From 93f89a3600f65d1834884e975f844ee668bf470b Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 11 Dec 2018 12:59:29 +0100 Subject: [PATCH 1/5] 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 973ae7efb2..46dca7a563 100644 --- a/compat/win32/fscache.c +++ b/compat/win32/fscache.c @@ -46,6 +46,7 @@ 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. */ @@ -202,6 +203,10 @@ 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, fdata->EaSize); fse->dirent.d_type = S_ISREG(fse->st_mode) ? DT_REG : From 5102ff85134055e7611127dd8c86655000d794b1 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Mon, 23 Apr 2018 23:20:00 +0200 Subject: [PATCH 2/5] fscache: Windows Docker volumes are *not* symbolic links ... even if they may look like them. As looking up the target of the "symbolic link" (just to see whether it starts with `/ContainerMappedDirectories/`) is pretty expensive, we do it when we can be *really* sure that there is a possibility that this might be the case. Signed-off-by: Johannes Schindelin Signed-off-by: JiSeop Moon --- compat/win32/fscache.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/compat/win32/fscache.c b/compat/win32/fscache.c index 46dca7a563..efe6be7e5e 100644 --- a/compat/win32/fscache.c +++ b/compat/win32/fscache.c @@ -207,8 +207,30 @@ static struct fsentry *fseentry_create_entry(struct fscache *cache, fdata->FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT ? fdata->EaSize : 0; + /* + * On certain Windows versions, host directories mapped into + * Windows Containers ("Volumes", see https://docs.docker.com/storage/volumes/) + * look like symbolic links, but their targets are paths that + * are valid only in kernel mode. + * + * Let's work around this by detecting that situation and + * telling Git that these are *not* symbolic links. + */ + if (fse->reparse_tag == IO_REPARSE_TAG_SYMLINK && + sizeof(buf) > (size_t)(list ? list->len + 1 : 0) + fse->len + 1 && + is_inside_windows_container()) { + size_t off = 0; + if (list) { + memcpy(buf, list->dirent.d_name, list->len); + buf[list->len] = '/'; + off = list->len + 1; + } + memcpy(buf + off, fse->dirent.d_name, fse->len); + buf[off + fse->len] = '\0'; + } + fse->st_mode = file_attr_to_st_mode(fdata->FileAttributes, - fdata->EaSize); + fdata->EaSize, buf); fse->dirent.d_type = S_ISREG(fse->st_mode) ? DT_REG : S_ISDIR(fse->st_mode) ? DT_DIR : DT_LNK; fse->u.s.st_size = S_ISLNK(fse->st_mode) ? MAX_PATH : From 76d49055687ee87f533b06a0fed6436774903c79 Mon Sep 17 00:00:00 2001 From: xungeng li Date: Wed, 7 Jun 2023 20:26:33 +0800 Subject: [PATCH 3/5] fscache: optionally enable wsl compability file mode bits The Windows Subsystem for Linux (WSL) version 2 allows to use `chmod` on NTFS volumes provided that they are mounted with metadata enabled (see https://devblogs.microsoft.com/commandline/chmod-chown-wsl-improvements/ for details), for example: $ chmod 0755 /mnt/d/test/a.sh In order to facilitate better collaboration between the Windows version of Git and the WSL version of Git, we can make the Windows version of Git also support reading and writing NTFS file modes in a manner compatible with WSL. Since this slightly slows down operations where lots of files are created (such as an initial checkout), this feature is only enabled when `core.WSLCompat` is set to true. Note that you also have to set `core.fileMode=true` in repositories that have been initialized without enabling WSL compatibility. There are several ways to enable metadata loading for NTFS volumes in WSL, one of which is to modify `/etc/wsl.conf` by adding: ``` [automount] enabled = true options = "metadata,umask=027,fmask=117" ``` And reboot WSL. It can also be enabled temporarily by this incantation: $ sudo umount /mnt/c && sudo mount -t drvfs C: /mnt/c -o metadata,uid=1000,gid=1000,umask=22,fmask=111 It's important to note that this modification is compatible with, but does not depend on WSL. The helper functions in this commit can operate independently and functions normally on devices where WSL is not installed or properly configured. Signed-off-by: xungeng li Signed-off-by: Johannes Schindelin --- compat/win32/fscache.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/compat/win32/fscache.c b/compat/win32/fscache.c index efe6be7e5e..e247e9a666 100644 --- a/compat/win32/fscache.c +++ b/compat/win32/fscache.c @@ -8,6 +8,7 @@ #include "config.h" #include "../../mem-pool.h" #include "ntifs.h" +#include "wsl.h" static volatile long initialized; static DWORD dwTlsIndex; @@ -242,6 +243,21 @@ static struct fsentry *fseentry_create_entry(struct fscache *cache, &(fse->u.s.st_mtim)); filetime_to_timespec((FILETIME *)&(fdata->CreationTime), &(fse->u.s.st_ctim)); + if (fdata->EaSize > 0 && + sizeof(buf) >= (size_t)(list ? list->len+1 : 0) + fse->len+1 && + are_wsl_compatible_mode_bits_enabled()) { + size_t off = 0; + wchar_t wpath[MAX_LONG_PATH]; + if (list && list->len) { + memcpy(buf, list->dirent.d_name, list->len); + buf[list->len] = '/'; + off = list->len + 1; + } + memcpy(buf + off, fse->dirent.d_name, fse->len); + buf[off + fse->len] = '\0'; + if (xutftowcs_long_path(wpath, buf) >= 0) + copy_wsl_mode_bits_from_disk(wpath, -1, &fse->st_mode); + } return fse; } From f4a1819615b575cad1fc98a5240f994824ba2a27 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 11 Dec 2018 12:17:49 +0100 Subject: [PATCH 4/5] 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 | 40 ++++++++++++++++++++++++++++++++++++++++ compat/win32/fscache.h | 1 + 4 files changed, 45 insertions(+), 1 deletion(-) diff --git a/compat/mingw.c b/compat/mingw.c index dbc507f2d5..5140c17ff0 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -3485,6 +3485,8 @@ 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 0e92950060..62b15f12d1 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -40,7 +40,8 @@ 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 e247e9a666..26ae9ab1c1 100644 --- a/compat/win32/fscache.c +++ b/compat/win32/fscache.c @@ -515,6 +515,7 @@ 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); @@ -575,6 +576,7 @@ 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); @@ -662,6 +664,44 @@ 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; +#pragma GCC diagnostic push +#ifdef __clang__ +#pragma GCC diagnostic ignored "-Wflexible-array-extensions" +#endif + struct heap_fsentry key[2]; +#pragma GCC diagnostic pop + 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].u.ent, NULL, path->buf, dirlen); + fsentry_init(&key[1].u.ent, &key[0].u.ent, path->buf + base, len - base); + fse = fscache_get(cache, &key[1].u.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 2b1525507c7dc13044f8f2e8f0ef36c246c83560 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 11 Dec 2018 12:17:49 +0100 Subject: [PATCH 5/5] 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 6ed555000f..e15d595c3d 100644 --- a/builtin/clean.c +++ b/builtin/clean.c @@ -1042,6 +1042,7 @@ int cmd_clean(int argc, if (repo_read_index(the_repository) < 0) die(_("index file corrupt")); + enable_fscache(the_repository->index->cache_nr); pl = add_pattern_list(&dir, EXC_CMDL, "--exclude option"); for (i = 0; i < exclude_list.nr; i++) @@ -1116,6 +1117,7 @@ int cmd_clean(int argc, } } + disable_fscache(); strbuf_release(&abs_path); strbuf_release(&buf); string_list_clear(&del_list, 0);