diff options
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/Makefile | 10 | ||||
| -rw-r--r-- | fs/ext4/fsmap.c | 722 | ||||
| -rw-r--r-- | fs/ext4/fsmap.h | 69 | ||||
| -rw-r--r-- | fs/ext4/ioctl.c | 90 | ||||
| -rw-r--r-- | fs/ext4/mballoc.c | 49 | ||||
| -rw-r--r-- | fs/ext4/mballoc.h | 17 | ||||
| -rw-r--r-- | fs/ext4/super.c | 1 |
7 files changed, 953 insertions, 5 deletions
diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile index 354103f3490c..d9beca1653c5 100644 --- a/fs/ext4/Makefile +++ b/fs/ext4/Makefile @@ -4,11 +4,11 @@ obj-$(CONFIG_EXT4_FS) += ext4.o -ext4-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o page-io.o \ - ioctl.o namei.o super.o symlink.o hash.o resize.o extents.o \ - ext4_jbd2.o migrate.o mballoc.o block_validity.o move_extent.o \ - mmp.o indirect.o extents_status.o xattr.o xattr_user.o \ - xattr_trusted.o inline.o readpage.o sysfs.o +ext4-y := balloc.o bitmap.o block_validity.o dir.o ext4_jbd2.o extents.o \ + extents_status.o file.o fsmap.o fsync.o hash.o ialloc.o \ + indirect.o inline.o inode.o ioctl.o mballoc.o migrate.o \ + mmp.o move_extent.o namei.o page-io.o readpage.o resize.o \ + super.o symlink.o sysfs.o xattr.o xattr_trusted.o xattr_user.o ext4-$(CONFIG_EXT4_FS_POSIX_ACL) += acl.o ext4-$(CONFIG_EXT4_FS_SECURITY) += xattr_security.o diff --git a/fs/ext4/fsmap.c b/fs/ext4/fsmap.c new file mode 100644 index 000000000000..b19436098837 --- /dev/null +++ b/fs/ext4/fsmap.c @@ -0,0 +1,722 @@ +/* + * Copyright (C) 2017 Oracle. All Rights Reserved. + * + * Author: Darrick J. Wong <darrick.wong@oracle.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#include "ext4.h" +#include <linux/fsmap.h> +#include "fsmap.h" +#include "mballoc.h" +#include <linux/sort.h> +#include <linux/list_sort.h> +#include <trace/events/ext4.h> + +/* Convert an ext4_fsmap to an fsmap. */ +void ext4_fsmap_from_internal(struct super_block *sb, struct fsmap *dest, + struct ext4_fsmap *src) +{ + dest->fmr_device = src->fmr_device; + dest->fmr_flags = src->fmr_flags; + dest->fmr_physical = src->fmr_physical << sb->s_blocksize_bits; + dest->fmr_owner = src->fmr_owner; + dest->fmr_offset = 0; + dest->fmr_length = src->fmr_length << sb->s_blocksize_bits; + dest->fmr_reserved[0] = 0; + dest->fmr_reserved[1] = 0; + dest->fmr_reserved[2] = 0; +} + +/* Convert an fsmap to an ext4_fsmap. */ +void ext4_fsmap_to_internal(struct super_block *sb, struct ext4_fsmap *dest, + struct fsmap *src) +{ + dest->fmr_device = src->fmr_device; + dest->fmr_flags = src->fmr_flags; + dest->fmr_physical = src->fmr_physical >> sb->s_blocksize_bits; + dest->fmr_owner = src->fmr_owner; + dest->fmr_length = src->fmr_length >> sb->s_blocksize_bits; +} + +/* getfsmap query state */ +struct ext4_getfsmap_info { + struct ext4_fsmap_head *gfi_head; + ext4_fsmap_format_t gfi_formatter; /* formatting fn */ + void *gfi_format_arg;/* format buffer */ + ext4_fsblk_t gfi_next_fsblk; /* next fsblock we expect */ + u32 gfi_dev; /* device id */ + ext4_group_t gfi_agno; /* bg number, if applicable */ + struct ext4_fsmap gfi_low; /* low rmap key */ + struct ext4_fsmap gfi_high; /* high rmap key */ + struct ext4_fsmap gfi_lastfree; /* free ext at end of last bg */ + struct list_head gfi_meta_list; /* fixed metadata list */ + bool gfi_last; /* last extent? */ +}; + +/* Associate a device with a getfsmap handler. */ +struct ext4_getfsmap_dev { + int (*gfd_fn)(struct super_block *sb, + struct ext4_fsmap *keys, + struct ext4_getfsmap_info *info); + u32 gfd_dev; +}; + +/* Compare two getfsmap device handlers. */ +static int ext4_getfsmap_dev_compare(const void *p1, const void *p2) +{ + const struct ext4_getfsmap_dev *d1 = p1; + const struct ext4_getfsmap_dev *d2 = p2; + + return d1->gfd_dev - d2->gfd_dev; +} + +/* Compare a record against our starting point */ +static bool ext4_getfsmap_rec_before_low_key(struct ext4_getfsmap_info *info, + struct ext4_fsmap *rec) +{ + return rec->fmr_physical < info->gfi_low.fmr_physical; +} + +/* + * Format a reverse mapping for getfsmap, having translated rm_startblock + * into the appropriate daddr units. + */ +static int ext4_getfsmap_helper(struct super_block *sb, + struct ext4_getfsmap_info *info, + struct ext4_fsmap *rec) +{ + struct ext4_fsmap fmr; + struct ext4_sb_info *sbi = EXT4_SB(sb); + ext4_fsblk_t rec_fsblk = rec->fmr_physical; + ext4_group_t agno; + ext4_grpblk_t cno; + int error; + + if (fatal_signal_pending(current)) + return -EINTR; + + /* + * Filter out records that start before our startpoint, if the + * caller requested that. + */ + if (ext4_getfsmap_rec_before_low_key(info, rec)) { + rec_fsblk += rec->fmr_length; + if (info->gfi_next_fsblk < rec_fsblk) + info->gfi_next_fsblk = rec_fsblk; + return EXT4_QUERY_RANGE_CONTINUE; + } + + /* Are we just counting mappings? */ + if (info->gfi_head->fmh_count == 0) { + if (rec_fsblk > info->gfi_next_fsblk) + info->gfi_head->fmh_entries++; + + if (info->gfi_last) + return EXT4_QUERY_RANGE_CONTINUE; + + info->gfi_head->fmh_entries++; + + rec_fsblk += rec->fmr_length; + if (info->gfi_next_fsblk < rec_fsblk) + info->gfi_next_fsblk = rec_fsblk; + return EXT4_QUERY_RANGE_CONTINUE; + } + + /* + * If the record starts past the last physical block we saw, + * then we've found a gap. Report the gap as being owned by + * whatever the caller specified is the missing owner. + */ + if (rec_fsblk > info->gfi_next_fsblk) { + if (info->gfi_head->fmh_entries >= info->gfi_head->fmh_count) + return EXT4_QUERY_RANGE_ABORT; + + ext4_get_group_no_and_offset(sb, info->gfi_next_fsblk, + &agno, &cno); + trace_ext4_fsmap_mapping(sb, info->gfi_dev, agno, + EXT4_C2B(sbi, cno), + rec_fsblk - info->gfi_next_fsblk, + EXT4_FMR_OWN_UNKNOWN); + + fmr.fmr_device = info->gfi_dev; + fmr.fmr_physical = info->gfi_next_fsblk; + fmr.fmr_owner = EXT4_FMR_OWN_UNKNOWN; + fmr.fmr_length = rec_fsblk - info->gfi_next_fsblk; + fmr.fmr_flags = FMR_OF_SPECIAL_OWNER; + error = info->gfi_formatter(&fmr, info->gfi_format_arg); + if (error) + return error; + info->gfi_head->fmh_entries++; + } + + if (info->gfi_last) + goto out; + + /* Fill out the extent we found */ + if (info->gfi_head->fmh_entries >= info->gfi_head->fmh_count) + return EXT4_QUERY_RANGE_ABORT; + + ext4_get_group_no_and_offset(sb, rec_fsblk, &agno, &cno); + trace_ext4_fsmap_mapping(sb, info->gfi_dev, agno, EXT4_C2B(sbi, cno), + rec->fmr_length, rec->fmr_owner); + + fmr.fmr_device = info->gfi_dev; + fmr.fmr_physical = rec_fsblk; + fmr.fmr_owner = rec->fmr_owner; + fmr.fmr_flags = FMR_OF_SPECIAL_OWNER; + fmr.fmr_length = rec->fmr_length; + error = info->gfi_formatter(&fmr, info->gfi_format_arg); + if (error) + return error; + info->gfi_head->fmh_entries++; + +out: + rec_fsblk += rec->fmr_length; + if (info->gfi_next_fsblk < rec_fsblk) + info->gfi_next_fsblk = rec_fsblk; + return EXT4_QUERY_RANGE_CONTINUE; +} + +static inline ext4_fsblk_t ext4_fsmap_next_pblk(struct ext4_fsmap *fmr) +{ + return fmr->fmr_physical + fmr->fmr_length; +} + +/* Transform a blockgroup's free record into a fsmap */ +static int ext4_getfsmap_datadev_helper(struct super_block *sb, + ext4_group_t agno, ext4_grpblk_t start, + ext4_grpblk_t len, void *priv) +{ + struct ext4_fsmap irec; + struct ext4_getfsmap_info *info = priv; + struct ext4_fsmap *p; + struct ext4_fsmap *tmp; + struct ext4_sb_info *sbi = EXT4_SB(sb); + ext4_fsblk_t fsb; + ext4_fsblk_t fslen; + int error; + + fsb = (EXT4_C2B(sbi, start) + ext4_group_first_block_no(sb, agno)); + fslen = EXT4_C2B(sbi, len); + + /* If the retained free extent record is set... */ + if (info->gfi_lastfree.fmr_owner) { + /* ...and abuts this one, lengthen it and return. */ + if (ext4_fsmap_next_pblk(&info->gfi_lastfree) == fsb) { + info->gfi_lastfree.fmr_length += fslen; + return 0; + } + + /* + * There's a gap between the two free extents; emit the + * retained extent prior to merging the meta_list. + */ + error = ext4_getfsmap_helper(sb, info, &info->gfi_lastfree); + if (error) + return error; + info->gfi_lastfree.fmr_owner = 0; + } + + /* Merge in any relevant extents from the meta_list */ + list_for_each_entry_safe(p, tmp, &info->gfi_meta_list, fmr_list) { + if (p->fmr_physical + p->fmr_length <= info->gfi_next_fsblk) { + list_del(&p->fmr_list); + kfree(p); + } else if (p->fmr_physical < fsb) { + error = ext4_getfsmap_helper(sb, info, p); + if (error) + return error; + + list_del(&p->fmr_list); + kfree(p); + } + } + + irec.fmr_device = 0; + irec.fmr_physical = fsb; + irec.fmr_length = fslen; + irec.fmr_owner = EXT4_FMR_OWN_FREE; + irec.fmr_flags = 0; + + /* If this is a free extent at the end of a bg, buffer it. */ + if (ext4_fsmap_next_pblk(&irec) == + ext4_group_first_block_no(sb, agno + 1)) { + info->gfi_lastfree = irec; + return 0; + } + + /* Otherwise, emit it */ + return ext4_getfsmap_helper(sb, info, &irec); +} + +/* Execute a getfsmap query against the log device. */ +static int ext4_getfsmap_logdev(struct super_block *sb, struct ext4_fsmap *keys, + struct ext4_getfsmap_info *info) +{ + journal_t *journal = EXT4_SB(sb)->s_journal; + struct ext4_fsmap irec; + + /* Set up search keys */ + info->gfi_low = keys[0]; + info->gfi_low.fmr_length = 0; + + memset(&info->gfi_high, 0xFF, sizeof(info->gfi_high)); + + trace_ext4_fsmap_low_key(sb, info->gfi_dev, 0, + info->gfi_low.fmr_physical, + info->gfi_low.fmr_length, + info->gfi_low.fmr_owner); + + trace_ext4_fsmap_high_key(sb, info->gfi_dev, 0, + info->gfi_high.fmr_physical, + info->gfi_high.fmr_length, + info->gfi_high.fmr_owner); + + if (keys[0].fmr_physical > 0) + return 0; + + /* Fabricate an rmap entry for the external log device. */ + irec.fmr_physical = journal->j_blk_offset; + irec.fmr_length = journal->j_maxlen; + irec.fmr_owner = EXT4_FMR_OWN_LOG; + irec.fmr_flags = 0; + + return ext4_getfsmap_helper(sb, info, &irec); +} + +/* Helper to fill out an ext4_fsmap. */ +static inline int ext4_getfsmap_fill(struct list_head *meta_list, + ext4_fsblk_t fsb, ext4_fsblk_t len, + uint64_t owner) +{ + struct ext4_fsmap *fsm; + + fsm = kmalloc(sizeof(*fsm), GFP_NOFS); + if (!fsm) + return -ENOMEM; + fsm->fmr_device = 0; + fsm->fmr_flags = 0; + fsm->fmr_physical = fsb; + fsm->fmr_owner = owner; + fsm->fmr_length = len; + list_add_tail(&fsm->fmr_list, meta_list); + + return 0; +} + +/* + * This function returns the number of file system metadata blocks at + * the beginning of a block group, including the reserved gdt blocks. + */ +static unsigned int ext4_getfsmap_find_sb(struct super_block *sb, + ext4_group_t agno, + struct list_head *meta_list) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + ext4_fsblk_t fsb = ext4_group_first_block_no(sb, agno); + ext4_fsblk_t len; + unsigned long first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); + unsigned long metagroup = agno / EXT4_DESC_PER_BLOCK(sb); + int error; + + /* Record the superblock. */ + if (ext4_bg_has_super(sb, agno)) { + error = ext4_getfsmap_fill(meta_list, fsb, 1, EXT4_FMR_OWN_FS); + if (error) + return error; + fsb++; + } + + /* Record the group descriptors. */ + len = ext4_bg_num_gdb(sb, agno); + if (!len) + return 0; + error = ext4_getfsmap_fill(meta_list, fsb, len, + EXT4_FMR_OWN_GDT); + if (error) + return error; + fsb += len; + + /* Reserved GDT blocks */ + if (!ext4_has_feature_meta_bg(sb) || metagroup < first_meta_bg) { + len = le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks); + error = ext4_getfsmap_fill(meta_list, fsb, len, + EXT4_FMR_OWN_RESV_GDT); + if (error) + return error; + } + + return 0; +} + +/* Compare two fsmap items. */ +static int ext4_getfsmap_compare(void *priv, + struct list_head *a, + struct list_head *b) +{ + struct ext4_fsmap *fa; + struct ext4_fsmap *fb; + + fa = container_of(a, struct ext4_fsmap, fmr_list); + fb = container_of(b, struct ext4_fsmap, fmr_list); + if (fa->fmr_physical < fb->fmr_physical) + return -1; + else if (fa->fmr_physical > fb->fmr_physical) + return 1; + return 0; +} + +/* Merge adjacent extents of fixed metadata. */ +static void ext4_getfsmap_merge_fixed_metadata(struct list_head *meta_list) +{ + struct ext4_fsmap *p; + struct ext4_fsmap *prev = NULL; + struct ext4_fsmap *tmp; + + list_for_each_entry_safe(p, tmp, meta_list, fmr_list) { + if (!prev) { + prev = p; + continue; + } + + if (prev->fmr_owner == p->fmr_owner && + prev->fmr_physical + prev->fmr_length == p->fmr_physical) { + prev->fmr_length += p->fmr_length; + list_del(&p->fmr_list); + kfree(p); + } else + prev = p; + } +} + +/* Free a list of fixed metadata. */ +static void ext4_getfsmap_free_fixed_metadata(struct list_head *meta_list) +{ + struct ext4_fsmap *p; + struct ext4_fsmap *tmp; + + list_for_each_entry_safe(p, tmp, meta_list, fmr_list) { + list_del(&p->fmr_list); + kfree(p); + } +} + +/* Find all the fixed metadata in the filesystem. */ +int ext4_getfsmap_find_fixed_metadata(struct super_block *sb, + struct list_head *meta_list) +{ + struct ext4_group_desc *gdp; + ext4_group_t agno; + int error; + + INIT_LIST_HEAD(meta_list); + + /* Collect everything. */ + for (agno = 0; agno < EXT4_SB(sb)->s_groups_count; agno++) { + gdp = ext4_get_group_desc(sb, agno, NULL); + if (!gdp) { + error = -EFSCORRUPTED; + goto err; + } + + /* Superblock & GDT */ + error = ext4_getfsmap_find_sb(sb, agno, meta_list); + if (error) + goto err; + + /* Block bitmap */ + error = ext4_getfsmap_fill(meta_list, + ext4_block_bitmap(sb, gdp), 1, + EXT4_FMR_OWN_BLKBM); + if (error) + goto err; + + /* Inode bitmap */ + error = ext4_getfsmap_fill(meta_list, + ext4_inode_bitmap(sb, gdp), 1, + EXT4_FMR_OWN_INOBM); + if (error) + goto err; + + /* Inodes */ + error = ext4_getfsmap_fill(meta_list, + ext4_inode_table(sb, gdp), + EXT4_SB(sb)->s_itb_per_group, + EXT4_FMR_OWN_INODES); + if (error) + goto err; + } + + /* Sort the list */ + list_sort(NULL, meta_list, ext4_getfsmap_compare); + + /* Merge adjacent extents */ + ext4_getfsmap_merge_fixed_metadata(meta_list); + + return 0; +err: + ext4_getfsmap_free_fixed_metadata(meta_list); + return error; +} + +/* Execute a getfsmap query against the buddy bitmaps */ +static int ext4_getfsmap_datadev(struct super_block *sb, + struct ext4_fsmap *keys, + struct ext4_getfsmap_info *info) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + ext4_fsblk_t start_fsb; + ext4_fsblk_t end_fsb; + ext4_fsblk_t eofs; + ext4_group_t start_ag; + ext4_group_t end_ag; + ext4_grpblk_t first_cluster; + ext4_grpblk_t last_cluster; + int error = 0; + + eofs = ext4_blocks_count(sbi->s_es); + if (keys[0].fmr_physical >= eofs) + return 0; + if (keys[1].fmr_physical >= eofs) + keys[1].fmr_physical = eofs - 1; + start_fsb = keys[0].fmr_physical; + end_fsb = keys[1].fmr_physical; + + /* Determine first and last group to examine based on start and end */ + ext4_get_group_no_and_offset(sb, start_fsb, &start_ag, &first_cluster); + ext4_get_group_no_and_offset(sb, end_fsb, &end_ag, &last_cluster); + + /* + * Convert the fsmap low/high keys to bg based keys. Initialize + * low to the fsmap low key and max out the high key to the end + * of the bg. + */ + info->gfi_low = keys[0]; + info->gfi_low.fmr_physical = EXT4_C2B(sbi, first_cluster); + info->gfi_low.fmr_length = 0; + + memset(&info->gfi_high, 0xFF, sizeof(info->gfi_high)); + + /* Assemble a list of all the fixed-location metadata. */ + error = ext4_getfsmap_find_fixed_metadata(sb, &info->gfi_meta_list); + if (error) + goto err; + + /* Query each bg */ + for (info->gfi_agno = start_ag; + info->gfi_agno <= end_ag; + info->gfi_agno++) { + /* + * Set the bg high key from the fsmap high key if this + * is the last bg that we're querying. + */ + if (info->gfi_agno == end_ag) { + info->gfi_high = keys[1]; + info->gfi_high.fmr_physical = EXT4_C2B(sbi, + last_cluster); + info->gfi_high.fmr_length = 0; + } + + trace_ext4_fsmap_low_key(sb, info->gfi_dev, info->gfi_agno, + info->gfi_low.fmr_physical, + info->gfi_low.fmr_length, + info->gfi_low.fmr_owner); + + trace_ext4_fsmap_high_key(sb, info->gfi_dev, info->gfi_agno, + info->gfi_high.fmr_physical, + info->gfi_high.fmr_length, + info->gfi_high.fmr_owner); + + error = ext4_mballoc_query_range(sb, info->gfi_agno, + EXT4_B2C(sbi, info->gfi_low.fmr_physical), + EXT4_B2C(sbi, info->gfi_high.fmr_physical), + ext4_getfsmap_datadev_helper, info); + if (error) + goto err; + + /* + * Set the bg low key to the start of the bg prior to + * moving on to the next bg. + */ + if (info->gfi_agno == start_ag) + memset(&info->gfi_low, 0, sizeof(info->gfi_low)); + } + + /* Do we have a retained free extent? */ + if (info->gfi_lastfree.fmr_owner) { + error = ext4_getfsmap_helper(sb, info, &info->gfi_lastfree); + if (error) + goto err; + } + + /* Report any gaps at the end of the bg */ + info->gfi_last = true; + error = ext4_getfsmap_datadev_helper(sb, end_ag, last_cluster, 0, info); + if (error) + goto err; + +err: + ext4_getfsmap_free_fixed_metadata(&info->gfi_meta_list); + return error; +} + +/* Do we recognize the device? */ +static bool ext4_getfsmap_is_valid_device(struct super_block *sb, + struct ext4_fsmap *fm) +{ + if (fm->fmr_device == 0 || fm->fmr_device == UINT_MAX || + fm->fmr_device == new_encode_dev(sb->s_bdev->bd_dev)) + return true; + if (EXT4_SB(sb)->journal_bdev && + fm->fmr_device == new_encode_dev(EXT4_SB(sb)->journal_bdev->bd_dev)) + return true; + return false; +} + +/* Ensure that the low key is less than the high key. */ +static bool ext4_getfsmap_check_keys(struct ext4_fsmap *low_key, + struct ext4_fsmap *high_key) +{ + if (low_key->fmr_device > high_key->fmr_device) + return false; + if (low_key->fmr_device < high_key->fmr_device) + return true; + + if (low_key->fmr_physical > high_key->fmr_physical) + return false; + if (low_key->fmr_physical < high_key->fmr_physical) + return true; + + if (low_key->fmr_owner > high_key->fmr_owner) + return false; + if (low_key->fmr_owner < high_key->fmr_owner) + return true; + + return false; +} + +#define EXT4_GETFSMAP_DEVS 2 +/* + * Get filesystem's extents as described in head, and format for + * output. Calls formatter to fill the user's buffer until all + * extents are mapped, until the passed-in head->fmh_count slots have + * been filled, or until the formatter short-circuits the loop, if it + * is tracking filled-in extents on its own. + * + * Key to Confusion + * ---------------- + * There are multiple levels of keys and counters at work here: + * _fsmap_head.fmh_keys -- low and high fsmap keys passed in; + * these reflect fs-wide block addrs. + * dkeys -- fmh_keys used to query each device; + * these are fmh_keys but w/ the low key + * bumped up by fmr_length. + * _getfsmap_info.gfi_next_fsblk-- next fs block we expect to see; this + * is how we detect gaps in the fsmap + * records and report them. + * _getfsmap_info.gfi_low/high -- per-bg low/high keys computed from + * dkeys; used to query the free space. + */ +int ext4_getfsmap(struct super_block *sb, struct ext4_fsmap_head *head, + ext4_fsmap_format_t formatter, void *arg) +{ + struct ext4_fsmap dkeys[2]; /* per-dev keys */ + struct ext4_getfsmap_dev handlers[EXT4_GETFSMAP_DEVS]; + struct ext4_getfsmap_info info = {0}; + int i; + int error = 0; + + if (head->fmh_iflags & ~FMH_IF_VALID) + return -EINVAL; + if (!ext4_getfsmap_is_valid_device(sb, &head->fmh_keys[0]) || + !ext4_getfsmap_is_valid_device(sb, &head->fmh_keys[1])) + return -EINVAL; + + head->fmh_entries = 0; + + /* Set up our device handlers. */ + memset(handlers, 0, sizeof(handlers)); + handlers[0].gfd_dev = new_encode_dev(sb->s_bdev->bd_dev); + handlers[0].gfd_fn = ext4_getfsmap_datadev; + if (EXT4_SB(sb)->journal_bdev) { + handlers[1].gfd_dev = new_encode_dev( + EXT4_SB(sb)->journal_bdev->bd_dev); + handlers[1].gfd_fn = ext4_getfsmap_logdev; + } + + sort(handlers, EXT4_GETFSMAP_DEVS, sizeof(struct ext4_getfsmap_dev), + ext4_getfsmap_dev_compare, NULL); + + /* + * To continue where we left off, we allow userspace to use the + * last mapping from a previous call as the low key of the next. + * This is identified by a non-zero length in the low key. We + * have to increment the low key in this scenario to ensure we + * don't return the same mapping again, and instead return the + * very next mapping. + * + * Bump the physical offset as there can be no other mapping for + * the same physical block range. + */ + dkeys[0] = head->fmh_keys[0]; + dkeys[0].fmr_physical += dkeys[0].fmr_length; + dkeys[0].fmr_owner = 0; + dkeys[0].fmr_length = 0; + memset(&dkeys[1], 0xFF, sizeof(struct ext4_fsmap)); + + if (!ext4_getfsmap_check_keys(dkeys, &head->fmh_keys[1])) + return -EINVAL; + + info.gfi_next_fsblk = head->fmh_keys[0].fmr_physical + + head->fmh_keys[0].fmr_length; + info.gfi_formatter = formatter; + info.gfi_format_arg = arg; + info.gfi_head = head; + + /* For each device we support... */ + for (i = 0; i < EXT4_GETFSMAP_DEVS; i++) { + /* Is this device within the range the user asked for? */ + if (!handlers[i].gfd_fn) + continue; + if (head->fmh_keys[0].fmr_device > handlers[i].gfd_dev) + continue; + if (head->fmh_keys[1].fmr_device < handlers[i].gfd_dev) + break; + + /* + * If this device number matches the high key, we have + * to pass the high key to the handler to limit the + * query results. If the device number exceeds the + * low key, zero out the low key so that we get + * everything from the beginning. + */ + if (handlers[i].gfd_dev == head->fmh_keys[1].fmr_device) + dkeys[1] = head->fmh_keys[1]; + if (handlers[i].gfd_dev > head->fmh_keys[0].fmr_device) + memset(&dkeys[0], 0, sizeof(struct ext4_fsmap)); + + info.gfi_dev = handlers[i].gfd_dev; + info.gfi_last = false; + info.gfi_agno = -1; + error = handlers[i].gfd_fn(sb, dkeys, &info); + if (error) + break; + info.gfi_next_fsblk = 0; + } + + head->fmh_oflags = FMH_OF_DEV_T; + return error; +} diff --git a/fs/ext4/fsmap.h b/fs/ext4/fsmap.h new file mode 100644 index 000000000000..9a2cd367cc66 --- /dev/null +++ b/fs/ext4/fsmap.h @@ -0,0 +1,69 @@ +/* + * Copyright (C) 2017 Oracle. All Rights Reserved. + * + * Author: Darrick J. Wong <darrick.wong@oracle.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#ifndef __EXT4_FSMAP_H__ +#define __EXT4_FSMAP_H__ + +struct fsmap; + +/* internal fsmap representation */ +struct ext4_fsmap { + struct list_head fmr_list; + dev_t fmr_device; /* device id */ + uint32_t fmr_flags; /* mapping flags */ + uint64_t fmr_physical; /* device offset of segment */ + uint64_t fmr_owner; /* owner id */ + uint64_t fmr_length; /* length of segment, blocks */ +}; + +struct ext4_fsmap_head { + uint32_t fmh_iflags; /* control flags */ + uint32_t fmh_oflags; /* output flags */ + unsigned int fmh_count; /* # of entries in array incl. input */ + unsigned int fmh_entries; /* # of entries filled in (output). */ + + struct ext4_fsmap fmh_keys[2]; /* low and high keys */ +}; + +void ext4_fsmap_from_internal(struct super_block *sb, struct fsmap *dest, + struct ext4_fsmap *src); +void ext4_fsmap_to_internal(struct super_block *sb, struct ext4_fsmap *dest, + struct fsmap *src); + +/* fsmap to userspace formatter - copy to user & advance pointer */ +typedef int (*ext4_fsmap_format_t)(struct ext4_fsmap *, void *); + +int ext4_getfsmap(struct super_block *sb, struct ext4_fsmap_head *head, + ext4_fsmap_format_t formatter, void *arg); + +#define EXT4_QUERY_RANGE_ABORT 1 +#define EXT4_QUERY_RANGE_CONTINUE 0 + +/* fmr_owner special values for FS_IOC_GETFSMAP; some share w/ XFS */ +#define EXT4_FMR_OWN_FREE FMR_OWN_FREE /* free space */ +#define EXT4_FMR_OWN_UNKNOWN FMR_OWN_UNKNOWN /* unknown owner */ +#define EXT4_FMR_OWN_FS FMR_OWNER('X', 1) /* static fs metadata */ +#define EXT4_FMR_OWN_LOG FMR_OWNER('X', 2) /* journalling log */ +#define EXT4_FMR_OWN_INODES FMR_OWNER('X', 5) /* inodes */ +#define EXT4_FMR_OWN_GDT FMR_OWNER('f', 1) /* group descriptors */ +#define EXT4_FMR_OWN_RESV_GDT FMR_OWNER('f', 2) /* reserved gdt blocks */ +#define EXT4_FMR_OWN_BLKBM FMR_OWNER('f', 3) /* inode bitmap */ +#define EXT4_FMR_OWN_INOBM FMR_OWNER('f', 4) /* block bitmap */ + +#endif /* __EXT4_FSMAP_H__ */ diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index a4273ddb9922..dfcb815275f1 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -19,6 +19,9 @@ #include <linux/delay.h> #include "ext4_jbd2.h" #include "ext4.h" +#include <linux/fsmap.h> +#include "fsmap.h" +#include <trace/events/ext4.h> /** * Swap memory between @a and @b for @len bytes. @@ -489,6 +492,90 @@ int ext4_shutdown(struct super_block *sb, unsigned long arg) return 0; } +struct getfsmap_info { + struct super_block *gi_sb; + struct fsmap_head __user *gi_data; + unsigned int gi_idx; + __u32 gi_last_flags; +}; + +static int ext4_getfsmap_format(struct ext4_fsmap *xfm, void *priv) +{ + struct getfsmap_info *info = priv; + struct fsmap fm; + + trace_ext4_getfsmap_mapping(info->gi_sb, xfm); + + info->gi_last_flags = xfm->fmr_flags; + ext4_fsmap_from_internal(info->gi_sb, &fm, xfm); + if (copy_to_user(&info->gi_data->fmh_recs[info->gi_idx++], &fm, + sizeof(struct fsmap))) + return -EFAULT; + + return 0; +} + +static int ext4_ioc_getfsmap(struct super_block *sb, + struct fsmap_head __user *arg) +{ + struct getfsmap_info info = {0}; + struct ext4_fsmap_head xhead = {0}; + struct fsmap_head head; + bool aborted = false; + int error; + + if (copy_from_user(&head, arg, sizeof(struct fsmap_head))) + return -EFAULT; + if (memchr_inv(head.fmh_reserved, 0, sizeof(head.fmh_reserved)) || + memchr_inv(head.fmh_keys[0].fmr_reserved, 0, + sizeof(head.fmh_keys[0].fmr_reserved)) || + memchr_inv(head.fmh_keys[1].fmr_reserved, 0, + sizeof(head.fmh_keys[1].fmr_reserved))) + return -EINVAL; + /* + * ext4 doesn't report file extents at all, so the only valid + * file offsets are the magic ones (all zeroes or all ones). + */ + if (head.fmh_keys[0].fmr_offset || + (head.fmh_keys[1].fmr_offset != 0 && + head.fmh_keys[1].fmr_offset != -1ULL)) + return -EINVAL; + + xhead.fmh_iflags = head.fmh_iflags; + xhead.fmh_count = head.fmh_count; + ext4_fsmap_to_internal(sb, &xhead.fmh_keys[0], &head.fmh_keys[0]); + ext4_fsmap_to_internal(sb, &xhead.fmh_keys[1], &head.fmh_keys[1]); + + trace_ext4_getfsmap_low_key(sb, &xhead.fmh_keys[0]); + trace_ext4_getfsmap_high_key(sb, &xhead.fmh_keys[1]); + + info.gi_sb = sb; + info.gi_data = arg; + error = ext4_getfsmap(sb, &xhead, ext4_getfsmap_format, &info); + if (error == EXT4_QUERY_RANGE_ABORT) { + error = 0; + aborted = true; + } else if (error) + return error; + + /* If we didn't abort, set the "last" flag in the last fmx */ + if (!aborted && info.gi_idx) { + info.gi_last_flags |= FMR_OF_LAST; + if (copy_to_user(&info.gi_data->fmh_recs[info.gi_idx - 1].fmr_flags, + &info.gi_last_flags, + sizeof(info.gi_last_flags))) + return -EFAULT; + } + + /* copy back header */ + head.fmh_entries = xhead.fmh_entries; + head.fmh_oflags = xhead.fmh_oflags; + if (copy_to_user(arg, &head, sizeof(struct fsmap_head))) + return -EFAULT; + + return 0; +} + long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct inode *inode = file_inode(filp); @@ -499,6 +586,8 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) ext4_debug("cmd = %u, arg = %lu\n", cmd, arg); switch (cmd) { + case FS_IOC_GETFSMAP: + return ext4_ioc_getfsmap(sb, (void __user *)arg); case EXT4_IOC_GETFLAGS: ext4_get_inode_flags(ei); flags = ei->i_flags & EXT4_FL_USER_VISIBLE; @@ -1009,6 +1098,7 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case EXT4_IOC_GET_ENCRYPTION_PWSALT: case EXT4_IOC_GET_ENCRYPTION_POLICY: case EXT4_IOC_SHUTDOWN: + case FS_IOC_GETFSMAP: break; default: return -ENOIOCTLCMD; diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index dbe51301c2bb..36de58a37653 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -5277,3 +5277,52 @@ out: range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits; return ret; } + +/* Iterate all the free extents in the group. */ +int +ext4_mballoc_query_range( + struct super_block *sb, + ext4_group_t group, + ext4_grpblk_t start, + ext4_grpblk_t end, + ext4_mballoc_query_range_fn formatter, + void *priv) +{ + void *bitmap; + ext4_grpblk_t next; + struct ext4_buddy e4b; + int error; + + error = ext4_mb_load_buddy(sb, group, &e4b); + if (error) + return error; + bitmap = e4b.bd_bitmap; + + ext4_lock_group(sb, group); + + start = (e4b.bd_info->bb_first_free > start) ? + e4b.bd_info->bb_first_free : start; + if (end >= EXT4_CLUSTERS_PER_GROUP(sb)) + end = EXT4_CLUSTERS_PER_GROUP(sb) - 1; + + while (start <= end) { + start = mb_find_next_zero_bit(bitmap, end + 1, start); + if (start > end) + break; + next = mb_find_next_bit(bitmap, end + 1, start); + + ext4_unlock_group(sb, group); + error = formatter(sb, group, start, next - start, priv); + if (error) + goto out_unload; + ext4_lock_group(sb, group); + + start = next + 1; + } + + ext4_unlock_group(sb, group); +out_unload: + ext4_mb_unload_buddy(&e4b); + + return error; +} diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h index 1aba469f8220..2bed62084a8c 100644 --- a/fs/ext4/mballoc.h +++ b/fs/ext4/mballoc.h @@ -199,4 +199,21 @@ static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb, return ext4_group_first_block_no(sb, fex->fe_group) + (fex->fe_start << EXT4_SB(sb)->s_cluster_bits); } + +typedef int (*ext4_mballoc_query_range_fn)( + struct super_block *sb, + ext4_group_t agno, + ext4_grpblk_t start, + ext4_grpblk_t len, + void *priv); + +int +ext4_mballoc_query_range( + struct super_block *sb, + ext4_group_t agno, + ext4_grpblk_t start, + ext4_grpblk_t end, + ext4_mballoc_query_range_fn formatter, + void *priv); + #endif diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 7b82487401d2..9ec8963ba604 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -49,6 +49,7 @@ #include "xattr.h" #include "acl.h" #include "mballoc.h" +#include "fsmap.h" #define CREATE_TRACE_POINTS #include <trace/events/ext4.h> |