cur; + xfs_extlen_t btblocks = 0; + int error; + + *nextents = 0; + *count = 0; + + if (!ifp) + return 0; + + switch (ifp->if_format) { + case XFS_DINODE_FMT_BTREE: + error = xfs_iread_extents(tp, ip, whichfork); + if (error) + return error; + + cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork); + error = xfs_btree_count_blocks(cur, &btblocks); + xfs_btree_del_cursor(cur, error); + if (error) + return error; + + /* + * xfs_btree_count_blocks includes the root block contained in + * the inode fork in @btblocks, so subtract one because we're + * only interested in allocated disk blocks. + */ + *count += btblocks - 1; + + fallthrough; + case XFS_DINODE_FMT_EXTENTS: + *nextents = xfs_bmap_count_leaves(ifp, count); + break; + } + + return 0; +} + +static int +xfs_getbmap_report_one( + struct xfs_inode *ip, + struct getbmapx *bmv, + struct kgetbmap *out, + int64_t bmv_end, + struct xfs_bmbt_irec *got) +{ + struct kgetbmap *p = out + bmv->bmv_entries; + bool shared = false; + int error; + + error = xfs_reflink_trim_around_shared(ip, got, &shared); + if (error) + return error; + + if (isnullstartblock(got->br_startblock) || + got->br_startblock == DELAYSTARTBLOCK) { + /* + * Delalloc extents that start beyond EOF can occur due to + * speculative EOF allocation when the delalloc extent is larger + * than the largest freespace extent at conversion time. These + * extents cannot be converted by data writeback, so can exist + * here even if we are not supposed to be finding delalloc + * extents. + */ + if (got->br_startoff < XFS_B_TO_FSB(ip->i_mount, XFS_ISIZE(ip))) + ASSERT((bmv->bmv_iflags & BMV_IF_DELALLOC) != 0); + + p->bmv_oflags |= BMV_OF_DELALLOC; + p->bmv_block = -2; + } else { + p->bmv_block = xfs_fsb_to_db(ip, got->br_startblock); + } + + if (got->br_state == XFS_EXT_UNWRITTEN && + (bmv->bmv_iflags & BMV_IF_PREALLOC)) + p->bmv_oflags |= BMV_OF_PREALLOC; + + if (shared) + p->bmv_oflags |= BMV_OF_SHARED; + + p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, got->br_startoff); + p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, got->br_blockcount); + + bmv->bmv_offset = p->bmv_offset + p->bmv_length; + bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset); + bmv->bmv_entries++; + return 0; +} + +static void +xfs_getbmap_report_hole( + struct xfs_inode *ip, + struct getbmapx *bmv, + struct kgetbmap *out, + int64_t bmv_end, + xfs_fileoff_t bno, + xfs_fileoff_t end) +{ + struct kgetbmap *p = out + bmv->bmv_entries; + + if (bmv->bmv_iflags & BMV_IF_NO_HOLES) + return; + + p->bmv_block = -1; + p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, bno); + p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, end - bno); + + bmv->bmv_offset = p->bmv_offset + p->bmv_length; + bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset); + bmv->bmv_entries++; +} + +static inline bool +xfs_getbmap_full( + struct getbmapx *bmv) +{ + return bmv->bmv_length == 0 || bmv->bmv_entries >= bmv->bmv_count - 1; +} + +static bool +xfs_getbmap_next_rec( + struct xfs_bmbt_irec *rec, + xfs_fileoff_t total_end) +{ + xfs_fileoff_t end = rec->br_startoff + rec->br_blockcount; + + if (end == total_end) + return false; + + rec->br_startoff += rec->br_blockcount; + if (!isnullstartblock(rec->br_startblock) && + rec->br_startblock != DELAYSTARTBLOCK) + rec->br_startblock += rec->br_blockcount; + rec->br_blockcount = total_end - end; + return true; +} + +/* + * Get inode's extents as described in bmv, and format for output. + * Calls formatter to fill the user's buffer until all extents + * are mapped, until the passed-in bmv->bmv_count slots have + * been filled, or until the formatter short-circuits the loop, + * if it is tracking filled-in extents on its own. + */ +int /* error code */ +xfs_getbmap( + struct xfs_inode *ip, + struct getbmapx *bmv, /* user bmap structure */ + struct kgetbmap *out) +{ + struct xfs_mount *mp = ip->i_mount; + int iflags = bmv->bmv_iflags; + int whichfork, lock, error = 0; + int64_t bmv_end, max_len; + xfs_fileoff_t bno, first_bno; + struct xfs_ifork *ifp; + struct xfs_bmbt_irec got, rec; + xfs_filblks_t len; + struct xfs_iext_cursor icur; + + if (bmv->bmv_iflags & ~BMV_IF_VALID) + return -EINVAL; +#ifndef DEBUG + /* Only allow CoW fork queries if we're debugging. */ + if (iflags & BMV_IF_COWFORK) + return -EINVAL; +#endif + if ((iflags & BMV_IF_ATTRFORK) && (iflags & BMV_IF_COWFORK)) + return -EINVAL; + + if (bmv->bmv_length < -1) + return -EINVAL; + bmv->bmv_entries = 0; + if (bmv->bmv_length == 0) + return 0; + + if (iflags & BMV_IF_ATTRFORK) + whichfork = XFS_ATTR_FORK; + else if (iflags & BMV_IF_COWFORK) + whichfork = XFS_COW_FORK; + else + whichfork = XFS_DATA_FORK; + + xfs_ilock(ip, XFS_IOLOCK_SHARED); + switch (whichfork) { + case XFS_ATTR_FORK: + lock = xfs_ilock_attr_map_shared(ip); + if (!xfs_inode_has_attr_fork(ip)) + goto out_unlock_ilock; + + max_len = 1LL << 32; + break; + case XFS_COW_FORK: + lock = XFS_ILOCK_SHARED; + xfs_ilock(ip, lock); + + /* No CoW fork? Just return */ + if (!xfs_ifork_ptr(ip, whichfork)) + goto out_unlock_ilock; + + if (xfs_get_cowextsz_hint(ip)) + max_len = mp->m_super->s_maxbytes; + else + max_len = XFS_ISIZE(ip); + break; + case XFS_DATA_FORK: + if (!(iflags & BMV_IF_DELALLOC) && + (ip->i_delayed_blks || XFS_ISIZE(ip) > ip->i_disk_size)) { + error = filemap_write_and_wait(VFS_I(ip)->i_mapping); + if (error) + goto out_unlock_iolock; + + /* + * Even after flushing the inode, there can still be + * delalloc blocks on the inode beyond EOF due to + * speculative preallocation. These are not removed + * until the release function is called or the inode + * is inactivated. Hence we cannot assert here that + * ip->i_delayed_blks == 0. + */ + } + + if (xfs_get_extsz_hint(ip) || + (ip->i_diflags & + (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))) + max_len = mp->m_super->s_maxbytes; + else + max_len = XFS_ISIZE(ip); + + lock = xfs_ilock_data_map_shared(ip); + break; + } + + ifp = xfs_ifork_ptr(ip, whichfork); + + switch (ifp->if_format) { + case XFS_DINODE_FMT_EXTENTS: + case XFS_DINODE_FMT_BTREE: + break; + case XFS_DINODE_FMT_LOCAL: + /* Local format inode forks report no extents. */ + goto out_unlock_ilock; + default: + error = -EINVAL; + goto out_unlock_ilock; + } + + if (bmv->bmv_length == -1) { + max_len = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, max_len)); + bmv->bmv_length = max(0LL, max_len - bmv->bmv_offset); + } + + bmv_end = bmv->bmv_offset + bmv->bmv_length; + + first_bno = bno = XFS_BB_TO_FSBT(mp, bmv->bmv_offset); + len = XFS_BB_TO_FSB(mp, bmv->bmv_length); + + error = xfs_iread_extents(NULL, ip, whichfork); + if (error) + goto out_unlock_ilock; + + if (!xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got)) { + /* + * Report a whole-file hole if the delalloc flag is set to + * stay compatible with the old implementation. + */ + if (iflags & BMV_IF_DELALLOC) + xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno, + XFS_B_TO_FSB(mp, XFS_ISIZE(ip))); + goto out_unlock_ilock; + } + + while (!xfs_getbmap_full(bmv)) { + xfs_trim_extent(&got, first_bno, len); + + /* + * Report an entry for a hole if this extent doesn't directly + * follow the previous one. + */ + if (got.br_startoff > bno) { + xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno, + got.br_startoff); + if (xfs_getbmap_full(bmv)) + break; + } + + /* + * In order to report shared extents accurately, we report each + * distinct shared / unshared part of a single bmbt record with + * an individual getbmapx record. + */ + bno = got.br_startoff + got.br_blockcount; + rec = got; + do { + error = xfs_getbmap_report_one(ip, bmv, out, bmv_end, + &rec); + if (error || xfs_getbmap_full(bmv)) + goto out_unlock_ilock; + } while (xfs_getbmap_next_rec(&rec, bno)); + + if (!xfs_iext_next_extent(ifp, &icur, &got)) { + xfs_fileoff_t end = XFS_B_TO_FSB(mp, XFS_ISIZE(ip)); + + out[bmv->bmv_entries - 1].bmv_oflags |= BMV_OF_LAST; + + if (whichfork != XFS_ATTR_FORK && bno < end && + !xfs_getbmap_full(bmv)) { + xfs_getbmap_report_hole(ip, bmv, out, bmv_end, + bno, end); + } + break; + } + + if (bno >= first_bno + len) + break; + } + +out_unlock_ilock: + xfs_iunlock(ip, lock); +out_unlock_iolock: + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + return error; +} + +/* + * Dead simple method of punching delalyed allocation blocks from a range in + * the inode. This will always punch out both the start and end blocks, even + * if the ranges only partially overlap them, so it is up to the caller to + * ensure that partial blocks are not passed in. + */ +int +xfs_bmap_punch_delalloc_range( + struct xfs_inode *ip, + xfs_fileoff_t start_fsb, + xfs_fileoff_t length) +{ + struct xfs_ifork *ifp = &ip->i_df; + xfs_fileoff_t end_fsb = start_fsb + length; + struct xfs_bmbt_irec got, del; + struct xfs_iext_cursor icur; + int error = 0; + + ASSERT(!xfs_need_iread_extents(ifp)); + + xfs_ilock(ip, XFS_ILOCK_EXCL); + if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &icur, &got)) + goto out_unlock; + + while (got.br_startoff + got.br_blockcount > start_fsb) { + del = got; + xfs_trim_extent(&del, start_fsb, length); + + /* + * A delete can push the cursor forward. Step back to the + * previous extent on non-delalloc or extents outside the + * target range. + */ + if (!del.br_blockcount || + !isnullstartblock(del.br_startblock)) { + if (!xfs_iext_prev_extent(ifp, &icur, &got)) + break; + continue; + } + + error = xfs_bmap_del_extent_delay(ip, XFS_DATA_FORK, &icur, + &got, &del); + if (error || !xfs_iext_get_extent(ifp, &icur, &got)) + break; + } + +out_unlock: + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; +} + +/* + * Test whether it is appropriate to check an inode for and free post EOF + * blocks. The 'force' parameter determines whether we should also consider + * regular files that are marked preallocated or append-only. + */ +bool +xfs_can_free_eofblocks( + struct xfs_inode *ip, + bool force) +{ + struct xfs_bmbt_irec imap; + struct xfs_mount *mp = ip->i_mount; + xfs_fileoff_t end_fsb; + xfs_fileoff_t last_fsb; + int nimaps = 1; + int error; + + /* + * Caller must either hold the exclusive io lock; or be inactivating + * the inode, which guarantees there are no other users of the inode. + */ + ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL) || + (VFS_I(ip)->i_state & I_FREEING)); + + /* prealloc/delalloc exists only on regular files */ + if (!S_ISREG(VFS_I(ip)->i_mode)) + return false; + + /* + * Zero sized files with no cached pages and delalloc blocks will not + * have speculative prealloc/delalloc blocks to remove. + */ + if (VFS_I(ip)->i_size == 0 && + VFS_I(ip)->i_mapping->nrpages == 0 && + ip->i_delayed_blks == 0) + return false; + + /* If we haven't read in the extent list, then don't do it now. */ + if (xfs_need_iread_extents(&ip->i_df)) + return false; + + /* + * Do not free real preallocated or append-only files unless the file + * has delalloc blocks and we are forced to remove them. + */ + if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)) + if (!force || ip->i_delayed_blks == 0) + return false; + + /* + * Do not try to free post-EOF blocks if EOF is beyond the end of the + * range supported by the page cache, because the truncation will loop + * forever. + */ + end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip)); + if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 1) + end_fsb = roundup_64(end_fsb, mp->m_sb.sb_rextsize); + last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes); + if (last_fsb <= end_fsb) + return false; + + /* + * Look up the mapping for the first block past EOF. If we can't find + * it, there's nothing to free. + */ + xfs_ilock(ip, XFS_ILOCK_SHARED); + error = xfs_bmapi_read(ip, end_fsb, last_fsb - end_fsb, &imap, &nimaps, + 0); + xfs_iunlock(ip, XFS_ILOCK_SHARED); + if (error || nimaps == 0) + return false; + + /* + * If there's a real mapping there or there are delayed allocation + * reservations, then we have post-EOF blocks to try to free. + */ + return imap.br_startblock != HOLESTARTBLOCK || ip->i_delayed_blks; +} + +/* + * This is called to free any blocks beyond eof. The caller must hold + * IOLOCK_EXCL unless we are in the inode reclaim path and have the only + * reference to the inode. + */ +int +xfs_free_eofblocks( + struct xfs_inode *ip) +{ + struct xfs_trans *tp; + struct xfs_mount *mp = ip->i_mount; + int error; + + /* Attach the dquots to the inode up front. */ + error = xfs_qm_dqattach(ip); + if (error) + return error; + + /* Wait on dio to ensure i_size has settled. */ + inode_dio_wait(VFS_I(ip)); + + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp); + if (error) { + ASSERT(xfs_is_shutdown(mp)); + return error; + } + + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); + + /* + * Do not update the on-disk file size. If we update the on-disk file + * size and then the system crashes before the contents of the file are + * flushed to disk then the files may be full of holes (ie NULL files + * bug). + */ + error = xfs_itruncate_extents_flags(&tp, ip, XFS_DATA_FORK, + XFS_ISIZE(ip), XFS_BMAPI_NODISCARD); + if (error) + goto err_cancel; + + error = xfs_trans_commit(tp); + if (error) + goto out_unlock; + + xfs_inode_clear_eofblocks_tag(ip); + goto out_unlock; + +err_cancel: + /* + * If we get an error at this point we simply don't + * bother truncating the file. + */ + xfs_trans_cancel(tp); +out_unlock: + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; +} + +int +xfs_alloc_file_space( + struct xfs_inode *ip, + xfs_off_t offset, + xfs_off_t len) +{ + xfs_mount_t *mp = ip->i_mount; + xfs_off_t count; + xfs_filblks_t allocated_fsb; + xfs_filblks_t allocatesize_fsb; + xfs_extlen_t extsz, temp; + xfs_fileoff_t startoffset_fsb; + xfs_fileoff_t endoffset_fsb; + int nimaps; + int rt; + xfs_trans_t *tp; + xfs_bmbt_irec_t imaps[1], *imapp; + int error; + + trace_xfs_alloc_file_space(ip); + + if (xfs_is_shutdown(mp)) + return -EIO; + + error = xfs_qm_dqattach(ip); + if (error) + return error; + + if (len <= 0) + return -EINVAL; + + rt = XFS_IS_REALTIME_INODE(ip); + extsz = xfs_get_extsz_hint(ip); + + count = len; + imapp = &imaps[0]; + nimaps = 1; + startoffset_fsb = XFS_B_TO_FSBT(mp, offset); + endoffset_fsb = XFS_B_TO_FSB(mp, offset + count); + allocatesize_fsb = endoffset_fsb - startoffset_fsb; + + /* + * Allocate file space until done or until there is an error + */ + while (allocatesize_fsb && !error) { + xfs_fileoff_t s, e; + unsigned int dblocks, rblocks, resblks; + + /* + * Determine space reservations for data/realtime. + */ + if (unlikely(extsz)) { + s = startoffset_fsb; + do_div(s, extsz); + s *= extsz; + e = startoffset_fsb + allocatesize_fsb; + div_u64_rem(startoffset_fsb, extsz, &temp); + if (temp) + e += temp; + div_u64_rem(e, extsz, &temp); + if (temp) + e += extsz - temp; + } else { + s = 0; + e = allocatesize_fsb; + } + + /* + * The transaction reservation is limited to a 32-bit block + * count, hence we need to limit the number of blocks we are + * trying to reserve to avoid an overflow. We can't allocate + * more than @nimaps extents, and an extent is limited on disk + * to XFS_BMBT_MAX_EXTLEN (21 bits), so use that to enforce the + * limit. + */ + resblks = min_t(xfs_fileoff_t, (e - s), + (XFS_MAX_BMBT_EXTLEN * nimaps)); + if (unlikely(rt)) { + dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0); + rblocks = resblks; + } else { + dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks); + rblocks = 0; + } + + error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, + dblocks, rblocks, false, &tp); + if (error) + break; + + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, + XFS_IEXT_ADD_NOSPLIT_CNT); + if (error == -EFBIG) + error = xfs_iext_count_upgrade(tp, ip, + XFS_IEXT_ADD_NOSPLIT_CNT); + if (error) + goto error; + + error = xfs_bmapi_write(tp, ip, startoffset_fsb, + allocatesize_fsb, XFS_BMAPI_PREALLOC, 0, imapp, + &nimaps); + if (error) + goto error; + + ip->i_diflags |= XFS_DIFLAG_PREALLOC; + xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); + + error = xfs_trans_commit(tp); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + if (error) + break; + + allocated_fsb = imapp->br_blockcount; + + if (nimaps == 0) { + error = -ENOSPC; + break; + } + + startoffset_fsb += allocated_fsb; + allocatesize_fsb -= allocated_fsb; + } + + return error; + +error: + xfs_trans_cancel(tp); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; +} + +static int +xfs_unmap_extent( + struct xfs_inode *ip, + xfs_fileoff_t startoffset_fsb, + xfs_filblks_t len_fsb, + int *done) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + uint resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0); + int error; + + error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, resblks, 0, + false, &tp); + if (error) + return error; + + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, + XFS_IEXT_PUNCH_HOLE_CNT); + if (error == -EFBIG) + error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT); + if (error) + goto out_trans_cancel; + + error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, done); + if (error) + goto out_trans_cancel; + + error = xfs_trans_commit(tp); +out_unlock: + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; + +out_trans_cancel: + xfs_trans_cancel(tp); + goto out_unlock; +} + +/* Caller must first wait for the completion of any pending DIOs if required. */ +int +xfs_flush_unmap_range( + struct xfs_inode *ip, + xfs_off_t offset, + xfs_off_t len) +{ + struct xfs_mount *mp = ip->i_mount; + struct inode *inode = VFS_I(ip); + xfs_off_t rounding, start, end; + int error; + + rounding = max_t(xfs_off_t, mp->m_sb.sb_blocksize, PAGE_SIZE); + start = round_down(offset, rounding); + end = round_up(offset + len, rounding) - 1; + + error = filemap_write_and_wait_range(inode->i_mapping, start, end); + if (error) + return error; + truncate_pagecache_range(inode, start, end); + return 0; +} + +int +xfs_free_file_space( + struct xfs_inode *ip, + xfs_off_t offset, + xfs_off_t len) +{ + struct xfs_mount *mp = ip->i_mount; + xfs_fileoff_t startoffset_fsb; + xfs_fileoff_t endoffset_fsb; + int done = 0, error; + + trace_xfs_free_file_space(ip); + + error = xfs_qm_dqattach(ip); + if (error) + return error; + + if (len <= 0) /* if nothing being freed */ + return 0; + + startoffset_fsb = XFS_B_TO_FSB(mp, offset); + endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len); + + /* We can only free complete realtime extents. */ + if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 1) { + startoffset_fsb = roundup_64(startoffset_fsb, + mp->m_sb.sb_rextsize); + endoffset_fsb = rounddown_64(endoffset_fsb, + mp->m_sb.sb_rextsize); + } + + /* + * Need to zero the stuff we're not freeing, on disk. + */ + if (endoffset_fsb > startoffset_fsb) { + while (!done) { + error = xfs_unmap_extent(ip, startoffset_fsb, + endoffset_fsb - startoffset_fsb, &done); + if (error) + return error; + } + } + + /* + * Now that we've unmap all full blocks we'll have to zero out any + * partial block at the beginning and/or end. xfs_zero_range is smart + * enough to skip any holes, including those we just created, but we + * must take care not to zero beyond EOF and enlarge i_size. + */ + if (offset >= XFS_ISIZE(ip)) + return 0; + if (offset + len > XFS_ISIZE(ip)) + len = XFS_ISIZE(ip) - offset; + error = xfs_zero_range(ip, offset, len, NULL); + if (error) + return error; + + /* + * If we zeroed right up to EOF and EOF straddles a page boundary we + * must make sure that the post-EOF area is also zeroed because the + * page could be mmap'd and xfs_zero_range doesn't do that for us. + * Writeback of the eof page will do this, albeit clumsily. + */ + if (offset + len >= XFS_ISIZE(ip) && offset_in_page(offset + len) > 0) { + error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, + round_down(offset + len, PAGE_SIZE), LLONG_MAX); + } + + return error; +} + +static int +xfs_prepare_shift( + struct xfs_inode *ip, + loff_t offset) +{ + struct xfs_mount *mp = ip->i_mount; + int error; + + /* + * Trim eofblocks to avoid shifting uninitialized post-eof preallocation + * into the accessible region of the file. + */ + if (xfs_can_free_eofblocks(ip, true)) { + error = xfs_free_eofblocks(ip); + if (error) + return error; + } + + /* + * Shift operations must stabilize the start block offset boundary along + * with the full range of the operation. If we don't, a COW writeback + * completion could race with an insert, front merge with the start + * extent (after split) during the shift and corrupt the file. Start + * with the block just prior to the start to stabilize the boundary. + */ + offset = round_down(offset, mp->m_sb.sb_blocksize); + if (offset) + offset -= mp->m_sb.sb_blocksize; + + /* + * Writeback and invalidate cache for the remainder of the file as we're + * about to shift down every extent from offset to EOF. + */ + error = xfs_flush_unmap_range(ip, offset, XFS_ISIZE(ip)); + if (error) + return error; + + /* + * Clean out anything hanging around in the cow fork now that + * we've flushed all the dirty data out to disk to avoid having + * CoW extents at the wrong offsets. + */ + if (xfs_inode_has_cow_data(ip)) { + error = xfs_reflink_cancel_cow_range(ip, offset, NULLFILEOFF, + true); + if (error) + return error; + } + + return 0; +} + +/* + * xfs_collapse_file_space() + * This routine frees disk space and shift extent for the given file. + * The first thing we do is to free data blocks in the specified range + * by calling xfs_free_file_space(). It would also sync dirty data + * and invalidate page cache over the region on which collapse range + * is working. And Shift extent records to the left to cover a hole. + * RETURNS: + * 0 on success + * errno on error + * + */ +int +xfs_collapse_file_space( + struct xfs_inode *ip, + xfs_off_t offset, + xfs_off_t len) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + int error; + xfs_fileoff_t next_fsb = XFS_B_TO_FSB(mp, offset + len); + xfs_fileoff_t shift_fsb = XFS_B_TO_FSB(mp, len); + bool done = false; + + ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL)); + ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL)); + + trace_xfs_collapse_file_space(ip); + + error = xfs_free_file_space(ip, offset, len); + if (error) + return error; + + error = xfs_prepare_shift(ip, offset); + if (error) + return error; + + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp); + if (error) + return error; + + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); + + while (!done) { + error = xfs_bmap_collapse_extents(tp, ip, &next_fsb, shift_fsb, + &done); + if (error) + goto out_trans_cancel; + if (done) + break; + + /* finish any deferred frees and roll the transaction */ + error = xfs_defer_finish(&tp); + if (error) + goto out_trans_cancel; + } + + error = xfs_trans_commit(tp); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; + +out_trans_cancel: + xfs_trans_cancel(tp); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; +} + +/* + * xfs_insert_file_space() + * This routine create hole space by shifting extents for the given file. + * The first thing we do is to sync dirty data and invalidate page cache + * over the region on which insert range is working. And split an extent + * to two extents at given offset by calling xfs_bmap_split_extent. + * And shift all extent records which are laying between [offset, + * last allocated extent] to the right to reserve hole range. + * RETURNS: + * 0 on success + * errno on error + */ +int +xfs_insert_file_space( + struct xfs_inode *ip, + loff_t offset, + loff_t len) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + int error; + xfs_fileoff_t stop_fsb = XFS_B_TO_FSB(mp, offset); + xfs_fileoff_t next_fsb = NULLFSBLOCK; + xfs_fileoff_t shift_fsb = XFS_B_TO_FSB(mp, len); + bool done = false; + + ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL)); + ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL)); + + trace_xfs_insert_file_space(ip); + + error = xfs_bmap_can_insert_extents(ip, stop_fsb, shift_fsb); + if (error) + return error; + + error = xfs_prepare_shift(ip, offset); + if (error) + return error; + + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, + XFS_DIOSTRAT_SPACE_RES(mp, 0), 0, 0, &tp); + if (error) + return error; + + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); + + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, + XFS_IEXT_PUNCH_HOLE_CNT); + if (error == -EFBIG) + error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT); + if (error) + goto out_trans_cancel; + + /* + * The extent shifting code works on extent granularity. So, if stop_fsb + * is not the starting block of extent, we need to split the extent at + * stop_fsb. + */ + error = xfs_bmap_split_extent(tp, ip, stop_fsb); + if (error) + goto out_trans_cancel; + + do { + error = xfs_defer_finish(&tp); + if (error) + goto out_trans_cancel; + + error = xfs_bmap_insert_extents(tp, ip, &next_fsb, shift_fsb, + &done, stop_fsb); + if (error) + goto out_trans_cancel; + } while (!done); + + error = xfs_trans_commit(tp); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; + +out_trans_cancel: + xfs_trans_cancel(tp); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; +} + +/* + * We need to check that the format of the data fork in the temporary inode is + * valid for the target inode before doing the swap. This is not a problem with + * attr1 because of the fixed fork offset, but attr2 has a dynamically sized + * data fork depending on the space the attribute fork is taking so we can get + * invalid formats on the target inode. + * + * E.g. target has space for 7 extents in extent format, temp inode only has + * space for 6. If we defragment down to 7 extents, then the tmp format is a + * btree, but when swapped it needs to be in extent format. Hence we can't just + * blindly swap data forks on attr2 filesystems. + * + * Note that we check the swap in both directions so that we don't end up with + * a corrupt temporary inode, either. + * + * Note that fixing the way xfs_fsr sets up the attribute fork in the source + * inode will prevent this situation from occurring, so all we do here is + * reject and log the attempt. basically we are putting the responsibility on + * userspace to get this right. + */ +static int +xfs_swap_extents_check_format( + struct xfs_inode *ip, /* target inode */ + struct xfs_inode *tip) /* tmp inode */ +{ + struct xfs_ifork *ifp = &ip->i_df; + struct xfs_ifork *tifp = &tip->i_df; + + /* User/group/project quota ids must match if quotas are enforced. */ + if (XFS_IS_QUOTA_ON(ip->i_mount) && + (!uid_eq(VFS_I(ip)->i_uid, VFS_I(tip)->i_uid) || + !gid_eq(VFS_I(ip)->i_gid, VFS_I(tip)->i_gid) || + ip->i_projid != tip->i_projid)) + return -EINVAL; + + /* Should never get a local format */ + if (ifp->if_format == XFS_DINODE_FMT_LOCAL || + tifp->if_format == XFS_DINODE_FMT_LOCAL) + return -EINVAL; + + /* + * if the target inode has less extents that then temporary inode then + * why did userspace call us? + */ + if (ifp->if_nextents < tifp->if_nextents) + return -EINVAL; + + /* + * If we have to use the (expensive) rmap swap method, we can + * handle any number of extents and any format. + */ + if (xfs_has_rmapbt(ip->i_mount)) + return 0; + + /* + * if the target inode is in extent form and the temp inode is in btree + * form then we will end up with the target inode in the wrong format + * as we already know there are less extents in the temp inode. + */ + if (ifp->if_format == XFS_DINODE_FMT_EXTENTS && + tifp->if_format == XFS_DINODE_FMT_BTREE) + return -EINVAL; + + /* Check temp in extent form to max in target */ + if (tifp->if_format == XFS_DINODE_FMT_EXTENTS && + tifp->if_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK)) + return -EINVAL; + + /* Check target in extent form to max in temp */ + if (ifp->if_format == XFS_DINODE_FMT_EXTENTS && + ifp->if_nextents > XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK)) + return -EINVAL; + + /* + * If we are in a btree format, check that the temp root block will fit + * in the target and that it has enough extents to be in btree format + * in the target. + * + * Note that we have to be careful to allow btree->extent conversions + * (a common defrag case) which will occur when the temp inode is in + * extent format... + */ + if (tifp->if_format == XFS_DINODE_FMT_BTREE) { + if (xfs_inode_has_attr_fork(ip) && + XFS_BMAP_BMDR_SPACE(tifp->if_broot) > xfs_inode_fork_boff(ip)) + return -EINVAL; + if (tifp->if_nextents <= XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK)) + return -EINVAL; + } + + /* Reciprocal target->temp btree format checks */ + if (ifp->if_format == XFS_DINODE_FMT_BTREE) { + if (xfs_inode_has_attr_fork(tip) && + XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > xfs_inode_fork_boff(tip)) + return -EINVAL; + if (ifp->if_nextents <= XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK)) + return -EINVAL; + } + + return 0; +} + +static int +xfs_swap_extent_flush( + struct xfs_inode *ip) +{ + int error; + + error = filemap_write_and_wait(VFS_I(ip)->i_mapping); + if (error) + return error; + truncate_pagecache_range(VFS_I(ip), 0, -1); + + /* Verify O_DIRECT for ftmp */ + if (VFS_I(ip)->i_mapping->nrpages) + return -EINVAL; + return 0; +} + +/* + * Move extents from one file to another, when rmap is enabled. + */ +STATIC int +xfs_swap_extent_rmap( + struct xfs_trans **tpp, + struct xfs_inode *ip, + struct xfs_inode *tip) +{ + struct xfs_trans *tp = *tpp; + struct xfs_bmbt_irec irec; + struct xfs_bmbt_irec uirec; + struct xfs_bmbt_irec tirec; + xfs_fileoff_t offset_fsb; + xfs_fileoff_t end_fsb; + xfs_filblks_t count_fsb; + int error; + xfs_filblks_t ilen; + xfs_filblks_t rlen; + int nimaps; + uint64_t tip_flags2; + + /* + * If the source file has shared blocks, we must flag the donor + * file as having shared blocks so that we get the shared-block + * rmap functions when we go to fix up the rmaps. The flags + * will be switch for reals later. + */ + tip_flags2 = tip->i_diflags2; + if (ip->i_diflags2 & XFS_DIFLAG2_REFLINK) + tip->i_diflags2 |= XFS_DIFLAG2_REFLINK; + + offset_fsb = 0; + end_fsb = XFS_B_TO_FSB(ip->i_mount, i_size_read(VFS_I(ip))); + count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb); + + while (count_fsb) { + /* Read extent from the donor file */ + nimaps = 1; + error = xfs_bmapi_read(tip, offset_fsb, count_fsb, &tirec, + &nimaps, 0); + if (error) + goto out; + ASSERT(nimaps == 1); + ASSERT(tirec.br_startblock != DELAYSTARTBLOCK); + + trace_xfs_swap_extent_rmap_remap(tip, &tirec); + ilen = tirec.br_blockcount; + + /* Unmap the old blocks in the source file. */ + while (tirec.br_blockcount) { + ASSERT(tp->t_firstblock == NULLFSBLOCK); + trace_xfs_swap_extent_rmap_remap_piece(tip, &tirec); + + /* Read extent from the source file */ + nimaps = 1; + error = xfs_bmapi_read(ip, tirec.br_startoff, + tirec.br_blockcount, &irec, + &nimaps, 0); + if (error) + goto out; + ASSERT(nimaps == 1); + ASSERT(tirec.br_startoff == irec.br_startoff); + trace_xfs_swap_extent_rmap_remap_piece(ip, &irec); + + /* Trim the extent. */ + uirec = tirec; + uirec.br_blockcount = rlen = min_t(xfs_filblks_t, + tirec.br_blockcount, + irec.br_blockcount); + trace_xfs_swap_extent_rmap_remap_piece(tip, &uirec); + + if (xfs_bmap_is_real_extent(&uirec)) { + error = xfs_iext_count_may_overflow(ip, + XFS_DATA_FORK, + XFS_IEXT_SWAP_RMAP_CNT); + if (error == -EFBIG) + error = xfs_iext_count_upgrade(tp, ip, + XFS_IEXT_SWAP_RMAP_CNT); + if (error) + goto out; + } + + if (xfs_bmap_is_real_extent(&irec)) { + error = xfs_iext_count_may_overflow(tip, + XFS_DATA_FORK, + XFS_IEXT_SWAP_RMAP_CNT); + if (error == -EFBIG) + error = xfs_iext_count_upgrade(tp, ip, + XFS_IEXT_SWAP_RMAP_CNT); + if (error) + goto out; + } + + /* Remove the mapping from the donor file. */ + xfs_bmap_unmap_extent(tp, tip, &uirec); + + /* Remove the mapping from the source file. */ + xfs_bmap_unmap_extent(tp, ip, &irec); + + /* Map the donor file's blocks into the source file. */ + xfs_bmap_map_extent(tp, ip, &uirec); + + /* Map the source file's blocks into the donor file. */ + xfs_bmap_map_extent(tp, tip, &irec); + + error = xfs_defer_finish(tpp); + tp = *tpp; + if (error) + goto out; + + tirec.br_startoff += rlen; + if (tirec.br_startblock != HOLESTARTBLOCK && + tirec.br_startblock != DELAYSTARTBLOCK) + tirec.br_startblock += rlen; + tirec.br_blockcount -= rlen; + } + + /* Roll on... */ + count_fsb -= ilen; + offset_fsb += ilen; + } + + tip->i_diflags2 = tip_flags2; + return 0; + +out: + trace_xfs_swap_extent_rmap_error(ip, error, _RET_IP_); + tip->i_diflags2 = tip_flags2; + return error; +} + +/* Swap the extents of two files by swapping data forks. */ +STATIC int +xfs_swap_extent_forks( + struct xfs_trans *tp, + struct xfs_inode *ip, + struct xfs_inode *tip, + int *src_log_flags, + int *target_log_flags) +{ + xfs_filblks_t aforkblks = 0; + xfs_filblks_t taforkblks = 0; + xfs_extnum_t junk; + uint64_t tmp; + int error; + + /* + * Count the number of extended attribute blocks + */ + if (xfs_inode_has_attr_fork(ip) && ip->i_af.if_nextents > 0 && + ip->i_af.if_format != XFS_DINODE_FMT_LOCAL) { + error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &junk, + &aforkblks); + if (error) + return error; + } + if (xfs_inode_has_attr_fork(tip) && tip->i_af.if_nextents > 0 && + tip->i_af.if_format != XFS_DINODE_FMT_LOCAL) { + error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK, &junk, + &taforkblks); + if (error) + return error; + } + + /* + * Btree format (v3) inodes have the inode number stamped in the bmbt + * block headers. We can't start changing the bmbt blocks until the + * inode owner change is logged so recovery does the right thing in the + * event of a crash. Set the owner change log flags now and leave the + * bmbt scan as the last step. + */ + if (xfs_has_v3inodes(ip->i_mount)) { + if (ip->i_df.if_format == XFS_DINODE_FMT_BTREE) + (*target_log_flags) |= XFS_ILOG_DOWNER; + if (tip->i_df.if_format == XFS_DINODE_FMT_BTREE) + (*src_log_flags) |= XFS_ILOG_DOWNER; + } + + /* + * Swap the data forks of the inodes + */ + swap(ip->i_df, tip->i_df); + + /* + * Fix the on-disk inode values + */ + tmp = (uint64_t)ip->i_nblocks; + ip->i_nblocks = tip->i_nblocks - taforkblks + aforkblks; + tip->i_nblocks = tmp + taforkblks - aforkblks; + + /* + * The extents in the source inode could still contain speculative + * preallocation beyond EOF (e.g. the file is open but not modified + * while defrag is in progress). In that case, we need to copy over the + * number of delalloc blocks the data fork in the source inode is + * tracking beyond EOF so that when the fork is truncated away when the + * temporary inode is unlinked we don't underrun the i_delayed_blks + * counter on that inode. + */ + ASSERT(tip->i_delayed_blks == 0); + tip->i_delayed_blks = ip->i_delayed_blks; + ip->i_delayed_blks = 0; + + switch (ip->i_df.if_format) { + case XFS_DINODE_FMT_EXTENTS: + (*src_log_flags) |= XFS_ILOG_DEXT; + break; + case XFS_DINODE_FMT_BTREE: + ASSERT(!xfs_has_v3inodes(ip->i_mount) || + (*src_log_flags & XFS_ILOG_DOWNER)); + (*src_log_flags) |= XFS_ILOG_DBROOT; + break; + } + + switch (tip->i_df.if_format) { + case XFS_DINODE_FMT_EXTENTS: + (*target_log_flags) |= XFS_ILOG_DEXT; + break; + case XFS_DINODE_FMT_BTREE: + (*target_log_flags) |= XFS_ILOG_DBROOT; + ASSERT(!xfs_has_v3inodes(ip->i_mount) || + (*target_log_flags & XFS_ILOG_DOWNER)); + break; + } + + return 0; +} + +/* + * Fix up the owners of the bmbt blocks to refer to the current inode. The + * change owner scan attempts to order all modified buffers in the current + * transaction. In the event of ordered buffer failure, the offending buffer is + * physically logged as a fallback and the scan returns -EAGAIN. We must roll + * the transaction in this case to replenish the fallback log reservation and + * restart the scan. This process repeats until the scan completes. + */ +static int +xfs_swap_change_owner( + struct xfs_trans **tpp, + struct xfs_inode *ip, + struct xfs_inode *tmpip) +{ + int error; + struct xfs_trans *tp = *tpp; + + do { + error = xfs_bmbt_change_owner(tp, ip, XFS_DATA_FORK, ip->i_ino, + NULL); + /* success or fatal error */ + if (error != -EAGAIN) + break; + + error = xfs_trans_roll(tpp); + if (error) + break; + tp = *tpp; + + /* + * Redirty both inodes so they can relog and keep the log tail + * moving forward. + */ + xfs_trans_ijoin(tp, ip, 0); + xfs_trans_ijoin(tp, tmpip, 0); + xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); + xfs_trans_log_inode(tp, tmpip, XFS_ILOG_CORE); + } while (true); + + return error; +} + +int +xfs_swap_extents( + struct xfs_inode *ip, /* target inode */ + struct xfs_inode *tip, /* tmp inode */ + struct xfs_swapext *sxp) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + struct xfs_bstat *sbp = &sxp->sx_stat; + int src_log_flags, target_log_flags; + int error = 0; + uint64_t f; + int resblks = 0; + unsigned int flags = 0; + + /* + * Lock the inodes against other IO, page faults and truncate to + * begin with. Then we can ensure the inodes are flushed and have no + * page cache safely. Once we have done this we can take the ilocks and + * do the rest of the checks. + */ + lock_two_nondirectories(VFS_I(ip), VFS_I(tip)); + filemap_invalidate_lock_two(VFS_I(ip)->i_mapping, + VFS_I(tip)->i_mapping); + + /* Verify that both files have the same format */ + if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) { + error = -EINVAL; + goto out_unlock; + } + + /* Verify both files are either real-time or non-realtime */ + if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) { + error = -EINVAL; + goto out_unlock; + } + + error = xfs_qm_dqattach(ip); + if (error) + goto out_unlock; + + error = xfs_qm_dqattach(tip); + if (error) + goto out_unlock; + + error = xfs_swap_extent_flush(ip); + if (error) + goto out_unlock; + error = xfs_swap_extent_flush(tip); + if (error) + goto out_unlock; + + if (xfs_inode_has_cow_data(tip)) { + error = xfs_reflink_cancel_cow_range(tip, 0, NULLFILEOFF, true); + if (error) + goto out_unlock; + } + + /* + * Extent "swapping" with rmap requires a permanent reservation and + * a block reservation because it's really just a remap operation + * performed with log redo items! + */ + if (xfs_has_rmapbt(mp)) { + int w = XFS_DATA_FORK; + uint32_t ipnext = ip->i_df.if_nextents; + uint32_t tipnext = tip->i_df.if_nextents; + + /* + * Conceptually this shouldn't affect the shape of either bmbt, + * but since we atomically move extents one by one, we reserve + * enough space to rebuild both trees. + */ + resblks = XFS_SWAP_RMAP_SPACE_RES(mp, ipnext, w); + resblks += XFS_SWAP_RMAP_SPACE_RES(mp, tipnext, w); + + /* + * If either inode straddles a bmapbt block allocation boundary, + * the rmapbt algorithm triggers repeated allocs and frees as + * extents are remapped. This can exhaust the block reservation + * prematurely and cause shutdown. Return freed blocks to the + * transaction reservation to counter this behavior. + */ + flags |= XFS_TRANS_RES_FDBLKS; + } + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, flags, + &tp); + if (error) + goto out_unlock; + + /* + * Lock and join the inodes to the tansaction so that transaction commit + * or cancel will unlock the inodes from this point onwards. + */ + xfs_lock_two_inodes(ip, XFS_ILOCK_EXCL, tip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); + xfs_trans_ijoin(tp, tip, 0); + + + /* Verify all data are being swapped */ + if (sxp->sx_offset != 0 || + sxp->sx_length != ip->i_disk_size || + sxp->sx_length != tip->i_disk_size) { + error = -EFAULT; + goto out_trans_cancel; + } + + trace_xfs_swap_extent_before(ip, 0); + trace_xfs_swap_extent_before(tip, 1); + + /* check inode formats now that data is flushed */ + error = xfs_swap_extents_check_format(ip, tip); + if (error) { + xfs_notice(mp, + "%s: inode 0x%llx format is incompatible for exchanging.", + __func__, ip->i_ino); + goto out_trans_cancel; + } + + /* + * Compare the current change & modify times with that + * passed in. If they differ, we abort this swap. + * This is the mechanism used to ensure the calling + * process that the file was not changed out from + * under it. + */ + if ((sbp->bs_ctime.tv_sec != VFS_I(ip)->i_ctime.tv_sec) || + (sbp->bs_ctime.tv_nsec != VFS_I(ip)->i_ctime.tv_nsec) || + (sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) || + (sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) { + error = -EBUSY; + goto out_trans_cancel; + } + + /* + * Note the trickiness in setting the log flags - we set the owner log + * flag on the opposite inode (i.e. the inode we are setting the new + * owner to be) because once we swap the forks and log that, log + * recovery is going to see the fork as owned by the swapped inode, + * not the pre-swapped inodes. + */ + src_log_flags = XFS_ILOG_CORE; + target_log_flags = XFS_ILOG_CORE; + + if (xfs_has_rmapbt(mp)) + error = xfs_swap_extent_rmap(&tp, ip, tip); + else + error = xfs_swap_extent_forks(tp, ip, tip, &src_log_flags, + &target_log_flags); + if (error) + goto out_trans_cancel; + + /* Do we have to swap reflink flags? */ + if ((ip->i_diflags2 & XFS_DIFLAG2_REFLINK) ^ + (tip->i_diflags2 & XFS_DIFLAG2_REFLINK)) { + f = ip->i_diflags2 & XFS_DIFLAG2_REFLINK; + ip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK; + ip->i_diflags2 |= tip->i_diflags2 & XFS_DIFLAG2_REFLINK; + tip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK; + tip->i_diflags2 |= f & XFS_DIFLAG2_REFLINK; + } + + /* Swap the cow forks. */ + if (xfs_has_reflink(mp)) { + ASSERT(!ip->i_cowfp || + ip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS); + ASSERT(!tip->i_cowfp || + tip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS); + + swap(ip->i_cowfp, tip->i_cowfp); + + if (ip->i_cowfp && ip->i_cowfp->if_bytes) + xfs_inode_set_cowblocks_tag(ip); + else + xfs_inode_clear_cowblocks_tag(ip); + if (tip->i_cowfp && tip->i_cowfp->if_bytes) + xfs_inode_set_cowblocks_tag(tip); + else + xfs_inode_clear_cowblocks_tag(tip); + } + + xfs_trans_log_inode(tp, ip, src_log_flags); + xfs_trans_log_inode(tp, tip, target_log_flags); + + /* + * The extent forks have been swapped, but crc=1,rmapbt=0 filesystems + * have inode number owner values in the bmbt blocks that still refer to + * the old inode. Scan each bmbt to fix up the owner values with the + * inode number of the current inode. + */ + if (src_log_flags & XFS_ILOG_DOWNER) { + error = xfs_swap_change_owner(&tp, ip, tip); + if (error) + goto out_trans_cancel; + } + if (target_log_flags & XFS_ILOG_DOWNER) { + error = xfs_swap_change_owner(&tp, tip, ip); + if (error) + goto out_trans_cancel; + } + + /* + * If this is a synchronous mount, make sure that the + * transaction goes to disk before returning to the user. + */ + if (xfs_has_wsync(mp)) + xfs_trans_set_sync(tp); + + error = xfs_trans_commit(tp); + + trace_xfs_swap_extent_after(ip, 0); + trace_xfs_swap_extent_after(tip, 1); + +out_unlock_ilock: + xfs_iunlock(ip, XFS_ILOCK_EXCL); + xfs_iunlock(tip, XFS_ILOCK_EXCL); +out_unlock: + filemap_invalidate_unlock_two(VFS_I(ip)->i_mapping, + VFS_I(tip)->i_mapping); + unlock_two_nondirectories(VFS_I(ip), VFS_I(tip)); + return error; + +out_trans_cancel: + xfs_trans_cancel(tp); + goto out_unlock_ilock; +} |