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2022-03-079pfs/9p.c: convert Doxygen -> kerneldoc formatChristian Schoenebeck1-27/+35
API doc comments in QEMU are supposed to be in kerneldoc format, so convert API doc comments from Doxygen format to kerneldoc format. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <4ece6ffa4465c271c6a7c42a3040f42780fcce87.1646314856.git.qemu_oss@crudebyte.com>
2022-03-079pfs/codir.c: convert Doxygen -> kerneldoc formatChristian Schoenebeck1-15/+15
API doc comments in QEMU are supposed to be in kerneldoc format, so convert API doc comments from Doxygen format to kerneldoc format. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <c76be7d38ea448c6417b2ffb5ccd6b711519a878.1646314856.git.qemu_oss@crudebyte.com>
2022-03-079pfs/9p.h: convert Doxygen -> kerneldoc formatChristian Schoenebeck1-6/+6
API doc comments in QEMU are supposed to be in kerneldoc format, so convert API doc comments from Doxygen format to kerneldoc format. Based-on: <E1nPTwO-0006pl-Np@lizzy.crudebyte.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <2b8f91de7bac3d3bc85d60eb08830a35a394be75.1646314856.git.qemu_oss@crudebyte.com>
2022-03-079pfs: drop Doxygen format from qemu_dirent_dup() API commentChristian Schoenebeck1-2/+2
API doc comments in QEMU are supposed to be in kerneldoc format, so drop occurrences of "@c" which is Doxygen format for fixed-width text. Link: https://lore.kernel.org/qemu-devel/CAFEAcA89+ENOM6x19OEF53Kd2DWkhN5SN21Va0D7yepJSa3Jyg@mail.gmail.com/ Based-on: <E1nP9Oz-00043L-KJ@lizzy.crudebyte.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <E1nPTwO-0006pl-Np@lizzy.crudebyte.com>
2022-03-079pfs: move qemu_dirent_dup() from osdep -> 9p-utilChristian Schoenebeck1-0/+30
Function qemu_dirent_dup() is currently only used by 9pfs server, so move it from project global header osdep.h to 9pfs specific header 9p-util.h. Link: https://lore.kernel.org/qemu-devel/CAFEAcA_=HAUNomKD2wurSVaAHa5mrk22A1oHKLWUDjk7v6Khmg@mail.gmail.com/ Based-on: <20220227223522.91937-12-wwcohen@gmail.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <E1nP9Oz-00043L-KJ@lizzy.crudebyte.com>
2022-03-079p: darwin: Implement compatibility for mknodatKeno Fischer4-2/+52
Darwin does not support mknodat. However, to avoid race conditions with later setting the permissions, we must avoid using mknod on the full path instead. We could try to fchdir, but that would cause problems if multiple threads try to call mknodat at the same time. However, luckily there is a solution: Darwin includes a function that sets the cwd for the current thread only. This should suffice to use mknod safely. This function (pthread_fchdir_np) is protected by a check in meson in a patch later in this series. Signed-off-by: Keno Fischer <keno@juliacomputing.com> Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com> [Will Cohen: - Adjust coding style - Replace clang references with gcc - Note radar filed with Apple for missing syscall - Replace direct syscall with pthread_fchdir_np and adjust patch notes accordingly - Declare pthread_fchdir_np with - __attribute__((weak_import)) to allow checking for its presence before usage - Move declarations above cplusplus guard - Add CONFIG_PTHREAD_FCHDIR_NP to meson and check for presence in 9p-util - Rebase to apply cleanly on top of the 2022-02-10 changes to 9pfs - Fix line over 90 characters formatting error] Signed-off-by: Will Cohen <wwcohen@gmail.com> Message-Id: <20220227223522.91937-10-wwcohen@gmail.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2022-03-079p: darwin: Compatibility for f/l*xattrKeno Fischer2-4/+25
On darwin `fgetxattr` takes two extra optional arguments, and the l* variants are not defined (in favor of an extra flag to the regular variants. Signed-off-by: Keno Fischer <keno@juliacomputing.com> [Michael Roitzsch: - Rebase for NixOS] Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com> Signed-off-by: Will Cohen <wwcohen@gmail.com> Message-Id: <20220227223522.91937-9-wwcohen@gmail.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2022-03-079p: darwin: *xattr_nofollow implementationsKeno Fischer2-0/+65
This implements the darwin equivalent of the functions that were moved to 9p-util(-linux) earlier in this series in the new 9p-util-darwin file. Signed-off-by: Keno Fischer <keno@juliacomputing.com> [Michael Roitzsch: - Rebase for NixOS] Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com> Signed-off-by: Will Cohen <wwcohen@gmail.com> Message-Id: <20220227223522.91937-8-wwcohen@gmail.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2022-03-079p: darwin: Move XATTR_SIZE_MAX->P9_XATTR_SIZE_MAXKeno Fischer2-1/+19
Signed-off-by: Keno Fischer <keno@juliacomputing.com> Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com> Because XATTR_SIZE_MAX is not defined on Darwin, create a cross-platform P9_XATTR_SIZE_MAX instead. [Will Cohen: - Adjust coding style - Lower XATTR_SIZE_MAX to 64k - Add explanatory context related to XATTR_SIZE_MAX] [Fabian Franz: - Move XATTR_SIZE_MAX reference from 9p.c to P9_XATTR_SIZE_MAX in 9p.h] Signed-off-by: Will Cohen <wwcohen@gmail.com> Signed-off-by: Fabian Franz <fabianfranz.oss@gmail.com> [Will Cohen: - For P9_XATTR_MAX, ensure that Linux uses XATTR_SIZE_MAX, Darwin uses 64k, and error out for undefined hosts] Signed-off-by: Will Cohen <wwcohen@gmail.com> Message-Id: <20220227223522.91937-7-wwcohen@gmail.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2022-03-079p: darwin: Ignore O_{NOATIME, DIRECT}Keno Fischer2-1/+16
Darwin doesn't have either of these flags. Darwin does have F_NOCACHE, which is similar to O_DIRECT, but has different enough semantics that other projects don't generally map them automatically. In any case, we don't support O_DIRECT on Linux at the moment either. Signed-off-by: Keno Fischer <keno@juliacomputing.com> [Michael Roitzsch: - Rebase for NixOS] Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com> [Will Cohen: - Adjust coding style] Signed-off-by: Will Cohen <wwcohen@gmail.com> Message-Id: <20220227223522.91937-6-wwcohen@gmail.com> [C.S.: - Fix compiler warning "unused label 'again'". ] Link: https://lore.kernel.org/qemu-devel/11201492.CjeqJxXfGd@silver/ Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2022-03-079p: darwin: Handle struct dirent differencesKeno Fischer6-4/+52
On darwin d_seekoff exists, but is optional and does not seem to be commonly used by file systems. Use `telldir` instead to obtain the seek offset and inject it into d_seekoff, and create a qemu_dirent_off helper to call it appropriately when appropriate. Signed-off-by: Keno Fischer <keno@juliacomputing.com> [Michael Roitzsch: - Rebase for NixOS] Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com> [Will Cohen: - Adjust to pass testing - Ensure that d_seekoff is filled using telldir on darwin, and create qemu_dirent_off helper to decide which to access] [Fabian Franz: - Add telldir error handling for darwin] Signed-off-by: Fabian Franz <fabianfranz.oss@gmail.com> [Will Cohen: - Ensure that telldir error handling uses signed int - Cleanup of telldir error handling - Remove superfluous error handling for qemu_dirent_off - Adjust formatting - Use qemu_dirent_off in codir.c - Declare qemu_dirent_off as static to prevent linker error - Move qemu_dirent_off above the end-of-file endif to fix compilation] Signed-off-by: Will Cohen <wwcohen@gmail.com> Message-Id: <20220227223522.91937-5-wwcohen@gmail.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2022-03-079p: darwin: Handle struct stat(fs) differencesKeno Fischer3-4/+36
Signed-off-by: Keno Fischer <keno@juliacomputing.com> Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com> [Will Cohen: - Note lack of f_namelen and f_frsize on Darwin - Ensure that tv_sec and tv_nsec are both initialized for Darwin and non-Darwin] Signed-off-by: Will Cohen <wwcohen@gmail.com> Message-Id: <20220227223522.91937-4-wwcohen@gmail.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2022-03-079p: Rename 9p-util -> 9p-util-linuxKeno Fischer2-2/+2
The current file only has the Linux versions of these functions. Rename the file accordingly and update the Makefile to only build it on Linux. A Darwin version of these will follow later in the series. Signed-off-by: Keno Fischer <keno@juliacomputing.com> [Michael Roitzsch: - Rebase for NixOS] Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com> Signed-off-by: Will Cohen <wwcohen@gmail.com> Reviewed-by: Greg Kurz <groug@kaod.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20220227223522.91937-3-wwcohen@gmail.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2022-03-079p: linux: Fix a couple Linux assumptionsKeno Fischer2-0/+6
- Guard Linux only headers. - Add qemu/statfs.h header to abstract over the which headers are needed for struct statfs - Define `ENOATTR` only if not only defined (it's defined in system headers on Darwin). Signed-off-by: Keno Fischer <keno@juliacomputing.com> [Michael Roitzsch: - Rebase for NixOS] Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com> While it might at first appear that fsdev/virtfs-proxy-header.c would need similar adjustment for darwin as file-op-9p here, a later patch in this series disables virtfs-proxy-helper for non-Linux. Allowing virtfs-proxy-helper on darwin could potentially be an additional optimization later. [Will Cohen: - Fix headers for Alpine - Integrate statfs.h back into file-op-9p.h - Remove superfluous header guards from file-opt-9p - Add note about virtfs-proxy-helper being disabled on non-Linux for this patch series] Signed-off-by: Will Cohen <wwcohen@gmail.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <20220227223522.91937-2-wwcohen@gmail.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2022-02-179pfs: Fix segfault in do_readdir_many caused by struct dirent overreadVitaly Chikunov3-5/+21
`struct dirent' returned from readdir(3) could be shorter (or longer) than `sizeof(struct dirent)', thus memcpy of sizeof length will overread into unallocated page causing SIGSEGV. Example stack trace: #0 0x00005555559ebeed v9fs_co_readdir_many (/usr/bin/qemu-system-x86_64 + 0x497eed) #1 0x00005555559ec2e9 v9fs_readdir (/usr/bin/qemu-system-x86_64 + 0x4982e9) #2 0x0000555555eb7983 coroutine_trampoline (/usr/bin/qemu-system-x86_64 + 0x963983) #3 0x00007ffff73e0be0 n/a (n/a + 0x0) While fixing this, provide a helper for any future `struct dirent' cloning. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/841 Cc: qemu-stable@nongnu.org Co-authored-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Vitaly Chikunov <vt@altlinux.org> Tested-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Acked-by: Greg Kurz <groug@kaod.org> Tested-by: Vitaly Chikunov <vt@altlinux.org> Message-Id: <20220216181821.3481527-1-vt@altlinux.org> [C.S. - Fix typo in source comment. ] Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2021-10-279pfs: use P9Array in v9fs_walk()Christian Schoenebeck1-12/+5
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Message-Id: <90c65d1c1ca11c1b434bb981b1fc7966f7711c8f.1633097129.git.qemu_oss@crudebyte.com>
2021-10-279pfs: make V9fsPath usable via P9Array APIChristian Schoenebeck1-0/+2
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Message-Id: <79a0ddf8375f6c95f0565ef155a1bf1e9387664f.1633097129.git.qemu_oss@crudebyte.com>
2021-10-279pfs: simplify blksize_to_iounit()Christian Schoenebeck1-2/+1
Use QEMU_ALIGN_DOWN() macro to reduce code and to make it more human readable. Suggested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <b84eb324d2ebdcc6f9c442c97b5b4d01eecb4f43.1632758315.git.qemu_oss@crudebyte.com>
2021-10-279pfs: deduplicate iounit codeChristian Schoenebeck1-21/+20
Remove redundant code that translates host fileystem's block size into 9p client (guest side) block size. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <129bb71d5119e61d335f1e3107e472e4beea223a.1632758315.git.qemu_oss@crudebyte.com>
2021-10-279pfs: fix wrong I/O block size in RgetattrChristian Schoenebeck1-1/+20
When client sent a 9p Tgetattr request then the wrong I/O block size value was returned by 9p server; instead of host file system's I/O block size it should rather return an I/O block size according to 9p session's 'msize' value, because the value returned to client should be an "optimum" block size for I/O (i.e. to maximize performance), it should not reflect the actual physical block size of the underlying storage media. The I/O block size of a host filesystem is typically 4k, so the value returned was far too low for good 9p I/O performance. This patch adds stat_to_iounit() with a similar approach as the existing get_iounit() function. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <E1mT2Js-0000DW-OH@lizzy.crudebyte.com>
2021-09-029pfs: fix crash in v9fs_walk()Christian Schoenebeck1-1/+3
v9fs_walk() utilizes the v9fs_co_run_in_worker({...}) macro to run the supplied fs driver code block on a background worker thread. When either the 'Twalk' client request was interrupted or if the client requested fid for that 'Twalk' request caused a stat error then that fs driver code block was left by 'break' keyword, with the intention to return from worker thread back to main thread as well: v9fs_co_run_in_worker({ if (v9fs_request_cancelled(pdu)) { err = -EINTR; break; } err = s->ops->lstat(&s->ctx, &dpath, &fidst); if (err < 0) { err = -errno; break; } ... }); However that 'break;' statement also skipped the v9fs_co_run_in_worker() macro's final and mandatory /* re-enter back to qemu thread */ qemu_coroutine_yield(); call and thus caused the rest of v9fs_walk() to be continued being executed on the worker thread instead of main thread, eventually leading to a crash in the transport virtio transport driver. To fix this issue and to prevent the same error from happening again by other users of v9fs_co_run_in_worker() in future, auto wrap the supplied code block into its own do { } while (0); loop inside the 'v9fs_co_run_in_worker' macro definition. Full discussion and backtrace: https://lists.gnu.org/archive/html/qemu-devel/2021-08/msg05209.html https://lists.gnu.org/archive/html/qemu-devel/2021-09/msg00174.html Fixes: 8d6cb100731c4d28535adbf2a3c2d1f29be3fef4 Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Cc: qemu-stable@nongnu.org Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <E1mLTBg-0002Bh-2D@lizzy.crudebyte.com>
2021-09-02hw/9pfs: use g_autofree in v9fs_walk() where possibleChristian Schoenebeck1-4/+3
Suggested-by: Greg Kurz <groug@kaod.org> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <b51670d2a39399535a035f6bc77c3cbeed85edae.1629208359.git.qemu_oss@crudebyte.com>
2021-09-02hw/9pfs: avoid 'path' copy in v9fs_walk()Christian Schoenebeck1-4/+4
The v9fs_walk() function resolves all client submitted path nodes to the local 'pathes' array. Using a separate string scalar variable 'path' inside the background worker thread loop and copying that local 'path' string scalar variable subsequently to the 'pathes' array (at the end of each loop iteration) is not necessary. Instead simply resolve each path directly to the 'pathes' array and don't use the string scalar variable 'path' inside the fs worker thread loop at all. The only advantage of the 'path' scalar was that in case of an error the respective 'pathes' element would not be filled. Right now this is not an issue as the v9fs_walk() function returns as soon as any error occurs. Suggested-by: Greg Kurz <groug@kaod.org> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <7dacbecf25b2c9b4a0ce12d689a8a535f09a31e3.1629208359.git.qemu_oss@crudebyte.com>
2021-07-059pfs: reduce latency of TwalkChristian Schoenebeck1-19/+70
As with previous performance optimization on Treaddir handling; reduce the overall latency, i.e. overall time spent on processing a Twalk request by reducing the amount of thread hops between the 9p server's main thread and fs worker thread(s). In fact this patch even reduces the thread hops for Twalk handling to its theoritical minimum of exactly 2 thread hops: main thread -> fs worker thread -> main thread This is achieved by doing all the required fs driver tasks altogether in a single v9fs_co_run_in_worker({ ... }); code block. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <1a6701674afc4f08d40396e3aa2631e18a4dbb33.1622821729.git.qemu_oss@crudebyte.com>
2021-07-059pfs: drop root_qidChristian Schoenebeck2-2/+0
There is no longer a user of root_qid, so drop it. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <6896dd161d3257db6b0513842a14f87ca191fdf6.1622821729.git.qemu_oss@crudebyte.com>
2021-07-059pfs: replace not_same_qid() by same_stat_id()Christian Schoenebeck1-3/+3
As we are actually only comparing the filesystem ID (i.e. device number and inode number pair) let's use the POSIX stat buffer instead of QIDs, because resolving QIDs requires to be done on 9p server's main thread only as it might mutate the server state if inode remapping is enabled. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <26aa465ff9cc9c07e053331554a02fdae3994417.1622821729.git.qemu_oss@crudebyte.com>
2021-07-059pfs: drop fid_to_qid()Christian Schoenebeck1-18/+5
There is only one user of fid_to_qid() which is v9fs_walk(). Let's open-code fid_to_qid() directly within v9fs_walk(), because fid_to_qid() hides the POSIX stat buffer which we are going to need in the subsequent patch. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <e9a4c9c7a0792ed4db6578d105a0823ea05bc324.1622821729.git.qemu_oss@crudebyte.com>
2021-07-059pfs: capture root statChristian Schoenebeck2-1/+10
We already capture the QID of the exported 9p root path, i.e. to prevent client access outside the defined, exported filesystem's tree. This is currently checked by comparing the root QID with another FID's QID. The problem with the latter is that resolving a QID of any given 9p path can only be done on 9p server's main thread, that's because it might mutate the server's state if inode remapping is enabled. For that reason also capture the POSIX stat info of the root path for being able to identify on any (e.g. worker) thread whether an arbitrary given path is identical to the export root. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <eb07d6c2e9925788454cfe33d3802e4ffb23ea9a.1622821729.git.qemu_oss@crudebyte.com>
2021-07-059pfs: fix not_same_qid()Christian Schoenebeck1-4/+1
There is only one user of not_same_qid() which is v9fs_walk() and the latter is using it for comparing a client supplied path with the 9p export root path, for the sole purpose to prevent a Twalk request from escaping from the exported 9p tree via "..". However for that specific purpose the implementation of not_same_qid() is wrong; if mtime of the 9p export root path changed between Tattach and Twalk then not_same_qid() returns true when actually comparing against the export root path. To fix for the actual semantic being used, only compare QID path members, but do not compare version or type members. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <ca0abae4a899d81c6e87f683732d6c1f56915232.1622821729.git.qemu_oss@crudebyte.com>
2021-07-059pfs: simplify v9fs_walk()Christian Schoenebeck1-4/+5
There is only one comparison between nwnames and P9_MAXWELEM required. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <E1liKiz-0006BC-Ja@lizzy.crudebyte.com>
2021-07-059pfs: add link to 9p developer docsChristian Schoenebeck15-0/+75
To lower the entry level for new developers, add a link to the 9p developer docs (i.e. qemu wiki) to MAINTAINERS and to the beginning of 9p source files, that is to: https://wiki.qemu.org/Documentation/9p Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Acked-by: Greg Kurz <groug@kaod.org> Message-Id: <E1leeDf-0008GZ-9q@lizzy.crudebyte.com>
2021-06-02docs: fix references to docs/devel/tracing.rstStefano Garzarella1-1/+1
Commit e50caf4a5c ("tracing: convert documentation to rST") converted docs/devel/tracing.txt to docs/devel/tracing.rst. We still have several references to the old file, so let's fix them with the following command: sed -i s/tracing.txt/tracing.rst/ $(git grep -l docs/devel/tracing.txt) Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20210517151702.109066-2-sgarzare@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-03-16hw/9pfs/9p-synth: Replaced qemu_mutex_lock with QEMU_LOCK_GUARDMahmoud Mandour1-8/+4
Replaced a call to qemu_mutex_lock and its respective call to qemu_mutex_unlock and used QEMU_LOCK_GUARD macro in their place. This simplifies the code by removing the call required to unlock and also eliminates goto paths. Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com> Acked-by: Greg Kurz <groug@kaod.org> Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Message-Id: <20210311031538.5325-9-ma.mandourr@gmail.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2021-03-09qtest: delete superfluous inclusions of qtest.hChen Qun1-1/+0
There are 23 files that include the "sysemu/qtest.h", but they do not use any qtest functions. Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com> Acked-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20210226081414.205946-1-kuhn.chenqun@huawei.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-01-229pfs: Convert reclaim list to QSLISTGreg Kurz2-10/+9
Use QSLIST instead of open-coding for a slightly improved readability. No behavioral change. Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Message-Id: <20210122143514.215780-1-groug@kaod.org> Signed-off-by: Greg Kurz <groug@kaod.org>
2021-01-229pfs: Improve unreclaim loopGreg Kurz1-14/+32
If a fid was actually re-opened by v9fs_reopen_fid(), we re-traverse the fid list from the head in case some other request created a fid that needs to be marked unreclaimable as well (i.e. the client opened a new handle on the path that is being unlinked). This is suboptimal since most if not all fids that require it have likely been taken care of already. This is mostly the result of new fids being added to the head of the list. Since the list is now a QSIMPLEQ, add new fids at the end instead to avoid the need to rewind. Take a reference on the fid to ensure it doesn't go away during v9fs_reopen_fid() and that it can be safely passed to QSIMPLEQ_NEXT() afterwards. Since the associated put_fid() can also yield, same is done with the next fid. So the logic here is to get a reference on a fid and only put it back during the next iteration after we could get a reference on the next fid. Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Message-Id: <20210121181510.1459390-1-groug@kaod.org> Signed-off-by: Greg Kurz <groug@kaod.org>
2021-01-219pfs: Convert V9fsFidState::fid_list to QSIMPLEQGreg Kurz2-25/+20
The fid_list is currently open-coded. This doesn't seem to serve any purpose that cannot be met with QEMU's generic lists. Let's go for a QSIMPLEQ : this will allow to add new fids at the end of the list and to improve the logic in v9fs_mark_fids_unreclaim(). Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Message-Id: <20210118142300.801516-3-groug@kaod.org> Signed-off-by: Greg Kurz <groug@kaod.org>
2021-01-219pfs: Convert V9fsFidState::clunked to boolGreg Kurz2-3/+3
This can only be 0 or 1. Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Message-Id: <20210118142300.801516-2-groug@kaod.org> Signed-off-by: Greg Kurz <groug@kaod.org>
2021-01-219pfs/proxy: Check return value of proxy_marshal()Greg Kurz1-1/+2
This should always successfully write exactly two 32-bit integers. Make it clear with an assert(), like v9fs_receive_status() and v9fs_receive_response() already do when unmarshalling the same header. Fixes: Coverity CID 1438968 Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Message-Id: <161035859647.1221144.4691749806675653934.stgit@bahia.lan> Signed-off-by: Greg Kurz <groug@kaod.org>
2021-01-159pfs: Fully restart unreclaim loop (CVE-2021-20181)Greg Kurz1-3/+3
Depending on the client activity, the server can be asked to open a huge number of file descriptors and eventually hit RLIMIT_NOFILE. This is currently mitigated using a reclaim logic : the server closes the file descriptors of idle fids, based on the assumption that it will be able to re-open them later. This assumption doesn't hold of course if the client requests the file to be unlinked. In this case, we loop on the entire fid list and mark all related fids as unreclaimable (the reclaim logic will just ignore them) and, of course, we open or re-open their file descriptors if needed since we're about to unlink the file. This is the purpose of v9fs_mark_fids_unreclaim(). Since the actual opening of a file can cause the coroutine to yield, another client request could possibly add a new fid that we may want to mark as non-reclaimable as well. The loop is thus restarted if the re-open request was actually transmitted to the backend. This is achieved by keeping a reference on the first fid (head) before traversing the list. This is wrong in several ways: - a potential clunk request from the client could tear the first fid down and cause the reference to be stale. This leads to a use-after-free error that can be detected with ASAN, using a custom 9p client - fids are added at the head of the list : restarting from the previous head will always miss fids added by a some other potential request All these problems could be avoided if fids were being added at the end of the list. This can be achieved with a QSIMPLEQ, but this is probably too much change for a bug fix. For now let's keep it simple and just restart the loop from the current head. Fixes: CVE-2021-20181 Buglink: https://bugs.launchpad.net/qemu/+bug/1911666 Reported-by: Zero Day Initiative <zdi-disclosures@trendmicro.com> Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Message-Id: <161064025265.1838153.15185571283519390907.stgit@bahia.lan> Signed-off-by: Greg Kurz <groug@kaod.org>
2020-11-05hw/9pfs: Fix Kconfig dependency problem between 9pfs and XenPhilippe Mathieu-Daudé2-5/+1
Commit b2c00bce54c ("meson: convert hw/9pfs, cleanup") introduced CONFIG_9PFS (probably a wrong conflict resolution). This config is not used anywhere. Backends depend on CONFIG_FSDEV_9P which itself depends on CONFIG_VIRTFS. Remove the invalid CONFIG_9PFS and use CONFIG_FSDEV_9P instead, to fix the './configure --without-default-devices --enable-xen' build: /usr/bin/ld: libcommon.fa.p/hw_xen_xen-legacy-backend.c.o: in function `xen_be_register_common': hw/xen/xen-legacy-backend.c:754: undefined reference to `xen_9pfs_ops' /usr/bin/ld: libcommon.fa.p/fsdev_qemu-fsdev.c.o:(.data.rel+0x8): undefined reference to `local_ops' /usr/bin/ld: libcommon.fa.p/fsdev_qemu-fsdev.c.o:(.data.rel+0x20): undefined reference to `synth_ops' /usr/bin/ld: libcommon.fa.p/fsdev_qemu-fsdev.c.o:(.data.rel+0x38): undefined reference to `proxy_ops' collect2: error: ld returned 1 exit status Fixes: b2c00bce54c ("meson: convert hw/9pfs, cleanup") Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Greg Kurz <groug@kaod.org> Tested-by: Greg Kurz <groug@kaod.org> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Message-Id: <20201104115706.3101190-3-philmd@redhat.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-11-05hw/9pfs : add space before the open parenthesis '('Xinhao Zhang1-1/+1
Fix code style. Space required before the open parenthesis '('. Signed-off-by: Xinhao Zhang <zhangxinhao1@huawei.com> Signed-off-by: Kai Deng <dengkai1@huawei.com> Reported-by: Euler Robot <euler.robot@huawei.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <20201030043515.1030223-3-zhangxinhao1@huawei.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-11-05hw/9pfs : open brace '{' following struct go on the same lineXinhao Zhang1-6/+3
Fix code style. Open braces for struct should go on the same line. Signed-off-by: Xinhao Zhang <zhangxinhao1@huawei.com> Signed-off-by: Kai Deng <dengkai1@huawei.com> Reported-by: Euler Robot <euler.robot@huawei.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <20201030043515.1030223-2-zhangxinhao1@huawei.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-11-05hw/9pfs : add spaces around operatorXinhao Zhang2-13/+13
Fix code style. Operator needs spaces both sides. Signed-off-by: Xinhao Zhang <zhangxinhao1@huawei.com> Signed-off-by: Kai Deng <dengkai1@huawei.com> Reported-by: Euler Robot <euler.robot@huawei.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <20201030043515.1030223-1-zhangxinhao1@huawei.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-10-199pfs: suppress performance warnings on qtest runsChristian Schoenebeck2-2/+6
Don't trigger any performance warning if we're just running test cases, because tests intentionally run for edge cases. So far performance warnings were suppressed for the 'synth' fs driver backend only. This patch suppresses them for all 9p fs driver backends. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <a2d2ff2163f8853ea782a7a1d4e6f2afd7c29ffe.1603106145.git.qemu_oss@crudebyte.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-09-18Use OBJECT_DECLARE_SIMPLE_TYPE when possibleEduardo Habkost1-3/+1
This converts existing DECLARE_INSTANCE_CHECKER usage to OBJECT_DECLARE_SIMPLE_TYPE when possible. $ ./scripts/codeconverter/converter.py -i \ --pattern=AddObjectDeclareSimpleType $(git grep -l '' -- '*.[ch]') Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Acked-by: Paul Durrant <paul@xen.org> Message-Id: <20200916182519.415636-6-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-159pfs: disable msize warning for synth driverChristian Schoenebeck2-1/+3
Previous patch introduced a performance warning being logged on host side if client connected with an 'msize' <= 8192. Disable this performance warning for the synth driver to prevent that warning from being printed whenever the 9pfs (qtest) test cases are running. Introduce a new export flag V9FS_NO_PERF_WARN for that purpose, which might also be used to disable such warnings from the CLI in future. We could have also prevented the warning by simply raising P9_MAX_SIZE in virtio-9p-test.c to any value larger than 8192, however in the context of test cases it makes sense running for edge cases, which includes the lowest 'msize' value supported by the server which is 4096, hence we want to preserve an msize of 4096 for the test client. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <E1kEyDy-0006nN-5A@lizzy.crudebyte.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-09-159pfs: log warning if msize <= 8192Christian Schoenebeck1-0/+9
It is essential to choose a reasonable high value for 'msize' to avoid severely degraded file I/O performance. This parameter can only be chosen on client/guest side, and a Linux client defaults to an 'msize' of only 8192 if the user did not explicitly specify a value for 'msize', which results in very poor file I/O performance. Unfortunately many users are not aware that they should specify an appropriate value for 'msize' to avoid severe performance issues, so log a performance warning (with a QEMU wiki link explaining this issue in detail) on host side in that case to make it more clear. Currently a client cannot automatically pick a reasonable value for 'msize', because a good value for 'msize' depends on the file I/O potential of the underlying storage on host side, i.e. a feature invisible to the client, and even then a user would still need to trade off between performance profit and additional RAM costs, i.e. with growing 'msize' (RAM occupation), performance still increases, but performance delta will shrink continuously. Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <e6fc84845c95816ad5baecb0abd6bfefdcf7ec9f.1599144062.git.qemu_oss@crudebyte.com> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-09-09Use DECLARE_*CHECKER* macrosEduardo Habkost1-2/+2
Generated using: $ ./scripts/codeconverter/converter.py -i \ --pattern=TypeCheckMacro $(git grep -l '' -- '*.[ch]') Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <20200831210740.126168-12-ehabkost@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <20200831210740.126168-13-ehabkost@redhat.com> Message-Id: <20200831210740.126168-14-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-09Move QOM typedefs and add missing includesEduardo Habkost1-3/+4
Some typedefs and macros are defined after the type check macros. This makes it difficult to automatically replace their definitions with OBJECT_DECLARE_TYPE. Patch generated using: $ ./scripts/codeconverter/converter.py -i \ --pattern=QOMStructTypedefSplit $(git grep -l '' -- '*.[ch]') which will split "typdef struct { ... } TypedefName" declarations. Followed by: $ ./scripts/codeconverter/converter.py -i --pattern=MoveSymbols \ $(git grep -l '' -- '*.[ch]') which will: - move the typedefs and #defines above the type check macros - add missing #include "qom/object.h" lines if necessary Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <20200831210740.126168-9-ehabkost@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <20200831210740.126168-10-ehabkost@redhat.com> Message-Id: <20200831210740.126168-11-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>