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authorChristoph Hellwig <hch@infradead.org>2009-04-29 10:50:48 -0400
committerFelix Blyakher <felixb@sgi.com>2009-04-30 00:28:31 -0500
commit5f79ed685fc6122018c4b5826e2e5bdb7bc6f109 (patch)
tree1d6ca51c760639bd1852c5af280ceca4cad91f08 /fs
parentb9ec9068d79e039507a247ebc5bc9c0ce53654ce (diff)
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/xfs/xfs_bmap.c162
1 files changed, 79 insertions, 83 deletions
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 3a6ed426327a..abe42448b1c0 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -5880,7 +5880,7 @@ 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 */
@@ -5899,30 +5899,8 @@ 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 &&
@@ -5936,11 +5914,37 @@ 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;
@@ -5949,42 +5953,34 @@ 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);
@@ -5995,23 +5991,25 @@ 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.
*/
+ error = ENOMEM;
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;
@@ -6023,10 +6021,12 @@ 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;
@@ -6041,36 +6041,32 @@ 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;
}