[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/fs/xfs/xfs_iomap.c b/src/kernel/linux/v4.14/fs/xfs/xfs_iomap.c
new file mode 100644
index 0000000..f179bdf
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/xfs/xfs_iomap.c
@@ -0,0 +1,1222 @@
+/*
+ * 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));
+ iomap->dax_dev = xfs_find_daxdev_for_inode(VFS_I(ip));
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+ 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 = xfs_aligned_fsb_count(offset_fsb, count_fsb, extsz);
+
+ 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 (imap->br_state == XFS_EXT_UNWRITTEN) {
+ 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);
+ 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;
+}
+
+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;
+}
+
+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;
+ }
+}
+
+/*
+ * 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;
+}
+
+static int
+xfs_file_iomap_begin_delay(
+ struct inode *inode,
+ loff_t offset,
+ loff_t count,
+ 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_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;
+ }
+
+ /*
+ * Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch
+ * them out if the write happens to fail.
+ */
+ iomap->flags = IOMAP_F_NEW;
+ 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;
+}
+
+/*
+ * 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 | XFS_BMAPI_PREALLOC;
+
+ /*
+ * 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);
+ 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;
+}
+
+int
+xfs_iomap_write_unwritten(
+ xfs_inode_t *ip,
+ xfs_off_t offset,
+ xfs_off_t count,
+ bool update_isize)
+{
+ 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;
+ struct inode *inode = VFS_I(ip);
+ 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;
+ if (update_isize && i_size > i_size_read(inode))
+ i_size_write(inode, i_size);
+ 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);
+ 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;
+}
+
+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) && imap->br_state == XFS_EXT_UNWRITTEN);
+}
+
+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;
+}
+
+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, 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);
+ }
+
+ if ((flags & IOMAP_NOWAIT) && !(ip->i_df.if_flags & XFS_IFEXTENTS)) {
+ error = -EAGAIN;
+ goto out_unlock;
+ }
+
+ 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);
+
+ error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
+ &nimaps, 0);
+ if (error)
+ goto out_unlock;
+
+ if (flags & IOMAP_REPORT) {
+ /* Trim the mapping to the nearest shared extent boundary. */
+ error = xfs_reflink_trim_around_shared(ip, &imap, &shared,
+ &trimmed);
+ if (error)
+ goto out_unlock;
+ }
+
+ if ((flags & (IOMAP_WRITE | IOMAP_ZERO)) && xfs_is_reflink_inode(ip)) {
+ if (flags & IOMAP_DIRECT) {
+ /*
+ * A reflinked inode will result in CoW alloc.
+ * FIXME: It could still overwrite on unshared extents
+ * and not need allocation.
+ */
+ if (flags & IOMAP_NOWAIT) {
+ error = -EAGAIN;
+ goto out_unlock;
+ }
+ /* may drop and re-acquire the ilock */
+ error = xfs_reflink_allocate_cow(ip, &imap, &shared,
+ &lockmode);
+ if (error)
+ goto out_unlock;
+ } else {
+ 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)) {
+ /*
+ * If nowait is set bail since we are going to make
+ * allocations.
+ */
+ if (flags & IOMAP_NOWAIT) {
+ error = -EAGAIN;
+ 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.
+ */
+ 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;
+
+ 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;
+}
+
+static int
+xfs_file_iomap_end_delalloc(
+ struct xfs_inode *ip,
+ loff_t offset,
+ loff_t length,
+ ssize_t written,
+ struct iomap *iomap)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ xfs_fileoff_t start_fsb;
+ xfs_fileoff_t end_fsb;
+ int error = 0;
+
+ /*
+ * Behave as if the write failed if drop writes is enabled. Set the NEW
+ * flag to force delalloc cleanup.
+ */
+ if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_DROP_WRITES)) {
+ iomap->flags |= IOMAP_F_NEW;
+ written = 0;
+ }
+
+ /*
+ * start_fsb refers to the first unused block after a short write. If
+ * nothing was written, round offset down to point at the first block in
+ * the range.
+ */
+ if (unlikely(!written))
+ start_fsb = XFS_B_TO_FSBT(mp, offset);
+ else
+ start_fsb = XFS_B_TO_FSB(mp, offset + written);
+ end_fsb = XFS_B_TO_FSB(mp, offset + length);
+
+ /*
+ * Trim delalloc blocks if they were allocated by this write and we
+ * didn't manage to write the whole range.
+ *
+ * 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 ((iomap->flags & IOMAP_F_NEW) && start_fsb < end_fsb) {
+ truncate_pagecache_range(VFS_I(ip), XFS_FSB_TO_B(mp, start_fsb),
+ XFS_FSB_TO_B(mp, end_fsb) - 1);
+
+ 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;
+}
+
+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, iomap);
+ return 0;
+}
+
+const 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_attr_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;
+}
+
+const struct iomap_ops xfs_xattr_iomap_ops = {
+ .iomap_begin = xfs_xattr_iomap_begin,
+};