[XFS] Add new getbmap flags.

This adds a new output flag, BMV_OF_LAST to indicate if we've hit
the last extent in the inode.  This potentially saves an extra call
from userspace to see when the whole mapping is done.

It also adds BMV_IF_DELALLOC and BMV_OF_DELALLOC to request, and
indicate, delayed-allocation extents.  In this case bmv_block
is set to -2 (-1 was already taken for HOLESTARTBLOCK; unfortunately
these are the reverse of the in-kernel constants.)

These new flags facilitate addition of the new fiemap interface.

Rather than adding sh_delalloc, remove sh_unwritten & just test
the flags directly.

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Niv Sardi <xaiki@sgi.com>

2 files changed, 37 insertions, 15 deletions

diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 8077580a7199..138308e70d14 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -5819,6 +5819,9 @@ xfs_getbmapx_fix_eof_hole(
 {
         __int64_t               fixlen;
         xfs_mount_t             *mp;            /* file system mount point */
+        xfs_ifork_t             *ifp;           /* inode fork pointer */
+        xfs_extnum_t            lastx;          /* last extent pointer */
+        xfs_fileoff_t           fileblock;
 
         if (startblock == HOLESTARTBLOCK) {
                 mp = ip->i_mount;
@@ -5832,7 +5835,15 @@ xfs_getbmapx_fix_eof_hole(
                         out->bmv_length = fixlen;
                 }
         } else {
-                out->bmv_block = XFS_FSB_TO_DB(ip, startblock);
+                if (startblock == DELAYSTARTBLOCK)
+                        out->bmv_block = -2;
+                else
+                        out->bmv_block = XFS_FSB_TO_DB(ip, startblock);
+                fileblock = XFS_BB_TO_FSB(ip->i_mount, out->bmv_offset);
+                ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+                if (xfs_iext_bno_to_ext(ifp, fileblock, &lastx) &&
+                   (lastx == (ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t))-1))
+                        out->bmv_oflags |= BMV_OF_LAST;
         }
 
         return 1;
@@ -5867,8 +5878,6 @@ xfs_getbmap(
         int                     whichfork;      /* data or attr fork */
         int                     prealloced;     /* this is a file with
                                                  * preallocated data space */
-        int                     sh_unwritten;   /* true, if unwritten */
-                                                /* extents listed separately */
         int                     iflags;         /* interface flags */
         int                     bmapi_flags;    /* flags for xfs_bmapi */
 
@@ -5876,7 +5885,6 @@ xfs_getbmap(
         iflags = bmv->bmv_iflags;
 
         whichfork = iflags & BMV_IF_ATTRFORK ? XFS_ATTR_FORK : XFS_DATA_FORK;
-        sh_unwritten = (iflags & BMV_IF_PREALLOC) != 0;
 
         /*      If the BMV_IF_NO_DMAPI_READ interface bit specified, do not
          *      generate a DMAPI read event.  Otherwise, if the DM_EVENT_READ
@@ -5947,8 +5955,9 @@ xfs_getbmap(
 
         xfs_ilock(ip, XFS_IOLOCK_SHARED);
 
-        if (whichfork == XFS_DATA_FORK &&
-                (ip->i_delayed_blks || ip->i_size > ip->i_d.di_size)) {
+        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);
@@ -5958,7 +5967,8 @@ xfs_getbmap(
                 }
         }
 
-        ASSERT(whichfork == XFS_ATTR_FORK || ip->i_delayed_blks == 0);
+        ASSERT(whichfork == XFS_ATTR_FORK || (iflags & BMV_IF_DELALLOC) ||
+               ip->i_delayed_blks == 0);
 
         lock = xfs_ilock_map_shared(ip);
 
@@ -5970,7 +5980,7 @@ xfs_getbmap(
                 nex = XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1;
 
         bmapi_flags = XFS_BMAPI_AFLAG(whichfork) |
-                        ((sh_unwritten) ? 0 : XFS_BMAPI_IGSTATE);
+                        ((iflags & BMV_IF_PREALLOC) ? 0 : XFS_BMAPI_IGSTATE);
 
         /*
          * Allocate enough space to handle "subnex" maps at a time.
@@ -5980,9 +5990,12 @@ xfs_getbmap(
 
         bmv->bmv_entries = 0;
 
-        if (XFS_IFORK_NEXTENTS(ip, whichfork) == 0) {
-                error = 0;
-                goto unlock_and_return;
+        if ((XFS_IFORK_NEXTENTS(ip, whichfork) == 0)) {
+                if (((iflags & BMV_IF_DELALLOC) == 0) ||
+                    whichfork == XFS_ATTR_FORK) {
+                        error = 0;
+                        goto unlock_and_return;
+                }
         }
 
         nexleft = nex;
@@ -5998,15 +6011,20 @@ xfs_getbmap(
                 ASSERT(nmap <= subnex);
 
                 for (i = 0; i < nmap && nexleft && bmv->bmv_length; i++) {
-                        out.bmv_oflags = (map[i].br_state == XFS_EXT_UNWRITTEN) ?
-                                        BMV_OF_PREALLOC : 0;
+                        out.bmv_oflags = 0;
+                        if (map[i].br_state == XFS_EXT_UNWRITTEN)
+                                out.bmv_oflags |= BMV_OF_PREALLOC;
+                        else if (map[i].br_startblock == DELAYSTARTBLOCK)
+                                out.bmv_oflags |= BMV_OF_DELALLOC;
                         out.bmv_offset = XFS_FSB_TO_BB(mp, map[i].br_startoff);
                         out.bmv_length = XFS_FSB_TO_BB(mp, map[i].br_blockcount);
                         out.bmv_unused1 = out.bmv_unused2 = 0;
-                        ASSERT(map[i].br_startblock != DELAYSTARTBLOCK);
+                        ASSERT(((iflags & BMV_IF_DELALLOC) != 0) ||
+                              (map[i].br_startblock != DELAYSTARTBLOCK));
                         if (map[i].br_startblock == HOLESTARTBLOCK &&
                             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 */
diff --git a/fs/xfs/xfs_fs.h b/fs/xfs/xfs_fs.h
index df859d62a163..4ae03bae992f 100644
--- a/fs/xfs/xfs_fs.h
+++ b/fs/xfs/xfs_fs.h
@@ -113,10 +113,14 @@ struct getbmapx {
 #define BMV_IF_ATTRFORK         0x1     /* return attr fork rather than data */
 #define BMV_IF_NO_DMAPI_READ    0x2     /* Do not generate DMAPI read event  */
 #define BMV_IF_PREALLOC         0x4     /* rtn status BMV_OF_PREALLOC if req */
-#define BMV_IF_VALID    (BMV_IF_ATTRFORK|BMV_IF_NO_DMAPI_READ|BMV_IF_PREALLOC)
+#define BMV_IF_DELALLOC         0x8     /* rtn status BMV_OF_DELALLOC if req */
+#define BMV_IF_VALID    \
+        (BMV_IF_ATTRFORK|BMV_IF_NO_DMAPI_READ|BMV_IF_PREALLOC|BMV_IF_DELALLOC)
 
 /*      bmv_oflags values - returned for for each non-header segment */
 #define BMV_OF_PREALLOC         0x1     /* segment = unwritten pre-allocation */
+#define BMV_OF_DELALLOC         0x2     /* segment = delayed allocation */
+#define BMV_OF_LAST             0x4     /* segment is the last in the file */
 
 /*
  * Structure for XFS_IOC_FSSETDM.