On Tue, Jun 11, 2019 at 11:48:09PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> Create a new ibulk structure incore to help us deal with bulk inode stat
> state tracking and then convert the bulkstat code to use the new iwalk
> iterator. This disentangles inode walking from bulk stat control for
> simpler code and enables us to isolate the formatter functions to the
> ioctl handling code.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> fs/xfs/xfs_ioctl.c | 70 ++++++--
> fs/xfs/xfs_ioctl.h | 5 +
> fs/xfs/xfs_ioctl32.c | 93 ++++++-----
> fs/xfs/xfs_itable.c | 431 ++++++++++++++++----------------------------------
> fs/xfs/xfs_itable.h | 79 ++++-----
> 5 files changed, 272 insertions(+), 406 deletions(-)
>
>
...
> diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c
> index 814ffe6fbab7..5d1c143bac18 100644
> --- a/fs/xfs/xfs_ioctl32.c
> +++ b/fs/xfs/xfs_ioctl32.c
...
> @@ -284,38 +266,59 @@ xfs_compat_ioc_bulkstat(
> return -EFAULT;
> bulkreq.ocount = compat_ptr(addr);
>
> - if (copy_from_user(&inlast, bulkreq.lastip, sizeof(__s64)))
> + if (copy_from_user(&lastino, bulkreq.lastip, sizeof(__s64)))
> return -EFAULT;
> + breq.startino = lastino + 1;
>
Spurious assignment?
> - if ((count = bulkreq.icount) <= 0)
> + if (bulkreq.icount <= 0)
> return -EINVAL;
>
> if (bulkreq.ubuffer == NULL)
> return -EINVAL;
>
> + breq.ubuffer = bulkreq.ubuffer;
> + breq.icount = bulkreq.icount;
> +
...
> diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
> index 3ca1c454afe6..58e411e11d6c 100644
> --- a/fs/xfs/xfs_itable.c
> +++ b/fs/xfs/xfs_itable.c
> @@ -14,47 +14,68 @@
...
> +STATIC int
> xfs_bulkstat_one_int(
> - struct xfs_mount *mp, /* mount point for filesystem */
> - xfs_ino_t ino, /* inode to get data for */
> - void __user *buffer, /* buffer to place output in */
> - int ubsize, /* size of buffer */
> - bulkstat_one_fmt_pf formatter, /* formatter, copy to user */
> - int *ubused, /* bytes used by me */
> - int *stat) /* BULKSTAT_RV_... */
> + struct xfs_mount *mp,
> + struct xfs_trans *tp,
> + xfs_ino_t ino,
> + void *data)
There's no need for a void pointer here given the current usage. We
might as well pass this as bc (and let the caller cast it, if
necessary).
That said, it also looks like the only reason we have the
xfs_bulkstat_iwalk wrapper caller of this function is to filter out
certain error values. If those errors are needed for the single inode
case, we could stick something in the bc to toggle that invalid inode
filtering behavior and eliminate the need for the wrapper entirely
(which would pass _one_int() into the iwalk infra directly and require
retaining the void pointer).
> {
> + struct xfs_bstat_chunk *bc = data;
> struct xfs_icdinode *dic; /* dinode core info pointer */
> struct xfs_inode *ip; /* incore inode pointer */
> struct inode *inode;
> - struct xfs_bstat *buf; /* return buffer */
> - int error = 0; /* error value */
> + struct xfs_bstat *buf = bc->buf;
> + int error = -EINVAL;
>
> - *stat = BULKSTAT_RV_NOTHING;
> + if (xfs_internal_inum(mp, ino))
> + goto out_advance;
>
> - if (!buffer || xfs_internal_inum(mp, ino))
> - return -EINVAL;
> -
> - buf = kmem_zalloc(sizeof(*buf), KM_SLEEP | KM_MAYFAIL);
> - if (!buf)
> - return -ENOMEM;
> -
> - error = xfs_iget(mp, NULL, ino,
> + error = xfs_iget(mp, tp, ino,
> (XFS_IGET_DONTCACHE | XFS_IGET_UNTRUSTED),
> XFS_ILOCK_SHARED, &ip);
> + if (error == -ENOENT || error == -EINVAL)
> + goto out_advance;
> if (error)
> - goto out_free;
> + goto out;
>
> ASSERT(ip != NULL);
> ASSERT(ip->i_imap.im_blkno != 0);
> @@ -119,43 +140,56 @@ xfs_bulkstat_one_int(
> xfs_iunlock(ip, XFS_ILOCK_SHARED);
> xfs_irele(ip);
>
> - error = formatter(buffer, ubsize, ubused, buf);
> - if (!error)
> - *stat = BULKSTAT_RV_DIDONE;
> + error = bc->formatter(bc->breq, buf);
> + if (error == XFS_IBULK_BUFFER_FULL) {
> + error = XFS_IWALK_ABORT;
Related to the earlier patch.. is there a need for IBULK_BUFFER_FULL if
the only user converts it to the generic abort error?
Most of these comments are minor/aesthetic, so:
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> + goto out_advance;
> + }
> + if (error)
> + goto out;
>
> - out_free:
> - kmem_free(buf);
> +out_advance:
> + /*
> + * Advance the cursor to the inode that comes after the one we just
> + * looked at. We want the caller to move along if the bulkstat
> + * information was copied successfully; if we tried to grab the inode
> + * but it's no longer allocated; or if it's internal metadata.
> + */
> + bc->breq->startino = ino + 1;
> +out:
> return error;
> }
>
> -/* Return 0 on success or positive error */
> -STATIC int
> -xfs_bulkstat_one_fmt(
> - void __user *ubuffer,
> - int ubsize,
> - int *ubused,
> - const xfs_bstat_t *buffer)
> -{
> - if (ubsize < sizeof(*buffer))
> - return -ENOMEM;
> - if (copy_to_user(ubuffer, buffer, sizeof(*buffer)))
> - return -EFAULT;
> - if (ubused)
> - *ubused = sizeof(*buffer);
> - return 0;
> -}
> -
> +/* Bulkstat a single inode. */
> int
> xfs_bulkstat_one(
> - xfs_mount_t *mp, /* mount point for filesystem */
> - xfs_ino_t ino, /* inode number to get data for */
> - void __user *buffer, /* buffer to place output in */
> - int ubsize, /* size of buffer */
> - int *ubused, /* bytes used by me */
> - int *stat) /* BULKSTAT_RV_... */
> + struct xfs_ibulk *breq,
> + bulkstat_one_fmt_pf formatter)
> {
> - return xfs_bulkstat_one_int(mp, ino, buffer, ubsize,
> - xfs_bulkstat_one_fmt, ubused, stat);
> + struct xfs_bstat_chunk bc = {
> + .formatter = formatter,
> + .breq = breq,
> + };
> + int error;
> +
> + ASSERT(breq->icount == 1);
> +
> + bc.buf = kmem_zalloc(sizeof(struct xfs_bstat), KM_SLEEP | KM_MAYFAIL);
> + if (!bc.buf)
> + return -ENOMEM;
> +
> + error = xfs_bulkstat_one_int(breq->mp, NULL, breq->startino, &bc);
> +
> + kmem_free(bc.buf);
> +
> + /*
> + * If we reported one inode to userspace then we abort because we hit
> + * the end of the buffer. Don't leak that back to userspace.
> + */
> + if (error == XFS_IWALK_ABORT)
> + error = 0;
> +
> + return error;
> }
>
> /*
> @@ -251,256 +285,69 @@ 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.
> - */
> 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,
> - xfs_agino_t *last_agino)
> +xfs_bulkstat_iwalk(
> + struct xfs_mount *mp,
> + struct xfs_trans *tp,
> + xfs_ino_t ino,
> + void *data)
> {
> - char __user **ubufp = acp->ac_ubuffer;
> - int chunkidx;
> - int error = 0;
> - xfs_agino_t agino = irbp->ir_startino;
> -
> - for (chunkidx = 0; chunkidx < XFS_INODES_PER_CHUNK;
> - chunkidx++, agino++) {
> - int fmterror;
> - int ubused;
> -
> - /* 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)
> - continue;
> -
> - /* Get the inode and fill in a single buffer */
> - ubused = statstruct_size;
> - 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;
> - }
> -
> - /* 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++;
> - }
> -
> - /*
> - * 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;
> + int error;
>
> + error = xfs_bulkstat_one_int(mp, tp, ino, data);
> + /* bulkstat just skips over missing inodes */
> + if (error == -ENOENT || error == -EINVAL)
> + return 0;
> return error;
> }
>
> /*
> - * Return stat information in bulk (by-inode) for the filesystem.
> + * Check the incoming lastino parameter.
> + *
> + * We allow any inode value that could map to physical space inside the
> + * filesystem because if there are no inodes there, bulkstat moves on to the
> + * next chunk. In other words, the magic agino value of zero takes us to the
> + * first chunk in the AG, and an agino value past the end of the AG takes us to
> + * the first chunk in the next AG.
> + *
> + * Therefore we can end early if the requested inode is beyond the end of the
> + * filesystem or doesn't map properly.
> */
> -int /* error status */
> -xfs_bulkstat(
> - xfs_mount_t *mp, /* mount point for filesystem */
> - xfs_ino_t *lastinop, /* last inode returned */
> - int *ubcountp, /* size of buffer/count returned */
> - bulkstat_one_pf formatter, /* func that'd fill a single buf */
> - size_t statstruct_size, /* sizeof struct filling */
> - char __user *ubuffer, /* buffer with inode stats */
> - int *done) /* 1 if there are more stats to get */
> +static inline bool
> +xfs_bulkstat_already_done(
> + struct xfs_mount *mp,
> + xfs_ino_t startino)
> {
> - xfs_buf_t *agbp; /* agi header buffer */
> - 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 */
> - xfs_inobt_rec_incore_t *irbuf; /* start of irec buffer */
> - int nirbuf; /* size of irbuf */
> - int ubcount; /* size of user's buffer */
> - struct xfs_bulkstat_agichunk ac;
> - int error = 0;
> + xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, startino);
> + xfs_agino_t agino = XFS_INO_TO_AGINO(mp, startino);
>
> - /*
> - * Get the last inode value, see if there's nothing to do.
> - */
> - agno = XFS_INO_TO_AGNO(mp, *lastinop);
> - agino = XFS_INO_TO_AGINO(mp, *lastinop);
> - if (agno >= mp->m_sb.sb_agcount ||
> - *lastinop != XFS_AGINO_TO_INO(mp, agno, agino)) {
> - *done = 1;
> - *ubcountp = 0;
> - return 0;
> - }
> + return agno >= mp->m_sb.sb_agcount ||
> + startino != XFS_AGINO_TO_INO(mp, agno, agino);
> +}
>
> - ubcount = *ubcountp; /* statstruct's */
> - ac.ac_ubuffer = &ubuffer;
> - ac.ac_ubleft = ubcount * statstruct_size; /* bytes */;
> - ac.ac_ubelem = 0;
> +/* Return stat information in bulk (by-inode) for the filesystem. */
> +int
> +xfs_bulkstat(
> + struct xfs_ibulk *breq,
> + bulkstat_one_fmt_pf formatter)
> +{
> + struct xfs_bstat_chunk bc = {
> + .formatter = formatter,
> + .breq = breq,
> + };
> + int error;
>
> - *ubcountp = 0;
> - *done = 0;
> + if (xfs_bulkstat_already_done(breq->mp, breq->startino))
> + return 0;
>
> - irbuf = kmem_zalloc_large(PAGE_SIZE * 4, KM_SLEEP);
> - if (!irbuf)
> + bc.buf = kmem_zalloc(sizeof(struct xfs_bstat), KM_SLEEP | KM_MAYFAIL);
> + if (!bc.buf)
> return -ENOMEM;
> - nirbuf = (PAGE_SIZE * 4) / sizeof(*irbuf);
>
> - /*
> - * Loop over the allocation groups, starting from the last
> - * inode returned; 0 means start of the allocation group.
> - */
> - 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_iwalk(breq->mp, NULL, breq->startino, xfs_bulkstat_iwalk,
> + breq->icount, &bc);
>
> - error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp);
> - if (error)
> - break;
> - /*
> - * Allocate and initialize a btree cursor for ialloc btree.
> - */
> - cur = xfs_inobt_init_cursor(mp, NULL, agbp, agno,
> - XFS_BTNUM_INO);
> - if (agino > 0) {
> - /*
> - * In the middle of an allocation group, we need to get
> - * the remainder of the chunk we're in.
> - */
> - struct xfs_inobt_rec_incore r;
> -
> - error = xfs_bulkstat_grab_ichunk(cur, agino, &icount, &r);
> - if (error)
> - goto del_cursor;
> - if (icount) {
> - irbp->ir_startino = r.ir_startino;
> - irbp->ir_holemask = r.ir_holemask;
> - irbp->ir_count = r.ir_count;
> - irbp->ir_freecount = r.ir_freecount;
> - irbp->ir_free = r.ir_free;
> - irbp++;
> - }
> - /* Increment to the next record */
> - 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, &stat);
> - }
> - if (error || stat == 0) {
> - end_of_ag = true;
> - goto del_cursor;
> - }
> -
> - /*
> - * Loop through inode btree records in this ag,
> - * until we run out of inodes or space in the buffer.
> - */
> - while (irbp < irbufend && icount < ubcount) {
> - struct xfs_inobt_rec_incore r;
> -
> - error = xfs_inobt_get_rec(cur, &r, &stat);
> - if (error || stat == 0) {
> - end_of_ag = true;
> - goto del_cursor;
> - }
> -
> - /*
> - * If this chunk has any allocated inodes, save it.
> - * Also start read-ahead now for this chunk.
> - */
> - if (r.ir_freecount < r.ir_count) {
> - xfs_bulkstat_ichunk_ra(mp, agno, &r);
> - irbp->ir_startino = r.ir_startino;
> - irbp->ir_holemask = r.ir_holemask;
> - irbp->ir_count = r.ir_count;
> - irbp->ir_freecount = r.ir_freecount;
> - irbp->ir_free = r.ir_free;
> - irbp++;
> - icount += r.ir_count - r.ir_freecount;
> - }
> - 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 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, error);
> - xfs_buf_relse(agbp);
> - if (error)
> - break;
> - /*
> - * 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 && ac.ac_ubleft >= statstruct_size;
> - irbp++) {
> - error = xfs_bulkstat_ag_ichunk(mp, agno, irbp,
> - formatter, statstruct_size, &ac,
> - &agino);
> - if (error)
> - break;
> -
> - cond_resched();
> - }
> -
> - /*
> - * If we've run out of space or had a formatting error, we
> - * are now done
> - */
> - 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 = ac.ac_ubelem;
> + kmem_free(bc.buf);
>
> /*
> * We found some inodes, so clear the error status and return them.
> @@ -509,17 +356,9 @@ xfs_bulkstat(
> * triggered again and propagated to userspace as there will be no
> * formatted inodes in the buffer.
> */
> - if (ac.ac_ubelem)
> + if (breq->ocount > 0)
> 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;
> -
> return error;
> }
>
> diff --git a/fs/xfs/xfs_itable.h b/fs/xfs/xfs_itable.h
> index 369e3f159d4e..7c5f1df360e6 100644
> --- a/fs/xfs/xfs_itable.h
> +++ b/fs/xfs/xfs_itable.h
> @@ -5,63 +5,46 @@
> #ifndef __XFS_ITABLE_H__
> #define __XFS_ITABLE_H__
>
> -/*
> - * xfs_bulkstat() is used to fill in xfs_bstat structures as well as dm_stat
> - * structures (by the dmi library). This is a pointer to a formatter function
> - * that will iget the inode and fill in the appropriate structure.
> - * see xfs_bulkstat_one() and xfs_dm_bulkstat_one() in dmapi_xfs.c
> - */
> -typedef int (*bulkstat_one_pf)(struct xfs_mount *mp,
> - xfs_ino_t ino,
> - void __user *buffer,
> - int ubsize,
> - int *ubused,
> - int *stat);
> +/* In-memory representation of a userspace request for batch inode data. */
> +struct xfs_ibulk {
> + struct xfs_mount *mp;
> + void __user *ubuffer; /* user output buffer */
> + xfs_ino_t startino; /* start with this inode */
> + unsigned int icount; /* number of elements in ubuffer */
> + unsigned int ocount; /* number of records returned */
> +};
> +
> +/* Return value that means we want to abort the walk. */
> +#define XFS_IBULK_ABORT (XFS_IWALK_ABORT)
> +
> +/* Return value that means the formatting buffer is now full. */
> +#define XFS_IBULK_BUFFER_FULL (XFS_IBULK_ABORT + 1)
>
> /*
> - * Values for stat return value.
> + * Advance the user buffer pointer by one record of the given size. If the
> + * buffer is now full, return the appropriate error code.
> */
> -#define BULKSTAT_RV_NOTHING 0
> -#define BULKSTAT_RV_DIDONE 1
> -#define BULKSTAT_RV_GIVEUP 2
> +static inline int
> +xfs_ibulk_advance(
> + struct xfs_ibulk *breq,
> + size_t bytes)
> +{
> + char __user *b = breq->ubuffer;
> +
> + breq->ubuffer = b + bytes;
> + breq->ocount++;
> + return breq->ocount == breq->icount ? XFS_IBULK_BUFFER_FULL : 0;
> +}
>
> /*
> * Return stat information in bulk (by-inode) for the filesystem.
> */
> -int /* error status */
> -xfs_bulkstat(
> - xfs_mount_t *mp, /* mount point for filesystem */
> - xfs_ino_t *lastino, /* last inode returned */
> - int *count, /* size of buffer/count returned */
> - bulkstat_one_pf formatter, /* func that'd fill a single buf */
> - size_t statstruct_size,/* sizeof struct that we're filling */
> - char __user *ubuffer,/* buffer with inode stats */
> - int *done); /* 1 if there are more stats to get */
>
> -typedef int (*bulkstat_one_fmt_pf)( /* used size in bytes or negative error */
> - void __user *ubuffer, /* buffer to write to */
> - int ubsize, /* remaining user buffer sz */
> - int *ubused, /* bytes used by formatter */
> - const xfs_bstat_t *buffer); /* buffer to read from */
> +typedef int (*bulkstat_one_fmt_pf)(struct xfs_ibulk *breq,
> + const struct xfs_bstat *bstat);
>
> -int
> -xfs_bulkstat_one_int(
> - xfs_mount_t *mp,
> - xfs_ino_t ino,
> - void __user *buffer,
> - int ubsize,
> - bulkstat_one_fmt_pf formatter,
> - int *ubused,
> - int *stat);
> -
> -int
> -xfs_bulkstat_one(
> - xfs_mount_t *mp,
> - xfs_ino_t ino,
> - void __user *buffer,
> - int ubsize,
> - int *ubused,
> - int *stat);
> +int xfs_bulkstat_one(struct xfs_ibulk *breq, bulkstat_one_fmt_pf formatter);
> +int xfs_bulkstat(struct xfs_ibulk *breq, bulkstat_one_fmt_pf formatter);
>
> typedef int (*inumbers_fmt_pf)(
> void __user *ubuffer, /* buffer to write to */
>
