search for: file_can_extents

...size = block_device_size (h->fd); + pthread_mutex_unlock (&lseek_lock); return size; } else { /* Regular file. */ @@ -501,6 +519,103 @@ file_trim (void *handle, uint32_t count, uint64_t offset, uint32_t flags) return 0; } +#ifdef SEEK_HOLE +/* Extents. */ + +static int +file_can_extents (void *handle) +{ + struct handle *h = handle; + off_t r; + + /* A simple test to see whether SEEK_HOLE etc is likely to work on + * the current filesystem. + */ + pthread_mutex_lock (&lseek_lock); + r = lseek (h->fd, 0, SEEK_HOLE); + pthread_mutex_unlock (&lseek_lock); + if (...

.../file/file.c | 141 ++++++++++++++++++++++++++++++++++--- > tests/Makefile.am | 5 ++ > tests/test-file-extents.sh | 57 +++++++++++++++ > 3 files changed, 193 insertions(+), 10 deletions(-) > > +#ifdef SEEK_HOLE > +/* Extents. */ > + > +static int > +file_can_extents (void *handle) > +{ > + struct handle *h = handle; > + off_t r; > + > + /* A simple test to see whether SEEK_HOLE etc is likely to work on > + * the current filesystem. > + */ > + pthread_mutex_lock (&lseek_lock); > + r = lseek (h->fd, 0, SEEK_HOLE); >...

...f 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 function that it expects the caller to grab the lock. > > +#ifdef SEEK_HOLE > +/* Extents. */ > + > +static int > +file_can_extents (void *handle) > +{ > + struct handle *h = handle; > + off_t r; > + > + /* A simple test to see whether SEEK_HOLE etc is likely to work on > + * the current filesystem. > + */ > + pthread_mutex_lock (&lseek_lock); > + r = lseek (h->fd, 0, SEEK_HOLE); >...

...size = block_device_size (h->fd); + pthread_mutex_unlock (&lseek_lock); return size; } else { /* Regular file. */ @@ -501,6 +521,103 @@ file_trim (void *handle, uint32_t count, uint64_t offset, uint32_t flags) return 0; } +#ifdef SEEK_HOLE +/* Extents. */ + +static int +file_can_extents (void *handle) +{ + struct handle *h = handle; + off_t r; + + /* A simple test to see whether SEEK_HOLE etc is likely to work on + * the current filesystem. + */ + pthread_mutex_lock (&lseek_lock); + r = lseek (h->fd, 0, SEEK_HOLE); + pthread_mutex_unlock (&lseek_lock); + if (...

...++++++++++--- > > tests/Makefile.am | 5 ++ > > tests/test-file-extents.sh | 57 +++++++++++++++ > > 3 files changed, 193 insertions(+), 10 deletions(-) > > > > > +#ifdef SEEK_HOLE > > +/* Extents. */ > > + > > +static int > > +file_can_extents (void *handle) > > +{ > > + struct handle *h = handle; > > + off_t r; > > + > > + /* A simple test to see whether SEEK_HOLE etc is likely to work on > > + * the current filesystem. > > + */ > > + pthread_mutex_lock (&lseek_lock); > >...

..."extents enabled, image currently all data"); + } + else { + nbdkit_debug ("extents enabled, image includes data before hole"); + h->init_sparse = true; + } + } + } + } +#endif + return h; } @@ -540,18 +589,8 @@ static int file_can_extents (void *handle) { struct handle *h = handle; - off_t r; - /* A simple test to see whether SEEK_HOLE etc is likely to work on - * the current filesystem. - */ - ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lseek_lock); - r = lseek (h->fd, 0, SEEK_HOLE); - if (r == -1) { - nbdkit_debug (&q...

...ile.c index dc99f992..27316b9f 100644 --- a/plugins/file/file.c +++ b/plugins/file/file.c @@ -170,7 +170,7 @@ file_open (int readonly) return NULL; } - flags = O_CLOEXEC|O_NOCTTY; + flags = O_CLOEXEC|O_NOCTTY|O_DIRECT; if (readonly) flags |= O_RDONLY; else @@ -551,7 +551,7 @@ file_can_extents (void *handle) nbdkit_debug ("extents disabled: lseek: SEEK_HOLE: %m"); return 0; } - return 1; + return 0; } static int diff --git a/plugins/python/examples/file.py b/plugins/python/examples/file.py index 866b8244..3652eb52 100644 --- a/plugins/python/examples/file.py...

...ile.c index dc99f992..27316b9f 100644 --- a/plugins/file/file.c +++ b/plugins/file/file.c @@ -170,7 +170,7 @@ file_open (int readonly) return NULL; } - flags = O_CLOEXEC|O_NOCTTY; + flags = O_CLOEXEC|O_NOCTTY|O_DIRECT; if (readonly) flags |= O_RDONLY; else @@ -551,7 +551,7 @@ file_can_extents (void *handle) nbdkit_debug ("extents disabled: lseek: SEEK_HOLE: %m"); return 0; } - return 1; + return 0; } static int diff --git a/plugins/python/examples/file.py b/plugins/python/examples/file.py index 866b8244..3652eb52 100644 --- a/plugins/python/examples/file.py...

...e/file.c > +++ b/plugins/file/file.c > @@ -170,7 +170,7 @@ file_open (int readonly) > return NULL; > } > > - flags = O_CLOEXEC|O_NOCTTY; > + flags = O_CLOEXEC|O_NOCTTY|O_DIRECT; > if (readonly) > flags |= O_RDONLY; > else > @@ -551,7 +551,7 @@ file_can_extents (void *handle) > nbdkit_debug ("extents disabled: lseek: SEEK_HOLE: %m"); > return 0; > } > - return 1; > + return 0; > } > > static int > diff --git a/plugins/python/examples/file.py b/plugins/python/examples/file.py > index 866b8244..3652...

...h->can_punch_hole = false; - - nbdkit_debug ("ignoring failed fallocate during trim: %m"); - } - } -#endif - - if ((flags & NBDKIT_FLAG_FUA) && file_flush (handle, 0) == -1) - return -1; - - return 0; -} - -#ifdef SEEK_HOLE -/* Extents. */ - -static int -file_can_extents (void *handle) -{ - struct handle *h = handle; - off_t r; - - /* A simple test to see whether SEEK_HOLE etc is likely to work on - * the current filesystem. - */ - ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lseek_lock); - r = lseek (h->fd, 0, SEEK_HOLE); - if (r == -1) { - nbdkit_debug (&...

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; /*

...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. */ @@ -554,7 +638,7 @@ file_can_extents (void *handle) /* A simple test to see whether SEEK_HOLE etc is likely to work on * the current filesystem. */ - ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lseek_lock); + ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock); r = lseek (h->fd, 0, SEEK_HOLE); if (r == -1) { nbdkit_debug (&...

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

I do have a question about whether patch 2 is right, or whether I've exposed a bigger problem in the truncate (and possibly other) filter, but the rest seem fairly straightforward. Eric Blake (4): server: Check for pthread lock failures truncate: Factor out reading real_size under mutex plugins: Check for mutex failures filters: Check for mutex failures filters/cache/cache.c

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

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

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.

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

I will be following up to this email with four separate threads each addressed to the appropriate single list, with proposed changes to: - the NBD protocol - qemu: both server and client - libnbd: client - nbdkit: server The feature in question adds a new optional NBD_INFO_ packet to the NBD_OPT_GO portion of handshake, adding up to 16 bits of information that the server can advertise to the

I'm still working my way through the filters before this series will be complete, but this is enough of a start to at least get some feedback on the idea of implementing another NBD protocol extension. Eric Blake (9): server: Internal hooks for implementing NBD_CMD_CACHE plugins: Add .cache callback file, split: Implement .cache with posix_fadvise nbd: Implement NBD_CMD_CACHE