block/vvfat.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
When using the vvfat driver with a directory that contains too many files,
QEMU currently crashes. We are trying to print the wrong path variable here.
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
block/vvfat.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/block/vvfat.c b/block/vvfat.c
index fc41841..6ae7458 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -975,8 +975,7 @@ static int init_directories(BDRVVVFATState* s,
if (mapping->mode & MODE_DIRECTORY) {
mapping->begin = cluster;
if(read_directory(s, i)) {
- error_setg(errp, "Could not read directory %s",
- mapping->path);
+ error_setg(errp, "Could not read directory \"%s\"", s->path);
return -1;
}
mapping = array_get(&(s->mapping), i);
--
1.8.3.1
On 07/18/2018 12:28 PM, Thomas Huth wrote: > When using the vvfat driver with a directory that contains too many files, > QEMU currently crashes. We are trying to print the wrong path variable here. > > Signed-off-by: Thomas Huth <thuth@redhat.com> > --- > block/vvfat.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/block/vvfat.c b/block/vvfat.c > index fc41841..6ae7458 100644 > --- a/block/vvfat.c > +++ b/block/vvfat.c > @@ -975,8 +975,7 @@ static int init_directories(BDRVVVFATState* s, > if (mapping->mode & MODE_DIRECTORY) { > mapping->begin = cluster; > if(read_directory(s, i)) { > - error_setg(errp, "Could not read directory %s", > - mapping->path); > + error_setg(errp, "Could not read directory \"%s\"", s->path); > return -1; > } > mapping = array_get(&(s->mapping), i); > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Am 18.07.2018 um 17:28 hat Thomas Huth geschrieben: > When using the vvfat driver with a directory that contains too many files, > QEMU currently crashes. We are trying to print the wrong path variable here. > > Signed-off-by: Thomas Huth <thuth@redhat.com> > --- > block/vvfat.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/block/vvfat.c b/block/vvfat.c > index fc41841..6ae7458 100644 > --- a/block/vvfat.c > +++ b/block/vvfat.c > @@ -975,8 +975,7 @@ static int init_directories(BDRVVVFATState* s, > if (mapping->mode & MODE_DIRECTORY) { > mapping->begin = cluster; > if(read_directory(s, i)) { > - error_setg(errp, "Could not read directory %s", > - mapping->path); > + error_setg(errp, "Could not read directory \"%s\"", s->path); Hm, I'm not sure if that's right. Before this patch we were printing the name of the subdirectory that couldn't be loaded, now it's the parent directory. My test case where this difference is visible is a subdirectory with chmod 000. > return -1; > } > mapping = array_get(&(s->mapping), i); Maybe the right solution would be moving the reloading of mapping to between the read_directory() call and the error path? Kevin
On 23.07.2018 16:33, Kevin Wolf wrote: > Am 18.07.2018 um 17:28 hat Thomas Huth geschrieben: >> When using the vvfat driver with a directory that contains too many files, >> QEMU currently crashes. We are trying to print the wrong path variable here. >> >> Signed-off-by: Thomas Huth <thuth@redhat.com> >> --- >> block/vvfat.c | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/block/vvfat.c b/block/vvfat.c >> index fc41841..6ae7458 100644 >> --- a/block/vvfat.c >> +++ b/block/vvfat.c >> @@ -975,8 +975,7 @@ static int init_directories(BDRVVVFATState* s, >> if (mapping->mode & MODE_DIRECTORY) { >> mapping->begin = cluster; >> if(read_directory(s, i)) { >> - error_setg(errp, "Could not read directory %s", >> - mapping->path); >> + error_setg(errp, "Could not read directory \"%s\"", s->path); > > Hm, I'm not sure if that's right. Before this patch we were printing > the name of the subdirectory that couldn't be loaded, now it's the > parent directory. > > My test case where this difference is visible is a subdirectory with > chmod 000. Right. >> return -1; >> } >> mapping = array_get(&(s->mapping), i); > > Maybe the right solution would be moving the reloading of mapping to > between the read_directory() call and the error path? No, that does not work either. The problem seems to be that read_directory() is changing the mapping->path pointer to something invalid in between, but I've been unable to track it down where it happens. This patch here seems to work for me, though: diff --git a/block/vvfat.c b/block/vvfat.c index fc41841..f2e7d50 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -973,10 +973,10 @@ static int init_directories(BDRVVVFATState* s, mapping = array_get(&(s->mapping), i); if (mapping->mode & MODE_DIRECTORY) { + char *path = mapping->path; mapping->begin = cluster; if(read_directory(s, i)) { - error_setg(errp, "Could not read directory %s", - mapping->path); + error_setg(errp, "Could not read directory %s", path); return -1; } mapping = array_get(&(s->mapping), i); Does this look reasonable for you, too? Thomas
Am 24.07.2018 um 11:56 hat Thomas Huth geschrieben: > On 23.07.2018 16:33, Kevin Wolf wrote: > > Am 18.07.2018 um 17:28 hat Thomas Huth geschrieben: > >> When using the vvfat driver with a directory that contains too many files, > >> QEMU currently crashes. We are trying to print the wrong path variable here. > >> > >> Signed-off-by: Thomas Huth <thuth@redhat.com> > >> --- > >> block/vvfat.c | 3 +-- > >> 1 file changed, 1 insertion(+), 2 deletions(-) > >> > >> diff --git a/block/vvfat.c b/block/vvfat.c > >> index fc41841..6ae7458 100644 > >> --- a/block/vvfat.c > >> +++ b/block/vvfat.c > >> @@ -975,8 +975,7 @@ static int init_directories(BDRVVVFATState* s, > >> if (mapping->mode & MODE_DIRECTORY) { > >> mapping->begin = cluster; > >> if(read_directory(s, i)) { > >> - error_setg(errp, "Could not read directory %s", > >> - mapping->path); > >> + error_setg(errp, "Could not read directory \"%s\"", s->path); > > > > Hm, I'm not sure if that's right. Before this patch we were printing > > the name of the subdirectory that couldn't be loaded, now it's the > > parent directory. > > > > My test case where this difference is visible is a subdirectory with > > chmod 000. > > Right. > > >> return -1; > >> } > >> mapping = array_get(&(s->mapping), i); > > > > Maybe the right solution would be moving the reloading of mapping to > > between the read_directory() call and the error path? > > No, that does not work either. The problem seems to be that > read_directory() is changing the mapping->path pointer to something > invalid in between, but I've been unable to track it down where it > happens. This patch here seems to work for me, though: > > diff --git a/block/vvfat.c b/block/vvfat.c > index fc41841..f2e7d50 100644 > --- a/block/vvfat.c > +++ b/block/vvfat.c > @@ -973,10 +973,10 @@ static int init_directories(BDRVVVFATState* s, > mapping = array_get(&(s->mapping), i); > > if (mapping->mode & MODE_DIRECTORY) { > + char *path = mapping->path; > mapping->begin = cluster; > if(read_directory(s, i)) { > - error_setg(errp, "Could not read directory %s", > - mapping->path); > + error_setg(errp, "Could not read directory %s", path); > return -1; > } > mapping = array_get(&(s->mapping), i); > > Does this look reasonable for you, too? I can't say I understand what's going on (the change I suggested did work for my test case, without valgrind errors), but the above patch doesn't look wrong to me at least. Kevin
On 24.07.2018 12:49, Kevin Wolf wrote: > Am 24.07.2018 um 11:56 hat Thomas Huth geschrieben: >> On 23.07.2018 16:33, Kevin Wolf wrote: >>> Am 18.07.2018 um 17:28 hat Thomas Huth geschrieben: >>>> When using the vvfat driver with a directory that contains too many files, >>>> QEMU currently crashes. We are trying to print the wrong path variable here. >>>> >>>> Signed-off-by: Thomas Huth <thuth@redhat.com> >>>> --- >>>> block/vvfat.c | 3 +-- >>>> 1 file changed, 1 insertion(+), 2 deletions(-) >>>> >>>> diff --git a/block/vvfat.c b/block/vvfat.c >>>> index fc41841..6ae7458 100644 >>>> --- a/block/vvfat.c >>>> +++ b/block/vvfat.c >>>> @@ -975,8 +975,7 @@ static int init_directories(BDRVVVFATState* s, >>>> if (mapping->mode & MODE_DIRECTORY) { >>>> mapping->begin = cluster; >>>> if(read_directory(s, i)) { >>>> - error_setg(errp, "Could not read directory %s", >>>> - mapping->path); >>>> + error_setg(errp, "Could not read directory \"%s\"", s->path); >>> >>> Hm, I'm not sure if that's right. Before this patch we were printing >>> the name of the subdirectory that couldn't be loaded, now it's the >>> parent directory. >>> >>> My test case where this difference is visible is a subdirectory with >>> chmod 000. >> >> Right. >> >>>> return -1; >>>> } >>>> mapping = array_get(&(s->mapping), i); >>> >>> Maybe the right solution would be moving the reloading of mapping to >>> between the read_directory() call and the error path? >> >> No, that does not work either. The problem seems to be that >> read_directory() is changing the mapping->path pointer to something >> invalid in between, but I've been unable to track it down where it >> happens. This patch here seems to work for me, though: >> >> diff --git a/block/vvfat.c b/block/vvfat.c >> index fc41841..f2e7d50 100644 >> --- a/block/vvfat.c >> +++ b/block/vvfat.c >> @@ -973,10 +973,10 @@ static int init_directories(BDRVVVFATState* s, >> mapping = array_get(&(s->mapping), i); >> >> if (mapping->mode & MODE_DIRECTORY) { >> + char *path = mapping->path; >> mapping->begin = cluster; >> if(read_directory(s, i)) { >> - error_setg(errp, "Could not read directory %s", >> - mapping->path); >> + error_setg(errp, "Could not read directory %s", path); >> return -1; >> } >> mapping = array_get(&(s->mapping), i); >> >> Does this look reasonable for you, too? > > I can't say I understand what's going on (the change I suggested did > work for my test case, without valgrind errors), but the above patch > doesn't look wrong to me at least. FWIW, my test: mkdir /tmp/vvfattest cd /tmp/vvfattest for ((x=0;x<=513;x++)); do mkdir $x; done qemu-system-x86_64 -drive \ file.driver=vvfat,file.dir=.,read-only=on,media=cdrom I'll send a proper patch with above suggestion. Thomas
© 2016 - 2024 Red Hat, Inc.