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Sun, 16 Jan 2022 21:58:34 +0100 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 13627af0-770f-11ec-a115-11989b9578b4 X-Virus-Scanned: Debian amavisd-new at aquilenet.fr Date: Sun, 16 Jan 2022 21:58:34 +0100 From: Samuel Thibault To: Juergen Gross Cc: minios-devel@lists.xenproject.org, xen-devel@lists.xenproject.org, wl@xen.org Subject: Re: [MINIOS PATCH v3 06/12] use alloc_file_type() and get_file_from_fd() in blkfront Message-ID: <20220116205834.n5duepw7txpitf4x@begin> Mail-Followup-To: Samuel Thibault , Juergen Gross , minios-devel@lists.xenproject.org, xen-devel@lists.xenproject.org, wl@xen.org References: <20220116083328.26524-1-jgross@suse.com> <20220116083328.26524-7-jgross@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220116083328.26524-7-jgross@suse.com> Organization: I am not organized User-Agent: NeoMutt/20170609 (1.8.3) X-Spamd-Bar: / Authentication-Results: hera.aquilenet.fr; none X-Rspamd-Server: hera X-Rspamd-Queue-Id: 530F72BC X-Spamd-Result: default: False [0.40 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; HAS_ORG_HEADER(0.00)[]; RCVD_COUNT_THREE(0.00)[3]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_LAST(0.00)[]; MID_RHS_NOT_FQDN(0.50)[] Juergen Gross, le dim. 16 janv. 2022 09:33:22 +0100, a ecrit: > Allocate the file type dynamically via alloc_file_type(). > > Instead of directly accessing the files[] array use get_file_from_fd(). > > Signed-off-by: Juergen Gross Reviewed-by: Samuel Thibault > --- > V3: > - switch to struct file * parameter for callbacks > - use __attribute__((constructor)) > --- > blkfront.c | 92 ++++++++++++++++++++++++++++++++++------------ > include/blkfront.h | 5 --- > include/lib.h | 3 +- > lib/sys.c | 24 ------------ > 4 files changed, 69 insertions(+), 55 deletions(-) > > diff --git a/blkfront.c b/blkfront.c > index e3f42bef..ed902702 100644 > --- a/blkfront.c > +++ b/blkfront.c > @@ -59,10 +59,10 @@ void blkfront_handler(evtchn_port_t port, struct pt_regs *regs, void *data) > { > #ifdef HAVE_LIBC > struct blkfront_dev *dev = data; > - int fd = dev->fd; > + struct file *file = get_file_from_fd(dev->fd); > > - if (fd != -1) > - files[fd].read = true; > + if ( file ) > + file->read = true; > #endif > wake_up(&blkfront_queue); > } > @@ -483,9 +483,13 @@ int blkfront_aio_poll(struct blkfront_dev *dev) > > moretodo: > #ifdef HAVE_LIBC > - if (dev->fd != -1) { > - files[dev->fd].read = false; > - mb(); /* Make sure to let the handler set read to 1 before we start looking at the ring */ > + { > + struct file *file = get_file_from_fd(dev->fd); > + > + if ( file ) { > + file->read = false; > + mb(); /* Make sure to let the handler set read to 1 before we start looking at the ring */ > + } > } > #endif > > @@ -554,22 +558,11 @@ moretodo: > } > > #ifdef HAVE_LIBC > -int blkfront_open(struct blkfront_dev *dev) > +static int blkfront_posix_rwop(struct file *file, uint8_t *buf, size_t count, > + bool write) > { > - /* Silently prevent multiple opens */ > - if(dev->fd != -1) { > - return dev->fd; > - } > - dev->fd = alloc_fd(FTYPE_BLK); > - printk("blk_open(%s) -> %d\n", dev->nodename, dev->fd); > - files[dev->fd].dev = dev; > - return dev->fd; > -} > - > -int blkfront_posix_rwop(int fd, uint8_t* buf, size_t count, int write) > -{ > - struct blkfront_dev* dev = files[fd].dev; > - off_t offset = files[fd].offset; > + struct blkfront_dev *dev = file->dev; > + off_t offset = file->offset; > struct blkfront_aiocb aiocb; > unsigned long long disksize = dev->info.sectors * dev->info.sector_size; > unsigned int blocksize = dev->info.sector_size; > @@ -711,14 +704,24 @@ int blkfront_posix_rwop(int fd, uint8_t* buf, size_t count, int write) > } > > free(copybuf); > - files[fd].offset += rc; > + file->offset += rc; > return rc; > > } > > -int blkfront_posix_fstat(int fd, struct stat* buf) > +static int blkfront_posix_read(struct file *file, void *buf, size_t nbytes) > { > - struct blkfront_dev* dev = files[fd].dev; > + return blkfront_posix_rwop(file, buf, nbytes, false); > +} > + > +static int blkfront_posix_write(struct file *file, const void *buf, size_t nbytes) > +{ > + return blkfront_posix_rwop(file, (void *)buf, nbytes, true); > +} > + > +static int blkfront_posix_fstat(struct file *file, struct stat *buf) > +{ > + struct blkfront_dev *dev = file->dev; > > buf->st_mode = dev->info.mode; > buf->st_uid = 0; > @@ -728,4 +731,45 @@ int blkfront_posix_fstat(int fd, struct stat* buf) > > return 0; > } > + > +static int blkfront_close_fd(struct file *file) > +{ > + shutdown_blkfront(file->dev); > + > + return 0; > +} > + > +static const struct file_ops blk_ops = { > + .name = "blk", > + .read = blkfront_posix_read, > + .write = blkfront_posix_write, > + .lseek = lseek_default, > + .close = blkfront_close_fd, > + .fstat = blkfront_posix_fstat, > + .select_rd = select_read_flag, > +}; > + > +static unsigned int ftype_blk; > + > +__attribute__((constructor)) > +static void blkfron_initialize(void) > +{ > + ftype_blk = alloc_file_type(&blk_ops); > +} > + > +int blkfront_open(struct blkfront_dev *dev) > +{ > + struct file *file; > + > + /* Silently prevent multiple opens */ > + if ( dev->fd != -1 ) > + return dev->fd; > + > + dev->fd = alloc_fd(ftype_blk); > + printk("blk_open(%s) -> %d\n", dev->nodename, dev->fd); > + file = get_file_from_fd(dev->fd); > + file->dev = dev; > + > + return dev->fd; > +} > #endif > diff --git a/include/blkfront.h b/include/blkfront.h > index 3528af9d..7f84a0a2 100644 > --- a/include/blkfront.h > +++ b/include/blkfront.h > @@ -28,17 +28,12 @@ struct blkfront_info > }; > struct blkfront_dev *init_blkfront(char *nodename, struct blkfront_info *info); > #ifdef HAVE_LIBC > -#include > /* POSIX IO functions: > * use blkfront_open() to get a file descriptor to the block device > * Don't use the other blkfront posix functions here directly, instead use > * read(), write(), lseek() and fstat() on the file descriptor > */ > int blkfront_open(struct blkfront_dev *dev); > -int blkfront_posix_rwop(int fd, uint8_t* buf, size_t count, int write); > -#define blkfront_posix_write(fd, buf, count) blkfront_posix_rwop(fd, (uint8_t*)buf, count, 1) > -#define blkfront_posix_read(fd, buf, count) blkfront_posix_rwop(fd, (uint8_t*)buf, count, 0) > -int blkfront_posix_fstat(int fd, struct stat* buf); > #endif > void blkfront_aio(struct blkfront_aiocb *aiocbp, int write); > #define blkfront_aio_read(aiocbp) blkfront_aio(aiocbp, 0) > diff --git a/include/lib.h b/include/lib.h > index 9b7eaae7..2f472b00 100644 > --- a/include/lib.h > +++ b/include/lib.h > @@ -166,8 +166,7 @@ extern struct wait_queue_head event_queue; > #define FTYPE_FB 6 > #define FTYPE_KBD 7 > #define FTYPE_TAP 8 > -#define FTYPE_BLK 9 > -#define FTYPE_N 10 > +#define FTYPE_N 9 > #define FTYPE_SPARE 16 > > struct file { > diff --git a/lib/sys.c b/lib/sys.c > index 39f51980..90684335 100644 > --- a/lib/sys.c > +++ b/lib/sys.c > @@ -343,11 +343,6 @@ int read(int fd, void *buf, size_t nbytes) > } > return ret * sizeof(union xenfb_in_event); > } > -#endif > -#ifdef CONFIG_BLKFRONT > - case FTYPE_BLK: { > - return blkfront_posix_read(fd, buf, nbytes); > - } > #endif > default: > break; > @@ -392,10 +387,6 @@ int write(int fd, const void *buf, size_t nbytes) > case FTYPE_TAP: > netfront_xmit(files[fd].dev, (void*) buf, nbytes); > return nbytes; > -#endif > -#ifdef CONFIG_BLKFRONT > - case FTYPE_BLK: > - return blkfront_posix_write(fd, buf, nbytes); > #endif > default: > break; > @@ -455,10 +446,6 @@ off_t lseek(int fd, off_t offset, int whence) > return ops->lseek(file, offset, whence); > > switch(file->type) { > -#ifdef CONFIG_BLKFRONT > - case FTYPE_BLK: > - break; > -#endif > case FTYPE_FILE: > break; > default: > @@ -505,11 +492,6 @@ int close(int fd) > shutdown_netfront(files[fd].dev); > break; > #endif > -#ifdef CONFIG_BLKFRONT > - case FTYPE_BLK: > - shutdown_blkfront(files[fd].dev); > - break; > -#endif > #ifdef CONFIG_KBDFRONT > case FTYPE_KBD: > shutdown_kbdfront(files[fd].dev); > @@ -591,10 +573,6 @@ int fstat(int fd, struct stat *buf) > buf->st_ctime = time(NULL); > return 0; > } > -#ifdef CONFIG_BLKFRONT > - case FTYPE_BLK: > - return blkfront_posix_fstat(fd, buf); > -#endif > default: > break; > } > @@ -710,7 +688,6 @@ static const char *const file_types[] = { > [FTYPE_CONSOLE] = "console", > [FTYPE_SOCKET] = "socket", > [FTYPE_TAP] = "net", > - [FTYPE_BLK] = "blk", > [FTYPE_KBD] = "kbd", > [FTYPE_FB] = "fb", > }; > @@ -896,7 +873,6 @@ static int select_poll(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exce > FD_CLR(i, exceptfds); > break; > case FTYPE_TAP: > - case FTYPE_BLK: > case FTYPE_KBD: > case FTYPE_FB: > if (FD_ISSET(i, readfds)) { > -- > 2.26.2 > -- Samuel After watching my newly-retired dad spend two weeks learning how to make a new folder, it became obvious that "intuitive" mostly means "what the writer or speaker of intuitive likes". (Bruce Ediger, bediger@teal.csn.org, in comp.os.linux.misc, on X the intuitiveness of a Mac interface.)