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synced 2024-09-12 13:55:32 +00:00
xfs: a couple getbmap cleanups
- reshuffle various conditionals for data vs attr fork to make the code more readable - do fine-grainded goto-based error handling - exit early from conditionals instead of keeping a long else branch around - allow kmem_alloc to fail Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Eric Sandeen <sandeen@sandeen.net> Reviewed-by: Felix Blyakher <felixb@sgi.com> Signed-off-by: Felix Blyakher <felixb@sgi.com>
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2ac00af7a6
commit
4be4a00fb5
1 changed files with 80 additions and 84 deletions
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@ -5880,7 +5880,7 @@ xfs_getbmap(
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void *arg) /* formatter arg */
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{
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__int64_t bmvend; /* last block requested */
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int error; /* return value */
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int error = 0; /* return value */
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__int64_t fixlen; /* length for -1 case */
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int i; /* extent number */
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int lock; /* lock state */
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@ -5899,30 +5899,8 @@ xfs_getbmap(
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mp = ip->i_mount;
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iflags = bmv->bmv_iflags;
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whichfork = iflags & BMV_IF_ATTRFORK ? XFS_ATTR_FORK : XFS_DATA_FORK;
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/* If the BMV_IF_NO_DMAPI_READ interface bit specified, do not
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* generate a DMAPI read event. Otherwise, if the DM_EVENT_READ
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* bit is set for the file, generate a read event in order
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* that the DMAPI application may do its thing before we return
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* the extents. Usually this means restoring user file data to
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* regions of the file that look like holes.
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*
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* The "old behavior" (from XFS_IOC_GETBMAP) is to not specify
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* BMV_IF_NO_DMAPI_READ so that read events are generated.
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* If this were not true, callers of ioctl( XFS_IOC_GETBMAP )
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* could misinterpret holes in a DMAPI file as true holes,
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* when in fact they may represent offline user data.
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*/
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if ((iflags & BMV_IF_NO_DMAPI_READ) == 0 &&
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DM_EVENT_ENABLED(ip, DM_EVENT_READ) &&
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whichfork == XFS_DATA_FORK) {
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error = XFS_SEND_DATA(mp, DM_EVENT_READ, ip, 0, 0, 0, NULL);
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if (error)
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return XFS_ERROR(error);
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}
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if (whichfork == XFS_ATTR_FORK) {
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if (XFS_IFORK_Q(ip)) {
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if (ip->i_d.di_aformat != XFS_DINODE_FMT_EXTENTS &&
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@ -5936,11 +5914,37 @@ xfs_getbmap(
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ip->i_mount);
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return XFS_ERROR(EFSCORRUPTED);
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}
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} else if (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
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ip->i_d.di_format != XFS_DINODE_FMT_BTREE &&
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ip->i_d.di_format != XFS_DINODE_FMT_LOCAL)
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return XFS_ERROR(EINVAL);
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if (whichfork == XFS_DATA_FORK) {
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prealloced = 0;
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fixlen = 1LL << 32;
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} else {
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/*
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* If the BMV_IF_NO_DMAPI_READ interface bit specified, do
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* not generate a DMAPI read event. Otherwise, if the
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* DM_EVENT_READ bit is set for the file, generate a read
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* event in order that the DMAPI application may do its thing
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* before we return the extents. Usually this means restoring
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* user file data to regions of the file that look like holes.
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*
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* The "old behavior" (from XFS_IOC_GETBMAP) is to not specify
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* BMV_IF_NO_DMAPI_READ so that read events are generated.
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* If this were not true, callers of ioctl(XFS_IOC_GETBMAP)
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* could misinterpret holes in a DMAPI file as true holes,
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* when in fact they may represent offline user data.
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*/
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if (DM_EVENT_ENABLED(ip, DM_EVENT_READ) &&
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!(iflags & BMV_IF_NO_DMAPI_READ)) {
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error = XFS_SEND_DATA(mp, DM_EVENT_READ, ip,
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0, 0, 0, NULL);
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if (error)
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return XFS_ERROR(error);
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}
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if (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
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ip->i_d.di_format != XFS_DINODE_FMT_BTREE &&
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ip->i_d.di_format != XFS_DINODE_FMT_LOCAL)
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return XFS_ERROR(EINVAL);
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if (xfs_get_extsz_hint(ip) ||
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ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC|XFS_DIFLAG_APPEND)){
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prealloced = 1;
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@ -5949,42 +5953,34 @@ xfs_getbmap(
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prealloced = 0;
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fixlen = ip->i_size;
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}
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} else {
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prealloced = 0;
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fixlen = 1LL << 32;
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}
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if (bmv->bmv_length == -1) {
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fixlen = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, fixlen));
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bmv->bmv_length = MAX( (__int64_t)(fixlen - bmv->bmv_offset),
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(__int64_t)0);
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} else if (bmv->bmv_length < 0)
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return XFS_ERROR(EINVAL);
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if (bmv->bmv_length == 0) {
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bmv->bmv_length =
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max_t(__int64_t, fixlen - bmv->bmv_offset, 0);
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} else if (bmv->bmv_length == 0) {
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bmv->bmv_entries = 0;
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return 0;
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} else if (bmv->bmv_length < 0) {
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return XFS_ERROR(EINVAL);
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}
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nex = bmv->bmv_count - 1;
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if (nex <= 0)
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return XFS_ERROR(EINVAL);
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bmvend = bmv->bmv_offset + bmv->bmv_length;
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xfs_ilock(ip, XFS_IOLOCK_SHARED);
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if (((iflags & BMV_IF_DELALLOC) == 0) &&
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(whichfork == XFS_DATA_FORK) &&
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(ip->i_delayed_blks || ip->i_size > ip->i_d.di_size)) {
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/* xfs_fsize_t last_byte = xfs_file_last_byte(ip); */
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error = xfs_flush_pages(ip, (xfs_off_t)0,
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-1, 0, FI_REMAPF);
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if (error) {
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xfs_iunlock(ip, XFS_IOLOCK_SHARED);
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return error;
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if (whichfork == XFS_DATA_FORK && !(iflags & BMV_IF_DELALLOC)) {
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if (ip->i_delayed_blks || ip->i_size > ip->i_d.di_size) {
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error = xfs_flush_pages(ip, 0, -1, 0, FI_REMAPF);
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if (error)
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goto out_unlock_iolock;
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}
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}
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ASSERT(whichfork == XFS_ATTR_FORK || (iflags & BMV_IF_DELALLOC) ||
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ip->i_delayed_blks == 0);
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ASSERT(ip->i_delayed_blks == 0);
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}
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lock = xfs_ilock_map_shared(ip);
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@ -5995,23 +5991,25 @@ xfs_getbmap(
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if (nex > XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1)
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nex = XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1;
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bmapi_flags = xfs_bmapi_aflag(whichfork) |
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((iflags & BMV_IF_PREALLOC) ? 0 : XFS_BMAPI_IGSTATE);
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bmapi_flags = xfs_bmapi_aflag(whichfork);
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if (!(iflags & BMV_IF_PREALLOC))
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bmapi_flags |= XFS_BMAPI_IGSTATE;
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/*
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* Allocate enough space to handle "subnex" maps at a time.
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*/
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error = ENOMEM;
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subnex = 16;
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map = kmem_alloc(subnex * sizeof(*map), KM_SLEEP);
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map = kmem_alloc(subnex * sizeof(*map), KM_MAYFAIL);
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if (!map)
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goto out_unlock_ilock;
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bmv->bmv_entries = 0;
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if ((XFS_IFORK_NEXTENTS(ip, whichfork) == 0)) {
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if (((iflags & BMV_IF_DELALLOC) == 0) ||
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whichfork == XFS_ATTR_FORK) {
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error = 0;
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goto unlock_and_return;
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}
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if (XFS_IFORK_NEXTENTS(ip, whichfork) == 0 &&
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(whichfork == XFS_ATTR_FORK || !(iflags & BMV_IF_DELALLOC))) {
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error = 0;
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goto out_free_map;
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}
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nexleft = nex;
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bmapi_flags, NULL, 0, map, &nmap,
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NULL, NULL);
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if (error)
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goto unlock_and_return;
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goto out_free_map;
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ASSERT(nmap <= subnex);
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for (i = 0; i < nmap && nexleft && bmv->bmv_length; i++) {
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int full = 0; /* user array is full */
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out.bmv_oflags = 0;
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if (map[i].br_state == XFS_EXT_UNWRITTEN)
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out.bmv_oflags |= BMV_OF_PREALLOC;
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whichfork == XFS_ATTR_FORK) {
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/* came to the end of attribute fork */
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out.bmv_oflags |= BMV_OF_LAST;
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goto unlock_and_return;
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} else {
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int full = 0; /* user array is full */
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if (!xfs_getbmapx_fix_eof_hole(ip, &out,
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prealloced, bmvend,
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map[i].br_startblock)) {
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goto unlock_and_return;
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}
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/* format results & advance arg */
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error = formatter(&arg, &out, &full);
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if (error || full)
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goto unlock_and_return;
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nexleft--;
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bmv->bmv_offset =
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out.bmv_offset + out.bmv_length;
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bmv->bmv_length = MAX((__int64_t)0,
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(__int64_t)(bmvend - bmv->bmv_offset));
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bmv->bmv_entries++;
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goto out_free_map;
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}
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if (!xfs_getbmapx_fix_eof_hole(ip, &out, prealloced,
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bmvend, map[i].br_startblock))
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goto out_free_map;
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/* format results & advance arg */
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error = formatter(&arg, &out, &full);
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if (error || full)
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goto out_free_map;
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nexleft--;
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bmv->bmv_offset =
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out.bmv_offset + out.bmv_length;
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bmv->bmv_length =
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max_t(__int64_t, 0, bmvend - bmv->bmv_offset);
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bmv->bmv_entries++;
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}
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} while (nmap && nexleft && bmv->bmv_length);
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unlock_and_return:
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xfs_iunlock_map_shared(ip, lock);
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xfs_iunlock(ip, XFS_IOLOCK_SHARED);
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out_free_map:
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kmem_free(map);
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out_unlock_ilock:
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xfs_iunlock_map_shared(ip, lock);
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out_unlock_iolock:
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xfs_iunlock(ip, XFS_IOLOCK_SHARED);
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return error;
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}
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