[XFS] use filldir internally

Currently xfs has a rather complicated internal scheme to allow for
different directory formats in IRIX. This patch rips all code related to
this out and pushes useage of the Linux filldir callback into the lowlevel
directory code. This does not make the code any less portable because
filldir can be used to create dirents of all possible variations
(including the IRIX ones as proved by the IRIX binary emulation code under
arch/mips/).

This patch get rid of an unessecary copy in the readdir path, about 400
lines of code and one of the last two users of the uio structure.

This version is updated to deal with dmapi aswell which greatly simplifies
the get_dirattrs code. The dmapi part has been tested using the
get_dirattrs tools from the xfstest dmapi suite1 with various small and
large directories.

SGI-PV: 968563
SGI-Modid: xfs-linux-melb:xfs-kern:29478a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

1 files changed, 44 insertions, 77 deletions

diff --git a/fs/xfs/xfs_dir2_sf.c b/fs/xfs/xfs_dir2_sf.c
index 38fc4f22b76d..c67d73572905 100644
--- a/fs/xfs/xfs_dir2_sf.c
+++ b/fs/xfs/xfs_dir2_sf.c
@@ -695,19 +695,18 @@ xfs_dir2_sf_create(
 int                                             /* error */
 xfs_dir2_sf_getdents(
         xfs_inode_t             *dp,            /* incore directory inode */
-        uio_t                   *uio,           /* caller's buffer control */
-        int                     *eofp,          /* eof reached? (out) */
-        xfs_dirent_t            *dbp,           /* caller's buffer */
-        xfs_dir2_put_t          put)            /* abi's formatting function */
+        void                    *dirent,
+        xfs_off_t               *offset,
+        filldir_t               filldir)
 {
-        int                     error;          /* error return value */
         int                     i;              /* shortform entry number */
         xfs_mount_t             *mp;            /* filesystem mount point */
         xfs_dir2_dataptr_t      off;            /* current entry's offset */
-        xfs_dir2_put_args_t     p;              /* arg package for put rtn */
         xfs_dir2_sf_entry_t     *sfep;          /* shortform directory entry */
         xfs_dir2_sf_t           *sfp;           /* shortform structure */
-        xfs_off_t                       dir_offset;
+        xfs_dir2_dataptr_t      dot_offset;
+        xfs_dir2_dataptr_t      dotdot_offset;
+        xfs_ino_t               ino;
 
         mp = dp->i_mount;
 
@@ -720,8 +719,6 @@ xfs_dir2_sf_getdents(
                 return XFS_ERROR(EIO);
         }
 
-        dir_offset = uio->uio_offset;
-
         ASSERT(dp->i_df.if_bytes == dp->i_d.di_size);
         ASSERT(dp->i_df.if_u1.if_data != NULL);
 
@@ -732,108 +729,78 @@ xfs_dir2_sf_getdents(
         /*
          * If the block number in the offset is out of range, we're done.
          */
-        if (xfs_dir2_dataptr_to_db(mp, dir_offset) > mp->m_dirdatablk) {
-                *eofp = 1;
+        if (xfs_dir2_dataptr_to_db(mp, *offset) > mp->m_dirdatablk)
                 return 0;
-        }
 
         /*
-         * Set up putargs structure.
+         * Precalculate offsets for . and .. as we will always need them.
+         *
+         * XXX(hch): the second argument is sometimes 0 and sometimes
+         * mp->m_dirdatablk.
          */
-        p.dbp = dbp;
-        p.put = put;
-        p.uio = uio;
+        dot_offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
+                                             XFS_DIR2_DATA_DOT_OFFSET);
+        dotdot_offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
+                                                XFS_DIR2_DATA_DOTDOT_OFFSET);
+
         /*
          * Put . entry unless we're starting past it.
          */
-        if (dir_offset <=
-                    xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
-                                               XFS_DIR2_DATA_DOT_OFFSET)) {
-                p.cook = xfs_dir2_db_off_to_dataptr(mp, 0,
-                                                XFS_DIR2_DATA_DOTDOT_OFFSET);
-                p.ino = dp->i_ino;
+        if (*offset <= dot_offset) {
+                ino = dp->i_ino;
 #if XFS_BIG_INUMS
-                p.ino += mp->m_inoadd;
+                ino += mp->m_inoadd;
 #endif
-                p.name = ".";
-                p.namelen = 1;
-
-                error = p.put(&p);
-
-                if (!p.done) {
-                        uio->uio_offset =
-                                xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
-                                                XFS_DIR2_DATA_DOT_OFFSET);
-                        return error;
+                if (filldir(dirent, ".", 1, dotdot_offset, ino, DT_DIR)) {
+                        *offset = dot_offset;
+                        return 0;
                 }
         }
 
         /*
          * Put .. entry unless we're starting past it.
          */
-        if (dir_offset <=
-                    xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
-                                               XFS_DIR2_DATA_DOTDOT_OFFSET)) {
-                p.cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
-                                                XFS_DIR2_DATA_FIRST_OFFSET);
-                p.ino = xfs_dir2_sf_get_inumber(sfp, &sfp->hdr.parent);
+        if (*offset <= dotdot_offset) {
+                off = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
+                                                  XFS_DIR2_DATA_FIRST_OFFSET);
+                ino = xfs_dir2_sf_get_inumber(sfp, &sfp->hdr.parent);
 #if XFS_BIG_INUMS
-                p.ino += mp->m_inoadd;
+                ino += mp->m_inoadd;
 #endif
-                p.name = "..";
-                p.namelen = 2;
-
-                error = p.put(&p);
-
-                if (!p.done) {
-                        uio->uio_offset =
-                                xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
-                                        XFS_DIR2_DATA_DOTDOT_OFFSET);
-                        return error;
+                if (filldir(dirent, "..", 2, off, ino, DT_DIR)) {
+                        *offset = dotdot_offset;
+                        return 0;
                 }
         }
 
         /*
          * Loop while there are more entries and put'ing works.
          */
-        for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp);
-                     i < sfp->hdr.count;
-                             i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) {
-
+        sfep = xfs_dir2_sf_firstentry(sfp);
+        for (i = 0; i < sfp->hdr.count; i++) {
                 off = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
                                 xfs_dir2_sf_get_offset(sfep));
 
-                if (dir_offset > off)
+                if (*offset > off) {
+                        sfep = xfs_dir2_sf_nextentry(sfp, sfep);
                         continue;
+                }
 
-                p.namelen = sfep->namelen;
-
-                p.cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
-                        xfs_dir2_sf_get_offset(sfep) +
-                        xfs_dir2_data_entsize(p.namelen));
-
-                p.ino = xfs_dir2_sf_get_inumber(sfp, xfs_dir2_sf_inumberp(sfep));
+                ino = xfs_dir2_sf_get_inumber(sfp, xfs_dir2_sf_inumberp(sfep));
 #if XFS_BIG_INUMS
-                p.ino += mp->m_inoadd;
+                ino += mp->m_inoadd;
 #endif
-                p.name = (char *)sfep->name;
-
-                error = p.put(&p);
 
-                if (!p.done) {
-                        uio->uio_offset = off;
-                        return error;
+                if (filldir(dirent, sfep->name, sfep->namelen,
+                            off + xfs_dir2_data_entsize(sfep->namelen),
+                            ino, DT_UNKNOWN)) {
+                        *offset = off;
+                        return 0;
                 }
+                sfep = xfs_dir2_sf_nextentry(sfp, sfep);
         }
 
-        /*
-         * They all fit.
-         */
-        *eofp = 1;
-
-        uio->uio_offset =
-                xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0);
-
+        *offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0);
         return 0;
 }