From f70c0a6f2693d44b56511d5f85bb386fb1a3f024 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 11 Dec 2018 12:59:29 +0100 Subject: [PATCH 1/3] fscache: remember the reparse tag for each entry We will use this in the next commit to implement an FSCache-aware version of is_mount_point(). Signed-off-by: Johannes Schindelin --- compat/win32/fscache.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/compat/win32/fscache.c b/compat/win32/fscache.c index 03e6e426f8..a659717eba 100644 --- a/compat/win32/fscache.c +++ b/compat/win32/fscache.c @@ -41,6 +41,7 @@ static struct trace_key trace_fscache = TRACE_KEY_INIT(FSCACHE); struct fsentry { struct hashmap_entry ent; mode_t st_mode; + ULONG reparse_tag; /* Pointer to the directory listing, or NULL for the listing itself. */ struct fsentry *list; /* Pointer to the next file entry of the list. */ @@ -189,6 +190,10 @@ static struct fsentry *fseentry_create_entry(struct fscache *cache, fse = fsentry_alloc(cache, list, buf, len); + fse->reparse_tag = + fdata->FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT ? + fdata->EaSize : 0; + fse->st_mode = file_attr_to_st_mode(fdata->FileAttributes); fse->dirent.d_type = S_ISDIR(fse->st_mode) ? DT_DIR : DT_REG; fse->u.s.st_size = fdata->EndOfFile.LowPart | From 42d7bf5f05fa9051a9ad59769b7c6b89e9acb8b4 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 11 Dec 2018 12:17:49 +0100 Subject: [PATCH 2/3] fscache: implement an FSCache-aware is_mount_point() When FSCache is active, we can cache the reparse tag and use it directly to determine whether a path refers to an NTFS junction, without any additional, costly I/O. Note: this change only makes a difference with the next commit, which will make use of the FSCache in `git clean` (contingent on `core.fscache` set, of course). Signed-off-by: Johannes Schindelin --- compat/mingw.c | 2 ++ compat/mingw.h | 3 ++- compat/win32/fscache.c | 35 +++++++++++++++++++++++++++++++++++ compat/win32/fscache.h | 1 + 4 files changed, 40 insertions(+), 1 deletion(-) diff --git a/compat/mingw.c b/compat/mingw.c index 858b42396e..081638117c 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2577,6 +2577,8 @@ pid_t waitpid(pid_t pid, int *status, int options) return -1; } +int (*win32_is_mount_point)(struct strbuf *path) = mingw_is_mount_point; + int mingw_is_mount_point(struct strbuf *path) { WIN32_FIND_DATAW findbuf = { 0 }; diff --git a/compat/mingw.h b/compat/mingw.h index 62cd12759b..8df0e4a22a 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -464,7 +464,8 @@ static inline void convert_slashes(char *path) } struct strbuf; int mingw_is_mount_point(struct strbuf *path); -#define is_mount_point mingw_is_mount_point +extern int (*win32_is_mount_point)(struct strbuf *path); +#define is_mount_point win32_is_mount_point #define CAN_UNLINK_MOUNT_POINTS 1 #define PATH_SEP ';' char *mingw_query_user_email(void); diff --git a/compat/win32/fscache.c b/compat/win32/fscache.c index a659717eba..f2ab078323 100644 --- a/compat/win32/fscache.c +++ b/compat/win32/fscache.c @@ -462,6 +462,7 @@ int fscache_enable(size_t initial_size) /* redirect opendir and lstat to the fscache implementations */ opendir = fscache_opendir; lstat = fscache_lstat; + win32_is_mount_point = fscache_is_mount_point; } initialized++; LeaveCriticalSection(&fscache_cs); @@ -522,6 +523,7 @@ void fscache_disable(void) /* reset opendir and lstat to the original implementations */ opendir = dirent_opendir; lstat = mingw_lstat; + win32_is_mount_point = mingw_is_mount_point; } LeaveCriticalSection(&fscache_cs); @@ -590,6 +592,39 @@ int fscache_lstat(const char *filename, struct stat *st) return 0; } +/* + * is_mount_point() replacement, uses cache if enabled, otherwise falls + * back to mingw_is_mount_point(). + */ +int fscache_is_mount_point(struct strbuf *path) +{ + int dirlen, base, len; + struct heap_fsentry key[2]; + struct fsentry *fse; + struct fscache *cache = fscache_getcache(); + + if (!cache || !do_fscache_enabled(cache, path->buf)) + return mingw_is_mount_point(path); + + cache->lstat_requests++; + /* split path into path + name */ + len = path->len; + if (len && is_dir_sep(path->buf[len - 1])) + len--; + base = len; + while (base && !is_dir_sep(path->buf[base - 1])) + base--; + dirlen = base ? base - 1 : 0; + + /* lookup entry for path + name in cache */ + fsentry_init(&key[0].ent, NULL, path->buf, dirlen); + fsentry_init(&key[1].ent, &key[0].ent, path->buf + base, len - base); + fse = fscache_get(cache, &key[1].ent); + if (!fse) + return mingw_is_mount_point(path); + return fse->reparse_tag == IO_REPARSE_TAG_MOUNT_POINT; +} + typedef struct fscache_DIR { struct DIR base_dir; /* extend base struct DIR */ struct fsentry *pfsentry; diff --git a/compat/win32/fscache.h b/compat/win32/fscache.h index 042b247a54..386c770a85 100644 --- a/compat/win32/fscache.h +++ b/compat/win32/fscache.h @@ -22,6 +22,7 @@ void fscache_flush(void); DIR *fscache_opendir(const char *dir); int fscache_lstat(const char *file_name, struct stat *buf); +int fscache_is_mount_point(struct strbuf *path); /* opaque fscache structure */ struct fscache; From 0b0c904d5b286a0bbe5302382c210d30a2a0dec6 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 11 Dec 2018 12:17:49 +0100 Subject: [PATCH 3/3] clean: make use of FSCache The `git clean` command needs to enumerate plenty of files and directories, and can therefore benefit from the FSCache. Signed-off-by: Johannes Schindelin --- builtin/clean.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/builtin/clean.c b/builtin/clean.c index ae8051e945..ac021f97ab 100644 --- a/builtin/clean.c +++ b/builtin/clean.c @@ -995,6 +995,7 @@ int cmd_clean(int argc, const char **argv, const char *prefix) if (read_cache() < 0) die(_("index file corrupt")); + enable_fscache(active_nr); if (!ignored) setup_standard_excludes(&dir); @@ -1084,6 +1085,7 @@ int cmd_clean(int argc, const char **argv, const char *prefix) } } + disable_fscache(); strbuf_release(&abs_path); strbuf_release(&buf); string_list_clear(&del_list, 0);