diff options
author | Richard Henderson <richard.henderson@linaro.org> | 2021-10-27 11:45:11 -0700 |
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committer | Richard Henderson <richard.henderson@linaro.org> | 2021-10-27 11:45:18 -0700 |
commit | c52d69e7dbaaed0ffdef8125e79218672c30161d (patch) | |
tree | faf814a00e86fa51c9a8f374055bb3669c808442 /hw | |
parent | 5c49c6c241e524b6ba7768de07cab6f2056feb90 (diff) | |
parent | 7e985780aaab93d2c5be9b62d8d386568dfb071e (diff) |
Merge remote-tracking branch 'remotes/cschoenebeck/tags/pull-9p-20211027' into staging
9pfs: performance fix and cleanup
* First patch fixes suboptimal I/O performance on guest due to previously
incorrect block size being transmitted to 9p client.
* Subsequent patches are cleanup ones intended to reduce code complexity.
* remotes/cschoenebeck/tags/pull-9p-20211027:
9pfs: use P9Array in v9fs_walk()
9pfs: make V9fsPath usable via P9Array API
9pfs: make V9fsString usable via P9Array API
fsdev/p9array.h: check scalar type in P9ARRAY_NEW()
9pfs: introduce P9Array
9pfs: simplify blksize_to_iounit()
9pfs: deduplicate iounit code
9pfs: fix wrong I/O block size in Rgetattr
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'hw')
-rw-r--r-- | hw/9pfs/9p.c | 70 |
1 files changed, 41 insertions, 29 deletions
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index c857b31321..15b3f4d385 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -50,6 +50,8 @@ enum { Oappend = 0x80, }; +P9ARRAY_DEFINE_TYPE(V9fsPath, v9fs_path_free); + static ssize_t pdu_marshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...) { ssize_t ret; @@ -1262,6 +1264,37 @@ static int coroutine_fn stat_to_v9stat(V9fsPDU *pdu, V9fsPath *path, #define P9_STATS_ALL 0x00003fffULL /* Mask for All fields above */ +/** + * Convert host filesystem's block size into an appropriate block size for + * 9p client (guest OS side). The value returned suggests an "optimum" block + * size for 9p I/O, i.e. to maximize performance. + * + * @pdu: 9p client request + * @blksize: host filesystem's block size + */ +static int32_t blksize_to_iounit(const V9fsPDU *pdu, int32_t blksize) +{ + int32_t iounit = 0; + V9fsState *s = pdu->s; + + /* + * iounit should be multiples of blksize (host filesystem block size) + * as well as less than (client msize - P9_IOHDRSZ) + */ + if (blksize) { + iounit = QEMU_ALIGN_DOWN(s->msize - P9_IOHDRSZ, blksize); + } + if (!iounit) { + iounit = s->msize - P9_IOHDRSZ; + } + return iounit; +} + +static int32_t stat_to_iounit(const V9fsPDU *pdu, const struct stat *stbuf) +{ + return blksize_to_iounit(pdu, stbuf->st_blksize); +} + static int stat_to_v9stat_dotl(V9fsPDU *pdu, const struct stat *stbuf, V9fsStatDotl *v9lstat) { @@ -1273,7 +1306,7 @@ static int stat_to_v9stat_dotl(V9fsPDU *pdu, const struct stat *stbuf, v9lstat->st_gid = stbuf->st_gid; v9lstat->st_rdev = stbuf->st_rdev; v9lstat->st_size = stbuf->st_size; - v9lstat->st_blksize = stbuf->st_blksize; + v9lstat->st_blksize = stat_to_iounit(pdu, stbuf); v9lstat->st_blocks = stbuf->st_blocks; v9lstat->st_atime_sec = stbuf->st_atime; v9lstat->st_atime_nsec = stbuf->st_atim.tv_nsec; @@ -1705,13 +1738,14 @@ static void coroutine_fn v9fs_walk(void *opaque) int name_idx; g_autofree V9fsQID *qids = NULL; int i, err = 0; - V9fsPath dpath, path, *pathes = NULL; + V9fsPath dpath, path; + P9ARRAY_REF(V9fsPath) pathes = NULL; uint16_t nwnames; struct stat stbuf, fidst; g_autofree struct stat *stbufs = NULL; size_t offset = 7; int32_t fid, newfid; - V9fsString *wnames = NULL; + P9ARRAY_REF(V9fsString) wnames = NULL; V9fsFidState *fidp; V9fsFidState *newfidp = NULL; V9fsPDU *pdu = opaque; @@ -1732,10 +1766,10 @@ static void coroutine_fn v9fs_walk(void *opaque) goto out_nofid; } if (nwnames) { - wnames = g_new0(V9fsString, nwnames); + P9ARRAY_NEW(V9fsString, wnames, nwnames); qids = g_new0(V9fsQID, nwnames); stbufs = g_new0(struct stat, nwnames); - pathes = g_new0(V9fsPath, nwnames); + P9ARRAY_NEW(V9fsPath, pathes, nwnames); for (i = 0; i < nwnames; i++) { err = pdu_unmarshal(pdu, offset, "s", &wnames[i]); if (err < 0) { @@ -1867,36 +1901,14 @@ out: v9fs_path_free(&path); out_nofid: pdu_complete(pdu, err); - if (nwnames && nwnames <= P9_MAXWELEM) { - for (name_idx = 0; name_idx < nwnames; name_idx++) { - v9fs_string_free(&wnames[name_idx]); - v9fs_path_free(&pathes[name_idx]); - } - g_free(wnames); - g_free(pathes); - } } static int32_t coroutine_fn get_iounit(V9fsPDU *pdu, V9fsPath *path) { struct statfs stbuf; - int32_t iounit = 0; - V9fsState *s = pdu->s; + int err = v9fs_co_statfs(pdu, path, &stbuf); - /* - * iounit should be multiples of f_bsize (host filesystem block size - * and as well as less than (client msize - P9_IOHDRSZ)) - */ - if (!v9fs_co_statfs(pdu, path, &stbuf)) { - if (stbuf.f_bsize) { - iounit = stbuf.f_bsize; - iounit *= (s->msize - P9_IOHDRSZ) / stbuf.f_bsize; - } - } - if (!iounit) { - iounit = s->msize - P9_IOHDRSZ; - } - return iounit; + return blksize_to_iounit(pdu, (err >= 0) ? stbuf.f_bsize : 0); } static void coroutine_fn v9fs_open(void *opaque) |