3 files changed, 142 insertions, 196 deletions

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 92e8f99a5857..281002689d64 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1338,7 +1338,10 @@ xfs_free_file_space(
         goto out;
 }
 
-
+/*
+ * Preallocate and zero a range of a file. This mechanism has the allocation
+ * semantics of fallocate and in addition converts data in the range to zeroes.
+ */
 int
 xfs_zero_file_space(
         struct xfs_inode        *ip,
@@ -1346,65 +1349,30 @@ xfs_zero_file_space(
         xfs_off_t               len)
 {
         struct xfs_mount        *mp = ip->i_mount;
-        uint                    granularity;
-        xfs_off_t               start_boundary;
-        xfs_off_t               end_boundary;
+        uint                    blksize;
         int                     error;
 
         trace_xfs_zero_file_space(ip);
 
-        granularity = max_t(uint, 1 << mp->m_sb.sb_blocklog, PAGE_CACHE_SIZE);
+        blksize = 1 << mp->m_sb.sb_blocklog;
 
         /*
-         * Round the range of extents we are going to convert inwards.  If the
-         * offset is aligned, then it doesn't get changed so we zero from the
-         * start of the block offset points to.
+         * Punch a hole and prealloc the range. We use hole punch rather than
+         * unwritten extent conversion for two reasons:
+         *
+         * 1.) Hole punch handles partial block zeroing for us.
+         *
+         * 2.) If prealloc returns ENOSPC, the file range is still zero-valued
+         * by virtue of the hole punch.
          */
-        start_boundary = round_up(offset, granularity);
-        end_boundary = round_down(offset + len, granularity);
-
-        ASSERT(start_boundary >= offset);
-        ASSERT(end_boundary <= offset + len);
-
-        if (start_boundary < end_boundary - 1) {
-                /*
-                 * Writeback the range to ensure any inode size updates due to
-                 * appending writes make it to disk (otherwise we could just
-                 * punch out the delalloc blocks).
-                 */
-                error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
-                                start_boundary, end_boundary - 1);
-                if (error)
-                        goto out;
-                truncate_pagecache_range(VFS_I(ip), start_boundary,
-                                         end_boundary - 1);
-
-                /* convert the blocks */
-                error = xfs_alloc_file_space(ip, start_boundary,
-                                        end_boundary - start_boundary - 1,
-                                        XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT);
-                if (error)
-                        goto out;
-
-                /* We've handled the interior of the range, now for the edges */
-                if (start_boundary != offset) {
-                        error = xfs_iozero(ip, offset, start_boundary - offset);
-                        if (error)
-                                goto out;
-                }
-
-                if (end_boundary != offset + len)
-                        error = xfs_iozero(ip, end_boundary,
-                                           offset + len - end_boundary);
-
-        } else {
-                /*
-                 * It's either a sub-granularity range or the range spanned lies
-                 * partially across two adjacent blocks.
-                 */
-                error = xfs_iozero(ip, offset, len);
-        }
+        error = xfs_free_file_space(ip, offset, len);
+        if (error)
+                goto out;
 
+        error = xfs_alloc_file_space(ip, round_down(offset, blksize),
+                                     round_up(offset + len, blksize) -
+                                     round_down(offset, blksize),
+                                     XFS_BMAPI_PREALLOC);
 out:
         return error;
 
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index f1deb961a296..894924a5129b 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -236,8 +236,10 @@ xfs_bulkstat_grab_ichunk(
         XFS_WANT_CORRUPTED_RETURN(stat == 1);
 
         /* Check if the record contains the inode in request */
-        if (irec->ir_startino + XFS_INODES_PER_CHUNK <= agino)
-                return -EINVAL;
+        if (irec->ir_startino + XFS_INODES_PER_CHUNK <= agino) {
+                *icount = 0;
+                return 0;
+        }
 
         idx = agino - irec->ir_startino + 1;
         if (idx < XFS_INODES_PER_CHUNK &&
@@ -262,75 +264,76 @@ xfs_bulkstat_grab_ichunk(
 
 #define XFS_BULKSTAT_UBLEFT(ubleft)     ((ubleft) >= statstruct_size)
 
+struct xfs_bulkstat_agichunk {
+        char            __user **ac_ubuffer;/* pointer into user's buffer */
+        int             ac_ubleft;      /* bytes left in user's buffer */
+        int             ac_ubelem;      /* spaces used in user's buffer */
+};
+
 /*
  * Process inodes in chunk with a pointer to a formatter function
  * that will iget the inode and fill in the appropriate structure.
  */
-int
+static int
 xfs_bulkstat_ag_ichunk(
         struct xfs_mount                *mp,
         xfs_agnumber_t                  agno,
         struct xfs_inobt_rec_incore     *irbp,
         bulkstat_one_pf                 formatter,
         size_t                          statstruct_size,
-        struct xfs_bulkstat_agichunk    *acp)
+        struct xfs_bulkstat_agichunk    *acp,
+        xfs_agino_t                     *last_agino)
 {
-        xfs_ino_t                       lastino = acp->ac_lastino;
         char                            __user **ubufp = acp->ac_ubuffer;
-        int                             ubleft = acp->ac_ubleft;
-        int                             ubelem = acp->ac_ubelem;
-        int                             chunkidx, clustidx;
+        int                             chunkidx;
         int                             error = 0;
-        xfs_agino_t                     agino;
+        xfs_agino_t                     agino = irbp->ir_startino;
 
-        for (agino = irbp->ir_startino, chunkidx = clustidx = 0;
-             XFS_BULKSTAT_UBLEFT(ubleft) &&
-             irbp->ir_freecount < XFS_INODES_PER_CHUNK;
-             chunkidx++, clustidx++, agino++) {
-                int             fmterror;       /* bulkstat formatter result */
+        for (chunkidx = 0; chunkidx < XFS_INODES_PER_CHUNK;
+             chunkidx++, agino++) {
+                int             fmterror;
                 int             ubused;
-                xfs_ino_t       ino = XFS_AGINO_TO_INO(mp, agno, agino);
 
-                ASSERT(chunkidx < XFS_INODES_PER_CHUNK);
+                /* inode won't fit in buffer, we are done */
+                if (acp->ac_ubleft < statstruct_size)
+                        break;
 
                 /* Skip if this inode is free */
-                if (XFS_INOBT_MASK(chunkidx) & irbp->ir_free) {
-                        lastino = ino;
+                if (XFS_INOBT_MASK(chunkidx) & irbp->ir_free)
                         continue;
-                }
-
-                /*
-                 * Count used inodes as free so we can tell when the
-                 * chunk is used up.
-                 */
-                irbp->ir_freecount++;
 
                 /* Get the inode and fill in a single buffer */
                 ubused = statstruct_size;
-                error = formatter(mp, ino, *ubufp, ubleft, &ubused, &fmterror);
-                if (fmterror == BULKSTAT_RV_NOTHING) {
-                        if (error && error != -ENOENT && error != -EINVAL) {
-                                ubleft = 0;
-                                break;
-                        }
-                        lastino = ino;
-                        continue;
-                }
-                if (fmterror == BULKSTAT_RV_GIVEUP) {
-                        ubleft = 0;
+                error = formatter(mp, XFS_AGINO_TO_INO(mp, agno, agino),
+                                  *ubufp, acp->ac_ubleft, &ubused, &fmterror);
+
+                if (fmterror == BULKSTAT_RV_GIVEUP ||
+                    (error && error != -ENOENT && error != -EINVAL)) {
+                        acp->ac_ubleft = 0;
                         ASSERT(error);
                         break;
                 }
-                if (*ubufp)
-                        *ubufp += ubused;
-                ubleft -= ubused;
-                ubelem++;
-                lastino = ino;
+
+                /* be careful not to leak error if at end of chunk */
+                if (fmterror == BULKSTAT_RV_NOTHING || error) {
+                        error = 0;
+                        continue;
+                }
+
+                *ubufp += ubused;
+                acp->ac_ubleft -= ubused;
+                acp->ac_ubelem++;
         }
 
-        acp->ac_lastino = lastino;
-        acp->ac_ubleft = ubleft;
-        acp->ac_ubelem = ubelem;
+        /*
+         * Post-update *last_agino. At this point, agino will always point one
+         * inode past the last inode we processed successfully. Hence we
+         * substract that inode when setting the *last_agino cursor so that we
+         * return the correct cookie to userspace. On the next bulkstat call,
+         * the inode under the lastino cookie will be skipped as we have already
+         * processed it here.
+         */
+        *last_agino = agino - 1;
 
         return error;
 }
@@ -353,45 +356,33 @@ xfs_bulkstat(
         xfs_agino_t             agino;  /* inode # in allocation group */
         xfs_agnumber_t          agno;   /* allocation group number */
         xfs_btree_cur_t         *cur;   /* btree cursor for ialloc btree */
-        int                     end_of_ag; /* set if we've seen the ag end */
-        int                     error;  /* error code */
-        int                     fmterror;/* bulkstat formatter result */
-        int                     i;      /* loop index */
-        int                     icount; /* count of inodes good in irbuf */
         size_t                  irbsize; /* size of irec buffer in bytes */
-        xfs_ino_t               ino;    /* inode number (filesystem) */
-        xfs_inobt_rec_incore_t  *irbp;  /* current irec buffer pointer */
         xfs_inobt_rec_incore_t  *irbuf; /* start of irec buffer */
-        xfs_inobt_rec_incore_t  *irbufend; /* end of good irec buffer entries */
-        xfs_ino_t               lastino; /* last inode number returned */
         int                     nirbuf; /* size of irbuf */
-        int                     rval;   /* return value error code */
-        int                     tmp;    /* result value from btree calls */
         int                     ubcount; /* size of user's buffer */
-        int                     ubleft; /* bytes left in user's buffer */
-        char                    __user *ubufp;  /* pointer into user's buffer */
-        int                     ubelem; /* spaces used in user's buffer */
+        struct xfs_bulkstat_agichunk ac;
+        int                     error = 0;
 
         /*
          * Get the last inode value, see if there's nothing to do.
          */
-        ino = (xfs_ino_t)*lastinop;
-        lastino = ino;
-        agno = XFS_INO_TO_AGNO(mp, ino);
-        agino = XFS_INO_TO_AGINO(mp, ino);
+        agno = XFS_INO_TO_AGNO(mp, *lastinop);
+        agino = XFS_INO_TO_AGINO(mp, *lastinop);
         if (agno >= mp->m_sb.sb_agcount ||
-            ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
+            *lastinop != XFS_AGINO_TO_INO(mp, agno, agino)) {
                 *done = 1;
                 *ubcountp = 0;
                 return 0;
         }
 
         ubcount = *ubcountp; /* statstruct's */
-        ubleft = ubcount * statstruct_size; /* bytes */
-        *ubcountp = ubelem = 0;
+        ac.ac_ubuffer = &ubuffer;
+        ac.ac_ubleft = ubcount * statstruct_size; /* bytes */;
+        ac.ac_ubelem = 0;
+
+        *ubcountp = 0;
         *done = 0;
-        fmterror = 0;
-        ubufp = ubuffer;
+
         irbuf = kmem_zalloc_greedy(&irbsize, PAGE_SIZE, PAGE_SIZE * 4);
         if (!irbuf)
                 return -ENOMEM;
@@ -402,9 +393,13 @@ xfs_bulkstat(
          * Loop over the allocation groups, starting from the last
          * inode returned; 0 means start of the allocation group.
          */
-        rval = 0;
-        while (XFS_BULKSTAT_UBLEFT(ubleft) && agno < mp->m_sb.sb_agcount) {
-                cond_resched();
+        while (agno < mp->m_sb.sb_agcount) {
+                struct xfs_inobt_rec_incore     *irbp = irbuf;
+                struct xfs_inobt_rec_incore     *irbufend = irbuf + nirbuf;
+                bool                            end_of_ag = false;
+                int                             icount = 0;
+                int                             stat;
+
                 error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp);
                 if (error)
                         break;
@@ -414,10 +409,6 @@ xfs_bulkstat(
                  */
                 cur = xfs_inobt_init_cursor(mp, NULL, agbp, agno,
                                             XFS_BTNUM_INO);
-                irbp = irbuf;
-                irbufend = irbuf + nirbuf;
-                end_of_ag = 0;
-                icount = 0;
                 if (agino > 0) {
                         /*
                          * In the middle of an allocation group, we need to get
@@ -427,22 +418,23 @@ xfs_bulkstat(
 
                         error = xfs_bulkstat_grab_ichunk(cur, agino, &icount, &r);
                         if (error)
-                                break;
+                                goto del_cursor;
                         if (icount) {
                                 irbp->ir_startino = r.ir_startino;
                                 irbp->ir_freecount = r.ir_freecount;
                                 irbp->ir_free = r.ir_free;
                                 irbp++;
-                                agino = r.ir_startino + XFS_INODES_PER_CHUNK;
                         }
                         /* Increment to the next record */
-                        error = xfs_btree_increment(cur, 0, &tmp);
+                        error = xfs_btree_increment(cur, 0, &stat);
                 } else {
                         /* Start of ag.  Lookup the first inode chunk */
-                        error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &tmp);
+                        error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &stat);
+                }
+                if (error || stat == 0) {
+                        end_of_ag = true;
+                        goto del_cursor;
                 }
-                if (error)
-                        break;
 
                 /*
                  * Loop through inode btree records in this ag,
@@ -451,10 +443,10 @@ xfs_bulkstat(
                 while (irbp < irbufend && icount < ubcount) {
                         struct xfs_inobt_rec_incore     r;
 
-                        error = xfs_inobt_get_rec(cur, &r, &i);
-                        if (error || i == 0) {
-                                end_of_ag = 1;
-                                break;
+                        error = xfs_inobt_get_rec(cur, &r, &stat);
+                        if (error || stat == 0) {
+                                end_of_ag = true;
+                                goto del_cursor;
                         }
 
                         /*
@@ -469,77 +461,79 @@ xfs_bulkstat(
                                 irbp++;
                                 icount += XFS_INODES_PER_CHUNK - r.ir_freecount;
                         }
-                        /*
-                         * Set agino to after this chunk and bump the cursor.
-                         */
-                        agino = r.ir_startino + XFS_INODES_PER_CHUNK;
-                        error = xfs_btree_increment(cur, 0, &tmp);
+                        error = xfs_btree_increment(cur, 0, &stat);
+                        if (error || stat == 0) {
+                                end_of_ag = true;
+                                goto del_cursor;
+                        }
                         cond_resched();
                 }
+
                 /*
-                 * Drop the btree buffers and the agi buffer.
-                 * We can't hold any of the locks these represent
-                 * when calling iget.
+                 * Drop the btree buffers and the agi buffer as we can't hold any
+                 * of the locks these represent when calling iget. If there is a
+                 * pending error, then we are done.
                  */
+del_cursor:
                 xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
                 xfs_buf_relse(agbp);
+                if (error)
+                        break;
                 /*
-                 * Now format all the good inodes into the user's buffer.
+                 * Now format all the good inodes into the user's buffer. The
+                 * call to xfs_bulkstat_ag_ichunk() sets up the agino pointer
+                 * for the next loop iteration.
                  */
                 irbufend = irbp;
                 for (irbp = irbuf;
-                     irbp < irbufend && XFS_BULKSTAT_UBLEFT(ubleft); irbp++) {
-                        struct xfs_bulkstat_agichunk ac;
-
-                        ac.ac_lastino = lastino;
-                        ac.ac_ubuffer = &ubuffer;
-                        ac.ac_ubleft = ubleft;
-                        ac.ac_ubelem = ubelem;
+                     irbp < irbufend && ac.ac_ubleft >= statstruct_size;
+                     irbp++) {
                         error = xfs_bulkstat_ag_ichunk(mp, agno, irbp,
-                                        formatter, statstruct_size, &ac);
+                                        formatter, statstruct_size, &ac,
+                                        &agino);
                         if (error)
-                                rval = error;
-
-                        lastino = ac.ac_lastino;
-                        ubleft = ac.ac_ubleft;
-                        ubelem = ac.ac_ubelem;
+                                break;
 
                         cond_resched();
                 }
+
                 /*
-                 * Set up for the next loop iteration.
+                 * If we've run out of space or had a formatting error, we
+                 * are now done
                  */
-                if (XFS_BULKSTAT_UBLEFT(ubleft)) {
-                        if (end_of_ag) {
-                                agno++;
-                                agino = 0;
-                        } else
-                                agino = XFS_INO_TO_AGINO(mp, lastino);
-                } else
+                if (ac.ac_ubleft < statstruct_size || error)
                         break;
+
+                if (end_of_ag) {
+                        agno++;
+                        agino = 0;
+                }
         }
         /*
          * Done, we're either out of filesystem or space to put the data.
          */
         kmem_free(irbuf);
-        *ubcountp = ubelem;
+        *ubcountp = ac.ac_ubelem;
+
         /*
-         * Found some inodes, return them now and return the error next time.
+         * We found some inodes, so clear the error status and return them.
+         * The lastino pointer will point directly at the inode that triggered
+         * any error that occurred, so on the next call the error will be
+         * triggered again and propagated to userspace as there will be no
+         * formatted inodes in the buffer.
          */
-        if (ubelem)
-                rval = 0;
-        if (agno >= mp->m_sb.sb_agcount) {
-                /*
-                 * If we ran out of filesystem, mark lastino as off
-                 * the end of the filesystem, so the next call
-                 * will return immediately.
-                 */
-                *lastinop = (xfs_ino_t)XFS_AGINO_TO_INO(mp, agno, 0);
+        if (ac.ac_ubelem)
+                error = 0;
+
+        /*
+         * If we ran out of filesystem, lastino will point off the end of
+         * the filesystem so the next call will return immediately.
+         */
+        *lastinop = XFS_AGINO_TO_INO(mp, agno, agino);
+        if (agno >= mp->m_sb.sb_agcount)
                 *done = 1;
-        } else
-                *lastinop = (xfs_ino_t)lastino;
 
-        return rval;
+        return error;
 }
 
 int
diff --git a/fs/xfs/xfs_itable.h b/fs/xfs/xfs_itable.h
index aaed08022eb9..6ea8b3912fa4 100644
--- a/fs/xfs/xfs_itable.h
+++ b/fs/xfs/xfs_itable.h
@@ -30,22 +30,6 @@ typedef int (*bulkstat_one_pf)(struct xfs_mount	*mp,
                                int              *ubused,
                                int              *stat);
 
-struct xfs_bulkstat_agichunk {
-        xfs_ino_t       ac_lastino;     /* last inode returned */
-        char            __user **ac_ubuffer;/* pointer into user's buffer */
-        int             ac_ubleft;      /* bytes left in user's buffer */
-        int             ac_ubelem;      /* spaces used in user's buffer */
-};
-
-int
-xfs_bulkstat_ag_ichunk(
-        struct xfs_mount                *mp,
-        xfs_agnumber_t                  agno,
-        struct xfs_inobt_rec_incore     *irbp,
-        bulkstat_one_pf                 formatter,
-        size_t                          statstruct_size,
-        struct xfs_bulkstat_agichunk    *acp);
-
 /*
  * Values for stat return value.
  */