// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2006 Silicon Graphics, Inc.
* Copyright (c) 2016-2018 Christoph Hellwig.
* All Rights Reserved.
*/
#include "xfs_platform.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_inode.h"
#include "xfs_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_bmap.h"
#include "xfs_bmap_util.h"
#include "xfs_errortag.h"
#include "xfs_error.h"
#include "xfs_trans.h"
#include "xfs_trans_space.h"
#include "xfs_inode_item.h"
#include "xfs_iomap.h"
#include "xfs_trace.h"
#include "xfs_quota.h"
#include "xfs_rtgroup.h"
#include "xfs_dquot_item.h"
#include "xfs_dquot.h"
#include "xfs_reflink.h"
#include "xfs_health.h"
#include "xfs_rtbitmap.h"
#include "xfs_icache.h"
#include "xfs_zone_alloc.h"
#define XFS_ALLOC_ALIGN(mp, off) \
(((off) >> mp->m_allocsize_log) << mp->m_allocsize_log)
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)I_INO(ip),
(unsigned long long)imap->br_startblock,
(unsigned long long)imap->br_startoff,
(unsigned long long)imap->br_blockcount,
imap->br_state);
xfs_bmap_mark_sick(ip, XFS_DATA_FORK);
return -EFSCORRUPTED;
}
u64
xfs_iomap_inode_sequence(
struct xfs_inode *ip,
u16 iomap_flags)
{
u64 cookie = 0;
if (iomap_flags & IOMAP_F_XATTR)
return READ_ONCE(ip->i_af.if_seq);
if ((iomap_flags & IOMAP_F_SHARED) && ip->i_cowfp)
cookie = (u64)READ_ONCE(ip->i_cowfp->if_seq) << 32;
return cookie | READ_ONCE(ip->i_df.if_seq);
}
/*
* Check that the iomap passed to us is still valid for the given offset and
* length.
*/
static bool
xfs_iomap_valid(
struct inode *inode,
const struct iomap *iomap)
{
struct xfs_inode *ip = XFS_I(inode);
if (iomap->type == IOMAP_HOLE)
return true;
if (iomap->validity_cookie !=
xfs_iomap_inode_sequence(ip, iomap->flags)) {
trace_xfs_iomap_invalid(ip, iomap);
return false;
}
XFS_ERRORTAG_DELAY(ip->i_mount, XFS_ERRTAG_WRITE_DELAY_MS);
return true;
}
const struct iomap_write_ops xfs_iomap_write_ops = {
.iomap_valid = xfs_iomap_valid,
};
int
xfs_bmbt_to_iomap(
struct xfs_inode *ip,
struct iomap *iomap,
struct xfs_bmbt_irec *imap,
unsigned int mapping_flags,
u16 iomap_flags,
u64 sequence_cookie)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_buftarg *target = xfs_inode_buftarg(ip);
if (unlikely(!xfs_valid_startblock(ip, imap->br_startblock))) {
xfs_bmap_mark_sick(ip, XFS_DATA_FORK);
return xfs_alert_fsblock_zero(ip, imap);
}
iomap->flags = iomap_flags;
if (imap->br_startblock == HOLESTARTBLOCK) {
iomap->addr = IOMAP_NULL_ADDR;
iomap->type = IOMAP_HOLE;
} else if (imap->br_startblock == DELAYSTARTBLOCK ||
isnullstartblock(imap->br_startblock)) {
iomap->addr = IOMAP_NULL_ADDR;
iomap->type = IOMAP_DELALLOC;
} else {
xfs_daddr_t daddr = xfs_fsb_to_db(ip, imap->br_startblock);
iomap->addr = BBTOB(daddr);
if (mapping_flags & IOMAP_DAX)
iomap->addr += target->bt_dax_part_off;
if (imap->br_state == XFS_EXT_UNWRITTEN)
iomap->type = IOMAP_UNWRITTEN;
else
iomap->type = IOMAP_MAPPED;
/*
* Mark iomaps starting at the first sector of a RTG as merge
* boundary so that each I/O completions is contained to a
* single RTG.
*/
if (XFS_IS_REALTIME_INODE(ip) && xfs_has_rtgroups(mp) &&
xfs_rtbno_is_group_start(mp, imap->br_startblock))
iomap->flags |= IOMAP_F_BOUNDARY;
}
iomap->offset = XFS_FSB_TO_B(mp, imap->br_startoff);
iomap->length = XFS_FSB_TO_B(mp, imap->br_blockcount);
if (mapping_flags & IOMAP_DAX) {
iomap->dax_dev = target->bt_daxdev;
} else {
iomap->bdev = target->bt_bdev;
if (bdev_has_integrity_csum(iomap->bdev))
iomap->flags |= IOMAP_F_INTEGRITY;
}
/*
* If the inode is dirty for datasync purposes, let iomap know so it
* doesn't elide the IO completion journal flushes on O_DSYNC IO.
*/
if (ip->i_itemp) {
struct xfs_inode_log_item *iip = ip->i_itemp;
spin_lock(&iip->ili_lock);
if (iip->ili_datasync_seq)
iomap->flags |= IOMAP_F_DIRTY;
spin_unlock(&iip->ili_lock);
}
iomap->validity_cookie = sequence_cookie;
return 0;
}
static void
xfs_hole_to_iomap(
struct xfs_inode *ip,
struct iomap *iomap,
xfs_fileoff_t offset_fsb,
xfs_fileoff_t end_fsb)
{
struct xfs_buftarg *target = xfs_inode_buftarg(ip);
iomap->addr = IOMAP_NULL_ADDR;
iomap->type = IOMAP_HOLE;
iomap->offset = XFS_FSB_TO_B(ip->i_mount, offset_fsb);
iomap->length = XFS_FSB_TO_B(ip->i_mount, end_fsb - offset_fsb);
iomap->bdev = target->bt_bdev;
iomap->dax_dev = target->bt_daxdev;
}
static inline xfs_fileoff_t
xfs_iomap_end_fsb(
struct xfs_mount *mp,
loff_t offset,
loff_t count)
{
ASSERT(offset <= mp->m_super->s_maxbytes);
return min(XFS_B_TO_FSB(mp, offset + count),
XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
}
static xfs_extlen_t
xfs_eof_alignment(
struct xfs_inode *ip)
{
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 && xfs_has_swalloc(mp))
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;
}
return align;
}
/*
* Check if last_fsb is outside the last extent, and if so grow it to the next
* stripe unit boundary.
*/
xfs_fileoff_t
xfs_iomap_eof_align_last_fsb(
struct xfs_inode *ip,
xfs_fileoff_t end_fsb)
{
struct xfs_ifork *ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
xfs_extlen_t extsz = xfs_get_extsz_hint(ip);
xfs_extlen_t align = xfs_eof_alignment(ip);
struct xfs_bmbt_irec irec;
struct xfs_iext_cursor icur;
ASSERT(!xfs_need_iread_extents(ifp));
/*
* Always round up the allocation request to the extent hint boundary.
*/
if (extsz) {
if (align)
align = roundup_64(align, extsz);
else
align = extsz;
}
if (align) {
xfs_fileoff_t aligned_end_fsb = roundup_64(end_fsb, align);
xfs_iext_last(ifp, &icur);
if (!xfs_iext_get_extent(ifp, &icur, &irec) ||
aligned_end_fsb >= irec.br_startoff + irec.br_blockcount)
return aligned_end_fsb;
}
return end_fsb;
}
int
xfs_iomap_write_direct(
struct xfs_inode *ip,
xfs_fileoff_t offset_fsb,
xfs_fileoff_t count_fsb,
unsigned int flags,
struct xfs_bmbt_irec *imap,
u64 *seq)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
xfs_filblks_t resaligned;
int nimaps;
unsigned int dblocks, rblocks;
bool force = false;
int error;
int bmapi_flags = XFS_BMAPI_PREALLOC;
int nr_exts = XFS_IEXT_ADD_NOSPLIT_CNT;
ASSERT(count_fsb > 0);
resaligned = xfs_aligned_fsb_count(offset_fsb, count_fsb,
xfs_get_extsz_hint(ip));
if (unlikely(XFS_IS_REALTIME_INODE(ip))) {
dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
rblocks = resaligned;
} else {
dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
rblocks = 0;
}
error = xfs_qm_dqattach(ip);
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 (flags & IOMAP_DAX) {
bmapi_flags = XFS_BMAPI_CONVERT | XFS_BMAPI_ZERO;
if (imap->br_state == XFS_EXT_UNWRITTEN) {
force = true;
nr_exts = XFS_IEXT_WRITE_UNWRITTEN_CNT;
dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
}
}
error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, dblocks,
rblocks, force, &tp);
if (error)
return error;
error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK, nr_exts);
if (error)
goto out_trans_cancel;
/*
* From this point onwards we overwrite the imap pointer that the
* caller gave to us.
*/
nimaps = 1;
error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, bmapi_flags, 0,
imap, &nimaps);
if (error)
goto out_trans_cancel;
/*
* Complete the transaction
*/
error = xfs_trans_commit(tp);
if (error)
goto out_unlock;
if (unlikely(!xfs_valid_startblock(ip, imap->br_startblock))) {
xfs_bmap_mark_sick(ip, XFS_DATA_FORK);
error = xfs_alert_fsblock_zero(ip, imap);
}
out_unlock:
*seq = xfs_iomap_inode_sequence(ip, 0);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return error;
out_trans_cancel:
xfs_trans_cancel(tp);
goto out_unlock;
}
STATIC bool
xfs_quota_need_throttle(
struct xfs_inode *ip,
xfs_dqtype_t type,
xfs_fsblock_t alloc_blocks)
{
struct xfs_dquot *dq = xfs_inode_dquot(ip, type);
struct xfs_dquot_res *res;
struct xfs_dquot_pre *pre;
if (!dq || !xfs_this_quota_on(ip->i_mount, type))
return false;
if (XFS_IS_REALTIME_INODE(ip)) {
res = &dq->q_rtb;
pre = &dq->q_rtb_prealloc;
} else {
res = &dq->q_blk;
pre = &dq->q_blk_prealloc;
}
/* no hi watermark, no throttle */
if (!pre->q_prealloc_hi_wmark)
return false;
/* under the lo watermark, no throttle */
if (res->reserved + alloc_blocks < pre->q_prealloc_lo_wmark)
return false;
return true;
}
STATIC void
xfs_quota_calc_throttle(
struct xfs_inode *ip,
xfs_dqtype_t type,
xfs_fsblock_t *qblocks,
int *qshift,
int64_t *qfreesp)
{
struct xfs_dquot *dq = xfs_inode_dquot(ip, type);
struct xfs_dquot_res *res;
struct xfs_dquot_pre *pre;
int64_t freesp;
int shift = 0;
if (!dq) {
res = NULL;
pre = NULL;
} else if (XFS_IS_REALTIME_INODE(ip)) {
res = &dq->q_rtb;
pre = &dq->q_rtb_prealloc;
} else {
res = &dq->q_blk;
pre = &dq->q_blk_prealloc;
}
/* no dq, or over hi wmark, squash the prealloc completely */
if (!res || res->reserved >= pre->q_prealloc_hi_wmark) {
*qblocks = 0;
*qfreesp = 0;
return;
}
freesp = pre->q_prealloc_hi_wmark - res->reserved;
if (freesp < pre->q_low_space[XFS_QLOWSP_5_PCNT]) {
shift = 2;
if (freesp < pre->q_low_space[XFS_QLOWSP_3_PCNT])
shift += 2;
if (freesp < pre->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;
}
}
static int64_t
xfs_iomap_freesp(
struct xfs_mount *mp,
unsigned int idx,
uint64_t low_space[XFS_LOWSP_MAX],
int *shift)
{
int64_t freesp;
freesp = xfs_estimate_freecounter(mp, idx);
if (freesp < low_space[XFS_LOWSP_5_PCNT]) {
*shift = 2;
if (freesp < low_space[XFS_LOWSP_4_PCNT])
(*shift)++;
if (freesp < low_space[XFS_LOWSP_3_PCNT])
(*shift)++;
if (freesp < low_space[XFS_LOWSP_2_PCNT])
(*shift)++;
if (freesp < low_space[XFS_LOWSP_1_PCNT])
(*shift)++;
}
return freesp;
}
/*
* 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 being full, the smaller the maximum preallocation.
*/
STATIC xfs_fsblock_t
xfs_iomap_prealloc_size(
struct xfs_inode *ip,
int whichfork,
loff_t offset,
loff_t count,
struct xfs_iext_cursor *icur)
{
struct xfs_iext_cursor ncur = *icur;
struct xfs_bmbt_irec prev, got;
struct xfs_mount *mp = ip->i_mount;
struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
int64_t freesp;
xfs_fsblock_t qblocks;
xfs_fsblock_t alloc_blocks = 0;
xfs_extlen_t plen;
int shift = 0;
int qshift = 0;
/*
* 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.
*/
if (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_allocsize_blocks))
return 0;
/*
* Use the minimum preallocation size for small files or if we are
* writing right after a hole.
*/
if (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign) ||
!xfs_iext_prev_extent(ifp, &ncur, &prev) ||
prev.br_startoff + prev.br_blockcount < offset_fsb)
return mp->m_allocsize_blocks;
/*
* Take the size of the preceding data extents as the basis for the
* preallocation size. Note that we don't care if the previous extents
* are written or not.
*/
plen = prev.br_blockcount;
while (xfs_iext_prev_extent(ifp, &ncur, &got)) {
if (plen > XFS_MAX_BMBT_EXTLEN / 2 ||
isnullstartblock(got.br_startblock) ||
got.br_startoff + got.br_blockcount != prev.br_startoff ||
got.br_startblock + got.br_blockcount != prev.br_startblock)
break;
plen += got.br_blockcount;
prev = got;
}
/*
* If the size of the extents 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
* XFS_BMBT_MAX_EXTLEN rather than falling short due to things like stripe
* unit/width alignment of real extents.
*/
alloc_blocks = plen * 2;
if (alloc_blocks > XFS_MAX_BMBT_EXTLEN)
alloc_blocks = XFS_B_TO_FSB(mp, offset);
qblocks = alloc_blocks;
/*
* XFS_BMBT_MAX_EXTLEN 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 XFS_BMBT_MAX_EXTLEN.
*/
alloc_blocks = XFS_FILEOFF_MIN(roundup_pow_of_two(XFS_MAX_BMBT_EXTLEN),
alloc_blocks);
if (unlikely(XFS_IS_REALTIME_INODE(ip)))
freesp = xfs_rtbxlen_to_blen(mp,
xfs_iomap_freesp(mp, XC_FREE_RTEXTENTS,
mp->m_low_rtexts, &shift));
else
freesp = xfs_iomap_freesp(mp, XC_FREE_BLOCKS, mp->m_low_space,
&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_DQTYPE_USER, alloc_blocks))
xfs_quota_calc_throttle(ip, XFS_DQTYPE_USER, &qblocks, &qshift,
&freesp);
if (xfs_quota_need_throttle(ip, XFS_DQTYPE_GROUP, alloc_blocks))
xfs_quota_calc_throttle(ip, XFS_DQTYPE_GROUP, &qblocks, &qshift,
&freesp);
if (xfs_quota_need_throttle(ip, XFS_DQTYPE_PROJ, alloc_blocks))
xfs_quota_calc_throttle(ip, XFS_DQTYPE_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 > XFS_MAX_BMBT_EXTLEN)
alloc_blocks = XFS_MAX_BMBT_EXTLEN;
/*
* 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 XFS_BMBT_MAX_EXTLEN.
*/
while (alloc_blocks && alloc_blocks >= freesp)
alloc_blocks >>= 4;
if (alloc_blocks < mp->m_allocsize_blocks)
alloc_blocks = mp->m_allocsize_blocks;
trace_xfs_iomap_prealloc_size(ip, alloc_blocks, shift,
mp->m_allocsize_blocks);
return alloc_blocks;
}
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;
int nimaps;
xfs_trans_t *tp;
xfs_bmbt_irec_t imap;
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;
/* Attach dquots so that bmbt splits are accounted correctly. */
error = xfs_qm_dqattach(ip);
if (error)
return error;
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_inode(ip, &M_RES(mp)->tr_write, resblks,
0, true, &tp);
if (error)
return error;
error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
XFS_IEXT_WRITE_UNWRITTEN_CNT);
if (error)
goto error_on_bmapi_transaction;
/*
* Modify the unwritten extent state of the buffer.
*/
nimaps = 1;
error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb,
XFS_BMAPI_CONVERT, resblks, &imap,
&nimaps);
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_disk_size = i_size;
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
}
error = xfs_trans_commit(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (error)
return error;
if (unlikely(!xfs_valid_startblock(ip, imap.br_startblock))) {
xfs_bmap_mark_sick(ip, XFS_DATA_FORK);
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_trans_cancel(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return error;
}
static inline bool
imap_needs_alloc(
struct inode *inode,
unsigned flags,
struct xfs_bmbt_irec *imap,
int nimaps)
{
/* don't allocate blocks when just zeroing */
if (flags & IOMAP_ZERO)
return false;
if (!nimaps ||
imap->br_startblock == HOLESTARTBLOCK ||
imap->br_startblock == DELAYSTARTBLOCK)
return true;
/* we convert unwritten extents before copying the data for DAX */
if ((flags & IOMAP_DAX) && imap->br_state == XFS_EXT_UNWRITTEN)
return true;
return false;
}
static inline bool
imap_needs_cow(
struct xfs_inode *ip,
unsigned int flags,
struct xfs_bmbt_irec *imap,
int nimaps)
{
if (!xfs_is_cow_inode(ip))
return false;
/* when zeroing we don't have to COW holes or unwritten extents */
if (flags & (IOMAP_UNSHARE | IOMAP_ZERO)) {
if (!nimaps ||
imap->br_startblock == HOLESTARTBLOCK ||
imap->br_state == XFS_EXT_UNWRITTEN)
return false;
}
return true;
}
/*
* Extents not yet cached requires exclusive access, don't block for
* IOMAP_NOWAIT.
*
* This is basically an opencoded xfs_ilock_data_map_shared() call, but with
* support for IOMAP_NOWAIT.
*/
static int
xfs_ilock_for_iomap(
struct xfs_inode *ip,
unsigned flags,
unsigned *lockmode)
{
if (flags & IOMAP_NOWAIT) {
if (xfs_need_iread_extents(&ip->i_df))
return -EAGAIN;
if (!xfs_ilock_nowait(ip, *lockmode))
return -EAGAIN;
} else {
if (xfs_need_iread_extents(&ip->i_df))
*lockmode = XFS_ILOCK_EXCL;
xfs_ilock(ip, *lockmode);
}
return 0;
}
/*
* Check that the imap we are going to return to the caller spans the entire
* range that the caller requested for the IO.
*/
static bool
imap_spans_range(
struct xfs_bmbt_irec *imap,
xfs_fileoff_t offset_fsb,
xfs_fileoff_t end_fsb)
{
if (imap->br_startoff > offset_fsb)
return false;
if (imap->br_startoff + imap->br_blockcount < end_fsb)
return false;
return true;
}
static bool
xfs_bmap_hw_atomic_write_possible(
struct xfs_inode *ip,
struct xfs_bmbt_irec *imap,
xfs_fileoff_t offset_fsb,
xfs_fileoff_t end_fsb)
{
struct xfs_mount *mp = ip->i_mount;
xfs_fsize_t len = XFS_FSB_TO_B(mp, end_fsb - offset_fsb);
/*
* atomic writes are required to be naturally aligned for disk blocks,
* which ensures that we adhere to block layer rules that we won't
* straddle any boundary or violate write alignment requirement.
*/
if (!IS_ALIGNED(imap->br_startblock, imap->br_blockcount))
return false;
/*
* Spanning multiple extents would mean that multiple BIOs would be
* issued, and so would lose atomicity required for REQ_ATOMIC-based
* atomics.
*/
if (!imap_spans_range(imap, offset_fsb, end_fsb))
return false;
/*
* The ->iomap_begin caller should ensure this, but check anyway.
*/
return len <= xfs_inode_buftarg(ip)->bt_awu_max;
}
static int
xfs_direct_write_iomap_begin(
struct inode *inode,
loff_t offset,
loff_t length,
unsigned flags,
struct iomap *iomap,
struct iomap *srcmap)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
struct xfs_bmbt_irec imap, cmap;
xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, length);
xfs_fileoff_t orig_end_fsb = end_fsb;
int nimaps = 1, error = 0;
bool shared = false;
u16 iomap_flags = 0;
bool needs_alloc;
unsigned int lockmode;
u64 seq;
ASSERT(flags & (IOMAP_WRITE | IOMAP_ZERO));
if (xfs_is_shutdown(mp))
return -EIO;
/*
* Writes that span EOF might trigger an IO size update on completion,
* so consider them to be dirty for the purposes of O_DSYNC even if
* there is no other metadata changes pending or have been made here.
*/
if (offset + length > i_size_read(inode))
iomap_flags |= IOMAP_F_DIRTY;
/* HW-offload atomics are always used in this path */
if (flags & IOMAP_ATOMIC)
iomap_flags |= IOMAP_F_ATOMIC_BIO;
/*
* COW writes may allocate delalloc space or convert unwritten COW
* extents, so we need to make sure to take the lock exclusively here.
*/
if (xfs_is_cow_inode(ip))
lockmode = XFS_ILOCK_EXCL;
else
lockmode = XFS_ILOCK_SHARED;
relock:
error = xfs_ilock_for_iomap(ip, flags, &lockmode);
if (error)
return error;
/*
* The reflink iflag could have changed since the earlier unlocked
* check, check if it again and relock if needed.
*/
if (xfs_is_cow_inode(ip) && lockmode == XFS_ILOCK_SHARED) {
xfs_iunlock(ip, lockmode);
lockmode = XFS_ILOCK_EXCL;
goto relock;
}
error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
&nimaps, 0);
if (error)
goto out_unlock;
if (imap_needs_cow(ip, flags, &imap, nimaps)) {
error = -EAGAIN;
if (flags & IOMAP_NOWAIT)
goto out_unlock;
/* may drop and re-acquire the ilock */
error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared,
&lockmode,
(flags & IOMAP_DIRECT) || IS_DAX(inode));
if (error)
goto out_unlock;
if (shared) {
if ((flags & IOMAP_ATOMIC) &&
!xfs_bmap_hw_atomic_write_possible(ip, &cmap,
offset_fsb, end_fsb)) {
error = -ENOPROTOOPT;
goto out_unlock;
}
goto out_found_cow;
}
end_fsb = imap.br_startoff + imap.br_blockcount;
length = XFS_FSB_TO_B(mp, end_fsb) - offset;
}
needs_alloc = imap_needs_alloc(inode, flags, &imap, nimaps);
if (flags & IOMAP_ATOMIC) {
error = -ENOPROTOOPT;
/*
* If we allocate less than what is required for the write
* then we may end up with multiple extents, which means that
* REQ_ATOMIC-based cannot be used, so avoid this possibility.
*/
if (needs_alloc && orig_end_fsb - offset_fsb > 1)
goto out_unlock;
if (!xfs_bmap_hw_atomic_write_possible(ip, &imap, offset_fsb,
orig_end_fsb))
goto out_unlock;
}
if (needs_alloc)
goto allocate_blocks;
/*
* NOWAIT and OVERWRITE I/O needs to span the entire requested I/O with
* a single map so that we avoid partial IO failures due to the rest of
* the I/O range not covered by this map triggering an EAGAIN condition
* when it is subsequently mapped and aborting the I/O.
*/
if (flags & (IOMAP_NOWAIT | IOMAP_OVERWRITE_ONLY)) {
error = -EAGAIN;
if (!imap_spans_range(&imap, offset_fsb, end_fsb))
goto out_unlock;
}
/*
* For overwrite only I/O, we cannot convert unwritten extents without
* requiring sub-block zeroing. This can only be done under an
* exclusive IOLOCK, hence return -EAGAIN if this is not a written
* extent to tell the caller to try again.
*/
if (flags & IOMAP_OVERWRITE_ONLY) {
error = -EAGAIN;
if (imap.br_state != XFS_EXT_NORM &&
((offset | length) & mp->m_blockmask))
goto out_unlock;
}
seq = xfs_iomap_inode_sequence(ip, iomap_flags);
xfs_iunlock(ip, lockmode);
trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap);
return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, iomap_flags, seq);
allocate_blocks:
error = -EAGAIN;
if (flags & (IOMAP_NOWAIT | IOMAP_OVERWRITE_ONLY))
goto out_unlock;
/*
* We cap the maximum length we map to a sane size 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);
end_fsb = xfs_iomap_end_fsb(mp, offset, length);
if (offset + length > XFS_ISIZE(ip))
end_fsb = xfs_iomap_eof_align_last_fsb(ip, end_fsb);
else if (nimaps && imap.br_startblock == HOLESTARTBLOCK)
end_fsb = min(end_fsb, imap.br_startoff + imap.br_blockcount);
xfs_iunlock(ip, lockmode);
error = xfs_iomap_write_direct(ip, offset_fsb, end_fsb - offset_fsb,
flags, &imap, &seq);
if (error)
return error;
trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap);
return xfs_bmbt_to_iomap(ip, iomap, &imap, flags,
iomap_flags | IOMAP_F_NEW, seq);
out_found_cow:
length = XFS_FSB_TO_B(mp, cmap.br_startoff + cmap.br_blockcount);
trace_xfs_iomap_found(ip, offset, length - offset, XFS_COW_FORK, &cmap);
if (imap.br_startblock != HOLESTARTBLOCK) {
seq = xfs_iomap_inode_sequence(ip, 0);
error = xfs_bmbt_to_iomap(ip, srcmap, &imap, flags, 0, seq);
if (error)
goto out_unlock;
}
seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED);
xfs_iunlock(ip, lockmode);
return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, IOMAP_F_SHARED, seq);
out_unlock:
if (lockmode)
xfs_iunlock(ip, lockmode);
return error;
}
static DEFINE_IOMAP_ITER_NEXT(xfs_direct_write_iomap_next,
xfs_direct_write_iomap_begin);
const struct iomap_ops xfs_direct_write_iomap_ops = {
.iomap_next = xfs_direct_write_iomap_next,
};
#ifdef CONFIG_XFS_RT
/*
* This is really simple. The space has already been reserved before taking the
* IOLOCK, the actual block allocation is done just before submitting the bio
* and only recorded in the extent map on I/O completion.
*/
static int
xfs_zoned_direct_write_iomap_begin(
struct inode *inode,
loff_t offset,
loff_t length,
unsigned flags,
struct iomap *iomap,
struct iomap *srcmap)
{
struct xfs_inode *ip = XFS_I(inode);
int error;
ASSERT(!(flags & IOMAP_OVERWRITE_ONLY));
/*
* Needs to be pushed down into the allocator so that only writes into
* a single zone can be supported.
*/
if (flags & IOMAP_NOWAIT)
return -EAGAIN;
/*
* Ensure the extent list is in memory in so that we don't have to do
* read it from the I/O completion handler.
*/
if (xfs_need_iread_extents(&ip->i_df)) {
xfs_ilock(ip, XFS_ILOCK_EXCL);
error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (error)
return error;
}
iomap->type = IOMAP_MAPPED;
iomap->flags = IOMAP_F_DIRTY;
iomap->bdev = ip->i_mount->m_rtdev_targp->bt_bdev;
iomap->offset = offset;
iomap->length = length;
iomap->flags = IOMAP_F_ANON_WRITE;
return 0;
}
static DEFINE_IOMAP_ITER_NEXT(xfs_zoned_direct_write_iomap_next,
xfs_zoned_direct_write_iomap_begin);
const struct iomap_ops xfs_zoned_direct_write_iomap_ops = {
.iomap_next = xfs_zoned_direct_write_iomap_next,
};
#endif /* CONFIG_XFS_RT */
#ifdef DEBUG
static void
xfs_check_atomic_cow_conversion(
struct xfs_inode *ip,
xfs_fileoff_t offset_fsb,
xfs_filblks_t count_fsb,
const struct xfs_bmbt_irec *cmap)
{
struct xfs_iext_cursor icur;
struct xfs_bmbt_irec cmap2 = { };
if (xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &cmap2))
xfs_trim_extent(&cmap2, offset_fsb, count_fsb);
ASSERT(cmap2.br_startoff == cmap->br_startoff);
ASSERT(cmap2.br_blockcount == cmap->br_blockcount);
ASSERT(cmap2.br_startblock == cmap->br_startblock);
ASSERT(cmap2.br_state == cmap->br_state);
}
#else
# define xfs_check_atomic_cow_conversion(...) ((void)0)
#endif
static int
xfs_atomic_write_cow_iomap_begin(
struct inode *inode,
loff_t offset,
loff_t length,
unsigned flags,
struct iomap *iomap,
struct iomap *srcmap)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
const xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
const xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + length);
const xfs_filblks_t count_fsb = end_fsb - offset_fsb;
xfs_filblks_t hole_count_fsb;
int nmaps = 1;
xfs_filblks_t resaligned;
struct xfs_bmbt_irec cmap;
struct xfs_iext_cursor icur;
struct xfs_trans *tp;
unsigned int dblocks = 0, rblocks = 0;
int error;
u64 seq;
ASSERT(flags & IOMAP_WRITE);
ASSERT(flags & IOMAP_DIRECT);
if (xfs_is_shutdown(mp))
return -EIO;
if (!xfs_can_sw_atomic_write(mp)) {
ASSERT(xfs_can_sw_atomic_write(mp));
return -EINVAL;
}
/* blocks are always allocated in this path */
if (flags & IOMAP_NOWAIT)
return -EAGAIN;
trace_xfs_iomap_atomic_write_cow(ip, offset, length);
retry:
xfs_ilock(ip, XFS_ILOCK_EXCL);
if (!ip->i_cowfp) {
ASSERT(!xfs_is_reflink_inode(ip));
xfs_ifork_init_cow(ip);
}
if (!xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &cmap))
cmap.br_startoff = end_fsb;
if (cmap.br_startoff <= offset_fsb) {
if (isnullstartblock(cmap.br_startblock))
goto convert_delay;
/*
* cmap could extend outside the write range due to previous
* speculative preallocations. We must trim cmap to the write
* range because the cow fork treats written mappings to mean
* "write in progress".
*/
xfs_trim_extent(&cmap, offset_fsb, count_fsb);
goto found;
}
hole_count_fsb = cmap.br_startoff - offset_fsb;
resaligned = xfs_aligned_fsb_count(offset_fsb, hole_count_fsb,
xfs_get_cowextsz_hint(ip));
xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (XFS_IS_REALTIME_INODE(ip)) {
dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
rblocks = resaligned;
} else {
dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
rblocks = 0;
}
error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, dblocks,
rblocks, false, &tp);
if (error)
return error;
/* extent layout could have changed since the unlock, so check again */
if (!xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &cmap))
cmap.br_startoff = end_fsb;
if (cmap.br_startoff <= offset_fsb) {
xfs_trans_cancel(tp);
if (isnullstartblock(cmap.br_startblock))
goto convert_delay;
xfs_trim_extent(&cmap, offset_fsb, count_fsb);
goto found;
}
/*
* Allocate the entire reservation as unwritten blocks.
*
* Use XFS_BMAPI_EXTSZALIGN to hint at aligning new extents according to
* extszhint, such that there will be a greater chance that future
* atomic writes to that same range will be aligned (and don't require
* this COW-based method).
*/
error = xfs_bmapi_write(tp, ip, offset_fsb, hole_count_fsb,
XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC |
XFS_BMAPI_EXTSZALIGN, 0, &cmap, &nmaps);
if (error) {
xfs_trans_cancel(tp);
goto out_unlock;
}
xfs_inode_set_cowblocks_tag(ip);
error = xfs_trans_commit(tp);
if (error)
goto out_unlock;
/*
* cmap could map more blocks than the range we passed into bmapi_write
* because of EXTSZALIGN or adjacent pre-existing unwritten mappings
* that were merged. Trim cmap to the original write range so that we
* don't convert more than we were asked to do for this write.
*/
xfs_trim_extent(&cmap, offset_fsb, count_fsb);
found:
if (cmap.br_state != XFS_EXT_NORM) {
error = xfs_reflink_convert_cow_locked(ip, cmap.br_startoff,
cmap.br_blockcount);
if (error)
goto out_unlock;
cmap.br_state = XFS_EXT_NORM;
xfs_check_atomic_cow_conversion(ip, offset_fsb, count_fsb,
&cmap);
}
trace_xfs_iomap_found(ip, offset, length, XFS_COW_FORK, &cmap);
seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, IOMAP_F_SHARED, seq);
convert_delay:
xfs_iunlock(ip, XFS_ILOCK_EXCL);
error = xfs_bmapi_convert_delalloc(ip, XFS_COW_FORK, offset, iomap,
NULL);
if (error)
return error;
/*
* Try the lookup again, because the delalloc conversion might have
* turned the COW mapping into unwritten, but we need it to be in
* written state.
*/
goto retry;
out_unlock:
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return error;
}
static DEFINE_IOMAP_ITER_NEXT(xfs_atomic_write_cow_iomap_next,
xfs_atomic_write_cow_iomap_begin);
const struct iomap_ops xfs_atomic_write_cow_iomap_ops = {
.iomap_next = xfs_atomic_write_cow_iomap_next,
};
static int
xfs_dax_write_iomap_end(
struct inode *inode,
loff_t pos,
loff_t length,
ssize_t written,
unsigned flags,
struct iomap *iomap)
{
struct xfs_inode *ip = XFS_I(inode);
if (!xfs_is_cow_inode(ip))
return 0;
if (!written)
return xfs_reflink_cancel_cow_range(ip, pos, length, true);
return xfs_reflink_end_cow(ip, pos, written);
}
static DEFINE_IOMAP_ITER_NEXT_END(xfs_dax_write_iomap_next,
xfs_direct_write_iomap_begin, xfs_dax_write_iomap_end);
const struct iomap_ops xfs_dax_write_iomap_ops = {
.iomap_next = xfs_dax_write_iomap_next,
};
/*
* Convert a hole to a delayed allocation.
*/
static void
xfs_bmap_add_extent_hole_delay(
struct xfs_inode *ip, /* incore inode pointer */
int whichfork,
struct xfs_iext_cursor *icur,
struct xfs_bmbt_irec *new) /* new data to add to file extents */
{
struct xfs_ifork *ifp; /* inode fork pointer */
xfs_bmbt_irec_t left; /* left neighbor extent entry */
xfs_filblks_t newlen=0; /* new indirect size */
xfs_filblks_t oldlen=0; /* old indirect size */
xfs_bmbt_irec_t right; /* right neighbor extent entry */
uint32_t state = xfs_bmap_fork_to_state(whichfork);
xfs_filblks_t temp; /* temp for indirect calculations */
ifp = xfs_ifork_ptr(ip, whichfork);
ASSERT(isnullstartblock(new->br_startblock));
/*
* Check and set flags if this segment has a left neighbor
*/
if (xfs_iext_peek_prev_extent(ifp, icur, &left)) {
state |= BMAP_LEFT_VALID;
if (isnullstartblock(left.br_startblock))
state |= BMAP_LEFT_DELAY;
}
/*
* Check and set flags if the current (right) segment exists.
* If it doesn't exist, we're converting the hole at end-of-file.
*/
if (xfs_iext_get_extent(ifp, icur, &right)) {
state |= BMAP_RIGHT_VALID;
if (isnullstartblock(right.br_startblock))
state |= BMAP_RIGHT_DELAY;
}
/*
* Set contiguity flags on the left and right neighbors.
* Don't let extents get too large, even if the pieces are contiguous.
*/
if ((state & BMAP_LEFT_VALID) && (state & BMAP_LEFT_DELAY) &&
left.br_startoff + left.br_blockcount == new->br_startoff &&
left.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
state |= BMAP_LEFT_CONTIG;
if ((state & BMAP_RIGHT_VALID) && (state & BMAP_RIGHT_DELAY) &&
new->br_startoff + new->br_blockcount == right.br_startoff &&
new->br_blockcount + right.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
(!(state & BMAP_LEFT_CONTIG) ||
(left.br_blockcount + new->br_blockcount +
right.br_blockcount <= XFS_MAX_BMBT_EXTLEN)))
state |= BMAP_RIGHT_CONTIG;
/*
* Switch out based on the contiguity flags.
*/
switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) {
case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
/*
* New allocation is contiguous with delayed allocations
* on the left and on the right.
* Merge all three into a single extent record.
*/
temp = left.br_blockcount + new->br_blockcount +
right.br_blockcount;
oldlen = startblockval(left.br_startblock) +
startblockval(new->br_startblock) +
startblockval(right.br_startblock);
newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
oldlen);
left.br_startblock = nullstartblock(newlen);
left.br_blockcount = temp;
xfs_iext_remove(ip, icur, state);
xfs_iext_prev(ifp, icur);
xfs_iext_update_extent(ip, state, icur, &left);
break;
case BMAP_LEFT_CONTIG:
/*
* New allocation is contiguous with a delayed allocation
* on the left.
* Merge the new allocation with the left neighbor.
*/
temp = left.br_blockcount + new->br_blockcount;
oldlen = startblockval(left.br_startblock) +
startblockval(new->br_startblock);
newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
oldlen);
left.br_blockcount = temp;
left.br_startblock = nullstartblock(newlen);
xfs_iext_prev(ifp, icur);
xfs_iext_update_extent(ip, state, icur, &left);
break;
case BMAP_RIGHT_CONTIG:
/*
* New allocation is contiguous with a delayed allocation
* on the right.
* Merge the new allocation with the right neighbor.
*/
temp = new->br_blockcount + right.br_blockcount;
oldlen = startblockval(new->br_startblock) +
startblockval(right.br_startblock);
newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
oldlen);
right.br_startoff = new->br_startoff;
right.br_startblock = nullstartblock(newlen);
right.br_blockcount = temp;
xfs_iext_update_extent(ip, state, icur, &right);
break;
case 0:
/*
* New allocation is not contiguous with another
* delayed allocation.
* Insert a new entry.
*/
oldlen = newlen = 0;
xfs_iext_insert(ip, icur, new, state);
break;
}
if (oldlen != newlen) {
ASSERT(oldlen > newlen);
xfs_add_fdblocks(ip->i_mount, oldlen - newlen);
/*
* Nothing to do for disk quota accounting here.
*/
xfs_mod_delalloc(ip, 0, (int64_t)newlen - oldlen);
}
}
/*
* Add a delayed allocation extent to an inode. Blocks are reserved from the
* global pool and the extent inserted into the inode in-core extent tree.
*
* On entry, got refers to the first extent beyond the offset of the extent to
* allocate or eof is specified if no such extent exists. On return, got refers
* to the extent record that was inserted to the inode fork.
*
* Note that the allocated extent may have been merged with contiguous extents
* during insertion into the inode fork. Thus, got does not reflect the current
* state of the inode fork on return. If necessary, the caller can use lastx to
* look up the updated record in the inode fork.
*/
static int
xfs_bmapi_reserve_delalloc(
struct xfs_inode *ip,
int whichfork,
xfs_fileoff_t off,
xfs_filblks_t len,
xfs_filblks_t prealloc,
struct xfs_bmbt_irec *got,
struct xfs_iext_cursor *icur,
int eof)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
xfs_extlen_t alen;
xfs_extlen_t indlen;
uint64_t fdblocks;
int error;
xfs_fileoff_t aoff;
bool use_cowextszhint =
whichfork == XFS_COW_FORK && !prealloc;
retry:
/*
* Cap the alloc length. Keep track of prealloc so we know whether to
* tag the inode before we return.
*/
aoff = off;
alen = XFS_FILBLKS_MIN(len + prealloc, XFS_MAX_BMBT_EXTLEN);
if (!eof)
alen = XFS_FILBLKS_MIN(alen, got->br_startoff - aoff);
if (prealloc && alen >= len)
prealloc = alen - len;
/*
* If we're targetting the COW fork but aren't creating a speculative
* posteof preallocation, try to expand the reservation to align with
* the COW extent size hint if there's sufficient free space.
*
* Unlike the data fork, the CoW cancellation functions will free all
* the reservations at inactivation, so we don't require that every
* delalloc reservation have a dirty pagecache.
*/
if (use_cowextszhint) {
struct xfs_bmbt_irec prev;
xfs_extlen_t extsz = xfs_get_cowextsz_hint(ip);
if (!xfs_iext_peek_prev_extent(ifp, icur, &prev))
prev.br_startoff = NULLFILEOFF;
error = xfs_bmap_extsize_align(mp, got, &prev, extsz, 0, eof,
1, 0, &aoff, &alen);
ASSERT(!error);
}
/*
* Make a transaction-less quota reservation for delayed allocation
* blocks. This number gets adjusted later. We return if we haven't
* allocated blocks already inside this loop.
*/
error = xfs_quota_reserve_blkres(ip, alen);
if (error)
goto out;
/*
* Split changing sb for alen and indlen since they could be coming
* from different places.
*/
indlen = (xfs_extlen_t)xfs_bmap_worst_indlen(ip, alen);
ASSERT(indlen > 0);
fdblocks = indlen;
if (XFS_IS_REALTIME_INODE(ip)) {
ASSERT(!xfs_is_zoned_inode(ip));
error = xfs_dec_frextents(mp, xfs_blen_to_rtbxlen(mp, alen));
if (error)
goto out_unreserve_quota;
} else {
fdblocks += alen;
}
error = xfs_dec_fdblocks(mp, fdblocks, false);
if (error)
goto out_unreserve_frextents;
ip->i_delayed_blks += alen;
xfs_mod_delalloc(ip, alen, indlen);
got->br_startoff = aoff;
got->br_startblock = nullstartblock(indlen);
got->br_blockcount = alen;
got->br_state = XFS_EXT_NORM;
xfs_bmap_add_extent_hole_delay(ip, whichfork, icur, got);
/*
* Tag the inode if blocks were preallocated. Note that COW fork
* preallocation can occur at the start or end of the extent, even when
* prealloc == 0, so we must also check the aligned offset and length.
*/
if (whichfork == XFS_DATA_FORK && prealloc)
xfs_inode_set_eofblocks_tag(ip);
if (whichfork == XFS_COW_FORK && (prealloc || aoff < off || alen > len))
xfs_inode_set_cowblocks_tag(ip);
return 0;
out_unreserve_frextents:
if (XFS_IS_REALTIME_INODE(ip))
xfs_add_frextents(mp, xfs_blen_to_rtbxlen(mp, alen));
out_unreserve_quota:
if (XFS_IS_QUOTA_ON(mp))
xfs_quota_unreserve_blkres(ip, alen);
out:
if (error == -ENOSPC || error == -EDQUOT) {
trace_xfs_delalloc_enospc(ip, off, len);
if (prealloc || use_cowextszhint) {
/* retry without any preallocation */
use_cowextszhint = false;
prealloc = 0;
goto retry;
}
}
return error;
}
static int
xfs_zoned_buffered_write_iomap_begin(
struct inode *inode,
loff_t offset,
loff_t count,
unsigned flags,
struct iomap *iomap,
struct iomap *srcmap)
{
struct iomap_iter *iter =
container_of(iomap, struct iomap_iter, iomap);
struct address_space *mapping = inode->i_mapping;
struct xfs_zone_alloc_ctx *ac = iter->private;
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_iomap_end_fsb(mp, offset, count);
u16 iomap_flags = IOMAP_F_SHARED;
unsigned int lockmode = XFS_ILOCK_EXCL;
xfs_filblks_t count_fsb;
xfs_extlen_t indlen;
struct xfs_bmbt_irec got;
struct xfs_iext_cursor icur;
int error = 0;
ASSERT(!xfs_get_extsz_hint(ip));
ASSERT(!(flags & IOMAP_UNSHARE));
ASSERT(ac);
if (xfs_is_shutdown(mp))
return -EIO;
error = xfs_qm_dqattach(ip);
if (error)
return error;
restart:
error = xfs_ilock_for_iomap(ip, flags, &lockmode);
if (error)
return error;
if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(&ip->i_df)) ||
XFS_TEST_ERROR(mp, XFS_ERRTAG_BMAPIFORMAT)) {
xfs_bmap_mark_sick(ip, XFS_DATA_FORK);
error = -EFSCORRUPTED;
goto out_unlock;
}
XFS_STATS_INC(mp, xs_blk_mapw);
error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);
if (error)
goto out_unlock;
/*
* For zeroing operations check if there is any data to zero first.
*
* For regular writes we always need to allocate new blocks, but need to
* provide the source mapping when the range is unaligned to support
* read-modify-write of the whole block in the page cache.
*
* In either case we need to limit the reported range to the boundaries
* of the source map in the data fork.
*/
if (!IS_ALIGNED(offset, mp->m_sb.sb_blocksize) ||
!IS_ALIGNED(offset + count, mp->m_sb.sb_blocksize) ||
(flags & IOMAP_ZERO)) {
struct xfs_bmbt_irec smap;
struct xfs_iext_cursor scur;
if (!xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &scur,
&smap))
smap.br_startoff = end_fsb; /* fake hole until EOF */
if (smap.br_startoff > offset_fsb) {
end_fsb = min(end_fsb, smap.br_startoff);
} else {
end_fsb = min(end_fsb,
smap.br_startoff + smap.br_blockcount);
xfs_trim_extent(&smap, offset_fsb,
end_fsb - offset_fsb);
error = xfs_bmbt_to_iomap(ip, srcmap, &smap, flags, 0,
xfs_iomap_inode_sequence(ip, 0));
if (error)
goto out_unlock;
}
}
if (!ip->i_cowfp)
xfs_ifork_init_cow(ip);
if (!xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &got))
got.br_startoff = end_fsb;
if (got.br_startoff <= offset_fsb) {
trace_xfs_reflink_cow_found(ip, &got);
goto done;
}
/*
* Cap the maximum length to keep the chunks of work done here somewhat
* symmetric with the work writeback does.
*/
end_fsb = min(end_fsb, got.br_startoff);
count_fsb = min3(end_fsb - offset_fsb, XFS_MAX_BMBT_EXTLEN,
XFS_B_TO_FSB(mp, 1024 * PAGE_SIZE));
/*
* When zeroing, don't allocate blocks for holes as they are already
* zeroes, but we need to ensure that no extents exist in both the data
* and COW fork to ensure this really is a hole.
*
* A window exists where we might observe a hole in both forks with
* valid data in cache. Writeback removes the COW fork blocks on
* submission but doesn't remap into the data fork until completion. If
* the data fork was previously a hole, we'll fail to zero. Until we
* find a way to avoid this transient state, check for dirty pagecache
* and flush to wait on blocks to land in the data fork.
*/
if ((flags & IOMAP_ZERO) && srcmap->type == IOMAP_HOLE) {
if (filemap_range_needs_writeback(mapping, offset,
offset + count - 1)) {
xfs_iunlock(ip, lockmode);
error = filemap_write_and_wait_range(mapping, offset,
offset + count - 1);
if (error)
return error;
goto restart;
}
xfs_hole_to_iomap(ip, iomap, offset_fsb, end_fsb);
goto out_unlock;
}
/*
* The block reservation is supposed to cover all blocks that the
* operation could possible write, but there is a nasty corner case
* where blocks could be stolen from underneath us:
*
* 1) while this thread iterates over a larger buffered write,
* 2) another thread is causing a write fault that calls into
* ->page_mkwrite in range this thread writes to, using up the
* delalloc reservation created by a previous call to this function.
* 3) another thread does direct I/O on the range that the write fault
* happened on, which causes writeback of the dirty data.
* 4) this then set the stale flag, which cuts the current iomap
* iteration short, causing the new call to ->iomap_begin that gets
* us here again, but now without a sufficient reservation.
*
* This is a very unusual I/O pattern, and nothing but generic/095 is
* known to hit it. There's not really much we can do here, so turn this
* into a short write.
*/
if (count_fsb > ac->reserved_blocks) {
xfs_warn_ratelimited(mp,
"Short write on ino 0x%llx comm %.20s due to three-way race with write fault and direct I/O",
I_INO(ip), current->comm);
count_fsb = ac->reserved_blocks;
if (!count_fsb) {
error = -EIO;
goto out_unlock;
}
}
error = xfs_quota_reserve_blkres(ip, count_fsb);
if (error)
goto out_unlock;
indlen = xfs_bmap_worst_indlen(ip, count_fsb);
error = xfs_dec_fdblocks(mp, indlen, false);
if (error)
goto out_unlock;
ip->i_delayed_blks += count_fsb;
xfs_mod_delalloc(ip, count_fsb, indlen);
got.br_startoff = offset_fsb;
got.br_startblock = nullstartblock(indlen);
got.br_blockcount = count_fsb;
got.br_state = XFS_EXT_NORM;
xfs_bmap_add_extent_hole_delay(ip, XFS_COW_FORK, &icur, &got);
ac->reserved_blocks -= count_fsb;
iomap_flags |= IOMAP_F_NEW;
trace_xfs_iomap_alloc(ip, offset, XFS_FSB_TO_B(mp, count_fsb),
XFS_COW_FORK, &got);
done:
error = xfs_bmbt_to_iomap(ip, iomap, &got, flags, iomap_flags,
xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED));
out_unlock:
xfs_iunlock(ip, lockmode);
return error;
}
static int
xfs_buffered_write_iomap_begin(
struct inode *inode,
loff_t offset,
loff_t count,
unsigned flags,
struct iomap *iomap,
struct iomap *srcmap)
{
struct iomap_iter *iter = container_of(iomap, struct iomap_iter,
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_iomap_end_fsb(mp, offset, count);
xfs_fileoff_t cow_fsb = NULLFILEOFF;
xfs_fileoff_t eof_fsb = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));
struct xfs_bmbt_irec imap, cmap;
struct xfs_iext_cursor icur, ccur;
xfs_fsblock_t prealloc_blocks = 0;
bool eof = false, cow_eof = false, shared = false;
int allocfork = XFS_DATA_FORK;
int error = 0;
unsigned int lockmode = XFS_ILOCK_EXCL;
unsigned int iomap_flags = 0;
u64 seq;
if (xfs_is_shutdown(mp))
return -EIO;
if (xfs_is_zoned_inode(ip))
return xfs_zoned_buffered_write_iomap_begin(inode, offset,
count, flags, iomap, srcmap);
/* we can't use delayed allocations when using extent size hints */
if (xfs_get_extsz_hint(ip))
return xfs_direct_write_iomap_begin(inode, offset, count,
flags, iomap, srcmap);
error = xfs_qm_dqattach(ip);
if (error)
return error;
error = xfs_ilock_for_iomap(ip, flags, &lockmode);
if (error)
return error;
if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(&ip->i_df)) ||
XFS_TEST_ERROR(mp, XFS_ERRTAG_BMAPIFORMAT)) {
xfs_bmap_mark_sick(ip, XFS_DATA_FORK);
error = -EFSCORRUPTED;
goto out_unlock;
}
XFS_STATS_INC(mp, xs_blk_mapw);
error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);
if (error)
goto out_unlock;
/*
* Search the data fork first to look up our source mapping. We always
* need the data fork map, as we have to return it to the iomap code so
* that the higher level write code can read data in to perform
* read-modify-write cycles for unaligned writes.
*
* Then search the COW fork extent list even if we did not find a data
* fork extent. This serves two purposes: first this implements the
* speculative preallocation using cowextsize, so that we also unshare
* block adjacent to shared blocks instead of just the shared blocks
* themselves. Second the lookup in the extent list is generally faster
* than going out to the shared extent tree.
*/
eof = !xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &icur, &imap);
if (eof)
imap.br_startoff = end_fsb; /* fake hole until the end */
if (xfs_is_cow_inode(ip)) {
if (!ip->i_cowfp) {
ASSERT(!xfs_is_reflink_inode(ip));
xfs_ifork_init_cow(ip);
}
cow_eof = !xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb,
&ccur, &cmap);
if (!cow_eof)
cow_fsb = cmap.br_startoff;
}
/* We never need to allocate blocks for unsharing a hole. */
if ((flags & IOMAP_UNSHARE) && imap.br_startoff > offset_fsb) {
xfs_hole_to_iomap(ip, iomap, offset_fsb, imap.br_startoff);
goto out_unlock;
}
/*
* We may need to zero over a hole in the data fork if it's fronted by
* COW blocks and dirty pagecache. Scan such file ranges for dirty
* cache and fill the iomap batch with folios that need zeroing.
*/
if ((flags & IOMAP_ZERO) && imap.br_startoff > offset_fsb) {
loff_t start, end;
unsigned int fbatch_count;
imap.br_blockcount = imap.br_startoff - offset_fsb;
imap.br_startoff = offset_fsb;
imap.br_startblock = HOLESTARTBLOCK;
imap.br_state = XFS_EXT_NORM;
if (cow_fsb == NULLFILEOFF)
goto found_imap;
if (cow_fsb > offset_fsb) {
xfs_trim_extent(&imap, offset_fsb,
cow_fsb - offset_fsb);
goto found_imap;
}
/* no zeroing beyond eof, so split at the boundary */
if (offset_fsb >= eof_fsb)
goto found_imap;
if (offset_fsb < eof_fsb && end_fsb > eof_fsb)
xfs_trim_extent(&imap, offset_fsb,
eof_fsb - offset_fsb);
/* COW fork blocks overlap the hole */
xfs_trim_extent(&imap, offset_fsb,
cmap.br_startoff + cmap.br_blockcount - offset_fsb);
start = XFS_FSB_TO_B(mp, imap.br_startoff);
end = XFS_FSB_TO_B(mp, imap.br_startoff + imap.br_blockcount);
fbatch_count = iomap_fill_dirty_folios(iter, &start, end,
&iomap_flags);
xfs_trim_extent(&imap, offset_fsb,
XFS_B_TO_FSB(mp, start) - offset_fsb);
/*
* Report the COW mapping if we have folios to zero. Otherwise
* ignore the COW blocks as preallocation and report a hole.
*/
if (fbatch_count) {
xfs_trim_extent(&cmap, imap.br_startoff,
imap.br_blockcount);
imap.br_startoff = end_fsb; /* fake hole */
goto found_cow;
}
goto found_imap;
}
/*
* For zeroing, trim extents that extend beyond the EOF block. If a
* delalloc extent starts beyond the EOF block, convert it to an
* unwritten extent.
*/
if (flags & IOMAP_ZERO) {
if (isnullstartblock(imap.br_startblock) &&
offset_fsb >= eof_fsb)
goto convert_delay;
if (offset_fsb < eof_fsb && end_fsb > eof_fsb)
end_fsb = eof_fsb;
/*
* Look up dirty folios for unwritten mappings within EOF.
* Providing this bypasses the flush iomap uses to trigger
* extent conversion when unwritten mappings have dirty
* pagecache in need of zeroing.
*
* Trim the mapping to the end pos of the lookup, which in turn
* was trimmed to the end of the batch if it became full before
* the end of the mapping.
*/
if (imap.br_state == XFS_EXT_UNWRITTEN &&
offset_fsb < eof_fsb) {
loff_t foffset = offset, fend;
fend = offset +
min(count, XFS_FSB_TO_B(mp, imap.br_blockcount));
iomap_fill_dirty_folios(iter, &foffset, fend,
&iomap_flags);
end_fsb = min_t(xfs_fileoff_t, end_fsb,
XFS_B_TO_FSB(mp, foffset));
}
xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb);
}
/*
* Now that we've handled any operation specific special cases, at this
* point we can report a COW mapping if found.
*/
if (xfs_is_cow_inode(ip) &&
!cow_eof && cmap.br_startoff <= offset_fsb) {
trace_xfs_reflink_cow_found(ip, &cmap);
goto found_cow;
}
if (imap.br_startoff <= offset_fsb) {
/*
* For reflink files we may need a delalloc reservation when
* overwriting shared extents. This includes zeroing of
* existing extents that contain data.
*/
if (!xfs_is_cow_inode(ip) ||
((flags & IOMAP_ZERO) && imap.br_state != XFS_EXT_NORM)) {
trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,
&imap);
goto found_imap;
}
xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb);
/* Trim the mapping to the nearest shared extent boundary. */
error = xfs_bmap_trim_cow(ip, &imap, &shared);
if (error)
goto out_unlock;
/* Not shared? Just report the (potentially capped) extent. */
if (!shared) {
trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,
&imap);
goto found_imap;
}
/*
* Fork all the shared blocks from our write offset until the
* end of the extent.
*/
allocfork = XFS_COW_FORK;
end_fsb = imap.br_startoff + imap.br_blockcount;
} else {
/*
* 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.
*
* 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 = xfs_iomap_end_fsb(mp, offset, count);
if (xfs_is_always_cow_inode(ip))
allocfork = XFS_COW_FORK;
}
if (eof && offset + count > XFS_ISIZE(ip)) {
/*
* Determine the initial size of the preallocation.
* We clean up any extra preallocation when the file is closed.
*/
if (xfs_has_allocsize(mp))
prealloc_blocks = mp->m_allocsize_blocks;
else if (allocfork == XFS_DATA_FORK)
prealloc_blocks = xfs_iomap_prealloc_size(ip, allocfork,
offset, count, &icur);
else
prealloc_blocks = xfs_iomap_prealloc_size(ip, allocfork,
offset, count, &ccur);
if (prealloc_blocks) {
xfs_extlen_t align;
xfs_off_t end_offset;
xfs_fileoff_t p_end_fsb;
end_offset = XFS_ALLOC_ALIGN(mp, offset + count - 1);
p_end_fsb = XFS_B_TO_FSBT(mp, end_offset) +
prealloc_blocks;
align = xfs_eof_alignment(ip);
if (align)
p_end_fsb = roundup_64(p_end_fsb, align);
p_end_fsb = min(p_end_fsb,
XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
ASSERT(p_end_fsb > offset_fsb);
prealloc_blocks = p_end_fsb - end_fsb;
}
}
/*
* 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;
if (allocfork == XFS_COW_FORK) {
error = xfs_bmapi_reserve_delalloc(ip, allocfork, offset_fsb,
end_fsb - offset_fsb, prealloc_blocks, &cmap,
&ccur, cow_eof);
if (error)
goto out_unlock;
trace_xfs_iomap_alloc(ip, offset, count, allocfork, &cmap);
goto found_cow;
}
error = xfs_bmapi_reserve_delalloc(ip, allocfork, offset_fsb,
end_fsb - offset_fsb, prealloc_blocks, &imap, &icur,
eof);
if (error)
goto out_unlock;
trace_xfs_iomap_alloc(ip, offset, count, allocfork, &imap);
found_imap:
seq = xfs_iomap_inode_sequence(ip, iomap_flags);
xfs_iunlock(ip, lockmode);
return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, iomap_flags, seq);
convert_delay:
xfs_iunlock(ip, lockmode);
truncate_pagecache(inode, offset);
error = xfs_bmapi_convert_delalloc(ip, XFS_DATA_FORK, offset,
iomap, NULL);
if (error)
return error;
trace_xfs_iomap_alloc(ip, offset, count, XFS_DATA_FORK, &imap);
return 0;
found_cow:
if (imap.br_startoff <= offset_fsb) {
error = xfs_bmbt_to_iomap(ip, srcmap, &imap, flags, 0,
xfs_iomap_inode_sequence(ip, 0));
if (error)
goto out_unlock;
} else {
xfs_trim_extent(&cmap, offset_fsb,
imap.br_startoff - offset_fsb);
}
iomap_flags |= IOMAP_F_SHARED;
seq = xfs_iomap_inode_sequence(ip, iomap_flags);
xfs_iunlock(ip, lockmode);
return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, iomap_flags, seq);
out_unlock:
xfs_iunlock(ip, lockmode);
return error;
}
static void
xfs_buffered_write_delalloc_punch(
struct inode *inode,
loff_t offset,
loff_t length,
struct iomap *iomap)
{
struct iomap_iter *iter =
container_of(iomap, struct iomap_iter, iomap);
xfs_bmap_punch_delalloc_range(XFS_I(inode),
(iomap->flags & IOMAP_F_SHARED) ?
XFS_COW_FORK : XFS_DATA_FORK,
offset, offset + length, iter->private);
}
static int
xfs_buffered_write_iomap_end(
struct inode *inode,
loff_t offset,
loff_t length,
ssize_t written,
unsigned flags,
struct iomap *iomap)
{
loff_t start_byte, end_byte;
/* If we didn't reserve the blocks, we're not allowed to punch them. */
if (iomap->type != IOMAP_DELALLOC || !(iomap->flags & IOMAP_F_NEW))
return 0;
/*
* iomap_page_mkwrite() will never fail in a way that requires delalloc
* extents that it allocated to be revoked. Hence never try to release
* them here.
*/
if (flags & IOMAP_FAULT)
return 0;
/* Nothing to do if we've written the entire delalloc extent */
start_byte = iomap_last_written_block(inode, offset, written);
end_byte = round_up(offset + length, i_blocksize(inode));
if (start_byte >= end_byte)
return 0;
/* For zeroing operations the callers already hold invalidate_lock. */
if (flags & (IOMAP_UNSHARE | IOMAP_ZERO)) {
rwsem_assert_held_write(&inode->i_mapping->invalidate_lock);
iomap_write_delalloc_release(inode, start_byte, end_byte, flags,
iomap, xfs_buffered_write_delalloc_punch);
} else {
filemap_invalidate_lock(inode->i_mapping);
iomap_write_delalloc_release(inode, start_byte, end_byte, flags,
iomap, xfs_buffered_write_delalloc_punch);
filemap_invalidate_unlock(inode->i_mapping);
}
return 0;
}
static DEFINE_IOMAP_ITER_NEXT_END(xfs_buffered_write_iomap_next,
xfs_buffered_write_iomap_begin, xfs_buffered_write_iomap_end);
const struct iomap_ops xfs_buffered_write_iomap_ops = {
.iomap_next = xfs_buffered_write_iomap_next,
};
int
xfs_read_iomap_begin(
struct inode *inode,
loff_t offset,
loff_t length,
unsigned flags,
struct iomap *iomap,
struct iomap *srcmap)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
struct xfs_bmbt_irec imap;
xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, length);
int nimaps = 1, error = 0;
bool shared = false;
unsigned int lockmode = XFS_ILOCK_SHARED;
u64 seq;
ASSERT(!(flags & (IOMAP_WRITE | IOMAP_ZERO)));
if (xfs_is_shutdown(mp))
return -EIO;
error = xfs_ilock_for_iomap(ip, flags, &lockmode);
if (error)
return error;
error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
&nimaps, 0);
if (!error && ((flags & IOMAP_REPORT) || IS_DAX(inode)))
error = xfs_reflink_trim_around_shared(ip, &imap, &shared);
seq = xfs_iomap_inode_sequence(ip, shared ? IOMAP_F_SHARED : 0);
xfs_iunlock(ip, lockmode);
if (error)
return error;
trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap);
return xfs_bmbt_to_iomap(ip, iomap, &imap, flags,
shared ? IOMAP_F_SHARED : 0, seq);
}
static DEFINE_IOMAP_ITER_NEXT(xfs_read_iomap_next, xfs_read_iomap_begin);
const struct iomap_ops xfs_read_iomap_ops = {
.iomap_next = xfs_read_iomap_next,
};
static int
xfs_seek_iomap_begin(
struct inode *inode,
loff_t offset,
loff_t length,
unsigned flags,
struct iomap *iomap,
struct iomap *srcmap)
{
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);
xfs_fileoff_t cow_fsb = NULLFILEOFF, data_fsb = NULLFILEOFF;
struct xfs_iext_cursor icur;
struct xfs_bmbt_irec imap, cmap;
int error = 0;
unsigned lockmode;
u64 seq;
if (xfs_is_shutdown(mp))
return -EIO;
lockmode = xfs_ilock_data_map_shared(ip);
error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);
if (error)
goto out_unlock;
if (xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &icur, &imap)) {
/*
* If we found a data extent we are done.
*/
if (imap.br_startoff <= offset_fsb)
goto done;
data_fsb = imap.br_startoff;
} else {
/*
* Fake a hole until the end of the file.
*/
data_fsb = xfs_iomap_end_fsb(mp, offset, length);
}
/*
* If a COW fork extent covers the hole, report it - capped to the next
* data fork extent:
*/
if (xfs_inode_has_cow_data(ip) &&
xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &cmap))
cow_fsb = cmap.br_startoff;
if (cow_fsb != NULLFILEOFF && cow_fsb <= offset_fsb) {
if (data_fsb < cow_fsb + cmap.br_blockcount)
end_fsb = min(end_fsb, data_fsb);
xfs_trim_extent(&cmap, offset_fsb, end_fsb - offset_fsb);
seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED);
error = xfs_bmbt_to_iomap(ip, iomap, &cmap, flags,
IOMAP_F_SHARED, seq);
/*
* This is a COW extent, so we must probe the page cache
* because there could be dirty page cache being backed
* by this extent.
*/
iomap->type = IOMAP_UNWRITTEN;
goto out_unlock;
}
/*
* Else report a hole, capped to the next found data or COW extent.
*/
if (cow_fsb != NULLFILEOFF && cow_fsb < data_fsb)
imap.br_blockcount = cow_fsb - offset_fsb;
else
imap.br_blockcount = data_fsb - offset_fsb;
imap.br_startoff = offset_fsb;
imap.br_startblock = HOLESTARTBLOCK;
imap.br_state = XFS_EXT_NORM;
done:
seq = xfs_iomap_inode_sequence(ip, 0);
xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb);
error = xfs_bmbt_to_iomap(ip, iomap, &imap, flags, 0, seq);
out_unlock:
xfs_iunlock(ip, lockmode);
return error;
}
static DEFINE_IOMAP_ITER_NEXT(xfs_seek_iomap_next, xfs_seek_iomap_begin);
const struct iomap_ops xfs_seek_iomap_ops = {
.iomap_next = xfs_seek_iomap_next,
};
static int
xfs_xattr_iomap_begin(
struct inode *inode,
loff_t offset,
loff_t length,
unsigned flags,
struct iomap *iomap,
struct iomap *srcmap)
{
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;
int seq;
if (xfs_is_shutdown(mp))
return -EIO;
lockmode = xfs_ilock_attr_map_shared(ip);
/* if there are no attribute fork or extents, return ENOENT */
if (!xfs_inode_has_attr_fork(ip) || !ip->i_af.if_nextents) {
error = -ENOENT;
goto out_unlock;
}
ASSERT(ip->i_af.if_format != XFS_DINODE_FMT_LOCAL);
error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
&nimaps, XFS_BMAPI_ATTRFORK);
out_unlock:
seq = xfs_iomap_inode_sequence(ip, IOMAP_F_XATTR);
xfs_iunlock(ip, lockmode);
if (error)
return error;
ASSERT(nimaps);
return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, IOMAP_F_XATTR, seq);
}
static DEFINE_IOMAP_ITER_NEXT(xfs_xattr_iomap_next, xfs_xattr_iomap_begin);
const struct iomap_ops xfs_xattr_iomap_ops = {
.iomap_next = xfs_xattr_iomap_next,
};
int
xfs_zero_range(
struct xfs_inode *ip,
loff_t pos,
loff_t len,
struct xfs_zone_alloc_ctx *ac,
bool *did_zero)
{
struct inode *inode = VFS_I(ip);
xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL);
if (IS_DAX(inode))
return dax_zero_range(inode, pos, len, did_zero,
&xfs_dax_write_iomap_ops);
return iomap_zero_range(inode, pos, len, did_zero,
&xfs_buffered_write_iomap_ops, &xfs_iomap_write_ops,
ac);
}
int
xfs_truncate_page(
struct xfs_inode *ip,
loff_t pos,
struct xfs_zone_alloc_ctx *ac,
bool *did_zero)
{
struct inode *inode = VFS_I(ip);
if (IS_DAX(inode))
return dax_truncate_page(inode, pos, did_zero,
&xfs_dax_write_iomap_ops);
return iomap_truncate_page(inode, pos, did_zero,
&xfs_buffered_write_iomap_ops, &xfs_iomap_write_ops,
ac);
}
