Add a common helper for finding the last extent in a file.
Largely based on a patch from Dave Chinner.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Alex Elder <aelder@xxxxxxx>
Index: xfs/fs/xfs/xfs_bmap.c
===================================================================
--- xfs.orig/fs/xfs/xfs_bmap.c 2011-09-11 08:44:25.179789415 -0400
+++ xfs/fs/xfs/xfs_bmap.c 2011-09-11 08:45:03.903122527 -0400
@@ -204,19 +204,6 @@ xfs_bmap_search_extents(
xfs_bmbt_irec_t *prevp); /* out: previous extent entry found */
/*
- * Check the last inode extent to determine whether this allocation will result
- * in blocks being allocated at the end of the file. When we allocate new data
- * blocks at the end of the file which do not start at the previous data block,
- * we will try to align the new blocks at stripe unit boundaries.
- */
-STATIC int /* error */
-xfs_bmap_isaeof(
- xfs_inode_t *ip, /* incore inode pointer */
- xfs_fileoff_t off, /* file offset in fsblocks */
- int whichfork, /* data or attribute fork */
- char *aeof); /* return value */
-
-/*
* Compute the worst-case number of indirect blocks that will be used
* for ip's delayed extent of length "len".
*/
@@ -3924,42 +3911,122 @@ xfs_bmap_last_before(
return 0;
}
+STATIC int
+xfs_bmap_last_extent(
+ struct xfs_trans *tp,
+ struct xfs_inode *ip,
+ int whichfork,
+ struct xfs_bmbt_irec *rec,
+ int *is_empty)
+{
+ struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
+ int error;
+ int nextents;
+
+ if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+ error = xfs_iread_extents(tp, ip, whichfork);
+ if (error)
+ return error;
+ }
+
+ nextents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
+ if (nextents == 0) {
+ *is_empty = 1;
+ return 0;
+ }
+
+ xfs_bmbt_get_all(xfs_iext_get_ext(ifp, nextents - 1), rec);
+ *is_empty = 0;
+ return 0;
+}
+
+/*
+ * Check the last inode extent to determine whether this allocation will result
+ * in blocks being allocated at the end of the file. When we allocate new data
+ * blocks at the end of the file which do not start at the previous data block,
+ * we will try to align the new blocks at stripe unit boundaries.
+ *
+ * Returns 0 in *aeof if the file (fork) is empty as any new write will be at,
+ * or past the EOF.
+ */
+STATIC int
+xfs_bmap_isaeof(
+ struct xfs_inode *ip,
+ xfs_fileoff_t off,
+ int whichfork,
+ char *aeof)
+{
+ struct xfs_bmbt_irec rec;
+ int is_empty;
+ int error;
+
+ *aeof = 0;
+ error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, &is_empty);
+ if (error || is_empty)
+ return error;
+
+ /*
+ * Check if we are allocation or past the last extent, or at least into
+ * the last delayed allocated extent.
+ */
+ *aeof = off >= rec.br_startoff + rec.br_blockcount ||
+ (off >= rec.br_startoff && isnullstartblock(rec.br_startblock));
+ return 0;
+}
+
+/*
+ * Check if the endoff is outside the last extent. If so the caller will grow
+ * the allocation to a stripe unit boundary. All offsets are considered outside
+ * the end of file for an empty fork, so 1 is returned in *eof in that case.
+ */
+int
+xfs_bmap_eof(
+ struct xfs_inode *ip,
+ xfs_fileoff_t endoff,
+ int whichfork,
+ int *eof)
+{
+ struct xfs_bmbt_irec rec;
+ int error;
+
+ error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, eof);
+ if (error || *eof)
+ return error;
+
+ *eof = endoff >= rec.br_startoff + rec.br_blockcount;
+ return 0;
+}
+
/*
* Returns the file-relative block number of the first block past eof in
* the file. This is not based on i_size, it is based on the extent records.
* Returns 0 for local files, as they do not have extent records.
*/
-int /* error */
+int
xfs_bmap_last_offset(
- xfs_trans_t *tp, /* transaction pointer */
- xfs_inode_t *ip, /* incore inode */
- xfs_fileoff_t *last_block, /* last block */
- int whichfork) /* data or attr fork */
+ struct xfs_trans *tp,
+ struct xfs_inode *ip,
+ xfs_fileoff_t *last_block,
+ int whichfork)
{
- xfs_bmbt_rec_host_t *ep; /* pointer to last extent */
- int error; /* error return value */
- xfs_ifork_t *ifp; /* inode fork pointer */
- xfs_extnum_t nextents; /* number of extent entries */
+ struct xfs_bmbt_irec rec;
+ int is_empty;
+ int error;
+
+ *last_block = 0;
+
+ if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL)
+ return 0;
if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE &&
- XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
- XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_LOCAL)
+ XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS)
return XFS_ERROR(EIO);
- if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
- *last_block = 0;
- return 0;
- }
- ifp = XFS_IFORK_PTR(ip, whichfork);
- if (!(ifp->if_flags & XFS_IFEXTENTS) &&
- (error = xfs_iread_extents(tp, ip, whichfork)))
+
+ error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, &is_empty);
+ if (error || is_empty)
return error;
- nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
- if (!nextents) {
- *last_block = 0;
- return 0;
- }
- ep = xfs_iext_get_ext(ifp, nextents - 1);
- *last_block = xfs_bmbt_get_startoff(ep) + xfs_bmbt_get_blockcount(ep);
+
+ *last_block = rec.br_startoff + rec.br_blockcount;
return 0;
}
@@ -5687,89 +5754,6 @@ xfs_getbmap(
return error;
}
-/*
- * Check the last inode extent to determine whether this allocation will result
- * in blocks being allocated at the end of the file. When we allocate new data
- * blocks at the end of the file which do not start at the previous data block,
- * we will try to align the new blocks at stripe unit boundaries.
- */
-STATIC int /* error */
-xfs_bmap_isaeof(
- xfs_inode_t *ip, /* incore inode pointer */
- xfs_fileoff_t off, /* file offset in fsblocks */
- int whichfork, /* data or attribute fork */
- char *aeof) /* return value */
-{
- int error; /* error return value */
- xfs_ifork_t *ifp; /* inode fork pointer */
- xfs_bmbt_rec_host_t *lastrec; /* extent record pointer */
- xfs_extnum_t nextents; /* number of file extents */
- xfs_bmbt_irec_t s; /* expanded extent record */
-
- ASSERT(whichfork == XFS_DATA_FORK);
- ifp = XFS_IFORK_PTR(ip, whichfork);
- if (!(ifp->if_flags & XFS_IFEXTENTS) &&
- (error = xfs_iread_extents(NULL, ip, whichfork)))
- return error;
- nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
- if (nextents == 0) {
- *aeof = 1;
- return 0;
- }
- /*
- * Go to the last extent
- */
- lastrec = xfs_iext_get_ext(ifp, nextents - 1);
- xfs_bmbt_get_all(lastrec, &s);
- /*
- * Check we are allocating in the last extent (for delayed allocations)
- * or past the last extent for non-delayed allocations.
- */
- *aeof = (off >= s.br_startoff &&
- off < s.br_startoff + s.br_blockcount &&
- isnullstartblock(s.br_startblock)) ||
- off >= s.br_startoff + s.br_blockcount;
- return 0;
-}
-
-/*
- * Check if the endoff is outside the last extent. If so the caller will grow
- * the allocation to a stripe unit boundary.
- */
-int /* error */
-xfs_bmap_eof(
- xfs_inode_t *ip, /* incore inode pointer */
- xfs_fileoff_t endoff, /* file offset in fsblocks */
- int whichfork, /* data or attribute fork */
- int *eof) /* result value */
-{
- xfs_fsblock_t blockcount; /* extent block count */
- int error; /* error return value */
- xfs_ifork_t *ifp; /* inode fork pointer */
- xfs_bmbt_rec_host_t *lastrec; /* extent record pointer */
- xfs_extnum_t nextents; /* number of file extents */
- xfs_fileoff_t startoff; /* extent starting file offset */
-
- ASSERT(whichfork == XFS_DATA_FORK);
- ifp = XFS_IFORK_PTR(ip, whichfork);
- if (!(ifp->if_flags & XFS_IFEXTENTS) &&
- (error = xfs_iread_extents(NULL, ip, whichfork)))
- return error;
- nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
- if (nextents == 0) {
- *eof = 1;
- return 0;
- }
- /*
- * Go to the last extent
- */
- lastrec = xfs_iext_get_ext(ifp, nextents - 1);
- startoff = xfs_bmbt_get_startoff(lastrec);
- blockcount = xfs_bmbt_get_blockcount(lastrec);
- *eof = endoff >= startoff + blockcount;
- return 0;
-}
-
#ifdef DEBUG
STATIC struct xfs_buf *
xfs_bmap_get_bp(
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