cregit-Linux how code gets into the kernel

Release 4.10 fs/xfs/xfs_iomap.c

Directory: fs/xfs
/*
 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
 * Copyright (c) 2016 Christoph Hellwig.
 * All Rights Reserved.
 *
 * 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.
 *
 * 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 <linux/iomap.h>
#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_mount.h"
#include "xfs_defer.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_bmap.h"
#include "xfs_bmap_util.h"
#include "xfs_error.h"
#include "xfs_trans.h"
#include "xfs_trans_space.h"
#include "xfs_iomap.h"
#include "xfs_trace.h"
#include "xfs_icache.h"
#include "xfs_quota.h"
#include "xfs_dquot_item.h"
#include "xfs_dquot.h"
#include "xfs_reflink.h"



#define XFS_WRITEIO_ALIGN(mp,off)	(((off) >> mp->m_writeio_log) \
                                                << mp->m_writeio_log)


void xfs_bmbt_to_iomap( struct xfs_inode *ip, struct iomap *iomap, struct xfs_bmbt_irec *imap) { struct xfs_mount *mp = ip->i_mount; if (imap->br_startblock == HOLESTARTBLOCK) { iomap->blkno = IOMAP_NULL_BLOCK; iomap->type = IOMAP_HOLE; } else if (imap->br_startblock == DELAYSTARTBLOCK) { iomap->blkno = IOMAP_NULL_BLOCK; iomap->type = IOMAP_DELALLOC; } else { iomap->blkno = xfs_fsb_to_db(ip, imap->br_startblock); if (imap->br_state == XFS_EXT_UNWRITTEN) iomap->type = IOMAP_UNWRITTEN; else iomap->type = IOMAP_MAPPED; } iomap->offset = XFS_FSB_TO_B(mp, imap->br_startoff); iomap->length = XFS_FSB_TO_B(mp, imap->br_blockcount); iomap->bdev = xfs_find_bdev_for_inode(VFS_I(ip)); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig149100.00%1100.00%
Total149100.00%1100.00%


xfs_extlen_t xfs_eof_alignment( struct xfs_inode *ip, xfs_extlen_t extsize) { struct xfs_mount *mp = ip->i_mount; xfs_extlen_t align = 0; if (!XFS_IS_REALTIME_INODE(ip)) { /* * Round up the allocation request to a stripe unit * (m_dalign) boundary if the file size is >= stripe unit * size, and we are allocating past the allocation eof. * * If mounted with the "-o swalloc" option the alignment is * increased from the strip unit size to the stripe width. */ if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC)) align = mp->m_swidth; else if (mp->m_dalign) align = mp->m_dalign; if (align && XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, align)) align = 0; } /* * Always round up the allocation request to an extent boundary * (when file on a real-time subvolume or has di_extsize hint). */ if (extsize) { if (align) align = roundup_64(align, extsize); else align = extsize; } return align; }

Contributors

PersonTokensPropCommitsCommitProp
nathan scottnathan scott6857.14%112.50%
christoph hellwigchristoph hellwig3932.77%337.50%
peter watkinspeter watkins65.04%112.50%
eric sandeeneric sandeen32.52%112.50%
lachlan mcilroylachlan mcilroy32.52%225.00%
Total119100.00%8100.00%


STATIC int xfs_iomap_eof_align_last_fsb( struct xfs_inode *ip, xfs_extlen_t extsize, xfs_fileoff_t *last_fsb) { xfs_extlen_t align = xfs_eof_alignment(ip, extsize); if (align) { xfs_fileoff_t new_last_fsb = roundup_64(*last_fsb, align); int eof, error; error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof); if (error) return error; if (eof) *last_fsb = new_last_fsb; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
nathan scottnathan scott4149.40%125.00%
christoph hellwigchristoph hellwig3238.55%125.00%
peter watkinspeter watkins89.64%125.00%
lachlan mcilroylachlan mcilroy22.41%125.00%
Total83100.00%4100.00%


STATIC int xfs_alert_fsblock_zero( xfs_inode_t *ip, xfs_bmbt_irec_t *imap) { xfs_alert_tag(ip->i_mount, XFS_PTAG_FSBLOCK_ZERO, "Access to block zero in inode %llu " "start_block: %llx start_off: %llx " "blkcnt: %llx extent-state: %x", (unsigned long long)ip->i_ino, (unsigned long long)imap->br_startblock, (unsigned long long)imap->br_startoff, (unsigned long long)imap->br_blockcount, imap->br_state); return -EFSCORRUPTED; }

Contributors

PersonTokensPropCommitsCommitProp
nathan scottnathan scott6591.55%233.33%
dave chinnerdave chinner57.04%350.00%
eric sandeeneric sandeen11.41%116.67%
Total71100.00%6100.00%


int xfs_iomap_write_direct( xfs_inode_t *ip, xfs_off_t offset, size_t count, xfs_bmbt_irec_t *imap, int nmaps) { xfs_mount_t *mp = ip->i_mount; xfs_fileoff_t offset_fsb; xfs_fileoff_t last_fsb; xfs_filblks_t count_fsb, resaligned; xfs_fsblock_t firstfsb; xfs_extlen_t extsz, temp; int nimaps; int quota_flag; int rt; xfs_trans_t *tp; struct xfs_defer_ops dfops; uint qblocks, resblks, resrtextents; int error; int lockmode; int bmapi_flags = XFS_BMAPI_PREALLOC; uint tflags = 0; rt = XFS_IS_REALTIME_INODE(ip); extsz = xfs_get_extsz_hint(ip); lockmode = XFS_ILOCK_SHARED; /* locked by caller */ ASSERT(xfs_isilocked(ip, lockmode)); offset_fsb = XFS_B_TO_FSBT(mp, offset); last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count))); if ((offset + count) > XFS_ISIZE(ip)) { /* * Assert that the in-core extent list is present since this can * call xfs_iread_extents() and we only have the ilock shared. * This should be safe because the lock was held around a bmapi * call in the caller and we only need it to access the in-core * list. */ ASSERT(XFS_IFORK_PTR(ip, XFS_DATA_FORK)->if_flags & XFS_IFEXTENTS); error = xfs_iomap_eof_align_last_fsb(ip, extsz, &last_fsb); if (error) goto out_unlock; } else { if (nmaps && (imap->br_startblock == HOLESTARTBLOCK)) last_fsb = MIN(last_fsb, (xfs_fileoff_t) imap->br_blockcount + imap->br_startoff); } count_fsb = last_fsb - offset_fsb; ASSERT(count_fsb > 0); resaligned = count_fsb; if (unlikely(extsz)) { if ((temp = do_mod(offset_fsb, extsz))) resaligned += temp; if ((temp = do_mod(resaligned, extsz))) resaligned += extsz - temp; } if (unlikely(rt)) { resrtextents = qblocks = resaligned; resrtextents /= mp->m_sb.sb_rextsize; resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0); quota_flag = XFS_QMOPT_RES_RTBLKS; } else { resrtextents = 0; resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); quota_flag = XFS_QMOPT_RES_REGBLKS; } /* * Drop the shared lock acquired by the caller, attach the dquot if * necessary and move on to transaction setup. */ xfs_iunlock(ip, lockmode); error = xfs_qm_dqattach(ip, 0); if (error) return error; /* * For DAX, we do not allocate unwritten extents, but instead we zero * the block before we commit the transaction. Ideally we'd like to do * this outside the transaction context, but if we commit and then crash * we may not have zeroed the blocks and this will be exposed on * recovery of the allocation. Hence we must zero before commit. * * Further, if we are mapping unwritten extents here, we need to zero * and convert them to written so that we don't need an unwritten extent * callback for DAX. This also means that we need to be able to dip into * the reserve block pool for bmbt block allocation if there is no space * left but we need to do unwritten extent conversion. */ if (IS_DAX(VFS_I(ip))) { bmapi_flags = XFS_BMAPI_CONVERT | XFS_BMAPI_ZERO; if (ISUNWRITTEN(imap)) { tflags |= XFS_TRANS_RESERVE; resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1; } } error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, resrtextents, tflags, &tp); if (error) return error; lockmode = XFS_ILOCK_EXCL; xfs_ilock(ip, lockmode); error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag); if (error) goto out_trans_cancel; xfs_trans_ijoin(tp, ip, 0); /* * From this point onwards we overwrite the imap pointer that the * caller gave to us. */ xfs_defer_init(&dfops, &firstfsb); nimaps = 1; error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, bmapi_flags, &firstfsb, resblks, imap, &nimaps, &dfops); if (error) goto out_bmap_cancel; /* * Complete the transaction */ error = xfs_defer_finish(&tp, &dfops, NULL); if (error) goto out_bmap_cancel; error = xfs_trans_commit(tp); if (error) goto out_unlock; /* * Copy any maps to caller's array and return any error. */ if (nimaps == 0) { error = -ENOSPC; goto out_unlock; } if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) error = xfs_alert_fsblock_zero(ip, imap); out_unlock: xfs_iunlock(ip, lockmode); return error; out_bmap_cancel: xfs_defer_cancel(&dfops); xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag); out_trans_cancel: xfs_trans_cancel(tp); goto out_unlock; }

Contributors

PersonTokensPropCommitsCommitProp
stephen lordstephen lord22734.55%25.56%
nathan scottnathan scott22033.49%513.89%
dave chinnerdave chinner7611.57%719.44%
brian fosterbrian foster6610.05%25.56%
christoph hellwigchristoph hellwig304.57%822.22%
eric sandeeneric sandeen142.13%411.11%
darrick j. wongdarrick j. wong101.52%25.56%
jeff liujeff liu60.91%12.78%
david chinnerdavid chinner50.76%38.33%
lachlan mcilroylachlan mcilroy30.46%25.56%
Total657100.00%36100.00%


STATIC bool xfs_quota_need_throttle( struct xfs_inode *ip, int type, xfs_fsblock_t alloc_blocks) { struct xfs_dquot *dq = xfs_inode_dquot(ip, type); if (!dq || !xfs_this_quota_on(ip->i_mount, type)) return false; /* no hi watermark, no throttle */ if (!dq->q_prealloc_hi_wmark) return false; /* under the lo watermark, no throttle */ if (dq->q_res_bcount + alloc_blocks < dq->q_prealloc_lo_wmark) return false; return true; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig4355.84%222.22%
dave chinnerdave chinner1114.29%222.22%
nathan scottnathan scott911.69%111.11%
john krueger* (same as john keller?)*john krueger* (same as john keller?)*810.39%111.11%
stephen lordstephen lord45.19%111.11%
lachlan mcilroylachlan mcilroy22.60%222.22%
Total77100.00%9100.00%


STATIC void xfs_quota_calc_throttle( struct xfs_inode *ip, int type, xfs_fsblock_t *qblocks, int *qshift, int64_t *qfreesp) { int64_t freesp; int shift = 0; struct xfs_dquot *dq = xfs_inode_dquot(ip, type); /* no dq, or over hi wmark, squash the prealloc completely */ if (!dq || dq->q_res_bcount >= dq->q_prealloc_hi_wmark) { *qblocks = 0; *qfreesp = 0; return; } freesp = dq->q_prealloc_hi_wmark - dq->q_res_bcount; if (freesp < dq->q_low_space[XFS_QLOWSP_5_PCNT]) { shift = 2; if (freesp < dq->q_low_space[XFS_QLOWSP_3_PCNT]) shift += 2; if (freesp < dq->q_low_space[XFS_QLOWSP_1_PCNT]) shift += 2; } if (freesp < *qfreesp) *qfreesp = freesp; /* only overwrite the throttle values if we are more aggressive */ if ((freesp >> shift) < (*qblocks >> *qshift)) { *qblocks = freesp; *qshift = shift; } }

Contributors

PersonTokensPropCommitsCommitProp
brian fosterbrian foster15288.89%233.33%
dave chinnerdave chinner95.26%233.33%
christoph hellwigchristoph hellwig63.51%116.67%
eric sandeeneric sandeen42.34%116.67%
Total171100.00%6100.00%

/* * If we are doing a write at the end of the file and there are no allocations * past this one, then extend the allocation out to the file system's write * iosize. * * If we don't have a user specified preallocation size, dynamically increase * the preallocation size as the size of the file grows. Cap the maximum size * at a single extent or less if the filesystem is near full. The closer the * filesystem is to full, the smaller the maximum prealocation. * * As an exception we don't do any preallocation at all if the file is smaller * than the minimum preallocation and we are using the default dynamic * preallocation scheme, as it is likely this is the only write to the file that * is going to be done. * * We clean up any extra space left over when the file is closed in * xfs_inactive(). */
STATIC xfs_fsblock_t xfs_iomap_prealloc_size( struct xfs_inode *ip, loff_t offset, loff_t count, xfs_extnum_t idx) { struct xfs_mount *mp = ip->i_mount; struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK); xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); struct xfs_bmbt_irec prev; int shift = 0; int64_t freesp; xfs_fsblock_t qblocks; int qshift = 0; xfs_fsblock_t alloc_blocks = 0; if (offset + count <= XFS_ISIZE(ip)) return 0; if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE) && (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_writeio_blocks))) return 0; /* * If an explicit allocsize is set, the file is small, or we * are writing behind a hole, then use the minimum prealloc: */ if ((mp->m_flags & XFS_MOUNT_DFLT_IOSIZE) || XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign) || !xfs_iext_get_extent(ifp, idx - 1, &prev) || prev.br_startoff + prev.br_blockcount < offset_fsb) return mp->m_writeio_blocks; /* * Determine the initial size of the preallocation. We are beyond the * current EOF here, but we need to take into account whether this is * a sparse write or an extending write when determining the * preallocation size. Hence we need to look up the extent that ends * at the current write offset and use the result to determine the * preallocation size. * * If the extent is a hole, then preallocation is essentially disabled. * Otherwise we take the size of the preceding data extent as the basis * for the preallocation size. If the size of the extent is greater than * half the maximum extent length, then use the current offset as the * basis. This ensures that for large files the preallocation size * always extends to MAXEXTLEN rather than falling short due to things * like stripe unit/width alignment of real extents. */ if (prev.br_blockcount <= (MAXEXTLEN >> 1)) alloc_blocks = prev.br_blockcount << 1; else alloc_blocks = XFS_B_TO_FSB(mp, offset); if (!alloc_blocks) goto check_writeio; qblocks = alloc_blocks; /* * MAXEXTLEN is not a power of two value but we round the prealloc down * to the nearest power of two value after throttling. To prevent the * round down from unconditionally reducing the maximum supported prealloc * size, we round up first, apply appropriate throttling, round down and * cap the value to MAXEXTLEN. */ alloc_blocks = XFS_FILEOFF_MIN(roundup_pow_of_two(MAXEXTLEN), alloc_blocks); freesp = percpu_counter_read_positive(&mp->m_fdblocks); if (freesp < mp->m_low_space[XFS_LOWSP_5_PCNT]) { shift = 2; if (freesp < mp->m_low_space[XFS_LOWSP_4_PCNT]) shift++; if (freesp < mp->m_low_space[XFS_LOWSP_3_PCNT]) shift++; if (freesp < mp->m_low_space[XFS_LOWSP_2_PCNT]) shift++; if (freesp < mp->m_low_space[XFS_LOWSP_1_PCNT]) shift++; } /* * Check each quota to cap the prealloc size, provide a shift value to * throttle with and adjust amount of available space. */ if (xfs_quota_need_throttle(ip, XFS_DQ_USER, alloc_blocks)) xfs_quota_calc_throttle(ip, XFS_DQ_USER, &qblocks, &qshift, &freesp); if (xfs_quota_need_throttle(ip, XFS_DQ_GROUP, alloc_blocks)) xfs_quota_calc_throttle(ip, XFS_DQ_GROUP, &qblocks, &qshift, &freesp); if (xfs_quota_need_throttle(ip, XFS_DQ_PROJ, alloc_blocks)) xfs_quota_calc_throttle(ip, XFS_DQ_PROJ, &qblocks, &qshift, &freesp); /* * The final prealloc size is set to the minimum of free space available * in each of the quotas and the overall filesystem. * * The shift throttle value is set to the maximum value as determined by * the global low free space values and per-quota low free space values. */ alloc_blocks = MIN(alloc_blocks, qblocks); shift = MAX(shift, qshift); if (shift) alloc_blocks >>= shift; /* * rounddown_pow_of_two() returns an undefined result if we pass in * alloc_blocks = 0. */ if (alloc_blocks) alloc_blocks = rounddown_pow_of_two(alloc_blocks); if (alloc_blocks > MAXEXTLEN) alloc_blocks = MAXEXTLEN; /* * If we are still trying to allocate more space than is * available, squash the prealloc hard. This can happen if we * have a large file on a small filesystem and the above * lowspace thresholds are smaller than MAXEXTLEN. */ while (alloc_blocks && alloc_blocks >= freesp) alloc_blocks >>= 4; check_writeio: if (alloc_blocks < mp->m_writeio_blocks) alloc_blocks = mp->m_writeio_blocks; trace_xfs_iomap_prealloc_size(ip, alloc_blocks, shift, mp->m_writeio_blocks); return alloc_blocks; }

Contributors

PersonTokensPropCommitsCommitProp
brian fosterbrian foster16934.63%646.15%
christoph hellwigchristoph hellwig16533.81%323.08%
dave chinnerdave chinner14930.53%323.08%
david chinnerdavid chinner51.02%17.69%
Total488100.00%13100.00%


static int xfs_file_iomap_begin_delay( struct inode *inode, loff_t offset, loff_t count, unsigned flags, struct iomap *iomap) { struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK); xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); xfs_fileoff_t maxbytes_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes); xfs_fileoff_t end_fsb; int error = 0, eof = 0; struct xfs_bmbt_irec got; xfs_extnum_t idx; xfs_fsblock_t prealloc_blocks = 0; ASSERT(!XFS_IS_REALTIME_INODE(ip)); ASSERT(!xfs_get_extsz_hint(ip)); xfs_ilock(ip, XFS_ILOCK_EXCL); if (unlikely(XFS_TEST_ERROR( (XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_EXTENTS && XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_BTREE), mp, XFS_ERRTAG_BMAPIFORMAT, XFS_RANDOM_BMAPIFORMAT))) { XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp); error = -EFSCORRUPTED; goto out_unlock; } XFS_STATS_INC(mp, xs_blk_mapw); if (!(ifp->if_flags & XFS_IFEXTENTS)) { error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK); if (error) goto out_unlock; } eof = !xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got); if (!eof && got.br_startoff <= offset_fsb) { if (xfs_is_reflink_inode(ip)) { bool shared; end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb); xfs_trim_extent(&got, offset_fsb, end_fsb - offset_fsb); error = xfs_reflink_reserve_cow(ip, &got, &shared); if (error) goto out_unlock; } trace_xfs_iomap_found(ip, offset, count, 0, &got); goto done; } error = xfs_qm_dqattach_locked(ip, 0); if (error) goto out_unlock; /* * We cap the maximum length we map here to MAX_WRITEBACK_PAGES pages * to keep the chunks of work done where somewhat symmetric with the * work writeback does. This is a completely arbitrary number pulled * out of thin air as a best guess for initial testing. * * Note that the values needs to be less than 32-bits wide until * the lower level functions are updated. */ count = min_t(loff_t, count, 1024 * PAGE_SIZE); end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb); if (eof) { prealloc_blocks = xfs_iomap_prealloc_size(ip, offset, count, idx); if (prealloc_blocks) { xfs_extlen_t align; xfs_off_t end_offset; xfs_fileoff_t p_end_fsb; end_offset = XFS_WRITEIO_ALIGN(mp, offset + count - 1); p_end_fsb = XFS_B_TO_FSBT(mp, end_offset) + prealloc_blocks; align = xfs_eof_alignment(ip, 0); if (align) p_end_fsb = roundup_64(p_end_fsb, align); p_end_fsb = min(p_end_fsb, maxbytes_fsb); ASSERT(p_end_fsb > offset_fsb); prealloc_blocks = p_end_fsb - end_fsb; } } retry: error = xfs_bmapi_reserve_delalloc(ip, XFS_DATA_FORK, offset_fsb, end_fsb - offset_fsb, prealloc_blocks, &got, &idx, eof); switch (error) { case 0: break; case -ENOSPC: case -EDQUOT: /* retry without any preallocation */ trace_xfs_delalloc_enospc(ip, offset, count); if (prealloc_blocks) { prealloc_blocks = 0; goto retry; } /*FALLTHRU*/ default: goto out_unlock; } trace_xfs_iomap_alloc(ip, offset, count, 0, &got); done: if (isnullstartblock(got.br_startblock)) got.br_startblock = DELAYSTARTBLOCK; if (!got.br_startblock) { error = xfs_alert_fsblock_zero(ip, &got); if (error) goto out_unlock; } xfs_bmbt_to_iomap(ip, iomap, &got); out_unlock: xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig40464.33%414.81%
nathan scottnathan scott619.71%311.11%
stephen lordstephen lord406.37%27.41%
dave chinnerdave chinner375.89%622.22%
brian fosterbrian foster325.10%311.11%
john krueger* (same as john keller?)*john krueger* (same as john keller?)*243.82%27.41%
glen overbyglen overby142.23%13.70%
eric sandeeneric sandeen60.96%27.41%
david chinnerdavid chinner40.64%27.41%
lachlan mcilroylachlan mcilroy40.64%13.70%
darrick j. wongdarrick j. wong20.32%13.70%
Total628100.00%27100.00%

/* * Pass in a delayed allocate extent, convert it to real extents; * return to the caller the extent we create which maps on top of * the originating callers request. * * Called without a lock on the inode. * * We no longer bother to look at the incoming map - all we have to * guarantee is that whatever we allocate fills the required range. */
int xfs_iomap_write_allocate( xfs_inode_t *ip, int whichfork, xfs_off_t offset, xfs_bmbt_irec_t *imap) { xfs_mount_t *mp = ip->i_mount; xfs_fileoff_t offset_fsb, last_block; xfs_fileoff_t end_fsb, map_start_fsb; xfs_fsblock_t first_block; struct xfs_defer_ops dfops; xfs_filblks_t count_fsb; xfs_trans_t *tp; int nimaps; int error = 0; int flags = XFS_BMAPI_DELALLOC; int nres; if (whichfork == XFS_COW_FORK) flags |= XFS_BMAPI_COWFORK; /* * Make sure that the dquots are there. */ error = xfs_qm_dqattach(ip, 0); if (error) return error; offset_fsb = XFS_B_TO_FSBT(mp, offset); count_fsb = imap->br_blockcount; map_start_fsb = imap->br_startoff; XFS_STATS_ADD(mp, xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb)); while (count_fsb != 0) { /* * Set up a transaction with which to allocate the * backing store for the file. Do allocations in a * loop until we get some space in the range we are * interested in. The other space that might be allocated * is in the delayed allocation extent on which we sit * but before our buffer starts. */ nimaps = 0; while (nimaps == 0) { nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); /* * We have already reserved space for the extent and any * indirect blocks when creating the delalloc extent, * there is no need to reserve space in this transaction * again. */ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, XFS_TRANS_RESERVE, &tp); if (error) return error; xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); xfs_defer_init(&dfops, &first_block); /* * it is possible that the extents have changed since * we did the read call as we dropped the ilock for a * while. We have to be careful about truncates or hole * punchs here - we are not allowed to allocate * non-delalloc blocks here. * * The only protection against truncation is the pages * for the range we are being asked to convert are * locked and hence a truncate will block on them * first. * * As a result, if we go beyond the range we really * need and hit an delalloc extent boundary followed by * a hole while we have excess blocks in the map, we * will fill the hole incorrectly and overrun the * transaction reservation. * * Using a single map prevents this as we are forced to * check each map we look for overlap with the desired * range and abort as soon as we find it. Also, given * that we only return a single map, having one beyond * what we can return is probably a bit silly. * * We also need to check that we don't go beyond EOF; * this is a truncate optimisation as a truncate sets * the new file size before block on the pages we * currently have locked under writeback. Because they * are about to be tossed, we don't need to write them * back.... */ nimaps = 1; end_fsb = XFS_B_TO_FSB(mp, XFS_ISIZE(ip)); error = xfs_bmap_last_offset(ip, &last_block, XFS_DATA_FORK); if (error) goto trans_cancel; last_block = XFS_FILEOFF_MAX(last_block, end_fsb); if ((map_start_fsb + count_fsb) > last_block) { count_fsb = last_block - map_start_fsb; if (count_fsb == 0) { error = -EAGAIN; goto trans_cancel; } } /* * From this point onwards we overwrite the imap * pointer that the caller gave to us. */ error = xfs_bmapi_write(tp, ip, map_start_fsb, count_fsb, flags, &first_block, nres, imap, &nimaps, &dfops); if (error) goto trans_cancel; error = xfs_defer_finish(&tp, &dfops, NULL); if (error) goto trans_cancel; error = xfs_trans_commit(tp); if (error) goto error0; xfs_iunlock(ip, XFS_ILOCK_EXCL); } /* * See if we were able to allocate an extent that * covers at least part of the callers request */ if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) return xfs_alert_fsblock_zero(ip, imap); if ((offset_fsb >= imap->br_startoff) && (offset_fsb < (imap->br_startoff + imap->br_blockcount))) { XFS_STATS_INC(mp, xs_xstrat_quick); return 0; } /* * So far we have not mapped the requested part of the * file, just surrounding data, try again. */ count_fsb -= imap->br_blockcount; map_start_fsb = imap->br_startoff + imap->br_blockcount; } trans_cancel: xfs_defer_cancel(&dfops); xfs_trans_cancel(tp); error0: xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; }

Contributors

PersonTokensPropCommitsCommitProp
stephen lordstephen lord32769.13%26.90%
christoph hellwigchristoph hellwig316.55%827.59%
darrick j. wongdarrick j. wong285.92%310.34%
glen overbyglen overby265.50%13.45%
nathan scottnathan scott183.81%310.34%
david chinnerdavid chinner183.81%310.34%
eric sandeeneric sandeen102.11%26.90%
jeff liujeff liu51.06%13.45%
bill o'donnellbill o'donnell40.85%13.45%
dave chinnerdave chinner40.85%310.34%
lachlan mcilroylachlan mcilroy10.21%13.45%
brian fosterbrian foster10.21%13.45%
Total473100.00%29100.00%


int xfs_iomap_write_unwritten( xfs_inode_t *ip, xfs_off_t offset, xfs_off_t count) { xfs_mount_t *mp = ip->i_mount; xfs_fileoff_t offset_fsb; xfs_filblks_t count_fsb; xfs_filblks_t numblks_fsb; xfs_fsblock_t firstfsb; int nimaps; xfs_trans_t *tp; xfs_bmbt_irec_t imap; struct xfs_defer_ops dfops; xfs_fsize_t i_size; uint resblks; int error; trace_xfs_unwritten_convert(ip, offset, count); offset_fsb = XFS_B_TO_FSBT(mp, offset); count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count); count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb); /* * Reserve enough blocks in this transaction for two complete extent * btree splits. We may be converting the middle part of an unwritten * extent and in this case we will insert two new extents in the btree * each of which could cause a full split. * * This reservation amount will be used in the first call to * xfs_bmbt_split() to select an AG with enough space to satisfy the * rest of the operation. */ resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1; do { /* * Set up a transaction to convert the range of extents * from unwritten to real. Do allocations in a loop until * we have covered the range passed in. * * Note that we can't risk to recursing back into the filesystem * here as we might be asked to write out the same inode that we * complete here and might deadlock on the iolock. */ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, XFS_TRANS_RESERVE | XFS_TRANS_NOFS, &tp); if (error) return error; xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); /* * Modify the unwritten extent state of the buffer. */ xfs_defer_init(&dfops, &firstfsb); nimaps = 1; error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, XFS_BMAPI_CONVERT, &firstfsb, resblks, &imap, &nimaps, &dfops); if (error) goto error_on_bmapi_transaction; /* * Log the updated inode size as we go. We have to be careful * to only log it up to the actual write offset if it is * halfway into a block. */ i_size = XFS_FSB_TO_B(mp, offset_fsb + count_fsb); if (i_size > offset + count) i_size = offset + count; i_size = xfs_new_eof(ip, i_size); if (i_size) { ip->i_d.di_size = i_size; xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); } error = xfs_defer_finish(&tp, &dfops, NULL); if (error) goto error_on_bmapi_transaction; error = xfs_trans_commit(tp); xfs_iunlock(ip, XFS_ILOCK_EXCL); if (error) return error; if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) return xfs_alert_fsblock_zero(ip, &imap); if ((numblks_fsb = imap.br_blockcount) == 0) { /* * The numblks_fsb value should always get * smaller, otherwise the loop is stuck. */ ASSERT(imap.br_blockcount); break; } offset_fsb += numblks_fsb; count_fsb -= numblks_fsb; } while (count_fsb > 0); return 0; error_on_bmapi_transaction: xfs_defer_cancel(&dfops); xfs_trans_cancel(tp); xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; }

Contributors

PersonTokensPropCommitsCommitProp
stephen lordstephen lord23357.96%28.00%
christoph hellwigchristoph hellwig7618.91%624.00%
nathan scottnathan scott5714.18%520.00%
eric sandeeneric sandeen133.23%312.00%
darrick j. wongdarrick j. wong102.49%28.00%
jeff liujeff liu61.49%14.00%
lachlan mcilroylachlan mcilroy20.50%28.00%
david chinnerdavid chinner20.50%14.00%
dave chinnerdave chinner20.50%28.00%
brian fosterbrian foster10.25%14.00%
Total402100.00%25100.00%


static inline bool imap_needs_alloc(struct inode *inode, struct xfs_bmbt_irec *imap, int nimaps) { return !nimaps || imap->br_startblock == HOLESTARTBLOCK || imap->br_startblock == DELAYSTARTBLOCK || (IS_DAX(inode) && ISUNWRITTEN(imap)); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig48100.00%2100.00%
Total48100.00%2100.00%


static inline bool need_excl_ilock(struct xfs_inode *ip, unsigned flags) { /* * COW writes will allocate delalloc space, so we need to make sure * to take the lock exclusively here. */ if (xfs_is_reflink_inode(ip) && (flags & (IOMAP_WRITE | IOMAP_ZERO))) return true; if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE)) return true; return false; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig56100.00%1100.00%
Total56100.00%1100.00%


static int xfs_file_iomap_begin( struct inode *inode, loff_t offset, loff_t length, unsigned flags, struct iomap *iomap) { struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; struct xfs_bmbt_irec imap; xfs_fileoff_t offset_fsb, end_fsb; int nimaps = 1, error = 0; bool shared = false, trimmed = false; unsigned lockmode; if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; if (((flags & (IOMAP_WRITE | IOMAP_DIRECT)) == IOMAP_WRITE) && !IS_DAX(inode) && !xfs_get_extsz_hint(ip)) { /* Reserve delalloc blocks for regular writeback. */ return xfs_file_iomap_begin_delay(inode, offset, length, flags, iomap); } if (need_excl_ilock(ip, flags)) { lockmode = XFS_ILOCK_EXCL; xfs_ilock(ip, XFS_ILOCK_EXCL); } else { lockmode = xfs_ilock_data_map_shared(ip); } ASSERT(offset <= mp->m_super->s_maxbytes); if ((xfs_fsize_t)offset + length > mp->m_super->s_maxbytes) length = mp->m_super->s_maxbytes - offset; offset_fsb = XFS_B_TO_FSBT(mp, offset); end_fsb = XFS_B_TO_FSB(mp, offset + length); if (xfs_is_reflink_inode(ip) && (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT)) { shared = xfs_reflink_find_cow_mapping(ip, offset, &imap); if (shared) { xfs_iunlock(ip, lockmode); goto alloc_done; } ASSERT(!isnullstartblock(imap.br_startblock)); } error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap, &nimaps, 0); if (error) goto out_unlock; if ((flags & IOMAP_REPORT) || (xfs_is_reflink_inode(ip) && (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT))) { /* Trim the mapping to the nearest shared extent boundary. */ error = xfs_reflink_trim_around_shared(ip, &imap, &shared, &trimmed); if (error) goto out_unlock; /* * We're here because we're trying to do a directio write to a * region that isn't aligned to a filesystem block. If the * extent is shared, fall back to buffered mode to handle the * RMW. */ if (!(flags & IOMAP_REPORT) && shared) { trace_xfs_reflink_bounce_dio_write(ip, &imap); error = -EREMCHG; goto out_unlock; } } if ((flags & (IOMAP_WRITE | IOMAP_ZERO)) && xfs_is_reflink_inode(ip)) { error = xfs_reflink_reserve_cow(ip, &imap, &shared); if (error) goto out_unlock; end_fsb = imap.br_startoff + imap.br_blockcount; length = XFS_FSB_TO_B(mp, end_fsb) - offset; } if ((flags & IOMAP_WRITE) && imap_needs_alloc(inode, &imap, nimaps)) { /* * We cap the maximum length we map here to MAX_WRITEBACK_PAGES * pages to keep the chunks of work done where somewhat symmetric * with the work writeback does. This is a completely arbitrary * number pulled out of thin air as a best guess for initial * testing. * * Note that the values needs to be less than 32-bits wide until * the lower level functions are updated. */ length = min_t(loff_t, length, 1024 * PAGE_SIZE); /* * xfs_iomap_write_direct() expects the shared lock. It * is unlocked on return. */ if (lockmode == XFS_ILOCK_EXCL) xfs_ilock_demote(ip, lockmode); error = xfs_iomap_write_direct(ip, offset, length, &imap, nimaps); if (error) return error; alloc_done: iomap->flags = IOMAP_F_NEW; trace_xfs_iomap_alloc(ip, offset, length, 0, &imap); } else { ASSERT(nimaps); xfs_iunlock(ip, lockmode); trace_xfs_iomap_found(ip, offset, length, 0, &imap); } xfs_bmbt_to_iomap(ip, iomap, &imap); if (shared) iomap->flags |= IOMAP_F_SHARED; return 0; out_unlock: xfs_iunlock(ip, lockmode); return error; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig55391.25%981.82%
darrick j. wongdarrick j. wong538.75%218.18%
Total606100.00%11100.00%


static int xfs_file_iomap_end_delalloc( struct xfs_inode *ip, loff_t offset, loff_t length, ssize_t written) { struct xfs_mount *mp = ip->i_mount; xfs_fileoff_t start_fsb; xfs_fileoff_t end_fsb; int error = 0; start_fsb = XFS_B_TO_FSB(mp, offset + written); end_fsb = XFS_B_TO_FSB(mp, offset + length); /* * Trim back delalloc blocks if we didn't manage to write the whole * range reserved. * * We don't need to care about racing delalloc as we hold i_mutex * across the reserve/allocate/unreserve calls. If there are delalloc * blocks in the range, they are ours. */ if (start_fsb < end_fsb) { xfs_ilock(ip, XFS_ILOCK_EXCL); error = xfs_bmap_punch_delalloc_range(ip, start_fsb, end_fsb - start_fsb); xfs_iunlock(ip, XFS_ILOCK_EXCL); if (error && !XFS_FORCED_SHUTDOWN(mp)) { xfs_alert(mp, "%s: unable to clean up ino %lld", __func__, ip->i_ino); return error; } } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig129100.00%1100.00%
Total129100.00%1100.00%


static int xfs_file_iomap_end( struct inode *inode, loff_t offset, loff_t length, ssize_t written, unsigned flags, struct iomap *iomap) { if ((flags & IOMAP_WRITE) && iomap->type == IOMAP_DELALLOC) return xfs_file_iomap_end_delalloc(XFS_I(inode), offset, length, written); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig60100.00%1100.00%
Total60100.00%1100.00%

struct iomap_ops xfs_iomap_ops = { .iomap_begin = xfs_file_iomap_begin, .iomap_end = xfs_file_iomap_end, };
static int xfs_xattr_iomap_begin( struct inode *inode, loff_t offset, loff_t length, unsigned flags, struct iomap *iomap) { struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + length); struct xfs_bmbt_irec imap; int nimaps = 1, error = 0; unsigned lockmode; if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; lockmode = xfs_ilock_data_map_shared(ip); /* if there are no attribute fork or extents, return ENOENT */ if (XFS_IFORK_Q(ip) || !ip->i_d.di_anextents) { error = -ENOENT; goto out_unlock; } ASSERT(ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL); error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap, &nimaps, XFS_BMAPI_ENTIRE | XFS_BMAPI_ATTRFORK); out_unlock: xfs_iunlock(ip, lockmode); if (!error) { ASSERT(nimaps); xfs_bmbt_to_iomap(ip, iomap, &imap); } return error; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig193100.00%1100.00%
Total193100.00%1100.00%

struct iomap_ops xfs_xattr_iomap_ops = { .iomap_begin = xfs_xattr_iomap_begin, };

Overall Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig205045.34%2828.00%
stephen lordstephen lord84218.62%22.00%
nathan scottnathan scott53911.92%88.00%
brian fosterbrian foster4259.40%1111.00%
dave chinnerdave chinner3166.99%1919.00%
darrick j. wongdarrick j. wong1092.41%77.00%
eric sandeeneric sandeen511.13%66.00%
glen overbyglen overby400.88%22.00%
david chinnerdavid chinner350.77%77.00%
john krueger* (same as john keller?)*john krueger* (same as john keller?)*320.71%33.00%
russell cattelanrussell cattelan300.66%11.00%
jeff liujeff liu170.38%11.00%
lachlan mcilroylachlan mcilroy170.38%33.00%
peter watkinspeter watkins140.31%11.00%
bill o'donnellbill o'donnell40.09%11.00%
Total4521100.00%100100.00%
Directory: fs/xfs
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