search for: block_device_size

...READ_MUTEX_INITIALIZER; + +/* to enable: -D file.zero=1 */ +int file_debug_zero; static void file_unload (void) @@ -220,6 +227,21 @@ file_close (void *handle) #define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL +/* For block devices, stat->st_size is not the true size. */ +static int64_t +block_device_size (int fd) +{ + off_t size; + + size = lseek (fd, 0, SEEK_END); + if (size == -1) { + nbdkit_error ("lseek (to find device size): %m"); + return -1; + } + + return size; +} + /* Get the file size. */ static int64_t file_get_size (void *handle) @@ -227,15 +249,11 @@ file_get_si...

...*/ > +int file_debug_zero; > > static void > file_unload (void) > @@ -220,6 +227,21 @@ file_close (void *handle) > > #define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL > > +/* For block devices, stat->st_size is not the true size. */ > +static int64_t > +block_device_size (int fd) > +{ > + off_t size; > + > + size = lseek (fd, 0, SEEK_END); Calling lseek without the lock? I'm not sure if you can guarantee that .size won't be called in parallel with some other .extents. /me reads ahead Oh, the caller has the lock. I might add a comment to this...

v2 was here: https://www.redhat.com/archives/libguestfs/2020-April/msg00075.html In v3: - Add [VAR=VALUE ...] to manual. - Various minor improvements to the manual. - Work (at least, in theory - not tested) with block devices or symlinks. I didn't document this because it's hard to ensure these files or block devices would be cleaned up, so here be dragons. - Remove O_NOCTTY. -

...-D file.zero=1 */ +int file_debug_zero; static void file_unload (void) @@ -220,6 +227,23 @@ file_close (void *handle) #define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL +/* For block devices, stat->st_size is not the true size. The caller + * grabs the lseek_lock. + */ +static int64_t +block_device_size (int fd) +{ + off_t size; + + size = lseek (fd, 0, SEEK_END); + if (size == -1) { + nbdkit_error ("lseek (to find device size): %m"); + return -1; + } + + return size; +} + /* Get the file size. */ static int64_t file_get_size (void *handle) @@ -227,15 +251,11 @@ file_get_si...

...return h->size; -} - /* This creates and runs the full "mkfs" (or whatever) command. */ static int run_command (const char *disk) @@ -263,37 +230,18 @@ run_command (const char *disk) return 0; } -/* For block devices, stat->st_size is not the true size. */ -static int64_t -block_device_size (int fd) -{ - off_t size; - - size = lseek (fd, 0, SEEK_END); - if (size == -1) { - nbdkit_error ("lseek: %m"); - return -1; - } - - return size; -} - static void * tmpdisk_open (int readonly) { - struct handle *h; + struct fileops *fops; CLEANUP_FREE char *dir = NULL,...

...<nbdkit-plugin.h> +#include "cleanup.h" #include "isaligned.h" #ifndef O_CLOEXEC @@ -250,12 +251,8 @@ file_get_size (void *handle) struct handle *h = handle; if (h->is_block_device) { - int64_t size; - - pthread_mutex_lock (&lseek_lock); - size = block_device_size (h->fd); - pthread_mutex_unlock (&lseek_lock); - return size; + ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lseek_lock); + return block_device_size (h->fd); } else { /* Regular file. */ struct stat statbuf; @@ -607,13 +604,8 @@ static int file_extents (void *handle, uin...

Needs some work still, see in particular the commit message for patch 3. Rich.

...ops->can_fallocate = true; + fops->can_zeroout = fops->is_block_device; + + return 0; +} + +void +close_fileops (struct fileops *fops) +{ + close (fops->fd); +} + +/* For block devices, stat->st_size is not the true size. The caller + * grabs the lseek_lock. + */ +static int64_t +block_device_size (int fd) +{ + off_t size; + + size = lseek (fd, 0, SEEK_END); + if (size == -1) { + nbdkit_error ("lseek (to find device size): %m"); + return -1; + } + + return size; +} + +/* Get the file size. */ +int64_t +fileops_get_size (void *handle) +{ + struct fileops *fops = handle;...

There's a lot of code in nbdkit-file-plugin which it would be nice to reuse elsewhere. One possible approach (as outlined here) is simply to move the file callbacks (like file.pread, file.pwrite, file.zero etc) to a new mini-library. They can then be consumed by other plugins fairly easily by doing: static void * foo_open (int readonly) { struct fileops *fops; int fd, flags; /*

...+ free (h->file); close (h->fd); free (h); } @@ -239,7 +323,7 @@ file_close (void *handle) #define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL /* For block devices, stat->st_size is not the true size. The caller - * grabs the lseek_lock. + * grabs the lock. */ static int64_t block_device_size (int fd) @@ -262,7 +346,7 @@ file_get_size (void *handle) struct handle *h = handle; if (h->is_block_device) { - ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lseek_lock); + ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock); return block_device_size (h->fd); } else { /* Regular file...

...c ('\n', fp); - putc ('\n', fp); + /* The command. */ fprintf (fp, "%s", command); if (fclose (fp) == EOF) { @@ -216,11 +263,28 @@ run_command (const char *disk) return 0; } +/* For block devices, stat->st_size is not the true size. */ +static int64_t +block_device_size (int fd) +{ + off_t size; + + size = lseek (fd, 0, SEEK_END); + if (size == -1) { + nbdkit_error ("lseek: %m"); + return -1; + } + + return size; +} + static void * tmpdisk_open (int readonly) { struct handle *h; - CLEANUP_FREE char *disk = NULL; + CLEANUP_FREE char *di...

There's more that can be done (in particular, use of CLEANUP_FREE), but this is enough to at least see if I'm on the right track. I couldn't figure out an obvious difference between common/include and common/utils, but it looks like the former is for things that are inlineable via .h only, while the latter is when you need to link in a convenience library, so this landed in the

...command killed by signal %d", WTERMSIG (r)); + return -1; + } + else if (WIFSTOPPED (r)) { + nbdkit_error ("command stopped by signal %d", WSTOPSIG (r)); + return -1; + } + + return 0; +} + +/* For block devices, stat->st_size is not the true size. */ +static int64_t +block_device_size (int fd) +{ + off_t size; + + size = lseek (fd, 0, SEEK_END); + if (size == -1) { + nbdkit_error ("lseek: %m"); + return -1; + } + + return size; +} + +static void * +ondemand_open (int readonly) +{ + struct handle *h; + CLEANUP_FREE char *disk = NULL; + int flags, err; + s...

Not sure what version we're up to, but this reimplements extents using the new simpler structure described in this thread: https://www.redhat.com/archives/libguestfs/2019-March/msg00077.html I also fixed most of the things that Eric pointed out in the previous review, although I need to go back over his replies and check I've got everything. This needs a bit more testing. However the

Here's changes to the file plugin (which I'm happy with) and a new exportname filter (which is still at RFC stage; I need to finish implementing strict mode in .open, and add tests). I also discovered that we really want .list_exports and .open to know when they are used on plaintext vs. tls clients for --tls=on, and we may want to split out a new .default_export callback rather than

I'm not sure exactly which version we're up to, but let's say it's version 4. I'm a lot happier with this version: - all filters have been reviewed and changed where I think that's necessary - can_extents is properly defined and implemented now - NBD protocol is followed - I believe it addresses all previous review points where possible The "only" thing

I want to post this but mainly for discussion and early review. It's not safe for these patches to all go upstream yet (because not all filters have been checked/adjusted), but if any patches were to go upstream then probably 1 & 2 only are safe. File, VDDK, memory and data plugins all work, although I have only done minimal testing on them. The current tests, such as they are, all

This has already been pushed upstream. I am simply posting these here so we have a reference in the mailing list in case we find bugs later (as I'm sure we will - it's a complex patch series). Great thanks to Eric Blake for tireless review on this one. It also seems to have identified a few minor bugs in qemu along the way. Rich.