From 6b3b279bd670c6a2fa23c9049820c814f0e2c846 Mon Sep 17 00:00:00 2001 From: Keno Fischer Date: Sun, 27 Feb 2022 17:35:15 -0500 Subject: 9p: darwin: Handle struct dirent differences 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 [Michael Roitzsch: - Rebase for NixOS] Signed-off-by: Michael Roitzsch [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 [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 Message-Id: <20220227223522.91937-5-wwcohen@gmail.com> Signed-off-by: Christian Schoenebeck Reviewed-by: Christian Schoenebeck --- hw/9pfs/9p-local.c | 9 +++++++++ hw/9pfs/9p-proxy.c | 16 +++++++++++++++- hw/9pfs/9p-synth.c | 4 ++++ hw/9pfs/9p-util.h | 16 ++++++++++++++++ hw/9pfs/9p.c | 7 +++++-- hw/9pfs/codir.c | 4 +++- 6 files changed, 52 insertions(+), 4 deletions(-) diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c index 1a5e3ee..f3272f0 100644 --- a/hw/9pfs/9p-local.c +++ b/hw/9pfs/9p-local.c @@ -562,6 +562,15 @@ again: if (!entry) { return NULL; } +#ifdef CONFIG_DARWIN + int off; + off = telldir(fs->dir.stream); + /* If telldir fails, fail the entire readdir call */ + if (off < 0) { + return NULL; + } + entry->d_seekoff = off; +#endif if (ctx->export_flags & V9FS_SM_MAPPED) { entry->d_type = DT_UNKNOWN; diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c index b166408..8b4b5cf 100644 --- a/hw/9pfs/9p-proxy.c +++ b/hw/9pfs/9p-proxy.c @@ -706,7 +706,21 @@ static off_t proxy_telldir(FsContext *ctx, V9fsFidOpenState *fs) static struct dirent *proxy_readdir(FsContext *ctx, V9fsFidOpenState *fs) { - return readdir(fs->dir.stream); + struct dirent *entry; + entry = readdir(fs->dir.stream); +#ifdef CONFIG_DARWIN + if (!entry) { + return NULL; + } + int td; + td = telldir(fs->dir.stream); + /* If telldir fails, fail the entire readdir call */ + if (td < 0) { + return NULL; + } + entry->d_seekoff = td; +#endif + return entry; } static void proxy_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off) diff --git a/hw/9pfs/9p-synth.c b/hw/9pfs/9p-synth.c index bf9b0c5..b3080e4 100644 --- a/hw/9pfs/9p-synth.c +++ b/hw/9pfs/9p-synth.c @@ -234,7 +234,11 @@ static void synth_direntry(V9fsSynthNode *node, offsetof(struct dirent, d_name) + sz); memcpy(entry->d_name, node->name, sz); entry->d_ino = node->attr->inode; +#ifdef CONFIG_DARWIN + entry->d_seekoff = off + 1; +#else entry->d_off = off + 1; +#endif } static struct dirent *synth_get_dentry(V9fsSynthNode *dir, diff --git a/hw/9pfs/9p-util.h b/hw/9pfs/9p-util.h index 546f46d..7449733 100644 --- a/hw/9pfs/9p-util.h +++ b/hw/9pfs/9p-util.h @@ -78,4 +78,20 @@ ssize_t flistxattrat_nofollow(int dirfd, const char *filename, ssize_t fremovexattrat_nofollow(int dirfd, const char *filename, const char *name); +/** + * Darwin has d_seekoff, which appears to function similarly to d_off. + * However, it does not appear to be supported on all file systems, + * so ensure it is manually injected earlier and call here when + * needed. + */ +static inline off_t qemu_dirent_off(struct dirent *dent) +{ +#ifdef CONFIG_DARWIN + return dent->d_seekoff; +#else + return dent->d_off; +#endif +} + + #endif diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 1563d7b..caf3b24 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -27,6 +27,7 @@ #include "virtio-9p.h" #include "fsdev/qemu-fsdev.h" #include "9p-xattr.h" +#include "9p-util.h" #include "coth.h" #include "trace.h" #include "migration/blocker.h" @@ -2281,7 +2282,7 @@ static int coroutine_fn v9fs_do_readdir_with_stat(V9fsPDU *pdu, count += len; v9fs_stat_free(&v9stat); v9fs_path_free(&path); - saved_dir_pos = dent->d_off; + saved_dir_pos = qemu_dirent_off(dent); } v9fs_readdir_unlock(&fidp->fs.dir); @@ -2420,6 +2421,7 @@ static int coroutine_fn v9fs_do_readdir(V9fsPDU *pdu, V9fsFidState *fidp, V9fsString name; int len, err = 0; int32_t count = 0; + off_t off; struct dirent *dent; struct stat *st; struct V9fsDirEnt *entries = NULL; @@ -2480,12 +2482,13 @@ static int coroutine_fn v9fs_do_readdir(V9fsPDU *pdu, V9fsFidState *fidp, qid.version = 0; } + off = qemu_dirent_off(dent); v9fs_string_init(&name); v9fs_string_sprintf(&name, "%s", dent->d_name); /* 11 = 7 + 4 (7 = start offset, 4 = space for storing count) */ len = pdu_marshal(pdu, 11 + count, "Qqbs", - &qid, dent->d_off, + &qid, off, dent->d_type, &name); v9fs_string_free(&name); diff --git a/hw/9pfs/codir.c b/hw/9pfs/codir.c index c0873bd..f96d8ac 100644 --- a/hw/9pfs/codir.c +++ b/hw/9pfs/codir.c @@ -22,6 +22,8 @@ #include "qemu/coroutine.h" #include "qemu/main-loop.h" #include "coth.h" +#include "9p-xattr.h" +#include "9p-util.h" /* * Intended to be called from bottom-half (e.g. background I/O thread) @@ -166,7 +168,7 @@ static int do_readdir_many(V9fsPDU *pdu, V9fsFidState *fidp, } size += len; - saved_dir_pos = dent->d_off; + saved_dir_pos = qemu_dirent_off(dent); } /* restore (last) saved position */ -- cgit v1.1