Re: [Qemu-devel] [PATCH v3 4/5] block: Convert open calls to qemu_open

[Corey Bryant <coreyb@linux.vnet.ibm.com>]

On 06/15/2012 10:36 AM, Luiz Capitulino wrote:
> On Thu, 14 Jun 2012 11:55:04 -0400
> Corey Bryant <coreyb@linux.vnet.ibm.com> wrote:
>
>> This patch converts all block layer open calls to qemu_open.  This
>> enables all block layer open paths to dup(X) a pre-opened file
>> descriptor if the filename is of the format /dev/fd/X.  This is
>> useful if QEMU is restricted from opening certain files.
>>
>> Note that this adds the O_CLOEXEC flag to the changed open paths
>> when the O_CLOEXEC macro is defined.
>
> Very minor comment, but I'd exchange this with the previous patch. Because
> this change is not only related to the /dev/fd/X feature and also because
> as soon as you introduce the /dev/fd/X it will work for all file formats.
>

Sure, not a problem.

>>
>> Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
>> ---
>> v2:
>>   -Convert calls to qemu_open instead of file_open (kwolf@redhat.com)
>>   -Mention introduction of O_CLOEXEC (kwolf@redhat.com)
>>
>> v3:
>>   -No changes
>>
>>   block/raw-posix.c |   18 +++++++++---------
>>   block/raw-win32.c |    4 ++--
>>   block/vdi.c       |    5 +++--
>>   block/vmdk.c      |   21 +++++++++------------
>>   block/vpc.c       |    2 +-
>>   block/vvfat.c     |   21 +++++++++++----------
>>   6 files changed, 35 insertions(+), 36 deletions(-)
>>
>> diff --git a/block/raw-posix.c b/block/raw-posix.c
>> index 03fcfcc..d8eff2f 100644
>> --- a/block/raw-posix.c
>> +++ b/block/raw-posix.c
>> @@ -568,8 +568,8 @@ static int raw_create(const char *filename, QEMUOptionParameter *options)
>>           options++;
>>       }
>>
>> -    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
>> -              0644);
>> +    fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
>> +                   0644);
>>       if (fd < 0) {
>>           result = -errno;
>>       } else {
>> @@ -741,7 +741,7 @@ static int hdev_open(BlockDriverState *bs, const char *filename, int flags)
>>           if ( bsdPath[ 0 ] != '\0' ) {
>>               strcat(bsdPath,"s0");
>>               /* some CDs don't have a partition 0 */
>> -            fd = open(bsdPath, O_RDONLY | O_BINARY | O_LARGEFILE);
>> +            fd = qemu_open(bsdPath, O_RDONLY | O_BINARY | O_LARGEFILE);
>>               if (fd < 0) {
>>                   bsdPath[strlen(bsdPath)-1] = '1';
>>               } else {
>> @@ -798,7 +798,7 @@ static int fd_open(BlockDriverState *bs)
>>   #endif
>>               return -EIO;
>>           }
>> -        s->fd = open(bs->filename, s->open_flags & ~O_NONBLOCK);
>> +        s->fd = qemu_open(bs->filename, s->open_flags & ~O_NONBLOCK);
>>           if (s->fd < 0) {
>>               s->fd_error_time = get_clock();
>>               s->fd_got_error = 1;
>> @@ -872,7 +872,7 @@ static int hdev_create(const char *filename, QEMUOptionParameter *options)
>>           options++;
>>       }
>>
>> -    fd = open(filename, O_WRONLY | O_BINARY);
>> +    fd = qemu_open(filename, O_WRONLY | O_BINARY);
>>       if (fd < 0)
>>           return -errno;
>>
>> @@ -950,7 +950,7 @@ static int floppy_probe_device(const char *filename)
>>       if (strstart(filename, "/dev/fd", NULL))
>>           prio = 50;
>>
>> -    fd = open(filename, O_RDONLY | O_NONBLOCK);
>> +    fd = qemu_open(filename, O_RDONLY | O_NONBLOCK);
>>       if (fd < 0) {
>>           goto out;
>>       }
>> @@ -1003,7 +1003,7 @@ static void floppy_eject(BlockDriverState *bs, bool eject_flag)
>>           close(s->fd);
>>           s->fd = -1;
>>       }
>> -    fd = open(bs->filename, s->open_flags | O_NONBLOCK);
>> +    fd = qemu_open(bs->filename, s->open_flags | O_NONBLOCK);
>>       if (fd >= 0) {
>>           if (ioctl(fd, FDEJECT, 0) < 0)
>>               perror("FDEJECT");
>> @@ -1053,7 +1053,7 @@ static int cdrom_probe_device(const char *filename)
>>       int prio = 0;
>>       struct stat st;
>>
>> -    fd = open(filename, O_RDONLY | O_NONBLOCK);
>> +    fd = qemu_open(filename, O_RDONLY | O_NONBLOCK);
>>       if (fd < 0) {
>>           goto out;
>>       }
>> @@ -1177,7 +1177,7 @@ static int cdrom_reopen(BlockDriverState *bs)
>>        */
>>       if (s->fd >= 0)
>>           close(s->fd);
>> -    fd = open(bs->filename, s->open_flags, 0644);
>> +    fd = qemu_open(bs->filename, s->open_flags, 0644);
>>       if (fd < 0) {
>>           s->fd = -1;
>>           return -EIO;
>> diff --git a/block/raw-win32.c b/block/raw-win32.c
>> index e4b0b75..8d7838d 100644
>> --- a/block/raw-win32.c
>> +++ b/block/raw-win32.c
>> @@ -255,8 +255,8 @@ static int raw_create(const char *filename, QEMUOptionParameter *options)
>>           options++;
>>       }
>>
>> -    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
>> -              0644);
>> +    fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
>> +                   0644);
>>       if (fd < 0)
>>           return -EIO;
>>       set_sparse(fd);
>> diff --git a/block/vdi.c b/block/vdi.c
>> index 119d3c7..6183fdf 100644
>> --- a/block/vdi.c
>> +++ b/block/vdi.c
>> @@ -648,8 +648,9 @@ static int vdi_create(const char *filename, QEMUOptionParameter *options)
>>           options++;
>>       }
>>
>> -    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
>> -              0644);
>> +    fd = qemu_open(filename,
>> +                   O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
>> +                   0644);
>>       if (fd < 0) {
>>           return -errno;
>>       }
>> diff --git a/block/vmdk.c b/block/vmdk.c
>> index 18e9b4c..557dc1b 100644
>> --- a/block/vmdk.c
>> +++ b/block/vmdk.c
>> @@ -1161,10 +1161,9 @@ static int vmdk_create_extent(const char *filename, int64_t filesize,
>>       VMDK4Header header;
>>       uint32_t tmp, magic, grains, gd_size, gt_size, gt_count;
>>
>> -    fd = open(
>> -        filename,
>> -        O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
>> -        0644);
>> +    fd = qemu_open(filename,
>> +                   O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
>> +                   0644);
>>       if (fd < 0) {
>>           return -errno;
>>       }
>> @@ -1484,15 +1483,13 @@ static int vmdk_create(const char *filename, QEMUOptionParameter *options)
>>               (flags & BLOCK_FLAG_COMPAT6 ? 6 : 4),
>>               total_size / (int64_t)(63 * 16 * 512));
>>       if (split || flat) {
>> -        fd = open(
>> -                filename,
>> -                O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
>> -                0644);
>> +        fd = qemu_open(filename,
>> +                       O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
>> +                       0644);
>>       } else {
>> -        fd = open(
>> -                filename,
>> -                O_WRONLY | O_BINARY | O_LARGEFILE,
>> -                0644);
>> +        fd = qemu_open(filename,
>> +                       O_WRONLY | O_BINARY | O_LARGEFILE,
>> +                       0644);
>>       }
>>       if (fd < 0) {
>>           return -errno;
>> diff --git a/block/vpc.c b/block/vpc.c
>> index 5cd13d1..60ebf5a 100644
>> --- a/block/vpc.c
>> +++ b/block/vpc.c
>> @@ -678,7 +678,7 @@ static int vpc_create(const char *filename, QEMUOptionParameter *options)
>>       }
>>
>>       /* Create the file */
>> -    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
>> +    fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
>>       if (fd < 0) {
>>           return -EIO;
>>       }
>> diff --git a/block/vvfat.c b/block/vvfat.c
>> index 0fd3367..81c3a19 100644
>> --- a/block/vvfat.c
>> +++ b/block/vvfat.c
>> @@ -1152,16 +1152,17 @@ static inline mapping_t* find_mapping_for_cluster(BDRVVVFATState* s,int cluster_
>>   static int open_file(BDRVVVFATState* s,mapping_t* mapping)
>>   {
>>       if(!mapping)
>> -	return -1;
>> +        return -1;
>>       if(!s->current_mapping ||
>> -	    strcmp(s->current_mapping->path,mapping->path)) {
>> -	/* open file */
>> -	int fd = open(mapping->path, O_RDONLY | O_BINARY | O_LARGEFILE);
>> -	if(fd<0)
>> -	    return -1;
>> -	vvfat_close_current_file(s);
>> -	s->current_fd = fd;
>> -	s->current_mapping = mapping;
>> +            strcmp(s->current_mapping->path, mapping->path)) {
>> +        /* open file */
>> +        int fd = qemu_open(mapping->path, O_RDONLY | O_BINARY | O_LARGEFILE);
>> +        if (fd < 0) {
>> +            return -1;
>> +        }
>> +        vvfat_close_current_file(s);
>> +        s->current_fd = fd;
>> +        s->current_mapping = mapping;
>>       }
>>       return 0;
>>   }
>> @@ -2215,7 +2216,7 @@ static int commit_one_file(BDRVVVFATState* s,
>>       for (i = s->cluster_size; i < offset; i += s->cluster_size)
>>   	c = modified_fat_get(s, c);
>>
>> -    fd = open(mapping->path, O_RDWR | O_CREAT | O_BINARY, 0666);
>> +    fd = qemu_open(mapping->path, O_RDWR | O_CREAT | O_BINARY, 0666);
>>       if (fd < 0) {
>>   	fprintf(stderr, "Could not open %s... (%s, %d)\n", mapping->path,
>>   		strerror(errno), errno);
>

-- 
Regards,
Corey