From: Daniel Rosenberg Date: Thu, 27 Oct 2016 00:36:05 +0000 (-0700) Subject: ANDROID: sdcardfs: Add gid and mask to private mount data X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8246a7813919115d8ad6acaee0a0b295599377a0;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git ANDROID: sdcardfs: Add gid and mask to private mount data Adds support for mount2, remount2, and the functions to allocate/clone/copy the private data The next patch will switch over to actually using it. Change-Id: I8a43da26021d33401f655f0b2784ead161c575e3 Signed-off-by: Daniel Rosenberg --- diff --git a/fs/sdcardfs/main.c b/fs/sdcardfs/main.c index 2decea3d1e3e..5400e7e63d27 100644 --- a/fs/sdcardfs/main.c +++ b/fs/sdcardfs/main.c @@ -49,7 +49,8 @@ static const match_table_t sdcardfs_tokens = { }; static int parse_options(struct super_block *sb, char *options, int silent, - int *debug, struct sdcardfs_mount_options *opts) + int *debug, struct sdcardfs_vfsmount_options *vfsopts, + struct sdcardfs_mount_options *opts) { char *p; substring_t args[MAX_OPT_ARGS]; @@ -58,9 +59,11 @@ static int parse_options(struct super_block *sb, char *options, int silent, /* by default, we use AID_MEDIA_RW as uid, gid */ opts->fs_low_uid = AID_MEDIA_RW; opts->fs_low_gid = AID_MEDIA_RW; + vfsopts->mask = 0; opts->mask = 0; opts->multiuser = false; opts->fs_user_id = 0; + vfsopts->gid = 0; opts->gid = 0; /* by default, 0MB is reserved */ opts->reserved_mb = 0; @@ -95,6 +98,7 @@ static int parse_options(struct super_block *sb, char *options, int silent, if (match_int(&args[0], &option)) return 0; opts->gid = option; + vfsopts->gid = option; break; case Opt_userid: if (match_int(&args[0], &option)) @@ -105,6 +109,7 @@ static int parse_options(struct super_block *sb, char *options, int silent, if (match_int(&args[0], &option)) return 0; opts->mask = option; + vfsopts->mask = option; break; case Opt_multiuser: opts->multiuser = true; @@ -135,6 +140,65 @@ static int parse_options(struct super_block *sb, char *options, int silent, return 0; } +int parse_options_remount(struct super_block *sb, char *options, int silent, + struct sdcardfs_vfsmount_options *vfsopts) +{ + char *p; + substring_t args[MAX_OPT_ARGS]; + int option; + int debug; + + if (!options) + return 0; + + while ((p = strsep(&options, ",")) != NULL) { + int token; + if (!*p) + continue; + + token = match_token(p, sdcardfs_tokens, args); + + switch (token) { + case Opt_debug: + debug = 1; + break; + case Opt_gid: + if (match_int(&args[0], &option)) + return 0; + vfsopts->gid = option; + + break; + case Opt_mask: + if (match_int(&args[0], &option)) + return 0; + vfsopts->mask = option; + break; + case Opt_multiuser: + case Opt_userid: + case Opt_fsuid: + case Opt_fsgid: + case Opt_reserved_mb: + printk( KERN_WARNING "Option \"%s\" can't be changed during remount\n", p); + break; + /* unknown option */ + default: + if (!silent) { + printk( KERN_ERR "Unrecognized mount option \"%s\" " + "or missing value", p); + } + return -EINVAL; + } + } + + if (debug) { + printk( KERN_INFO "sdcardfs : options - debug:%d\n", debug); + printk( KERN_INFO "sdcardfs : options - gid:%d\n", vfsopts->gid); + printk( KERN_INFO "sdcardfs : options - mask:%d\n", vfsopts->mask); + } + + return 0; +} + #if 0 /* * our custom d_alloc_root work-alike @@ -172,14 +236,15 @@ EXPORT_SYMBOL_GPL(sdcardfs_super_list); * There is no need to lock the sdcardfs_super_info's rwsem as there is no * way anyone can have a reference to the superblock at this point in time. */ -static int sdcardfs_read_super(struct super_block *sb, const char *dev_name, - void *raw_data, int silent) +static int sdcardfs_read_super(struct vfsmount *mnt, struct super_block *sb, + const char *dev_name, void *raw_data, int silent) { int err = 0; int debug; struct super_block *lower_sb; struct path lower_path; struct sdcardfs_sb_info *sb_info; + struct sdcardfs_vfsmount_options *mnt_opt = mnt->data; struct inode *inode; printk(KERN_INFO "sdcardfs version 2.0\n"); @@ -212,7 +277,7 @@ static int sdcardfs_read_super(struct super_block *sb, const char *dev_name, sb_info = sb->s_fs_info; /* parse options */ - err = parse_options(sb, raw_data, silent, &debug, &sb_info->options); + err = parse_options(sb, raw_data, silent, &debug, mnt_opt, &sb_info->options); if (err) { printk(KERN_ERR "sdcardfs: invalid options\n"); goto out_freesbi; @@ -306,9 +371,9 @@ out: } /* A feature which supports mount_nodev() with options */ -static struct dentry *mount_nodev_with_options(struct file_system_type *fs_type, - int flags, const char *dev_name, void *data, - int (*fill_super)(struct super_block *, const char *, void *, int)) +static struct dentry *mount_nodev_with_options(struct vfsmount *mnt, + struct file_system_type *fs_type, int flags, const char *dev_name, void *data, + int (*fill_super)(struct vfsmount *, struct super_block *, const char *, void *, int)) { int error; @@ -319,7 +384,7 @@ static struct dentry *mount_nodev_with_options(struct file_system_type *fs_type, s->s_flags = flags; - error = fill_super(s, dev_name, data, flags & MS_SILENT ? 1 : 0); + error = fill_super(mnt, s, dev_name, data, flags & MS_SILENT ? 1 : 0); if (error) { deactivate_locked_super(s); return ERR_PTR(error); @@ -328,15 +393,27 @@ static struct dentry *mount_nodev_with_options(struct file_system_type *fs_type, return dget(s->s_root); } -struct dentry *sdcardfs_mount(struct file_system_type *fs_type, int flags, +static struct dentry *sdcardfs_mount(struct vfsmount *mnt, + struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data) { /* * dev_name is a lower_path_name, * raw_data is a option string. */ - return mount_nodev_with_options(fs_type, flags, dev_name, - raw_data, sdcardfs_read_super); + return mount_nodev_with_options(mnt, fs_type, flags, dev_name, + raw_data, sdcardfs_read_super); +} + +static struct dentry *sdcardfs_mount_wrn(struct file_system_type *fs_type, int flags, + const char *dev_name, void *raw_data) +{ + WARN(1, "sdcardfs does not support mount. Use mount2.\n"); + return ERR_PTR(-EINVAL); +} + +void *sdcardfs_alloc_mnt_data(void) { + return kmalloc(sizeof(struct sdcardfs_vfsmount_options), GFP_KERNEL); } void sdcardfs_kill_sb(struct super_block *sb) { @@ -353,7 +430,9 @@ void sdcardfs_kill_sb(struct super_block *sb) { static struct file_system_type sdcardfs_fs_type = { .owner = THIS_MODULE, .name = SDCARDFS_NAME, - .mount = sdcardfs_mount, + .mount = sdcardfs_mount_wrn, + .mount2 = sdcardfs_mount, + .alloc_mnt_data = sdcardfs_alloc_mnt_data, .kill_sb = sdcardfs_kill_sb, .fs_flags = 0, }; diff --git a/fs/sdcardfs/sdcardfs.h b/fs/sdcardfs/sdcardfs.h index 5132f1dc5a4d..22ef29857022 100644 --- a/fs/sdcardfs/sdcardfs.h +++ b/fs/sdcardfs/sdcardfs.h @@ -193,6 +193,14 @@ struct sdcardfs_mount_options { unsigned int reserved_mb; }; +struct sdcardfs_vfsmount_options { + gid_t gid; + mode_t mask; +}; + +extern int parse_options_remount(struct super_block *sb, char *options, int silent, + struct sdcardfs_vfsmount_options *vfsopts); + /* sdcardfs super-block data in memory */ struct sdcardfs_sb_info { struct super_block *sb; diff --git a/fs/sdcardfs/super.c b/fs/sdcardfs/super.c index 0a465395aab7..edda32b68dc0 100644 --- a/fs/sdcardfs/super.c +++ b/fs/sdcardfs/super.c @@ -108,6 +108,50 @@ static int sdcardfs_remount_fs(struct super_block *sb, int *flags, char *options return err; } +/* + * @mnt: mount point we are remounting + * @sb: superblock we are remounting + * @flags: numeric mount options + * @options: mount options string + */ +static int sdcardfs_remount_fs2(struct vfsmount *mnt, struct super_block *sb, + int *flags, char *options) +{ + int err = 0; + + /* + * The VFS will take care of "ro" and "rw" flags among others. We + * can safely accept a few flags (RDONLY, MANDLOCK), and honor + * SILENT, but anything else left over is an error. + */ + if ((*flags & ~(MS_RDONLY | MS_MANDLOCK | MS_SILENT | MS_REMOUNT)) != 0) { + printk(KERN_ERR + "sdcardfs: remount flags 0x%x unsupported\n", *flags); + err = -EINVAL; + } + printk(KERN_INFO "Remount options were %s for vfsmnt %p.\n", options, mnt); + err = parse_options_remount(sb, options, *flags & ~MS_SILENT, mnt->data); + + + return err; +} + +static void* sdcardfs_clone_mnt_data(void *data) { + struct sdcardfs_vfsmount_options* opt = kmalloc(sizeof(struct sdcardfs_vfsmount_options), GFP_KERNEL); + struct sdcardfs_vfsmount_options* old = data; + if(!opt) return NULL; + opt->gid = old->gid; + opt->mask = old->mask; + return opt; +} + +static void sdcardfs_copy_mnt_data(void *data, void *newdata) { + struct sdcardfs_vfsmount_options* old = data; + struct sdcardfs_vfsmount_options* new = newdata; + old->gid = new->gid; + old->mask = new->mask; +} + /* * Called by iput() when the inode reference count reached zero * and the inode is not hashed anywhere. Used to clear anything @@ -191,19 +235,24 @@ static void sdcardfs_umount_begin(struct super_block *sb) lower_sb->s_op->umount_begin(lower_sb); } -static int sdcardfs_show_options(struct seq_file *m, struct dentry *root) +static int sdcardfs_show_options(struct vfsmount *mnt, struct seq_file *m, struct dentry *root) { struct sdcardfs_sb_info *sbi = SDCARDFS_SB(root->d_sb); struct sdcardfs_mount_options *opts = &sbi->options; + struct sdcardfs_vfsmount_options *vfsopts = mnt->data; if (opts->fs_low_uid != 0) - seq_printf(m, ",uid=%u", opts->fs_low_uid); + seq_printf(m, ",fsuid=%u", opts->fs_low_uid); if (opts->fs_low_gid != 0) - seq_printf(m, ",gid=%u", opts->fs_low_gid); - + seq_printf(m, ",fsgid=%u", opts->fs_low_gid); + if (vfsopts->gid != 0) + seq_printf(m, ",gid=%u", vfsopts->gid); if (opts->multiuser) seq_printf(m, ",multiuser"); - + if (vfsopts->mask) + seq_printf(m, ",mask=%u", vfsopts->mask); + if (opts->fs_user_id) + seq_printf(m, ",userid=%u", opts->fs_user_id); if (opts->reserved_mb != 0) seq_printf(m, ",reserved=%uMB", opts->reserved_mb); @@ -214,9 +263,12 @@ const struct super_operations sdcardfs_sops = { .put_super = sdcardfs_put_super, .statfs = sdcardfs_statfs, .remount_fs = sdcardfs_remount_fs, + .remount_fs2 = sdcardfs_remount_fs2, + .clone_mnt_data = sdcardfs_clone_mnt_data, + .copy_mnt_data = sdcardfs_copy_mnt_data, .evict_inode = sdcardfs_evict_inode, .umount_begin = sdcardfs_umount_begin, - .show_options = sdcardfs_show_options, + .show_options2 = sdcardfs_show_options, .alloc_inode = sdcardfs_alloc_inode, .destroy_inode = sdcardfs_destroy_inode, .drop_inode = generic_delete_inode,