[PATCH 3/6] merge xfs_imap into xfs_dilocate

Christoph Hellwig
2008-10-27T13:41:46Z

[-- Attachment #1: xfs-merge-xfs_imap-xfs_dilocate --]
[-- Type: text/plain, Size: 12712 bytes --]

xfs_imap is the only caller of xfs_dilocate and doesn't add any significant
value. Merge the two functions and document the various cases we have for
inode cluster lookup in the new xfs_imap.

Also remove the unused im_agblkno and im_ioffset fields from struct xfs_imap
while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: linux-2.6-xfs/fs/xfs/xfs_ialloc.c
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/xfs_ialloc.c 2008-10-25 13:28:32.000000000 +0200
+++ linux-2.6-xfs/fs/xfs/xfs_ialloc.c 2008-10-25 13:28:50.000000000 +0200
@@ -40,6 +40,7 @@
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_bmap.h"
+#include "xfs_imap.h"

/*
@@ -1196,36 +1197,28 @@ error0:
}

/*
- * Return the location of the inode in bno/off, for mapping it into a buffer.
+ * Return the location of the inode in imap, for mapping it into a buffer.
*/
-/*ARGSUSED*/
int
-xfs_dilocate(
- xfs_mount_t *mp, /* file system mount structure */
- xfs_trans_t *tp, /* transaction pointer */
+xfs_imap(
+ xfs_mount_t *mp, /* file system mount structure */
+ xfs_trans_t *tp, /* transaction pointer */
xfs_ino_t ino, /* inode to locate */
- xfs_fsblock_t *bno, /* output: block containing inode */
- int *len, /* output: num blocks in inode cluster */
- int *off, /* output: index in block of inode */
- uint flags) /* flags concerning inode lookup */
+ struct xfs_imap *imap, /* location map structure */
+ uint flags) /* flags for inode btree lookup */
{
xfs_agblock_t agbno; /* block number of inode in the alloc group */
- xfs_buf_t *agbp; /* agi buffer */
xfs_agino_t agino; /* inode number within alloc group */
xfs_agnumber_t agno; /* allocation group number */
int blks_per_cluster; /* num blocks per inode cluster */
xfs_agblock_t chunk_agbno; /* first block in inode chunk */
- xfs_agino_t chunk_agino; /* first agino in inode chunk */
- __int32_t chunk_cnt; /* count of free inodes in chunk */
- xfs_inofree_t chunk_free; /* mask of free inodes in chunk */
xfs_agblock_t cluster_agbno; /* first block in inode cluster */
- xfs_btree_cur_t *cur; /* inode btree cursor */
int error; /* error code */
- int i; /* temp state */
int offset; /* index of inode in its buffer */
int offset_agbno; /* blks from chunk start to inode */

ASSERT(ino != NULLFSINO);
+
/*
* Split up the inode number into its parts.
*/
@@ -1240,20 +1233,20 @@ xfs_dilocate(
return XFS_ERROR(EINVAL);
if (agno >= mp->m_sb.sb_agcount) {
xfs_fs_cmn_err(CE_ALERT, mp,
- "xfs_dilocate: agno (%d) >= "
+ "xfs_imap: agno (%d) >= "
"mp->m_sb.sb_agcount (%d)",
agno, mp->m_sb.sb_agcount);
}
if (agbno >= mp->m_sb.sb_agblocks) {
xfs_fs_cmn_err(CE_ALERT, mp,
- "xfs_dilocate: agbno (0x%llx) >= "
+ "xfs_imap: agbno (0x%llx) >= "
"mp->m_sb.sb_agblocks (0x%lx)",
(unsigned long long) agbno,
(unsigned long) mp->m_sb.sb_agblocks);
}
if (ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
xfs_fs_cmn_err(CE_ALERT, mp,
- "xfs_dilocate: ino (0x%llx) != "
+ "xfs_imap: ino (0x%llx) != "
"XFS_AGINO_TO_INO(mp, agno, agino) "
"(0x%llx)",
ino, XFS_AGINO_TO_INO(mp, agno, agino));
@@ -1262,34 +1255,65 @@ xfs_dilocate(
#endif /* DEBUG */
return XFS_ERROR(EINVAL);
}
- if ((mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(mp))) {
+
+ /*
+ * If the inode cluster size is the same as the blocksize or
+ * bigger we get to the buffer by simple arithmetics.
+ */
+ if (XFS_INODE_CLUSTER_SIZE(mp) <= mp->m_sb.sb_blocksize) {
offset = XFS_INO_TO_OFFSET(mp, ino);
ASSERT(offset < mp->m_sb.sb_inopblock);
- *bno = XFS_AGB_TO_FSB(mp, agno, agbno);
- *off = offset;
- *len = 1;
+
+ imap->im_blkno = XFS_AGB_TO_DADDR(mp, agno, agbno);
+ imap->im_len = XFS_FSB_TO_BB(mp, 1);
+ imap->im_boffset = (ushort)(offset << mp->m_sb.sb_inodelog);
return 0;
}
+
blks_per_cluster = XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_blocklog;
- if (*bno != NULLFSBLOCK) {
+
+ /*
+ * If we get a block number passed from bulkstat we can use it to
+ * find the buffer easily.
+ */
+ if (imap->im_blkno) {
offset = XFS_INO_TO_OFFSET(mp, ino);
ASSERT(offset < mp->m_sb.sb_inopblock);
- cluster_agbno = XFS_FSB_TO_AGBNO(mp, *bno);
- *off = ((agbno - cluster_agbno) * mp->m_sb.sb_inopblock) +
- offset;
- *len = blks_per_cluster;
+
+ cluster_agbno = XFS_DADDR_TO_AGBNO(mp, imap->im_blkno);
+ offset += (agbno - cluster_agbno) * mp->m_sb.sb_inopblock;
+
+ imap->im_len = XFS_FSB_TO_BB(mp, blks_per_cluster);
+ imap->im_boffset = (ushort)(offset << mp->m_sb.sb_inodelog);
return 0;
}
+
+ /*
+ * With aligned inodes it's again quite simple and we can skip the
+ * btree lookup.
+ */
if (mp->m_inoalign_mask) {
offset_agbno = agbno & mp->m_inoalign_mask;
chunk_agbno = agbno - offset_agbno;
+
+ /*
+ * Worst case: we actually have to actually perform a lookup in the
+ * inode btree.
+ */
} else {
+ xfs_btree_cur_t *cur; /* inode btree cursor */
+ xfs_agino_t chunk_agino; /* first agino in inode chunk */
+ __int32_t chunk_cnt; /* count of free inodes in chunk */
+ xfs_inofree_t chunk_free; /* mask of free inodes in chunk */
+ xfs_buf_t *agbp; /* agi buffer */
+ int i; /* temp state */
+
down_read(&mp->m_peraglock);
error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
up_read(&mp->m_peraglock);
if (error) {
#ifdef DEBUG
- xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
+ xfs_fs_cmn_err(CE_ALERT, mp, "xfs_imap: "
"xfs_ialloc_read_agi() returned "
"error %d, agno %d",
error, agno);
@@ -1299,7 +1323,7 @@ xfs_dilocate(
cur = xfs_inobt_init_cursor(mp, tp, agbp, agno);
if ((error = xfs_inobt_lookup_le(cur, agino, 0, 0, &i))) {
#ifdef DEBUG
- xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
+ xfs_fs_cmn_err(CE_ALERT, mp, "xfs_imap: "
"xfs_inobt_lookup_le() failed");
#endif /* DEBUG */
goto error0;
@@ -1307,18 +1331,19 @@ xfs_dilocate(
if ((error = xfs_inobt_get_rec(cur, &chunk_agino, &chunk_cnt,
&chunk_free, &i))) {
#ifdef DEBUG
- xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
+ xfs_fs_cmn_err(CE_ALERT, mp, "xfs_imap: "
"xfs_inobt_get_rec() failed");
#endif /* DEBUG */
goto error0;
}
if (i == 0) {
#ifdef DEBUG
- xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
+ xfs_fs_cmn_err(CE_ALERT, mp, "xfs_imap: "
"xfs_inobt_get_rec() failed");
#endif /* DEBUG */
error = XFS_ERROR(EINVAL);
}
+ error0:
xfs_trans_brelse(tp, agbp);
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
if (error)
@@ -1326,19 +1351,35 @@ xfs_dilocate(
chunk_agbno = XFS_AGINO_TO_AGBNO(mp, chunk_agino);
offset_agbno = agbno - chunk_agbno;
}
+
ASSERT(agbno >= chunk_agbno);
cluster_agbno = chunk_agbno +
((offset_agbno / blks_per_cluster) * blks_per_cluster);
offset = ((agbno - cluster_agbno) * mp->m_sb.sb_inopblock) +
XFS_INO_TO_OFFSET(mp, ino);
- *bno = XFS_AGB_TO_FSB(mp, agno, cluster_agbno);
- *off = offset;
- *len = blks_per_cluster;
+
+ imap->im_blkno = XFS_AGB_TO_DADDR(mp, agno, cluster_agbno);
+ imap->im_len = XFS_FSB_TO_BB(mp, blks_per_cluster);
+ imap->im_boffset = (ushort)(offset << mp->m_sb.sb_inodelog);
+
+ /*
+ * If the inode number maps to a block outside the bounds
+ * of the file system then return NULL rather than calling
+ * read_buf and panicing when we get an error from the
+ * driver.
+ */
+ if ((imap->im_blkno + imap->im_len) >
+ XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)) {
+ xfs_fs_cmn_err(CE_ALERT, mp, "xfs_imap: "
+ "(imap->im_blkno (0x%llx) + imap->im_len (0x%llx)) > "
+ " XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) (0x%llx)",
+ (unsigned long long) imap->im_blkno,
+ (unsigned long long) imap->im_len,
+ XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks));
+ return EINVAL;
+ }
+
return 0;
-error0:
- xfs_trans_brelse(tp, agbp);
- xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
- return error;
}

/*
Index: linux-2.6-xfs/fs/xfs/xfs_ialloc.h
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/xfs_ialloc.h 2008-10-01 06:30:30.000000000 +0200
+++ linux-2.6-xfs/fs/xfs/xfs_ialloc.h 2008-10-25 13:28:50.000000000 +0200
@@ -20,6 +20,7 @@

struct xfs_buf;
struct xfs_dinode;
+struct xfs_imap;
struct xfs_mount;
struct xfs_trans;

@@ -104,17 +105,14 @@ xfs_difree(
xfs_ino_t *first_ino); /* first inode in deleted cluster */

/*
- * Return the location of the inode in bno/len/off,
- * for mapping it into a buffer.
+ * Return the location of the inode in imap, for mapping it into a buffer.
*/
int
-xfs_dilocate(
+xfs_imap(
struct xfs_mount *mp, /* file system mount structure */
struct xfs_trans *tp, /* transaction pointer */
xfs_ino_t ino, /* inode to locate */
- xfs_fsblock_t *bno, /* output: block containing inode */
- int *len, /* output: num blocks in cluster*/
- int *off, /* output: index in block of inode */
+ struct xfs_imap *imap, /* location map structure */
uint flags); /* flags for inode btree lookup */

/*
Index: linux-2.6-xfs/fs/xfs/xfs_imap.h
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/xfs_imap.h 2008-10-01 06:30:30.000000000 +0200
+++ linux-2.6-xfs/fs/xfs/xfs_imap.h 2008-10-25 13:28:50.000000000 +0200
@@ -25,14 +25,7 @@
typedef struct xfs_imap {
xfs_daddr_t im_blkno; /* starting BB of inode chunk */
uint im_len; /* length in BBs of inode chunk */
- xfs_agblock_t im_agblkno; /* logical block of inode chunk in ag */
- ushort im_ioffset; /* inode offset in block in "inodes" */
ushort im_boffset; /* inode offset in block in bytes */
} xfs_imap_t;

-struct xfs_mount;
-struct xfs_trans;
-int xfs_imap(struct xfs_mount *, struct xfs_trans *, xfs_ino_t,
- xfs_imap_t *, uint);
-
#endif /* __XFS_IMAP_H__ */
Index: linux-2.6-xfs/fs/xfs/xfs_inode.c
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/xfs_inode.c 2008-10-25 13:28:32.000000000 +0200
+++ linux-2.6-xfs/fs/xfs/xfs_inode.c 2008-10-25 13:28:50.000000000 +0200
@@ -266,7 +266,7 @@ xfs_inotobp(
* in once, thus we can use the mapping information stored in the inode
* rather than calling xfs_imap(). This allows us to avoid the overhead
* of looking at the inode btree for small block file systems
- * (see xfs_dilocate()).
+ * (see xfs_imap()).
*/
int
xfs_itobp(
@@ -2505,64 +2505,6 @@ xfs_idata_realloc(
ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
}

-
-
-
-/*
- * Map inode to disk block and offset.
- *
- * mp -- the mount point structure for the current file system
- * tp -- the current transaction
- * ino -- the inode number of the inode to be located
- * imap -- this structure is filled in with the information necessary
- * to retrieve the given inode from disk
- * flags -- flags to pass to xfs_dilocate indicating whether or not
- * lookups in the inode btree were OK or not
- */
-int
-xfs_imap(
- xfs_mount_t *mp,
- xfs_trans_t *tp,
- xfs_ino_t ino,
- xfs_imap_t *imap,
- uint flags)
-{
- xfs_fsblock_t fsbno;
- int len;
- int off;
- int error;
-
- fsbno = imap->im_blkno ?
- XFS_DADDR_TO_FSB(mp, imap->im_blkno) : NULLFSBLOCK;
- error = xfs_dilocate(mp, tp, ino, &fsbno, &len, &off, flags);
- if (error)
- return error;
-
- imap->im_blkno = XFS_FSB_TO_DADDR(mp, fsbno);
- imap->im_len = XFS_FSB_TO_BB(mp, len);
- imap->im_agblkno = XFS_FSB_TO_AGBNO(mp, fsbno);
- imap->im_ioffset = (ushort)off;
- imap->im_boffset = (ushort)(off << mp->m_sb.sb_inodelog);
-
- /*
- * If the inode number maps to a block outside the bounds
- * of the file system then return NULL rather than calling
- * read_buf and panicing when we get an error from the
- * driver.
- */
- if ((imap->im_blkno + imap->im_len) >
- XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)) {
- xfs_fs_cmn_err(CE_ALERT, mp, "xfs_imap: "
- "(imap->im_blkno (0x%llx) + imap->im_len (0x%llx)) > "
- " XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) (0x%llx)",
- (unsigned long long) imap->im_blkno,
- (unsigned long long) imap->im_len,
- XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks));
- return EINVAL;
- }
- return 0;
-}
-
void
xfs_idestroy_fork(
xfs_inode_t *ip,
Index: linux-2.6-xfs/fs/xfs/xfs_inode.h
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/xfs_inode.h 2008-10-25 13:28:32.000000000 +0200
+++ linux-2.6-xfs/fs/xfs/xfs_inode.h 2008-10-25 13:28:50.000000000 +0200
@@ -157,7 +157,7 @@ typedef struct xfs_icdinode {
#define XFS_IFEXTIREC 0x08 /* Indirection array of extent blocks */

/*
- * Flags for xfs_inotobp, xfs_imap() and xfs_dilocate().
+ * Flags for xfs_inotobp and xfs_imap().
*/
#define XFS_IMAP_BULKSTAT 0x1

--