On Fri, Nov 07, 2014 at 12:14:59AM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> The bulkstat main loop progress is tracked by the "lastino"
> variable, which is a full 64 bit inode. However, the loop actually
> works on agno/agino pairs, and so there's a significant disconnect
> between the rest of the loop and the main cursor. Convert this to
> use the agino, and pass the agino into the chunk formatting function
> and convert it too.
>
> This gets rid of the inconsistency in the loop processing, and
> finally makes it simple for us to skip inodes at any point in the
> loop simply by incrementing the agino cursor.
>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
> ---
> fs/xfs/xfs_itable.c | 68 ++++++++++++++++++++++++++---------------------------
> 1 file changed, 34 insertions(+), 34 deletions(-)
>
> diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
> index ff3f431..05e83a6 100644
> --- a/fs/xfs/xfs_itable.c
> +++ b/fs/xfs/xfs_itable.c
> @@ -282,30 +282,31 @@ xfs_bulkstat_ag_ichunk(
> bulkstat_one_pf formatter,
> size_t statstruct_size,
> struct xfs_bulkstat_agichunk *acp,
> - xfs_ino_t *lastino)
> + xfs_agino_t *last_agino)
> {
> char __user **ubufp = acp->ac_ubuffer;
> int chunkidx;
> int error = 0;
> - xfs_agino_t agino;
> + xfs_agino_t agino = irbp->ir_startino;
>
> - agino = irbp->ir_startino;
> 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);
> +
> + /* 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;
> - }
>
> /* Get the inode and fill in a single buffer */
> ubused = statstruct_size;
> - error = formatter(mp, ino, *ubufp, acp->ac_ubleft,
> - &ubused, &fmterror);
> + 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;
> @@ -315,7 +316,6 @@ xfs_bulkstat_ag_ichunk(
>
> /* be careful not to leak error if at end of chunk */
> if (fmterror == BULKSTAT_RV_NOTHING || error) {
> - *lastino = ino;
> error = 0;
> continue;
> }
> @@ -323,12 +323,18 @@ xfs_bulkstat_ag_ichunk(
> *ubufp += ubused;
> acp->ac_ubleft -= ubused;
> acp->ac_ubelem++;
> - *lastino = ino;
> -
> - if (acp->ac_ubleft < statstruct_size)
> - break;
> }
>
> + /*
> + * 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;
> }
>
> @@ -352,7 +358,6 @@ xfs_bulkstat(
> xfs_btree_cur_t *cur; /* btree cursor for ialloc btree */
> size_t irbsize; /* size of irec buffer in bytes */
> xfs_inobt_rec_incore_t *irbuf; /* start of irec buffer */
> - xfs_ino_t lastino; /* last inode number returned */
> int nirbuf; /* size of irbuf */
> int ubcount; /* size of user's buffer */
> struct xfs_bulkstat_agichunk ac;
> @@ -361,11 +366,10 @@ xfs_bulkstat(
> /*
> * Get the last inode value, see if there's nothing to do.
> */
> - lastino = *lastinop;
> - agno = XFS_INO_TO_AGNO(mp, lastino);
> - agino = XFS_INO_TO_AGINO(mp, lastino);
> + agno = XFS_INO_TO_AGNO(mp, *lastinop);
> + agino = XFS_INO_TO_AGINO(mp, *lastinop);
> if (agno >= mp->m_sb.sb_agcount ||
> - lastino != XFS_AGINO_TO_INO(mp, agno, agino)) {
> + *lastinop != XFS_AGINO_TO_INO(mp, agno, agino)) {
> *done = 1;
> *ubcountp = 0;
> return 0;
> @@ -420,7 +424,6 @@ xfs_bulkstat(
> 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, &stat);
> @@ -461,7 +464,6 @@ xfs_bulkstat(
> /*
> * Set agino to after this chunk and bump the cursor.
> */
This comment could be updated since it's not safe to set agino here any
longer. Other than that, this all looks pretty good to me now:
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> - agino = r.ir_startino + XFS_INODES_PER_CHUNK;
> error = xfs_btree_increment(cur, 0, &stat);
> if (error || stat == 0) {
> end_of_ag = true;
> @@ -481,7 +483,9 @@ del_cursor:
> 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;
> @@ -489,7 +493,7 @@ del_cursor:
> irbp++) {
> error = xfs_bulkstat_ag_ichunk(mp, agno, irbp,
> formatter, statstruct_size, &ac,
> - &lastino);
> + &agino);
> if (error)
> break;
>
> @@ -506,8 +510,7 @@ del_cursor:
> if (end_of_ag) {
> agno++;
> agino = 0;
> - } else
> - agino = XFS_INO_TO_AGINO(mp, lastino);
> + }
> }
> /*
> * Done, we're either out of filesystem or space to put the data.
> @@ -525,16 +528,13 @@ del_cursor:
> if (ac.ac_ubelem)
> error = 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 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 error;
> }
> --
> 2.0.0
>
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