diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/ext4.h | 9 | ||||
| -rw-r--r-- | fs/ext4/ioctl.c | 309 | ||||
| -rw-r--r-- | fs/ext4/resize.c | 19 | ||||
| -rw-r--r-- | fs/ext4/super.c | 4 |
4 files changed, 334 insertions, 7 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 714201fa9e6f..5c8de74f5b40 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1298,6 +1298,8 @@ extern void ext4_set_bits(void *bm, int cur, int len); /* Metadata checksum algorithm codes */ #define EXT4_CRC32C_CHKSUM 1 +#define EXT4_LABEL_MAX 16 + /* * Structure of the super block */ @@ -1347,7 +1349,7 @@ struct ext4_super_block { /*60*/ __le32 s_feature_incompat; /* incompatible feature set */ __le32 s_feature_ro_compat; /* readonly-compatible feature set */ /*68*/ __u8 s_uuid[16]; /* 128-bit uuid for volume */ -/*78*/ char s_volume_name[16]; /* volume name */ +/*78*/ char s_volume_name[EXT4_LABEL_MAX]; /* volume name */ /*88*/ char s_last_mounted[64] __nonstring; /* directory where last mounted */ /*C8*/ __le32 s_algorithm_usage_bitmap; /* For compression */ /* @@ -3094,6 +3096,9 @@ extern int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, ext4_fsblk_t n_blocks_count); extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count); +extern unsigned int ext4_list_backups(struct super_block *sb, + unsigned int *three, unsigned int *five, + unsigned int *seven); /* super.c */ extern struct buffer_head *ext4_sb_bread(struct super_block *sb, @@ -3108,6 +3113,8 @@ extern int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait); extern void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block); extern int ext4_seq_options_show(struct seq_file *seq, void *offset); extern int ext4_calculate_overhead(struct super_block *sb); +extern __le32 ext4_superblock_csum(struct super_block *sb, + struct ext4_super_block *es); extern void ext4_superblock_csum_set(struct super_block *sb); extern int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup); diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 798d9d828795..bbbedf27b71c 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -27,6 +27,248 @@ #include "fsmap.h" #include <trace/events/ext4.h> +typedef void ext4_update_sb_callback(struct ext4_super_block *es, + const void *arg); + +/* + * Superblock modification callback function for changing file system + * label + */ +static void ext4_sb_setlabel(struct ext4_super_block *es, const void *arg) +{ + /* Sanity check, this should never happen */ + BUILD_BUG_ON(sizeof(es->s_volume_name) < EXT4_LABEL_MAX); + + memcpy(es->s_volume_name, (char *)arg, EXT4_LABEL_MAX); +} + +static +int ext4_update_primary_sb(struct super_block *sb, handle_t *handle, + ext4_update_sb_callback func, + const void *arg) +{ + int err = 0; + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct buffer_head *bh = sbi->s_sbh; + struct ext4_super_block *es = sbi->s_es; + + trace_ext4_update_sb(sb, bh->b_blocknr, 1); + + BUFFER_TRACE(bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, sb, + bh, + EXT4_JTR_NONE); + if (err) + goto out_err; + + lock_buffer(bh); + func(es, arg); + ext4_superblock_csum_set(sb); + unlock_buffer(bh); + + if (buffer_write_io_error(bh) || !buffer_uptodate(bh)) { + ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to " + "superblock detected"); + clear_buffer_write_io_error(bh); + set_buffer_uptodate(bh); + } + + err = ext4_handle_dirty_metadata(handle, NULL, bh); + if (err) + goto out_err; + err = sync_dirty_buffer(bh); +out_err: + ext4_std_error(sb, err); + return err; +} + +/* + * Update one backup superblock in the group 'grp' using the callback + * function 'func' and argument 'arg'. If the handle is NULL the + * modification is not journalled. + * + * Returns: 0 when no modification was done (no superblock in the group) + * 1 when the modification was successful + * <0 on error + */ +static int ext4_update_backup_sb(struct super_block *sb, + handle_t *handle, ext4_group_t grp, + ext4_update_sb_callback func, const void *arg) +{ + int err = 0; + ext4_fsblk_t sb_block; + struct buffer_head *bh; + unsigned long offset = 0; + struct ext4_super_block *es; + + if (!ext4_bg_has_super(sb, grp)) + return 0; + + /* + * For the group 0 there is always 1k padding, so we have + * either adjust offset, or sb_block depending on blocksize + */ + if (grp == 0) { + sb_block = 1 * EXT4_MIN_BLOCK_SIZE; + offset = do_div(sb_block, sb->s_blocksize); + } else { + sb_block = ext4_group_first_block_no(sb, grp); + offset = 0; + } + + trace_ext4_update_sb(sb, sb_block, handle ? 1 : 0); + + bh = ext4_sb_bread(sb, sb_block, 0); + if (IS_ERR(bh)) + return PTR_ERR(bh); + + if (handle) { + BUFFER_TRACE(bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, sb, + bh, + EXT4_JTR_NONE); + if (err) + goto out_bh; + } + + es = (struct ext4_super_block *) (bh->b_data + offset); + lock_buffer(bh); + if (ext4_has_metadata_csum(sb) && + es->s_checksum != ext4_superblock_csum(sb, es)) { + ext4_msg(sb, KERN_ERR, "Invalid checksum for backup " + "superblock %llu\n", sb_block); + unlock_buffer(bh); + err = -EFSBADCRC; + goto out_bh; + } + func(es, arg); + if (ext4_has_metadata_csum(sb)) + es->s_checksum = ext4_superblock_csum(sb, es); + set_buffer_uptodate(bh); + unlock_buffer(bh); + + if (err) + goto out_bh; + + if (handle) { + err = ext4_handle_dirty_metadata(handle, NULL, bh); + if (err) + goto out_bh; + } else { + BUFFER_TRACE(bh, "marking dirty"); + mark_buffer_dirty(bh); + } + err = sync_dirty_buffer(bh); + +out_bh: + brelse(bh); + ext4_std_error(sb, err); + return (err) ? err : 1; +} + +/* + * Update primary and backup superblocks using the provided function + * func and argument arg. + * + * Only the primary superblock and at most two backup superblock + * modifications are journalled; the rest is modified without journal. + * This is safe because e2fsck will re-write them if there is a problem, + * and we're very unlikely to ever need more than two backups. + */ +static +int ext4_update_superblocks_fn(struct super_block *sb, + ext4_update_sb_callback func, + const void *arg) +{ + handle_t *handle; + ext4_group_t ngroups; + unsigned int three = 1; + unsigned int five = 5; + unsigned int seven = 7; + int err = 0, ret, i; + ext4_group_t grp, primary_grp; + struct ext4_sb_info *sbi = EXT4_SB(sb); + + /* + * We can't update superblocks while the online resize is running + */ + if (test_and_set_bit_lock(EXT4_FLAGS_RESIZING, + &sbi->s_ext4_flags)) { + ext4_msg(sb, KERN_ERR, "Can't modify superblock while" + "performing online resize"); + return -EBUSY; + } + + /* + * We're only going to update primary superblock and two + * backup superblocks in this transaction. + */ + handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 3); + if (IS_ERR(handle)) { + err = PTR_ERR(handle); + goto out; + } + + /* Update primary superblock */ + err = ext4_update_primary_sb(sb, handle, func, arg); + if (err) { + ext4_msg(sb, KERN_ERR, "Failed to update primary " + "superblock"); + goto out_journal; + } + + primary_grp = ext4_get_group_number(sb, sbi->s_sbh->b_blocknr); + ngroups = ext4_get_groups_count(sb); + + /* + * Update backup superblocks. We have to start from group 0 + * because it might not be where the primary superblock is + * if the fs is mounted with -o sb=<backup_sb_block> + */ + i = 0; + grp = 0; + while (grp < ngroups) { + /* Skip primary superblock */ + if (grp == primary_grp) + goto next_grp; + + ret = ext4_update_backup_sb(sb, handle, grp, func, arg); + if (ret < 0) { + /* Ignore bad checksum; try to update next sb */ + if (ret == -EFSBADCRC) + goto next_grp; + err = ret; + goto out_journal; + } + + i += ret; + if (handle && i > 1) { + /* + * We're only journalling primary superblock and + * two backup superblocks; the rest is not + * journalled. + */ + err = ext4_journal_stop(handle); + if (err) + goto out; + handle = NULL; + } +next_grp: + grp = ext4_list_backups(sb, &three, &five, &seven); + } + +out_journal: + if (handle) { + ret = ext4_journal_stop(handle); + if (ret && !err) + err = ret; + } +out: + clear_bit_unlock(EXT4_FLAGS_RESIZING, &sbi->s_ext4_flags); + smp_mb__after_atomic(); + return err ? err : 0; +} + /** * Swap memory between @a and @b for @len bytes. * @@ -847,6 +1089,64 @@ static int ext4_ioctl_checkpoint(struct file *filp, unsigned long arg) return err; } +static int ext4_ioctl_setlabel(struct file *filp, const char __user *user_label) +{ + size_t len; + int ret = 0; + char new_label[EXT4_LABEL_MAX + 1]; + struct super_block *sb = file_inode(filp)->i_sb; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + /* + * Copy the maximum length allowed for ext4 label with one more to + * find the required terminating null byte in order to test the + * label length. The on disk label doesn't need to be null terminated. + */ + if (copy_from_user(new_label, user_label, EXT4_LABEL_MAX + 1)) + return -EFAULT; + + len = strnlen(new_label, EXT4_LABEL_MAX + 1); + if (len > EXT4_LABEL_MAX) + return -EINVAL; + + /* + * Clear the buffer after the new label + */ + memset(new_label + len, 0, EXT4_LABEL_MAX - len); + + ret = mnt_want_write_file(filp); + if (ret) + return ret; + + ret = ext4_update_superblocks_fn(sb, ext4_sb_setlabel, new_label); + + mnt_drop_write_file(filp); + return ret; +} + +static int ext4_ioctl_getlabel(struct ext4_sb_info *sbi, char __user *user_label) +{ + char label[EXT4_LABEL_MAX + 1]; + + /* + * EXT4_LABEL_MAX must always be smaller than FSLABEL_MAX because + * FSLABEL_MAX must include terminating null byte, while s_volume_name + * does not have to. + */ + BUILD_BUG_ON(EXT4_LABEL_MAX >= FSLABEL_MAX); + + memset(label, 0, sizeof(label)); + lock_buffer(sbi->s_sbh); + strncpy(label, sbi->s_es->s_volume_name, EXT4_LABEL_MAX); + unlock_buffer(sbi->s_sbh); + + if (copy_to_user(user_label, label, sizeof(label))) + return -EFAULT; + return 0; +} + static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct inode *inode = file_inode(filp); @@ -1261,6 +1561,13 @@ resizefs_out: case EXT4_IOC_CHECKPOINT: return ext4_ioctl_checkpoint(filp, arg); + case FS_IOC_GETFSLABEL: + return ext4_ioctl_getlabel(EXT4_SB(sb), (void __user *)arg); + + case FS_IOC_SETFSLABEL: + return ext4_ioctl_setlabel(filp, + (const void __user *)arg); + default: return -ENOTTY; } @@ -1336,6 +1643,8 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case EXT4_IOC_GETSTATE: case EXT4_IOC_GET_ES_CACHE: case EXT4_IOC_CHECKPOINT: + case FS_IOC_GETFSLABEL: + case FS_IOC_SETFSLABEL: break; default: return -ENOIOCTLCMD; diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index b63cb88ccdae..ee8f02f406cb 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -717,12 +717,23 @@ out: * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... */ -static unsigned ext4_list_backups(struct super_block *sb, unsigned *three, - unsigned *five, unsigned *seven) +unsigned int ext4_list_backups(struct super_block *sb, unsigned int *three, + unsigned int *five, unsigned int *seven) { - unsigned *min = three; + struct ext4_super_block *es = EXT4_SB(sb)->s_es; + unsigned int *min = three; int mult = 3; - unsigned ret; + unsigned int ret; + + if (ext4_has_feature_sparse_super2(sb)) { + do { + if (*min > 2) + return UINT_MAX; + ret = le32_to_cpu(es->s_backup_bgs[*min - 1]); + *min += 1; + } while (!ret); + return ret; + } if (!ext4_has_feature_sparse_super(sb)) { ret = *min; diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 435f24787030..806ce0893322 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -279,8 +279,8 @@ static int ext4_verify_csum_type(struct super_block *sb, return es->s_checksum_type == EXT4_CRC32C_CHKSUM; } -static __le32 ext4_superblock_csum(struct super_block *sb, - struct ext4_super_block *es) +__le32 ext4_superblock_csum(struct super_block *sb, + struct ext4_super_block *es) { struct ext4_sb_info *sbi = EXT4_SB(sb); int offset = offsetof(struct ext4_super_block, s_checksum); |