On 11/09/2012 04:10 AM, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> It's a buggy, unnecessary wrapper that is duplicating
> truncate_pagecache_range().
>
> When replacing the call in xfs_change_file_space(), also ensure that
> the length being allocated/freed is always positive before making
> any changes. These checks are done in the lower extent manipulation
> functions, too, but we need to do them before any page cache
> operations.
>
> Reported-by: Andrew Dahl <adahl@xxxxxxx>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
> ---
> fs/xfs/xfs_dfrag.c | 3 +--
> fs/xfs/xfs_fs_subr.c | 12 ------------
> fs/xfs/xfs_vnodeops.c | 28 +++++++++++++++++++++++-----
> fs/xfs/xfs_vnodeops.h | 2 --
> 4 files changed, 24 insertions(+), 21 deletions(-)
>
> diff --git a/fs/xfs/xfs_dfrag.c b/fs/xfs/xfs_dfrag.c
> index b9b8646..b2c63a2 100644
> --- a/fs/xfs/xfs_dfrag.c
> +++ b/fs/xfs/xfs_dfrag.c
> @@ -315,8 +315,7 @@ xfs_swap_extents(
> * are safe. We don't really care if non-io related
> * fields change.
> */
> -
> - xfs_tosspages(ip, 0, -1, FI_REMAPF);
> + truncate_pagecache_range(VFS_I(ip), 0, -1);
>
> tp = xfs_trans_alloc(mp, XFS_TRANS_SWAPEXT);
> if ((error = xfs_trans_reserve(tp, 0,
> diff --git a/fs/xfs/xfs_fs_subr.c b/fs/xfs/xfs_fs_subr.c
> index 652b875..d49de3d 100644
> --- a/fs/xfs/xfs_fs_subr.c
> +++ b/fs/xfs/xfs_fs_subr.c
> @@ -25,18 +25,6 @@
> * note: all filemap functions return negative error codes. These
> * need to be inverted before returning to the xfs core functions.
> */
> -void
> -xfs_tosspages(
> - xfs_inode_t *ip,
> - xfs_off_t first,
> - xfs_off_t last,
> - int fiopt)
> -{
> - /* can't toss partial tail pages, so mask them out */
> - last &= ~(PAGE_SIZE - 1);
> - truncate_inode_pages_range(VFS_I(ip)->i_mapping, first, last - 1);
> -}
> -
> int
> xfs_flushinval_pages(
> xfs_inode_t *ip,
> diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
> index c2ddd7a..f7de578 100644
> --- a/fs/xfs/xfs_vnodeops.c
> +++ b/fs/xfs/xfs_vnodeops.c
> @@ -2118,7 +2118,6 @@ xfs_change_file_space(
> xfs_fsize_t fsize;
> int setprealloc;
> xfs_off_t startoffset;
> - xfs_off_t llen;
> xfs_trans_t *tp;
> struct iattr iattr;
> int prealloc_type;
> @@ -2139,12 +2138,30 @@ xfs_change_file_space(
> return XFS_ERROR(EINVAL);
> }
>
> - llen = bf->l_len > 0 ? bf->l_len - 1 : bf->l_len;
> + /*
> + * length of <= 0 for resv/unresv/zero is invalid. length for
> + * alloc/free is ignored completely and we have no idea what userspace
> + * might have set it to, so set it to zero to allow range
> + * checks to pass.
> + */
> + switch (cmd) {
> + case XFS_IOC_ZERO_RANGE:
> + case XFS_IOC_RESVSP:
> + case XFS_IOC_RESVSP64:
> + case XFS_IOC_UNRESVSP:
> + case XFS_IOC_UNRESVSP64:
> + if (bf->l_len <= 0)
> + return XFS_ERROR(EINVAL);
> + break;
> + default:
> + bf->l_len = 0;
> + break;
> + }
>
> if (bf->l_start < 0 ||
> bf->l_start > mp->m_super->s_maxbytes ||
> - bf->l_start + llen < 0 ||
> - bf->l_start + llen > mp->m_super->s_maxbytes)
> + bf->l_start + bf->l_len < 0 ||
> + bf->l_start + bf->l_len >= mp->m_super->s_maxbytes)
> return XFS_ERROR(EINVAL);
>
> bf->l_whence = 0;
> @@ -2169,7 +2186,8 @@ xfs_change_file_space(
> switch (cmd) {
> case XFS_IOC_ZERO_RANGE:
> prealloc_type |= XFS_BMAPI_CONVERT;
> - xfs_tosspages(ip, startoffset, startoffset + bf->l_len, 0);
> + truncate_pagecache_range(VFS_I(ip), startoffset,
> + round_down(startoffset + bf->l_len, PAGE_SIZE) - 1);
When calling XFS_IOC_ZERO_RANGE with a range [0, 4095] or [0,1] it's
tossing pages because the call to round_down() is returning 0 and
passing -1 in for the end will toss all pages. So, we need to make sure
round_down() isn't going to return a 0, or that (startoffset +
bf->l_len) > PAGE_SIZE.
So, something like...
xfs_off_t end;
[...]
if((end = round_down(startoffset + bf->l_len, PAGE_SIZE)) > 0) {
truncate_pagecache_range(VFS_I(ip), startoffset, end - 1);
}
> /* FALLTHRU */
> case XFS_IOC_RESVSP:
> case XFS_IOC_RESVSP64:
> diff --git a/fs/xfs/xfs_vnodeops.h b/fs/xfs/xfs_vnodeops.h
> index 52fafc4..d48141d 100644
> --- a/fs/xfs/xfs_vnodeops.h
> +++ b/fs/xfs/xfs_vnodeops.h
> @@ -48,8 +48,6 @@ int xfs_attr_set(struct xfs_inode *dp, const unsigned char *name,
> int xfs_attr_remove(struct xfs_inode *dp, const unsigned char *name, int flags);
> int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
> int flags, struct attrlist_cursor_kern *cursor);
> -void xfs_tosspages(struct xfs_inode *inode, xfs_off_t first,
> - xfs_off_t last, int fiopt);
> int xfs_flushinval_pages(struct xfs_inode *ip, xfs_off_t first,
> xfs_off_t last, int fiopt);
> int xfs_flush_pages(struct xfs_inode *ip, xfs_off_t first,
>
Beyond that one change, it looks good!
-Andrew
_______________________________________________
xfs mailing list
xfs@xxxxxxxxxxx
http://oss.sgi.com/mailman/listinfo/xfs
