Messages in this thread | | | From | Markus Pargmann <> | Subject | Re: [PATCH] nbd: Fix return value check for debugfs_create_*() | Date | Fri, 12 Feb 2016 15:57:23 +0100 |
| |
Hi,
On Friday, February 05, 2016 09:48:21 PM weiyj_lk@163.com wrote: > From: Wei Yongjun <yongjun_wei@trendmicro.com.cn> > > In case of error, the function debugfs_create_*() returns NULL > pointer not ERR_PTR() if debugfs is enabled. The IS_ERR() test > in the return value check should be replaced with NULL test.
I tried to fix this already but it didn't reach 4.5. It is queued for 4.6. Please have a look at http://git.pengutronix.de/?p=mpa/linux-nbd.git;a=commitdiff;h=27ea43fe2a32f63bb6f442dafc2133232b8af4a6;hp=92e963f50fc74041b5e9e744c330dca48e04f08d whether this works for you as well. The difference is that I removed all error checks for the debugfs files. The code looks nicer but of course there are no error messages if it went wrong.
Thanks,
Markus
> > Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> > --- > drivers/block/nbd.c | 50 ++++++++++++++++++++++++-------------------------- > 1 file changed, 24 insertions(+), 26 deletions(-) > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c > index e4c5cc1..02bc697 100644 > --- a/drivers/block/nbd.c > +++ b/drivers/block/nbd.c > @@ -895,49 +895,47 @@ static int nbd_dev_dbg_init(struct nbd_device *nbd) > struct dentry *f; > > dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir); > - if (IS_ERR_OR_NULL(dir)) { > - dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s' (%ld)\n", > - nbd_name(nbd), PTR_ERR(dir)); > - return PTR_ERR(dir); > + if (!dir) { > + dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n", > + nbd_name(nbd)); > + return -ENOMEM; > } > nbd->dbg_dir = dir; > > f = debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops); > - if (IS_ERR_OR_NULL(f)) { > - dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'tasks', %ld\n", > - PTR_ERR(f)); > - return PTR_ERR(f); > + if (!f) { > + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'tasks'\n"); > + goto fail; > } > > f = debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize); > - if (IS_ERR_OR_NULL(f)) { > - dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'size_bytes', %ld\n", > - PTR_ERR(f)); > - return PTR_ERR(f); > + if (!f) { > + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'size_bytes'\n"); > + goto fail; > } > > f = debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout); > - if (IS_ERR_OR_NULL(f)) { > - dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'timeout', %ld\n", > - PTR_ERR(f)); > - return PTR_ERR(f); > + if (!f) { > + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'timeout'\n"); > + goto fail; > } > > f = debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize); > - if (IS_ERR_OR_NULL(f)) { > - dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'blocksize', %ld\n", > - PTR_ERR(f)); > - return PTR_ERR(f); > + if (!f) { > + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'blocksize'\n"); > + goto fail; > } > > f = debugfs_create_file("flags", 0444, dir, &nbd, &nbd_dbg_flags_ops); > - if (IS_ERR_OR_NULL(f)) { > - dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'flags', %ld\n", > - PTR_ERR(f)); > - return PTR_ERR(f); > + if (!f) { > + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'flags'\n"); > + goto fail; > } > > return 0; > +fail: > + debugfs_remove_recursive(nbd->dbg_dir); > + return -ENOMEM; > } > > static void nbd_dev_dbg_close(struct nbd_device *nbd) > @@ -950,8 +948,8 @@ static int nbd_dbg_init(void) > struct dentry *dbg_dir; > > dbg_dir = debugfs_create_dir("nbd", NULL); > - if (IS_ERR(dbg_dir)) > - return PTR_ERR(dbg_dir); > + if (!dbg_dir) > + return -ENOMEM; > > nbd_dbg_dir = dbg_dir; > > >
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