Just output the '\0' separate list of supported file systems for block devices directly rather than going through a pointless round of string manipulation.
Based on an earlier patch from Al Viro <[email protected]>. Signed-off-by: Christoph Hellwig <[email protected]> --- fs/filesystems.c | 24 ++++++++++++++---------- include/linux/fs.h | 2 +- init/do_mounts.c | 20 +------------------- 3 files changed, 16 insertions(+), 30 deletions(-) diff --git a/fs/filesystems.c b/fs/filesystems.c index 90b8d879fbaf..7c136251607a 100644 --- a/fs/filesystems.c +++ b/fs/filesystems.c @@ -209,21 +209,25 @@ SYSCALL_DEFINE3(sysfs, int, option, unsigned long, arg1, unsigned long, arg2) } #endif -int __init get_filesystem_list(char *buf) +void __init list_bdev_fs_names(char *buf, size_t size) { - int len = 0; - struct file_system_type * tmp; + struct file_system_type *p; + size_t len; read_lock(&file_systems_lock); - tmp = file_systems; - while (tmp && len < PAGE_SIZE - 80) { - len += sprintf(buf+len, "%s\t%s\n", - (tmp->fs_flags & FS_REQUIRES_DEV) ? "" : "nodev", - tmp->name); - tmp = tmp->next; + for (p = file_systems; p; p = p->next) { + if (!(p->fs_flags & FS_REQUIRES_DEV)) + continue; + len = strlen(p->name) + 1; + if (len > size) { + pr_warn("%s: truncating file system list\n", __func__); + break; + } + memcpy(buf, p->name, len); + buf += len; + size -= len; } read_unlock(&file_systems_lock); - return len; } #ifdef CONFIG_PROC_FS diff --git a/include/linux/fs.h b/include/linux/fs.h index f4ed7bf1130d..cdcd7f2a2c3f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3624,7 +3624,7 @@ int proc_nr_dentry(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos); int proc_nr_inodes(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos); -int __init get_filesystem_list(char *buf); +void __init list_bdev_fs_names(char *buf, size_t size); #define __FMODE_EXEC ((__force int) FMODE_EXEC) #define __FMODE_NONOTIFY ((__force int) FMODE_NONOTIFY) diff --git a/init/do_mounts.c b/init/do_mounts.c index bdeb90b8d669..ffbe4deeb274 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -348,24 +348,6 @@ static void __init split_fs_names(char *page, char *names) *page = '\0'; } -static void __init get_all_fs_names(char *page) -{ - int len = get_filesystem_list(page); - char *s = page, *p, *next; - - page[len] = '\0'; - for (p = page - 1; p; p = next) { - next = strchr(++p, '\n'); - if (*p++ != '\t') - continue; - while ((*s++ = *p++) != '\n') - ; - s[-1] = '\0'; - } - - *s = '\0'; -} - static int __init do_mount_root(const char *name, const char *fs, const int flags, const void *data) { @@ -415,7 +397,7 @@ void __init mount_block_root(char *name, int flags) if (root_fs_names) split_fs_names(fs_names, root_fs_names); else - get_all_fs_names(fs_names); + list_bdev_fs_names(fs_names, PAGE_SIZE); retry: for (p = fs_names; *p; p += strlen(p)+1) { int err = do_mount_root(name, p, flags, root_mount_data); -- 2.30.2 _______________________________________________ Virtio-fs mailing list [email protected] https://listman.redhat.com/mailman/listinfo/virtio-fs
