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author | Lennart Poettering <lennart@poettering.net> | 2021-02-26 17:39:55 +0100 |
---|---|---|
committer | Luca Boccassi <luca.boccassi@gmail.com> | 2022-01-18 11:33:27 +0000 |
commit | 190c6bcfc3518bec964ab740085ac88ccc86dcc7 (patch) | |
tree | 66d7ab34bafb57a4d63916fa98abc4328818a1c6 | |
parent | ea89c6c6bf5763591858e2fb7f320f08cd870b17 (diff) | |
download | systemd-190c6bcfc3518bec964ab740085ac88ccc86dcc7.tar.gz |
btrfs-util: add helper that abstracts "might be btrfs subvol?" check
Let#s not hardcode inode nr 256 everywhere, but abstract this check
slightly.
(cherry picked from commit 674b04ff1b6deab17f5d36c036c0275ba94e1ebc)
-rw-r--r-- | src/basic/btrfs-util.c | 6 | ||||
-rw-r--r-- | src/basic/btrfs-util.h | 10 | ||||
-rw-r--r-- | src/basic/rm-rf.c | 2 | ||||
-rw-r--r-- | src/import/export-tar.c | 2 | ||||
-rw-r--r-- | src/shared/machine-image.c | 3 |
5 files changed, 16 insertions, 7 deletions
diff --git a/src/basic/btrfs-util.c b/src/basic/btrfs-util.c index 2634659aa0..f0df51a7ed 100644 --- a/src/basic/btrfs-util.c +++ b/src/basic/btrfs-util.c @@ -91,7 +91,7 @@ int btrfs_is_subvol_fd(int fd) { if (fstat(fd, &st) < 0) return -errno; - if (!S_ISDIR(st.st_mode) || st.st_ino != 256) + if (!btrfs_might_be_subvol(&st)) return 0; return btrfs_is_filesystem(fd); @@ -194,7 +194,7 @@ int btrfs_subvol_set_read_only_fd(int fd, bool b) { if (fstat(fd, &st) < 0) return -errno; - if (!S_ISDIR(st.st_mode) || st.st_ino != 256) + if (!btrfs_might_be_subvol(&st)) return -EINVAL; if (ioctl(fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags) < 0) @@ -229,7 +229,7 @@ int btrfs_subvol_get_read_only_fd(int fd) { if (fstat(fd, &st) < 0) return -errno; - if (!S_ISDIR(st.st_mode) || st.st_ino != 256) + if (!btrfs_might_be_subvol(&st)) return -EINVAL; if (ioctl(fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags) < 0) diff --git a/src/basic/btrfs-util.h b/src/basic/btrfs-util.h index c8b44f6162..0f569b6f50 100644 --- a/src/basic/btrfs-util.h +++ b/src/basic/btrfs-util.h @@ -127,3 +127,13 @@ static inline int btrfs_log_dev_root(int level, int ret, const char *p) { "File system behind %s is reported by btrfs to be backed by pseudo-device /dev/root, which is not a valid userspace accessible device node. " "Cannot determine correct backing block device.", p); } + +static inline bool btrfs_might_be_subvol(const struct stat *st) { + if (!st) + return false; + + /* Returns true if this 'struct stat' looks like it could refer to a btrfs subvolume. To make a final + * decision, needs to be combined with an fstatfs() check to see if this is actually btrfs. */ + + return S_ISDIR(st->st_mode) && st->st_ino == 256; +} diff --git a/src/basic/rm-rf.c b/src/basic/rm-rf.c index b0d682f764..4c39ce8290 100644 --- a/src/basic/rm-rf.c +++ b/src/basic/rm-rf.c @@ -147,7 +147,7 @@ int rm_rf_children(int fd, RemoveFlags flags, struct stat *root_dev) { if (r > 0) continue; - if ((flags & REMOVE_SUBVOLUME) && st.st_ino == 256) { + if ((flags & REMOVE_SUBVOLUME) && btrfs_might_be_subvol(&st)) { /* This could be a subvolume, try to remove it */ diff --git a/src/import/export-tar.c b/src/import/export-tar.c index b8b650f01e..1e6b2c1268 100644 --- a/src/import/export-tar.c +++ b/src/import/export-tar.c @@ -283,7 +283,7 @@ int tar_export_start(TarExport *e, const char *path, int fd, ImportCompressType e->quota_referenced = (uint64_t) -1; - if (e->st.st_ino == 256) { /* might be a btrfs subvolume? */ + if (btrfs_might_be_subvol(&e->st)) { BtrfsQuotaInfo q; r = btrfs_subvol_get_subtree_quota_fd(sfd, 0, &q); diff --git a/src/shared/machine-image.c b/src/shared/machine-image.c index 671a56b9e9..c7cf5e9dba 100644 --- a/src/shared/machine-image.c +++ b/src/shared/machine-image.c @@ -248,8 +248,7 @@ static int image_make( if (fd < 0) return -errno; - /* btrfs subvolumes have inode 256 */ - if (st->st_ino == 256) { + if (btrfs_might_be_subvol(st)) { r = btrfs_is_filesystem(fd); if (r < 0) |