[PATCH 1/2] xfs: a couple getbmap cleanups
Christoph Hellwig
hch at infradead.org
Sun Mar 29 02:44:26 CDT 2009
ping^2?
On Mon, Mar 16, 2009 at 02:30:53AM -0400, Christoph Hellwig wrote:
> ping?
>
> On Tue, Feb 24, 2009 at 08:38:58AM -0500, Christoph Hellwig wrote:
> > - 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 at lst.de>
> >
> > Index: xfs/fs/xfs/xfs_bmap.c
> > ===================================================================
> > --- xfs.orig/fs/xfs/xfs_bmap.c 2009-02-23 18:08:35.352924726 +0100
> > +++ xfs/fs/xfs/xfs_bmap.c 2009-02-23 18:23:49.527051836 +0100
> > @@ -5857,7 +5857,7 @@ xfs_getbmap(
> > void *arg) /* formatter arg */
> > {
> > __int64_t bmvend; /* last block requested */
> > - int error; /* return value */
> > + int error = 0; /* return value */
> > __int64_t fixlen; /* length for -1 case */
> > int i; /* extent number */
> > int lock; /* lock state */
> > @@ -5876,30 +5876,8 @@ xfs_getbmap(
> >
> > mp = ip->i_mount;
> > iflags = bmv->bmv_iflags;
> > -
> > whichfork = iflags & BMV_IF_ATTRFORK ? XFS_ATTR_FORK : XFS_DATA_FORK;
> >
> > - /* If the BMV_IF_NO_DMAPI_READ interface bit specified, do not
> > - * generate a DMAPI read event. Otherwise, if the DM_EVENT_READ
> > - * bit is set for the file, generate a read event in order
> > - * that the DMAPI application may do its thing before we return
> > - * the extents. Usually this means restoring user file data to
> > - * regions of the file that look like holes.
> > - *
> > - * The "old behavior" (from XFS_IOC_GETBMAP) is to not specify
> > - * BMV_IF_NO_DMAPI_READ so that read events are generated.
> > - * If this were not true, callers of ioctl( XFS_IOC_GETBMAP )
> > - * could misinterpret holes in a DMAPI file as true holes,
> > - * when in fact they may represent offline user data.
> > - */
> > - if ((iflags & BMV_IF_NO_DMAPI_READ) == 0 &&
> > - DM_EVENT_ENABLED(ip, DM_EVENT_READ) &&
> > - whichfork == XFS_DATA_FORK) {
> > - error = XFS_SEND_DATA(mp, DM_EVENT_READ, ip, 0, 0, 0, NULL);
> > - if (error)
> > - return XFS_ERROR(error);
> > - }
> > -
> > if (whichfork == XFS_ATTR_FORK) {
> > if (XFS_IFORK_Q(ip)) {
> > if (ip->i_d.di_aformat != XFS_DINODE_FMT_EXTENTS &&
> > @@ -5913,11 +5891,37 @@ xfs_getbmap(
> > ip->i_mount);
> > return XFS_ERROR(EFSCORRUPTED);
> > }
> > - } else if (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
> > - ip->i_d.di_format != XFS_DINODE_FMT_BTREE &&
> > - ip->i_d.di_format != XFS_DINODE_FMT_LOCAL)
> > - return XFS_ERROR(EINVAL);
> > - if (whichfork == XFS_DATA_FORK) {
> > +
> > + prealloced = 0;
> > + fixlen = 1LL << 32;
> > + } else {
> > + /*
> > + * If the BMV_IF_NO_DMAPI_READ interface bit specified, do
> > + * not generate a DMAPI read event. Otherwise, if the
> > + * DM_EVENT_READ bit is set for the file, generate a read
> > + * event in order that the DMAPI application may do its thing
> > + * before we return the extents. Usually this means restoring
> > + * user file data to regions of the file that look like holes.
> > + *
> > + * The "old behavior" (from XFS_IOC_GETBMAP) is to not specify
> > + * BMV_IF_NO_DMAPI_READ so that read events are generated.
> > + * If this were not true, callers of ioctl(XFS_IOC_GETBMAP)
> > + * could misinterpret holes in a DMAPI file as true holes,
> > + * when in fact they may represent offline user data.
> > + */
> > + if (DM_EVENT_ENABLED(ip, DM_EVENT_READ) &&
> > + !(iflags & BMV_IF_NO_DMAPI_READ)) {
> > + error = XFS_SEND_DATA(mp, DM_EVENT_READ, ip,
> > + 0, 0, 0, NULL);
> > + if (error)
> > + return XFS_ERROR(error);
> > + }
> > +
> > + if (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
> > + ip->i_d.di_format != XFS_DINODE_FMT_BTREE &&
> > + ip->i_d.di_format != XFS_DINODE_FMT_LOCAL)
> > + return XFS_ERROR(EINVAL);
> > +
> > if (xfs_get_extsz_hint(ip) ||
> > ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC|XFS_DIFLAG_APPEND)){
> > prealloced = 1;
> > @@ -5926,42 +5930,34 @@ xfs_getbmap(
> > prealloced = 0;
> > fixlen = ip->i_size;
> > }
> > - } else {
> > - prealloced = 0;
> > - fixlen = 1LL << 32;
> > }
> >
> > if (bmv->bmv_length == -1) {
> > fixlen = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, fixlen));
> > - bmv->bmv_length = MAX( (__int64_t)(fixlen - bmv->bmv_offset),
> > - (__int64_t)0);
> > - } else if (bmv->bmv_length < 0)
> > - return XFS_ERROR(EINVAL);
> > - if (bmv->bmv_length == 0) {
> > + bmv->bmv_length =
> > + max_t(__int64_t, fixlen - bmv->bmv_offset, 0);
> > + } else if (bmv->bmv_length == 0) {
> > bmv->bmv_entries = 0;
> > return 0;
> > + } else if (bmv->bmv_length < 0) {
> > + return XFS_ERROR(EINVAL);
> > }
> > +
> > nex = bmv->bmv_count - 1;
> > if (nex <= 0)
> > return XFS_ERROR(EINVAL);
> > bmvend = bmv->bmv_offset + bmv->bmv_length;
> >
> > xfs_ilock(ip, XFS_IOLOCK_SHARED);
> > -
> > - if (((iflags & BMV_IF_DELALLOC) == 0) &&
> > - (whichfork == XFS_DATA_FORK) &&
> > - (ip->i_delayed_blks || ip->i_size > ip->i_d.di_size)) {
> > - /* xfs_fsize_t last_byte = xfs_file_last_byte(ip); */
> > - error = xfs_flush_pages(ip, (xfs_off_t)0,
> > - -1, 0, FI_REMAPF);
> > - if (error) {
> > - xfs_iunlock(ip, XFS_IOLOCK_SHARED);
> > - return error;
> > + if (whichfork == XFS_DATA_FORK && !(iflags & BMV_IF_DELALLOC)) {
> > + if (ip->i_delayed_blks || ip->i_size > ip->i_d.di_size) {
> > + error = xfs_flush_pages(ip, 0, -1, 0, FI_REMAPF);
> > + if (error)
> > + goto out_unlock_iolock;
> > }
> > - }
> >
> > - ASSERT(whichfork == XFS_ATTR_FORK || (iflags & BMV_IF_DELALLOC) ||
> > - ip->i_delayed_blks == 0);
> > + ASSERT(ip->i_delayed_blks == 0);
> > + }
> >
> > lock = xfs_ilock_map_shared(ip);
> >
> > @@ -5972,23 +5968,24 @@ xfs_getbmap(
> > if (nex > XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1)
> > nex = XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1;
> >
> > - bmapi_flags = xfs_bmapi_aflag(whichfork) |
> > - ((iflags & BMV_IF_PREALLOC) ? 0 : XFS_BMAPI_IGSTATE);
> > + bmapi_flags = xfs_bmapi_aflag(whichfork);
> > + if (!(iflags & BMV_IF_PREALLOC))
> > + bmapi_flags |= XFS_BMAPI_IGSTATE;
> >
> > /*
> > * Allocate enough space to handle "subnex" maps at a time.
> > */
> > subnex = 16;
> > - map = kmem_alloc(subnex * sizeof(*map), KM_SLEEP);
> > + map = kmem_alloc(subnex * sizeof(*map), KM_MAYFAIL);
> > + if (!map)
> > + goto out_unlock_ilock;
> >
> > bmv->bmv_entries = 0;
> >
> > - if ((XFS_IFORK_NEXTENTS(ip, whichfork) == 0)) {
> > - if (((iflags & BMV_IF_DELALLOC) == 0) ||
> > - whichfork == XFS_ATTR_FORK) {
> > - error = 0;
> > - goto unlock_and_return;
> > - }
> > + if (XFS_IFORK_NEXTENTS(ip, whichfork) == 0 &&
> > + (whichfork == XFS_ATTR_FORK || !(iflags & BMV_IF_DELALLOC))) {
> > + error = 0;
> > + goto out_free_map;
> > }
> >
> > nexleft = nex;
> > @@ -6000,10 +5997,12 @@ xfs_getbmap(
> > bmapi_flags, NULL, 0, map, &nmap,
> > NULL, NULL);
> > if (error)
> > - goto unlock_and_return;
> > + goto out_free_map;
> > ASSERT(nmap <= subnex);
> >
> > for (i = 0; i < nmap && nexleft && bmv->bmv_length; i++) {
> > + int full = 0; /* user array is full */
> > +
> > out.bmv_oflags = 0;
> > if (map[i].br_state == XFS_EXT_UNWRITTEN)
> > out.bmv_oflags |= BMV_OF_PREALLOC;
> > @@ -6018,36 +6017,32 @@ xfs_getbmap(
> > whichfork == XFS_ATTR_FORK) {
> > /* came to the end of attribute fork */
> > out.bmv_oflags |= BMV_OF_LAST;
> > - goto unlock_and_return;
> > - } else {
> > - int full = 0; /* user array is full */
> > -
> > - if (!xfs_getbmapx_fix_eof_hole(ip, &out,
> > - prealloced, bmvend,
> > - map[i].br_startblock)) {
> > - goto unlock_and_return;
> > - }
> > -
> > - /* format results & advance arg */
> > - error = formatter(&arg, &out, &full);
> > - if (error || full)
> > - goto unlock_and_return;
> > - nexleft--;
> > - bmv->bmv_offset =
> > - out.bmv_offset + out.bmv_length;
> > - bmv->bmv_length = MAX((__int64_t)0,
> > - (__int64_t)(bmvend - bmv->bmv_offset));
> > - bmv->bmv_entries++;
> > + goto out_free_map;
> > }
> > +
> > + if (!xfs_getbmapx_fix_eof_hole(ip, &out, prealloced,
> > + bmvend, map[i].br_startblock))
> > + goto out_free_map;
> > +
> > + /* format results & advance arg */
> > + error = formatter(&arg, &out, &full);
> > + if (error || full)
> > + goto out_free_map;
> > + nexleft--;
> > + bmv->bmv_offset =
> > + out.bmv_offset + out.bmv_length;
> > + bmv->bmv_length =
> > + max_t(__int64_t, 0, bmvend - bmv->bmv_offset);
> > + bmv->bmv_entries++;
> > }
> > } while (nmap && nexleft && bmv->bmv_length);
> >
> > -unlock_and_return:
> > + out_free_map:
> > + kmem_free(map);
> > + out_unlock_ilock:
> > xfs_iunlock_map_shared(ip, lock);
> > + out_unlock_iolock:
> > xfs_iunlock(ip, XFS_IOLOCK_SHARED);
> > -
> > - kmem_free(map);
> > -
> > return error;
> > }
> >
> >
> > _______________________________________________
> > xfs mailing list
> > xfs at oss.sgi.com
> > http://oss.sgi.com/mailman/listinfo/xfs
> ---end quoted text---
>
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> http://oss.sgi.com/mailman/listinfo/xfs
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