Re: [libvirt] [PATCH v3 4/5] block: Convert open calls to qemu_open

On Thu, 14 Jun 2012 11:55:04 -0400 Corey Bryant <coreyb(a)linux.vnet.ibm.com&gt; 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.

> > Signed-off-by: Corey Bryant <coreyb(a)linux.vnet.ibm.com&gt; > --- > v2: > -Convert calls to qemu_open instead of file_open (kwolf(a)redhat.com) > -Mention introduction of O_CLOEXEC (kwolf(a)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);