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GET /api/1.1/patches/2230307/?format=api
{ "id": 2230307, "url": "http://patchwork.ozlabs.org/api/1.1/patches/2230307/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linux-ext4/patch/177747214733.4107473.11688396903521099167.stgit@frogsfrogsfrogs/", "project": { "id": 8, "url": "http://patchwork.ozlabs.org/api/1.1/projects/8/?format=api", "name": "Linux ext4 filesystem development", "link_name": "linux-ext4", "list_id": "linux-ext4.vger.kernel.org", "list_email": "linux-ext4@vger.kernel.org", "web_url": null, "scm_url": null, "webscm_url": null }, "msgid": "<177747214733.4107473.11688396903521099167.stgit@frogsfrogsfrogs>", "date": "2026-04-29T14:55:30", "name": "[11/19] fuse2fs: try to create loop device when ext4 device is a regular file", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "4427d5282b47423e636c223f87aee2200af106f0", "submitter": { "id": 77032, "url": "http://patchwork.ozlabs.org/api/1.1/people/77032/?format=api", "name": "Darrick J. Wong", "email": "djwong@kernel.org" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/linux-ext4/patch/177747214733.4107473.11688396903521099167.stgit@frogsfrogsfrogs/mbox/", "series": [ { "id": 502087, "url": "http://patchwork.ozlabs.org/api/1.1/series/502087/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linux-ext4/list/?series=502087", "date": "2026-04-29T14:53:09", "name": "[01/19] fuse2fs: implement bare minimum iomap for file mapping reporting", "version": 1, "mbox": "http://patchwork.ozlabs.org/series/502087/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/2230307/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/2230307/checks/", "tags": {}, "headers": { "Return-Path": "\n <SRS0=JWzy=C4=vger.kernel.org=linux-ext4+bounces-16200-patchwork-incoming=ozlabs.org@ozlabs.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "linux-ext4@vger.kernel.org" ], "Delivered-To": [ "patchwork-incoming@legolas.ozlabs.org", "patchwork-incoming@ozlabs.org" ], "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256\n header.s=k20201202 header.b=P4YI/BYM;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org\n (client-ip=150.107.74.76; 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arc=none smtp.client-ip=10.30.226.201" ], "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org;\n\ts=k20201202; t=1777474530;\n\tbh=kGPJpQ8Ekl8cAe77Vbn2RNWO3109l029dBRceAVZtWg=;\n\th=Date:Subject:From:To:Cc:In-Reply-To:References:From;\n\tb=P4YI/BYMA/9/4ve9W+oH6Zppi6pQx7q6o6vDt7guVfnmRcfmLXZu+ocxK9qt/wRde\n\t /DcV7DpzzhoknR0nqCtqKEjqgTCCGw+BBKAf8Dv1GLgUHnydUeqWqRQZQO+yLyKTTY\n\t 3Rc6EeedAt1wEgjo79poqd/bYvLKhDe6DwsdWt4UyORoHtR55K/vTulnhKntZPDGqG\n\t snRxGJ6KflhvhA/+9gKymiSVThrhmxv09oejzxSb8Pduc/INNut2UG2H5AWfoxG3v9\n\t +fqlEc/uK4CzY1qakKvmNxbeeDFPhu0s2wBHpoEv6dkL+lv3GAgAjtGl3gMeJl+Dsd\n\t NYq8mJCyhtn6g==", "Date": "Wed, 29 Apr 2026 07:55:30 -0700", "Subject": "[PATCH 11/19] fuse2fs: try to create loop device when ext4 device is\n a regular file", "From": "\"Darrick J. Wong\" <djwong@kernel.org>", "To": "tytso@mit.edu", "Cc": "bernd@bsbernd.com, miklos@szeredi.hu, linux-ext4@vger.kernel.org,\n neal@gompa.dev, linux-fsdevel@vger.kernel.org, fuse-devel@lists.linux.dev,\n joannelkoong@gmail.com", "Message-ID": "<177747214733.4107473.11688396903521099167.stgit@frogsfrogsfrogs>", "In-Reply-To": "<177747214459.4107473.9520724883867588970.stgit@frogsfrogsfrogs>", "References": "<177747214459.4107473.9520724883867588970.stgit@frogsfrogsfrogs>", "Precedence": "bulk", "X-Mailing-List": "linux-ext4@vger.kernel.org", "List-Id": "<linux-ext4.vger.kernel.org>", "List-Subscribe": "<mailto:linux-ext4+subscribe@vger.kernel.org>", "List-Unsubscribe": "<mailto:linux-ext4+unsubscribe@vger.kernel.org>", "MIME-Version": "1.0", "Content-Type": "text/plain; charset=\"utf-8\"", "Content-Transfer-Encoding": "7bit", "X-Spam-Status": "No, score=-1.2 required=5.0 tests=ARC_SIGNED,ARC_VALID,\n\tDKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DMARC_PASS,\n\tMAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=disabled\n\tversion=4.0.1", "X-Spam-Checker-Version": "SpamAssassin 4.0.1 (2024-03-25) on gandalf.ozlabs.org" }, "content": "From: Darrick J. Wong <djwong@kernel.org>\n\nIf the filesystem device is a regular file, try to create a loop device\nfor it so that we can take advantage of iomap.\n\nSigned-off-by: \"Darrick J. Wong\" <djwong@kernel.org>\n---\n configure | 41 +++++++++++++++++++\n configure.ac | 23 +++++++++++\n fuse4fs/fuse4fs.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++++-\n lib/config.h.in | 3 +\n misc/fuse2fs.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++++++-\n 5 files changed, 292 insertions(+), 4 deletions(-)", "diff": "diff --git a/configure b/configure\nindex 344c7af2ee48f8..ba1556b34257a6 100755\n--- a/configure\n+++ b/configure\n@@ -14691,6 +14691,47 @@ printf \"%s\\n\" \"#define HAVE_FUSE_IOMAP 1\" >>confdefs.h\n \n fi\n \n+if test -n \"$have_fuse_iomap\"; then\n+\t{ printf \"%s\\n\" \"$as_me:${as_lineno-$LINENO}: checking for fuse_loopdev.h in libfuse\" >&5\n+printf %s \"checking for fuse_loopdev.h in libfuse... \" >&6; }\n+\tcat confdefs.h - <<_ACEOF >conftest.$ac_ext\n+/* end confdefs.h. */\n+\n+\t#define _GNU_SOURCE\n+\t#define _FILE_OFFSET_BITS\t64\n+\t#define FUSE_USE_VERSION\t399\n+\t#include <fuse_loopdev.h>\n+\n+int\n+main (void)\n+{\n+\n+\n+ ;\n+ return 0;\n+}\n+\n+_ACEOF\n+if ac_fn_c_try_link \"$LINENO\"\n+then :\n+ have_fuse_loopdev=yes\n+\t { printf \"%s\\n\" \"$as_me:${as_lineno-$LINENO}: result: yes\" >&5\n+printf \"%s\\n\" \"yes\" >&6; }\n+else case e in #(\n+ e) { printf \"%s\\n\" \"$as_me:${as_lineno-$LINENO}: result: no\" >&5\n+printf \"%s\\n\" \"no\" >&6; } ;;\n+esac\n+fi\n+rm -f core conftest.err conftest.$ac_objext conftest.beam \\\n+ conftest$ac_exeext conftest.$ac_ext\n+fi\n+if test -n \"$have_fuse_loopdev\"\n+then\n+\n+printf \"%s\\n\" \"#define HAVE_FUSE_LOOPDEV 1\" >>confdefs.h\n+\n+fi\n+\n have_fuse_lowlevel=\n if test -n \"$FUSE_USE_VERSION\"\n then\ndiff --git a/configure.ac b/configure.ac\nindex 8d85e9966877ea..8cfde4d85489e5 100644\n--- a/configure.ac\n+++ b/configure.ac\n@@ -1432,6 +1432,29 @@ then\n \tAC_DEFINE(HAVE_FUSE_IOMAP, 1, [Define to 1 if fuse supports iomap])\n fi\n \n+dnl\n+dnl Check if fuse library has fuse_loopdev.h, which it only gained after adding\n+dnl iomap support.\n+dnl\n+if test -n \"$have_fuse_iomap\"; then\n+\tAC_MSG_CHECKING(for fuse_loopdev.h in libfuse)\n+\tAC_LINK_IFELSE(\n+\t[\tAC_LANG_PROGRAM([[\n+\t#define _GNU_SOURCE\n+\t#define _FILE_OFFSET_BITS\t64\n+\t#define FUSE_USE_VERSION\t399\n+\t#include <fuse_loopdev.h>\n+\t\t]], [[\n+\t\t]])\n+\t], have_fuse_loopdev=yes\n+\t AC_MSG_RESULT(yes),\n+\t AC_MSG_RESULT(no))\n+fi\n+if test -n \"$have_fuse_loopdev\"\n+then\n+\tAC_DEFINE(HAVE_FUSE_LOOPDEV, 1, [Define to 1 if fuse supports loopdev operations])\n+fi\n+\n dnl\n dnl Check if the FUSE lowlevel library is supported\n dnl\ndiff --git a/fuse4fs/fuse4fs.c b/fuse4fs/fuse4fs.c\nindex 68f1f7c02df223..3c3debb6f60ac7 100644\n--- a/fuse4fs/fuse4fs.c\n+++ b/fuse4fs/fuse4fs.c\n@@ -27,6 +27,9 @@\n #include <unistd.h>\n #include <ctype.h>\n #include <assert.h>\n+#ifdef HAVE_FUSE_LOOPDEV\n+# include <fuse_loopdev.h>\n+#endif\n #define FUSE_DARWIN_ENABLE_EXTENSIONS 0\n #ifdef __SET_FOB_FOR_FUSE\n # error Do not set magic value __SET_FOB_FOR_FUSE!!!!\n@@ -262,6 +265,10 @@ struct fuse4fs {\n \tpthread_mutex_t bfl;\n \tchar *device;\n \tchar *shortdev;\n+#ifdef HAVE_FUSE_LOOPDEV\n+\tchar *loop_device;\n+\tint loop_fd;\n+#endif\n \n \t/* options set by fuse_opt_parse must be of type int */\n \tint ro;\n@@ -285,6 +292,7 @@ struct fuse4fs {\n \tenum fuse4fs_feature_toggle iomap_want;\n \tenum fuse4fs_iomap_state iomap_state;\n \tuint32_t iomap_dev;\n+\tuint64_t iomap_cap;\n #endif\n \tunsigned int blockmask;\n \tunsigned long offset;\n@@ -913,8 +921,23 @@ static inline int fuse4fs_iomap_enabled(const struct fuse4fs *ff)\n {\n \treturn ff->iomap_state >= IOMAP_ENABLED;\n }\n+\n+static inline void fuse4fs_discover_iomap(struct fuse4fs *ff)\n+{\n+\tif (ff->iomap_want == FT_DISABLE)\n+\t\treturn;\n+\n+\tff->iomap_cap = fuse_lowlevel_discover_iomap(-1);\n+}\n+\n+static inline bool fuse4fs_can_iomap(const struct fuse4fs *ff)\n+{\n+\treturn ff->iomap_cap & FUSE_IOMAP_SUPPORT_FILEIO;\n+}\n #else\n # define fuse4fs_iomap_enabled(...)\t(0)\n+# define fuse4fs_discover_iomap(...)\t((void)0)\n+# define fuse4fs_can_iomap(...)\t\t(false)\n #endif\n \n static inline void fuse4fs_dump_extents(struct fuse4fs *ff, ext2_ino_t ino,\n@@ -1584,6 +1607,76 @@ static void fuse4fs_release_lockfile(struct fuse4fs *ff)\n \tfree(ff->lockfile);\n }\n \n+#ifdef HAVE_FUSE_LOOPDEV\n+static int fuse4fs_try_losetup(struct fuse4fs *ff, int flags)\n+{\n+\tbool rw = flags & EXT2_FLAG_RW;\n+\tint dev_fd;\n+\tint ret;\n+\n+\t/*\n+\t * Only transform a regular file into a loopdev for iomap, and only if\n+\t * the service helper isn't required to that for us.\n+\t */\n+\tif (!fuse4fs_can_iomap(ff) || fuse4fs_is_service(ff))\n+\t\treturn 0;\n+\n+\t/* open the actual target device, see if it's a regular file */\n+\tdev_fd = open(ff->device, rw ? O_RDWR : O_RDONLY);\n+\tif (dev_fd < 0) {\n+\t\terr_printf(ff, \"%s: %s\\n\", _(\"while opening fs\"),\n+\t\t\t error_message(errno));\n+\t\treturn -1;\n+\t}\n+\n+\tret = fuse_loopdev_setup(dev_fd, rw ? O_RDWR : O_RDONLY, ff->device, 5,\n+\t\t\t\t &ff->loop_fd, &ff->loop_device);\n+\tif (ret == -EBUSY) {\n+\t\t/*\n+\t\t * If the setup function returned EBUSY, there is already a\n+\t\t * loop device backed by this file. Report that the file is\n+\t\t * already in use. Ignore the other errors because we can\n+\t\t * otherwise handle filesystem in a file.\n+\t\t */\n+\t\terr_printf(ff, \"%s: %s\\n\", _(\"while opening fs loopdev\"),\n+\t\t\t\t error_message(errno));\n+\t\tclose(dev_fd);\n+\t\treturn -1;\n+\t}\n+\n+\tclose(dev_fd);\n+\treturn 0;\n+}\n+\n+static void fuse4fs_detach_losetup(struct fuse4fs *ff)\n+{\n+\tif (ff->loop_fd >= 0)\n+\t\tclose(ff->loop_fd);\n+\tff->loop_fd = -1;\n+}\n+\n+static void fuse4fs_undo_losetup(struct fuse4fs *ff)\n+{\n+\tfuse4fs_detach_losetup(ff);\n+\tfree(ff->loop_device);\n+\tff->loop_device = NULL;\n+}\n+\n+static inline const char *fuse4fs_device(const struct fuse4fs *ff)\n+{\n+\t/*\n+\t * If we created a loop device for the file passed in, open that.\n+\t * Otherwise open the path the user gave us.\n+\t */\n+\treturn ff->loop_device ? ff->loop_device : ff->device;\n+}\n+#else\n+# define fuse4fs_try_losetup(...)\t(0)\n+# define fuse4fs_detach_losetup(...)\t((void)0)\n+# define fuse4fs_undo_losetup(...)\t((void)0)\n+# define fuse4fs_device(ff)\t\t((ff)->device)\n+#endif\n+\n static void fuse4fs_unmount(struct fuse4fs *ff)\n {\n \tchar uuid[UUID_STR_SIZE];\n@@ -1607,6 +1700,7 @@ static void fuse4fs_unmount(struct fuse4fs *ff)\n \t}\n \n \tfuse4fs_service_close_bdev(ff);\n+\tfuse4fs_undo_losetup(ff);\n \n \tif (ff->lockfile)\n \t\tfuse4fs_release_lockfile(ff);\n@@ -1620,6 +1714,8 @@ static errcode_t fuse4fs_open(struct fuse4fs *ff)\n \t\t EXT2_FLAG_EXCLUSIVE | EXT2_FLAG_WRITE_FULL_SUPER;\n \terrcode_t err;\n \n+\tfuse4fs_discover_iomap(ff);\n+\n \tif (ff->lockfile) {\n \t\terr = fuse4fs_acquire_lockfile(ff);\n \t\tif (err)\n@@ -1632,6 +1728,12 @@ static errcode_t fuse4fs_open(struct fuse4fs *ff)\n \tif (ff->directio)\n \t\tflags |= EXT2_FLAG_DIRECT_IO;\n \n+\tdbg_printf(ff, \"opening with flags=0x%x\\n\", flags);\n+\n+\terr = fuse4fs_try_losetup(ff, flags);\n+\tif (err)\n+\t\treturn err;\n+\n \t/*\n \t * If the filesystem is stored on a block device, the _EXCLUSIVE flag\n \t * causes libext2fs to try to open the block device with O_EXCL. If\n@@ -1666,8 +1768,8 @@ static errcode_t fuse4fs_open(struct fuse4fs *ff)\n \t\tif (fuse4fs_is_service(ff))\n \t\t\terr = fuse4fs_service_openfs(ff, options, &flags);\n \t\telse\n-\t\t\terr = ext2fs_open2(ff->device, options, flags, 0, 0,\n-\t\t\t\t\t unix_io_manager, &ff->fs);\n+\t\t\terr = ext2fs_open2(fuse4fs_device(ff), options, flags,\n+\t\t\t\t\t 0, 0, unix_io_manager, &ff->fs);\n \t\tif ((err == EPERM || err == EACCES) &&\n \t\t (!ff->ro || (flags & EXT2_FLAG_RW))) {\n \t\t\t/*\n@@ -1681,6 +1783,11 @@ static errcode_t fuse4fs_open(struct fuse4fs *ff)\n \t\t\tflags &= ~EXT2_FLAG_RW;\n \t\t\tff->ro = 1;\n \n+\t\t\tfuse4fs_undo_losetup(ff);\n+\t\t\terr = fuse4fs_try_losetup(ff, flags);\n+\t\t\tif (err)\n+\t\t\t\treturn err;\n+\n \t\t\t/* Force the loop to run once more */\n \t\t\terr = -1;\n \t\t}\n@@ -2129,6 +2236,8 @@ static void op_init(void *userdata, struct fuse_conn_info *conn)\n \tfuse4fs_iomap_enable(conn, ff);\n \tconn->time_gran = 1;\n \n+\tfuse4fs_detach_losetup(ff);\n+\n \tif (ff->opstate == F4OP_WRITABLE)\n \t\tfuse4fs_read_bitmaps(ff);\n \n@@ -7737,6 +7846,9 @@ int main(int argc, char *argv[])\n \t\t.iomap_want = FT_DEFAULT,\n \t\t.iomap_state = IOMAP_UNKNOWN,\n \t\t.iomap_dev = FUSE_IOMAP_DEV_NULL,\n+#endif\n+#ifdef HAVE_FUSE_LOOPDEV\n+\t\t.loop_fd = -1,\n #endif\n \t};\n \terrcode_t err;\ndiff --git a/lib/config.h.in b/lib/config.h.in\nindex 58338cc926590e..96ed5479181a5b 100644\n--- a/lib/config.h.in\n+++ b/lib/config.h.in\n@@ -151,6 +151,9 @@\n /* Define to 1 if fuse supports iomap */\n #undef HAVE_FUSE_IOMAP\n \n+/* Define to 1 if fuse supports loopdev operations */\n+#undef HAVE_FUSE_LOOPDEV\n+\n /* Define to 1 if fuse supports lowlevel API */\n #undef HAVE_FUSE_LOWLEVEL\n \ndiff --git a/misc/fuse2fs.c b/misc/fuse2fs.c\nindex f7653dc6c20c3f..3c76eba683a10d 100644\n--- a/misc/fuse2fs.c\n+++ b/misc/fuse2fs.c\n@@ -25,6 +25,9 @@\n #include <sys/ioctl.h>\n #include <unistd.h>\n #include <ctype.h>\n+#ifdef HAVE_FUSE_LOOPDEV\n+# include <fuse_loopdev.h>\n+#endif\n #define FUSE_DARWIN_ENABLE_EXTENSIONS 0\n #ifdef __SET_FOB_FOR_FUSE\n # error Do not set magic value __SET_FOB_FOR_FUSE!!!!\n@@ -245,6 +248,10 @@ struct fuse2fs {\n \tpthread_mutex_t bfl;\n \tchar *device;\n \tchar *shortdev;\n+#ifdef HAVE_FUSE_LOOPDEV\n+\tchar *loop_device;\n+\tint loop_fd;\n+#endif\n \n \t/* options set by fuse_opt_parse must be of type int */\n \tint ro;\n@@ -268,6 +275,7 @@ struct fuse2fs {\n \tenum fuse2fs_feature_toggle iomap_want;\n \tenum fuse2fs_iomap_state iomap_state;\n \tuint32_t iomap_dev;\n+\tuint64_t iomap_cap;\n #endif\n \tunsigned int blockmask;\n \tunsigned long offset;\n@@ -725,9 +733,23 @@ static inline int fuse2fs_iomap_enabled(const struct fuse2fs *ff)\n {\n \treturn ff->iomap_state >= IOMAP_ENABLED;\n }\n+\n+static inline void fuse2fs_discover_iomap(struct fuse2fs *ff)\n+{\n+\tif (ff->iomap_want == FT_DISABLE)\n+\t\treturn;\n+\n+\tff->iomap_cap = fuse_lowlevel_discover_iomap(-1);\n+}\n+\n+static inline bool fuse2fs_can_iomap(const struct fuse2fs *ff)\n+{\n+\treturn ff->iomap_cap & FUSE_IOMAP_SUPPORT_FILEIO;\n+}\n #else\n # define fuse2fs_iomap_enabled(...)\t(0)\n-# define fuse2fs_iomap_enabled(...)\t(0)\n+# define fuse2fs_discover_iomap(...)\t((void)0)\n+# define fuse2fs_can_iomap(...)\t\t(false)\n #endif\n \n static inline void fuse2fs_dump_extents(struct fuse2fs *ff, ext2_ino_t ino,\n@@ -1201,6 +1223,73 @@ static void fuse2fs_release_lockfile(struct fuse2fs *ff)\n \tfree(ff->lockfile);\n }\n \n+#ifdef HAVE_FUSE_LOOPDEV\n+static int fuse2fs_try_losetup(struct fuse2fs *ff, int flags)\n+{\n+\tbool rw = flags & EXT2_FLAG_RW;\n+\tint dev_fd;\n+\tint ret;\n+\n+\t/* Only transform a regular file into a loopdev for iomap */\n+\tif (!fuse2fs_can_iomap(ff))\n+\t\treturn 0;\n+\n+\t/* open the actual target device, see if it's a regular file */\n+\tdev_fd = open(ff->device, rw ? O_RDWR : O_RDONLY);\n+\tif (dev_fd < 0) {\n+\t\terr_printf(ff, \"%s: %s\\n\", _(\"while opening fs\"),\n+\t\t\t error_message(errno));\n+\t\treturn -1;\n+\t}\n+\n+\tret = fuse_loopdev_setup(dev_fd, rw ? O_RDWR : O_RDONLY, ff->device, 5,\n+\t\t\t\t &ff->loop_fd, &ff->loop_device);\n+\tif (ret == -EBUSY) {\n+\t\t/*\n+\t\t * If the setup function returned EBUSY, there is already a\n+\t\t * loop device backed by this file. Report that the file is\n+\t\t * already in use. Ignore the other errors because we can\n+\t\t * otherwise handle filesystem in a file.\n+\t\t */\n+\t\terr_printf(ff, \"%s: %s\\n\", _(\"while opening fs loopdev\"),\n+\t\t\t\t error_message(-ret));\n+\t\tclose(dev_fd);\n+\t\treturn -1;\n+\t}\n+\n+\tclose(dev_fd);\n+\treturn 0;\n+}\n+\n+static void fuse2fs_detach_losetup(struct fuse2fs *ff)\n+{\n+\tif (ff->loop_fd >= 0)\n+\t\tclose(ff->loop_fd);\n+\tff->loop_fd = -1;\n+}\n+\n+static void fuse2fs_undo_losetup(struct fuse2fs *ff)\n+{\n+\tfuse2fs_detach_losetup(ff);\n+\tfree(ff->loop_device);\n+\tff->loop_device = NULL;\n+}\n+\n+static inline const char *fuse2fs_device(const struct fuse2fs *ff)\n+{\n+\t/*\n+\t * If we created a loop device for the file passed in, open that.\n+\t * Otherwise open the path the user gave us.\n+\t */\n+\treturn ff->loop_device ? ff->loop_device : ff->device;\n+}\n+#else\n+# define fuse2fs_try_losetup(...)\t(0)\n+# define fuse2fs_detach_losetup(...)\t((void)0)\n+# define fuse2fs_undo_losetup(...)\t((void)0)\n+# define fuse2fs_device(ff)\t\t((ff)->device)\n+#endif\n+\n static void fuse2fs_unmount(struct fuse2fs *ff)\n {\n \tchar uuid[UUID_STR_SIZE];\n@@ -1218,6 +1307,8 @@ static void fuse2fs_unmount(struct fuse2fs *ff)\n \t\t\t\t uuid);\n \t}\n \n+\tfuse2fs_undo_losetup(ff);\n+\n \tif (ff->lockfile)\n \t\tfuse2fs_release_lockfile(ff);\n }\n@@ -1230,6 +1321,8 @@ static errcode_t fuse2fs_open(struct fuse2fs *ff)\n \t\t EXT2_FLAG_EXCLUSIVE | EXT2_FLAG_WRITE_FULL_SUPER;\n \terrcode_t err;\n \n+\tfuse2fs_discover_iomap(ff);\n+\n \tif (ff->lockfile) {\n \t\terr = fuse2fs_acquire_lockfile(ff);\n \t\tif (err)\n@@ -1242,6 +1335,12 @@ static errcode_t fuse2fs_open(struct fuse2fs *ff)\n \tif (ff->directio)\n \t\tflags |= EXT2_FLAG_DIRECT_IO;\n \n+\tdbg_printf(ff, \"opening with flags=0x%x\\n\", flags);\n+\n+\terr = fuse2fs_try_losetup(ff, flags);\n+\tif (err)\n+\t\treturn err;\n+\n \t/*\n \t * If the filesystem is stored on a block device, the _EXCLUSIVE flag\n \t * causes libext2fs to try to open the block device with O_EXCL. If\n@@ -1273,7 +1372,7 @@ static errcode_t fuse2fs_open(struct fuse2fs *ff)\n \t */\n \tdeadline = init_deadline(FUSE2FS_OPEN_TIMEOUT);\n \tdo {\n-\t\terr = ext2fs_open2(ff->device, options, flags, 0, 0,\n+\t\terr = ext2fs_open2(fuse2fs_device(ff), options, flags, 0, 0,\n \t\t\t\t unix_io_manager, &ff->fs);\n \t\tif ((err == EPERM || err == EACCES) &&\n \t\t (!ff->ro || (flags & EXT2_FLAG_RW))) {\n@@ -1288,6 +1387,11 @@ static errcode_t fuse2fs_open(struct fuse2fs *ff)\n \t\t\tflags &= ~EXT2_FLAG_RW;\n \t\t\tff->ro = 1;\n \n+\t\t\tfuse2fs_undo_losetup(ff);\n+\t\t\terr = fuse2fs_try_losetup(ff, flags);\n+\t\t\tif (err)\n+\t\t\t\treturn err;\n+\n \t\t\t/* Force the loop to run once more */\n \t\t\terr = -1;\n \t\t}\n@@ -1744,6 +1848,8 @@ static void *op_init(struct fuse_conn_info *conn,\n \t\tcfg->debug = 1;\n \tcfg->nullpath_ok = 1;\n \n+\tfuse2fs_detach_losetup(ff);\n+\n \tif (ff->opstate == F2OP_WRITABLE)\n \t\tfuse2fs_read_bitmaps(ff);\n \n@@ -6852,6 +6958,9 @@ int main(int argc, char *argv[])\n \t\t.iomap_want = FT_DEFAULT,\n \t\t.iomap_state = IOMAP_UNKNOWN,\n \t\t.iomap_dev = FUSE_IOMAP_DEV_NULL,\n+#endif\n+#ifdef HAVE_FUSE_LOOPDEV\n+\t\t.loop_fd = -1,\n #endif\n \t};\n \terrcode_t err;\n", "prefixes": [ "11/19" ] }