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linux/fs/ext4/ialloc.c
Theodore Ts'o 7827a7f6eb ext4: clean up error handling when orphan list is corrupted 
Instead of just printing warning messages, if the orphan list is
corrupted, declare the file system is corrupted.  If there are any
reserved inodes in the orphaned inode list, declare the file system
corrupted and stop right away to avoid doing more potential damage to
the file system.

Cc: stable@vger.kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-04-30 00:49:54 -04:00

1391 lines
38 KiB
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/*
* linux/fs/ext4/ialloc.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* BSD ufs-inspired inode and directory allocation by
* Stephen Tweedie (sct@redhat.com), 1993
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
*/
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/quotaops.h>
#include <linux/buffer_head.h>
#include <linux/random.h>
#include <linux/bitops.h>
#include <linux/blkdev.h>
#include <asm/byteorder.h>
#include "ext4.h"
#include "ext4_jbd2.h"
#include "xattr.h"
#include "acl.h"
#include <trace/events/ext4.h>
/*
* ialloc.c contains the inodes allocation and deallocation routines
*/
/*
* The free inodes are managed by bitmaps. A file system contains several
* blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
* block for inodes, N blocks for the inode table and data blocks.
*
* The file system contains group descriptors which are located after the
* super block. Each descriptor contains the number of the bitmap block and
* the free blocks count in the block.
*/
/*
* To avoid calling the atomic setbit hundreds or thousands of times, we only
* need to use it within a single byte (to ensure we get endianness right).
* We can use memset for the rest of the bitmap as there are no other users.
*/
void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
{
int i;
if (start_bit >= end_bit)
return;
ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
ext4_set_bit(i, bitmap);
if (i < end_bit)
memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
}
/* Initializes an uninitialized inode bitmap */
static int ext4_init_inode_bitmap(struct super_block *sb,
struct buffer_head *bh,
ext4_group_t block_group,
struct ext4_group_desc *gdp)
{
struct ext4_group_info *grp;
struct ext4_sb_info *sbi = EXT4_SB(sb);
J_ASSERT_BH(bh, buffer_locked(bh));
/* If checksum is bad mark all blocks and inodes use to prevent
* allocation, essentially implementing a per-group read-only flag. */
if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
grp = ext4_get_group_info(sb, block_group);
if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
percpu_counter_sub(&sbi->s_freeclusters_counter,
grp->bb_free);
set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
int count;
count = ext4_free_inodes_count(sb, gdp);
percpu_counter_sub(&sbi->s_freeinodes_counter,
count);
}
set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
return -EFSBADCRC;
}
memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
bh->b_data);
ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
EXT4_INODES_PER_GROUP(sb) / 8);
ext4_group_desc_csum_set(sb, block_group, gdp);
return 0;
}
void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
{
if (uptodate) {
set_buffer_uptodate(bh);
set_bitmap_uptodate(bh);
}
unlock_buffer(bh);
put_bh(bh);
}
static int ext4_validate_inode_bitmap(struct super_block *sb,
struct ext4_group_desc *desc,
ext4_group_t block_group,
struct buffer_head *bh)
{
ext4_fsblk_t blk;
struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
struct ext4_sb_info *sbi = EXT4_SB(sb);
if (buffer_verified(bh))
return 0;
if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
return -EFSCORRUPTED;
ext4_lock_group(sb, block_group);
blk = ext4_inode_bitmap(sb, desc);
if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
EXT4_INODES_PER_GROUP(sb) / 8)) {
ext4_unlock_group(sb, block_group);
ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
"inode_bitmap = %llu", block_group, blk);
grp = ext4_get_group_info(sb, block_group);
if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
int count;
count = ext4_free_inodes_count(sb, desc);
percpu_counter_sub(&sbi->s_freeinodes_counter,
count);
}
set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
return -EFSBADCRC;
}
set_buffer_verified(bh);
ext4_unlock_group(sb, block_group);
return 0;
}
/*
* Read the inode allocation bitmap for a given block_group, reading
* into the specified slot in the superblock's bitmap cache.
*
* Return buffer_head of bitmap on success or NULL.
*/
static struct buffer_head *
ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
{
struct ext4_group_desc *desc;
struct buffer_head *bh = NULL;
ext4_fsblk_t bitmap_blk;
int err;
desc = ext4_get_group_desc(sb, block_group, NULL);
if (!desc)
return ERR_PTR(-EFSCORRUPTED);
bitmap_blk = ext4_inode_bitmap(sb, desc);
bh = sb_getblk(sb, bitmap_blk);
if (unlikely(!bh)) {
ext4_error(sb, "Cannot read inode bitmap - "
"block_group = %u, inode_bitmap = %llu",
block_group, bitmap_blk);
return ERR_PTR(-EIO);
}
if (bitmap_uptodate(bh))
goto verify;
lock_buffer(bh);
if (bitmap_uptodate(bh)) {
unlock_buffer(bh);
goto verify;
}
ext4_lock_group(sb, block_group);
if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
err = ext4_init_inode_bitmap(sb, bh, block_group, desc);
set_bitmap_uptodate(bh);
set_buffer_uptodate(bh);
set_buffer_verified(bh);
ext4_unlock_group(sb, block_group);
unlock_buffer(bh);
if (err) {
ext4_error(sb, "Failed to init inode bitmap for group "
"%u: %d", block_group, err);
goto out;
}
return bh;
}
ext4_unlock_group(sb, block_group);
if (buffer_uptodate(bh)) {
/*
* if not uninit if bh is uptodate,
* bitmap is also uptodate
*/
set_bitmap_uptodate(bh);
unlock_buffer(bh);
goto verify;
}
/*
* submit the buffer_head for reading
*/
trace_ext4_load_inode_bitmap(sb, block_group);
bh->b_end_io = ext4_end_bitmap_read;
get_bh(bh);
submit_bh(READ | REQ_META | REQ_PRIO, bh);
wait_on_buffer(bh);
if (!buffer_uptodate(bh)) {
put_bh(bh);
ext4_error(sb, "Cannot read inode bitmap - "
"block_group = %u, inode_bitmap = %llu",
block_group, bitmap_blk);
return ERR_PTR(-EIO);
}
verify:
err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
if (err)
goto out;
return bh;
out:
put_bh(bh);
return ERR_PTR(err);
}
/*
* NOTE! When we get the inode, we're the only people
* that have access to it, and as such there are no
* race conditions we have to worry about. The inode
* is not on the hash-lists, and it cannot be reached
* through the filesystem because the directory entry
* has been deleted earlier.
*
* HOWEVER: we must make sure that we get no aliases,
* which means that we have to call "clear_inode()"
* _before_ we mark the inode not in use in the inode
* bitmaps. Otherwise a newly created file might use
* the same inode number (not actually the same pointer
* though), and then we'd have two inodes sharing the
* same inode number and space on the harddisk.
*/
void ext4_free_inode(handle_t *handle, struct inode *inode)
{
struct super_block *sb = inode->i_sb;
int is_directory;
unsigned long ino;
struct buffer_head *bitmap_bh = NULL;
struct buffer_head *bh2;
ext4_group_t block_group;
unsigned long bit;
struct ext4_group_desc *gdp;
struct ext4_super_block *es;
struct ext4_sb_info *sbi;
int fatal = 0, err, count, cleared;
struct ext4_group_info *grp;
if (!sb) {
printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
"nonexistent device\n", __func__, __LINE__);
return;
}
if (atomic_read(&inode->i_count) > 1) {
ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
__func__, __LINE__, inode->i_ino,
atomic_read(&inode->i_count));
return;
}
if (inode->i_nlink) {
ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
__func__, __LINE__, inode->i_ino, inode->i_nlink);
return;
}
sbi = EXT4_SB(sb);
ino = inode->i_ino;
ext4_debug("freeing inode %lu\n", ino);
trace_ext4_free_inode(inode);
/*
* Note: we must free any quota before locking the superblock,
* as writing the quota to disk may need the lock as well.
*/
dquot_initialize(inode);
ext4_xattr_delete_inode(handle, inode);
dquot_free_inode(inode);
dquot_drop(inode);
is_directory = S_ISDIR(inode->i_mode);
/* Do this BEFORE marking the inode not in use or returning an error */
ext4_clear_inode(inode);
es = EXT4_SB(sb)->s_es;
if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
ext4_error(sb, "reserved or nonexistent inode %lu", ino);
goto error_return;
}
block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
/* Don't bother if the inode bitmap is corrupt. */
grp = ext4_get_group_info(sb, block_group);
if (IS_ERR(bitmap_bh)) {
fatal = PTR_ERR(bitmap_bh);
bitmap_bh = NULL;
goto error_return;
}
if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
fatal = -EFSCORRUPTED;
goto error_return;
}
BUFFER_TRACE(bitmap_bh, "get_write_access");
fatal = ext4_journal_get_write_access(handle, bitmap_bh);
if (fatal)
goto error_return;
fatal = -ESRCH;
gdp = ext4_get_group_desc(sb, block_group, &bh2);
if (gdp) {
BUFFER_TRACE(bh2, "get_write_access");
fatal = ext4_journal_get_write_access(handle, bh2);
}
ext4_lock_group(sb, block_group);
cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
if (fatal || !cleared) {
ext4_unlock_group(sb, block_group);
goto out;
}
count = ext4_free_inodes_count(sb, gdp) + 1;
ext4_free_inodes_set(sb, gdp, count);
if (is_directory) {
count = ext4_used_dirs_count(sb, gdp) - 1;
ext4_used_dirs_set(sb, gdp, count);
percpu_counter_dec(&sbi->s_dirs_counter);
}
ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
EXT4_INODES_PER_GROUP(sb) / 8);
ext4_group_desc_csum_set(sb, block_group, gdp);
ext4_unlock_group(sb, block_group);
percpu_counter_inc(&sbi->s_freeinodes_counter);
if (sbi->s_log_groups_per_flex) {
ext4_group_t f = ext4_flex_group(sbi, block_group);
atomic_inc(&sbi->s_flex_groups[f].free_inodes);
if (is_directory)
atomic_dec(&sbi->s_flex_groups[f].used_dirs);
}
BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
out:
if (cleared) {
BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
if (!fatal)
fatal = err;
} else {
ext4_error(sb, "bit already cleared for inode %lu", ino);
if (gdp && !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
int count;
count = ext4_free_inodes_count(sb, gdp);
percpu_counter_sub(&sbi->s_freeinodes_counter,
count);
}
set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
}
error_return:
brelse(bitmap_bh);
ext4_std_error(sb, fatal);
}
struct orlov_stats {
__u64 free_clusters;
__u32 free_inodes;
__u32 used_dirs;
};
/*
* Helper function for Orlov's allocator; returns critical information
* for a particular block group or flex_bg. If flex_size is 1, then g
* is a block group number; otherwise it is flex_bg number.
*/
static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
int flex_size, struct orlov_stats *stats)
{
struct ext4_group_desc *desc;
struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups;
if (flex_size > 1) {
stats->free_inodes = atomic_read(&flex_group[g].free_inodes);
stats->free_clusters = atomic64_read(&flex_group[g].free_clusters);
stats->used_dirs = atomic_read(&flex_group[g].used_dirs);
return;
}
desc = ext4_get_group_desc(sb, g, NULL);
if (desc) {
stats->free_inodes = ext4_free_inodes_count(sb, desc);
stats->free_clusters = ext4_free_group_clusters(sb, desc);
stats->used_dirs = ext4_used_dirs_count(sb, desc);
} else {
stats->free_inodes = 0;
stats->free_clusters = 0;
stats->used_dirs = 0;
}
}
/*
* Orlov's allocator for directories.
*
* We always try to spread first-level directories.
*
* If there are blockgroups with both free inodes and free blocks counts
* not worse than average we return one with smallest directory count.
* Otherwise we simply return a random group.
*
* For the rest rules look so:
*
* It's OK to put directory into a group unless
* it has too many directories already (max_dirs) or
* it has too few free inodes left (min_inodes) or
* it has too few free blocks left (min_blocks) or
* Parent's group is preferred, if it doesn't satisfy these
* conditions we search cyclically through the rest. If none
* of the groups look good we just look for a group with more
* free inodes than average (starting at parent's group).
*/
static int find_group_orlov(struct super_block *sb, struct inode *parent,
ext4_group_t *group, umode_t mode,
const struct qstr *qstr)
{
ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
struct ext4_sb_info *sbi = EXT4_SB(sb);
ext4_group_t real_ngroups = ext4_get_groups_count(sb);
int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
unsigned int freei, avefreei, grp_free;
ext4_fsblk_t freeb, avefreec;
unsigned int ndirs;
int max_dirs, min_inodes;
ext4_grpblk_t min_clusters;
ext4_group_t i, grp, g, ngroups;
struct ext4_group_desc *desc;
struct orlov_stats stats;
int flex_size = ext4_flex_bg_size(sbi);
struct dx_hash_info hinfo;
ngroups = real_ngroups;
if (flex_size > 1) {
ngroups = (real_ngroups + flex_size - 1) >>
sbi->s_log_groups_per_flex;
parent_group >>= sbi->s_log_groups_per_flex;
}
freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
avefreei = freei / ngroups;
freeb = EXT4_C2B(sbi,
percpu_counter_read_positive(&sbi->s_freeclusters_counter));
avefreec = freeb;
do_div(avefreec, ngroups);
ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
if (S_ISDIR(mode) &&
((parent == d_inode(sb->s_root)) ||
(ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
int best_ndir = inodes_per_group;
int ret = -1;
if (qstr) {
hinfo.hash_version = DX_HASH_HALF_MD4;
hinfo.seed = sbi->s_hash_seed;
ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
grp = hinfo.hash;
} else
grp = prandom_u32();
parent_group = (unsigned)grp % ngroups;
for (i = 0; i < ngroups; i++) {
g = (parent_group + i) % ngroups;
get_orlov_stats(sb, g, flex_size, &stats);
if (!stats.free_inodes)
continue;
if (stats.used_dirs >= best_ndir)
continue;
if (stats.free_inodes < avefreei)
continue;
if (stats.free_clusters < avefreec)
continue;
grp = g;
ret = 0;
best_ndir = stats.used_dirs;
}
if (ret)
goto fallback;
found_flex_bg:
if (flex_size == 1) {
*group = grp;
return 0;
}
/*
* We pack inodes at the beginning of the flexgroup's
* inode tables. Block allocation decisions will do
* something similar, although regular files will
* start at 2nd block group of the flexgroup. See
* ext4_ext_find_goal() and ext4_find_near().
*/
grp *= flex_size;
for (i = 0; i < flex_size; i++) {
if (grp+i >= real_ngroups)
break;
desc = ext4_get_group_desc(sb, grp+i, NULL);
if (desc && ext4_free_inodes_count(sb, desc)) {
*group = grp+i;
return 0;
}
}
goto fallback;
}
max_dirs = ndirs / ngroups + inodes_per_group / 16;
min_inodes = avefreei - inodes_per_group*flex_size / 4;
if (min_inodes < 1)
min_inodes = 1;
min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
/*
* Start looking in the flex group where we last allocated an
* inode for this parent directory
*/
if (EXT4_I(parent)->i_last_alloc_group != ~0) {
parent_group = EXT4_I(parent)->i_last_alloc_group;
if (flex_size > 1)
parent_group >>= sbi->s_log_groups_per_flex;
}
for (i = 0; i < ngroups; i++) {
grp = (parent_group + i) % ngroups;
get_orlov_stats(sb, grp, flex_size, &stats);
if (stats.used_dirs >= max_dirs)
continue;
if (stats.free_inodes < min_inodes)
continue;
if (stats.free_clusters < min_clusters)
continue;
goto found_flex_bg;
}
fallback:
ngroups = real_ngroups;
avefreei = freei / ngroups;
fallback_retry:
parent_group = EXT4_I(parent)->i_block_group;
for (i = 0; i < ngroups; i++) {
grp = (parent_group + i) % ngroups;
desc = ext4_get_group_desc(sb, grp, NULL);
if (desc) {
grp_free = ext4_free_inodes_count(sb, desc);
if (grp_free && grp_free >= avefreei) {
*group = grp;
return 0;
}
}
}
if (avefreei) {
/*
* The free-inodes counter is approximate, and for really small
* filesystems the above test can fail to find any blockgroups
*/
avefreei = 0;
goto fallback_retry;
}
return -1;
}
static int find_group_other(struct super_block *sb, struct inode *parent,
ext4_group_t *group, umode_t mode)
{
ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
struct ext4_group_desc *desc;
int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
/*
* Try to place the inode is the same flex group as its
* parent. If we can't find space, use the Orlov algorithm to
* find another flex group, and store that information in the
* parent directory's inode information so that use that flex
* group for future allocations.
*/
if (flex_size > 1) {
int retry = 0;
try_again:
parent_group &= ~(flex_size-1);
last = parent_group + flex_size;
if (last > ngroups)
last = ngroups;
for (i = parent_group; i < last; i++) {
desc = ext4_get_group_desc(sb, i, NULL);
if (desc && ext4_free_inodes_count(sb, desc)) {
*group = i;
return 0;
}
}
if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
retry = 1;
parent_group = EXT4_I(parent)->i_last_alloc_group;
goto try_again;
}
/*
* If this didn't work, use the Orlov search algorithm
* to find a new flex group; we pass in the mode to
* avoid the topdir algorithms.
*/
*group = parent_group + flex_size;
if (*group > ngroups)
*group = 0;
return find_group_orlov(sb, parent, group, mode, NULL);
}
/*
* Try to place the inode in its parent directory
*/
*group = parent_group;
desc = ext4_get_group_desc(sb, *group, NULL);
if (desc && ext4_free_inodes_count(sb, desc) &&
ext4_free_group_clusters(sb, desc))
return 0;
/*
* We're going to place this inode in a different blockgroup from its
* parent. We want to cause files in a common directory to all land in
* the same blockgroup. But we want files which are in a different
* directory which shares a blockgroup with our parent to land in a
* different blockgroup.
*
* So add our directory's i_ino into the starting point for the hash.
*/
*group = (*group + parent->i_ino) % ngroups;
/*
* Use a quadratic hash to find a group with a free inode and some free
* blocks.
*/
for (i = 1; i < ngroups; i <<= 1) {
*group += i;
if (*group >= ngroups)
*group -= ngroups;
desc = ext4_get_group_desc(sb, *group, NULL);
if (desc && ext4_free_inodes_count(sb, desc) &&
ext4_free_group_clusters(sb, desc))
return 0;
}
/*
* That failed: try linear search for a free inode, even if that group
* has no free blocks.
*/
*group = parent_group;
for (i = 0; i < ngroups; i++) {
if (++*group >= ngroups)
*group = 0;
desc = ext4_get_group_desc(sb, *group, NULL);
if (desc && ext4_free_inodes_count(sb, desc))
return 0;
}
return -1;
}
/*
* In no journal mode, if an inode has recently been deleted, we want
* to avoid reusing it until we're reasonably sure the inode table
* block has been written back to disk. (Yes, these values are
* somewhat arbitrary...)
*/
#define RECENTCY_MIN 5
#define RECENTCY_DIRTY 30
static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
{
struct ext4_group_desc *gdp;
struct ext4_inode *raw_inode;
struct buffer_head *bh;
unsigned long dtime, now;
int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
int offset, ret = 0, recentcy = RECENTCY_MIN;
gdp = ext4_get_group_desc(sb, group, NULL);
if (unlikely(!gdp))
return 0;
bh = sb_getblk(sb, ext4_inode_table(sb, gdp) +
(ino / inodes_per_block));
if (unlikely(!bh) || !buffer_uptodate(bh))
/*
* If the block is not in the buffer cache, then it
* must have been written out.
*/
goto out;
offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
raw_inode = (struct ext4_inode *) (bh->b_data + offset);
dtime = le32_to_cpu(raw_inode->i_dtime);
now = get_seconds();
if (buffer_dirty(bh))
recentcy += RECENTCY_DIRTY;
if (dtime && (dtime < now) && (now < dtime + recentcy))
ret = 1;
out:
brelse(bh);
return ret;
}
/*
* There are two policies for allocating an inode. If the new inode is
* a directory, then a forward search is made for a block group with both
* free space and a low directory-to-inode ratio; if that fails, then of
* the groups with above-average free space, that group with the fewest
* directories already is chosen.
*
* For other inodes, search forward from the parent directory's block
* group to find a free inode.
*/
struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
umode_t mode, const struct qstr *qstr,
__u32 goal, uid_t *owner, int handle_type,
unsigned int line_no, int nblocks)
{
struct super_block *sb;
struct buffer_head *inode_bitmap_bh = NULL;
struct buffer_head *group_desc_bh;
ext4_group_t ngroups, group = 0;
unsigned long ino = 0;
struct inode *inode;
struct ext4_group_desc *gdp = NULL;
struct ext4_inode_info *ei;
struct ext4_sb_info *sbi;
int ret2, err;
struct inode *ret;
ext4_group_t i;
ext4_group_t flex_group;
struct ext4_group_info *grp;
int encrypt = 0;
/* Cannot create files in a deleted directory */
if (!dir || !dir->i_nlink)
return ERR_PTR(-EPERM);
if ((ext4_encrypted_inode(dir) ||
DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
err = ext4_get_encryption_info(dir);
if (err)
return ERR_PTR(err);
if (ext4_encryption_info(dir) == NULL)
return ERR_PTR(-EPERM);
if (!handle)
nblocks += EXT4_DATA_TRANS_BLOCKS(dir->i_sb);
encrypt = 1;
}
sb = dir->i_sb;
ngroups = ext4_get_groups_count(sb);
trace_ext4_request_inode(dir, mode);
inode = new_inode(sb);
if (!inode)
return ERR_PTR(-ENOMEM);
ei = EXT4_I(inode);
sbi = EXT4_SB(sb);
/*
* Initialize owners and quota early so that we don't have to account
* for quota initialization worst case in standard inode creating
* transaction
*/
if (owner) {
inode->i_mode = mode;
i_uid_write(inode, owner[0]);
i_gid_write(inode, owner[1]);
} else if (test_opt(sb, GRPID)) {
inode->i_mode = mode;
inode->i_uid = current_fsuid();
inode->i_gid = dir->i_gid;
} else
inode_init_owner(inode, dir, mode);
if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_PROJECT) &&
ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
ei->i_projid = EXT4_I(dir)->i_projid;
else
ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
err = dquot_initialize(inode);
if (err)
goto out;
if (!goal)
goal = sbi->s_inode_goal;
if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
ret2 = 0;
goto got_group;
}
if (S_ISDIR(mode))
ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
else
ret2 = find_group_other(sb, dir, &group, mode);
got_group:
EXT4_I(dir)->i_last_alloc_group = group;
err = -ENOSPC;
if (ret2 == -1)
goto out;
/*
* Normally we will only go through one pass of this loop,
* unless we get unlucky and it turns out the group we selected
* had its last inode grabbed by someone else.
*/
for (i = 0; i < ngroups; i++, ino = 0) {
err = -EIO;
gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
if (!gdp)
goto out;
/*
* Check free inodes count before loading bitmap.
*/
if (ext4_free_inodes_count(sb, gdp) == 0) {
if (++group == ngroups)
group = 0;
continue;
}
grp = ext4_get_group_info(sb, group);
/* Skip groups with already-known suspicious inode tables */
if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
if (++group == ngroups)
group = 0;
continue;
}
brelse(inode_bitmap_bh);
inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
/* Skip groups with suspicious inode tables */
if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
IS_ERR(inode_bitmap_bh)) {
inode_bitmap_bh = NULL;
if (++group == ngroups)
group = 0;
continue;
}
repeat_in_this_group:
ino = ext4_find_next_zero_bit((unsigned long *)
inode_bitmap_bh->b_data,
EXT4_INODES_PER_GROUP(sb), ino);
if (ino >= EXT4_INODES_PER_GROUP(sb))
goto next_group;
if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) {
ext4_error(sb, "reserved inode found cleared - "
"inode=%lu", ino + 1);
continue;
}
if ((EXT4_SB(sb)->s_journal == NULL) &&
recently_deleted(sb, group, ino)) {
ino++;
goto next_inode;
}
if (!handle) {
BUG_ON(nblocks <= 0);
handle = __ext4_journal_start_sb(dir->i_sb, line_no,
handle_type, nblocks,
0);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
ext4_std_error(sb, err);
goto out;
}
}
BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
if (err) {
ext4_std_error(sb, err);
goto out;
}
ext4_lock_group(sb, group);
ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
ext4_unlock_group(sb, group);
ino++; /* the inode bitmap is zero-based */
if (!ret2)
goto got; /* we grabbed the inode! */
next_inode:
if (ino < EXT4_INODES_PER_GROUP(sb))
goto repeat_in_this_group;
next_group:
if (++group == ngroups)
group = 0;
}
err = -ENOSPC;
goto out;
got:
BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
if (err) {
ext4_std_error(sb, err);
goto out;
}
BUFFER_TRACE(group_desc_bh, "get_write_access");
err = ext4_journal_get_write_access(handle, group_desc_bh);
if (err) {
ext4_std_error(sb, err);
goto out;
}
/* We may have to initialize the block bitmap if it isn't already */
if (ext4_has_group_desc_csum(sb) &&
gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
struct buffer_head *block_bitmap_bh;
block_bitmap_bh = ext4_read_block_bitmap(sb, group);
if (IS_ERR(block_bitmap_bh)) {
err = PTR_ERR(block_bitmap_bh);
goto out;
}
BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
err = ext4_journal_get_write_access(handle, block_bitmap_bh);
if (err) {
brelse(block_bitmap_bh);
ext4_std_error(sb, err);
goto out;
}
BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
/* recheck and clear flag under lock if we still need to */
ext4_lock_group(sb, group);
if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
ext4_free_group_clusters_set(sb, gdp,
ext4_free_clusters_after_init(sb, group, gdp));
ext4_block_bitmap_csum_set(sb, group, gdp,
block_bitmap_bh);
ext4_group_desc_csum_set(sb, group, gdp);
}
ext4_unlock_group(sb, group);
brelse(block_bitmap_bh);
if (err) {
ext4_std_error(sb, err);
goto out;
}
}
/* Update the relevant bg descriptor fields */
if (ext4_has_group_desc_csum(sb)) {
int free;
struct ext4_group_info *grp = ext4_get_group_info(sb, group);
down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
ext4_lock_group(sb, group); /* while we modify the bg desc */
free = EXT4_INODES_PER_GROUP(sb) -
ext4_itable_unused_count(sb, gdp);
if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
free = 0;
}
/*
* Check the relative inode number against the last used
* relative inode number in this group. if it is greater
* we need to update the bg_itable_unused count
*/
if (ino > free)
ext4_itable_unused_set(sb, gdp,
(EXT4_INODES_PER_GROUP(sb) - ino));
up_read(&grp->alloc_sem);
} else {
ext4_lock_group(sb, group);
}
ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
if (S_ISDIR(mode)) {
ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
if (sbi->s_log_groups_per_flex) {
ext4_group_t f = ext4_flex_group(sbi, group);
atomic_inc(&sbi->s_flex_groups[f].used_dirs);
}
}
if (ext4_has_group_desc_csum(sb)) {
ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
EXT4_INODES_PER_GROUP(sb) / 8);
ext4_group_desc_csum_set(sb, group, gdp);
}
ext4_unlock_group(sb, group);
BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
if (err) {
ext4_std_error(sb, err);
goto out;
}
percpu_counter_dec(&sbi->s_freeinodes_counter);
if (S_ISDIR(mode))
percpu_counter_inc(&sbi->s_dirs_counter);
if (sbi->s_log_groups_per_flex) {
flex_group = ext4_flex_group(sbi, group);
atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes);
}
inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
/* This is the optimal IO size (for stat), not the fs block size */
inode->i_blocks = 0;
inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
ext4_current_time(inode);
memset(ei->i_data, 0, sizeof(ei->i_data));
ei->i_dir_start_lookup = 0;
ei->i_disksize = 0;
/* Don't inherit extent flag from directory, amongst others. */
ei->i_flags =
ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
ei->i_file_acl = 0;
ei->i_dtime = 0;
ei->i_block_group = group;
ei->i_last_alloc_group = ~0;
ext4_set_inode_flags(inode);
if (IS_DIRSYNC(inode))
ext4_handle_sync(handle);
if (insert_inode_locked(inode) < 0) {
/*
* Likely a bitmap corruption causing inode to be allocated
* twice.
*/
err = -EIO;
ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
inode->i_ino);
goto out;
}
spin_lock(&sbi->s_next_gen_lock);
inode->i_generation = sbi->s_next_generation++;
spin_unlock(&sbi->s_next_gen_lock);
/* Precompute checksum seed for inode metadata */
if (ext4_has_metadata_csum(sb)) {
__u32 csum;
__le32 inum = cpu_to_le32(inode->i_ino);
__le32 gen = cpu_to_le32(inode->i_generation);
csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
sizeof(inum));
ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
sizeof(gen));
}
ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
ext4_set_inode_state(inode, EXT4_STATE_NEW);
ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
ei->i_inline_off = 0;
if (ext4_has_feature_inline_data(sb))
ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
ret = inode;
err = dquot_alloc_inode(inode);
if (err)
goto fail_drop;
err = ext4_init_acl(handle, inode, dir);
if (err)
goto fail_free_drop;
err = ext4_init_security(handle, inode, dir, qstr);
if (err)
goto fail_free_drop;
if (ext4_has_feature_extents(sb)) {
/* set extent flag only for directory, file and normal symlink*/
if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
ext4_ext_tree_init(handle, inode);
}
}
if (ext4_handle_valid(handle)) {
ei->i_sync_tid = handle->h_transaction->t_tid;
ei->i_datasync_tid = handle->h_transaction->t_tid;
}
if (encrypt) {
err = ext4_inherit_context(dir, inode);
if (err)
goto fail_free_drop;
}
err = ext4_mark_inode_dirty(handle, inode);
if (err) {
ext4_std_error(sb, err);
goto fail_free_drop;
}
ext4_debug("allocating inode %lu\n", inode->i_ino);
trace_ext4_allocate_inode(inode, dir, mode);
brelse(inode_bitmap_bh);
return ret;
fail_free_drop:
dquot_free_inode(inode);
fail_drop:
clear_nlink(inode);
unlock_new_inode(inode);
out:
dquot_drop(inode);
inode->i_flags |= S_NOQUOTA;
iput(inode);
brelse(inode_bitmap_bh);
return ERR_PTR(err);
}
/* Verify that we are loading a valid orphan from disk */
struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
{
unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
ext4_group_t block_group;
int bit;
struct buffer_head *bitmap_bh = NULL;
struct inode *inode = NULL;
int err = -EFSCORRUPTED;
if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
goto bad_orphan;
block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
if (IS_ERR(bitmap_bh)) {
ext4_error(sb, "inode bitmap error %ld for orphan %lu",
ino, PTR_ERR(bitmap_bh));
return (struct inode *) bitmap_bh;
}
/* Having the inode bit set should be a 100% indicator that this
* is a valid orphan (no e2fsck run on fs). Orphans also include
* inodes that were being truncated, so we can't check i_nlink==0.
*/
if (!ext4_test_bit(bit, bitmap_bh->b_data))
goto bad_orphan;
inode = ext4_iget(sb, ino);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
ext4_error(sb, "couldn't read orphan inode %lu (err %d)",
ino, err);
return inode;
}
/*
* If the orphans has i_nlinks > 0 then it should be able to
* be truncated, otherwise it won't be removed from the orphan
* list during processing and an infinite loop will result.
* Similarly, it must not be a bad inode.
*/
if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
is_bad_inode(inode))
goto bad_orphan;
if (NEXT_ORPHAN(inode) > max_ino)
goto bad_orphan;
brelse(bitmap_bh);
return inode;
bad_orphan:
ext4_error(sb, "bad orphan inode %lu", ino);
if (bitmap_bh)
printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
bit, (unsigned long long)bitmap_bh->b_blocknr,
ext4_test_bit(bit, bitmap_bh->b_data));
if (inode) {
printk(KERN_ERR "is_bad_inode(inode)=%d\n",
is_bad_inode(inode));
printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
NEXT_ORPHAN(inode));
printk(KERN_ERR "max_ino=%lu\n", max_ino);
printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
/* Avoid freeing blocks if we got a bad deleted inode */
if (inode->i_nlink == 0)
inode->i_blocks = 0;
iput(inode);
}
brelse(bitmap_bh);
return ERR_PTR(err);
}
unsigned long ext4_count_free_inodes(struct super_block *sb)
{
unsigned long desc_count;
struct ext4_group_desc *gdp;
ext4_group_t i, ngroups = ext4_get_groups_count(sb);
#ifdef EXT4FS_DEBUG
struct ext4_super_block *es;
unsigned long bitmap_count, x;
struct buffer_head *bitmap_bh = NULL;
es = EXT4_SB(sb)->s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < ngroups; i++) {
gdp = ext4_get_group_desc(sb, i, NULL);
if (!gdp)
continue;
desc_count += ext4_free_inodes_count(sb, gdp);
brelse(bitmap_bh);
bitmap_bh = ext4_read_inode_bitmap(sb, i);
if (IS_ERR(bitmap_bh)) {
bitmap_bh = NULL;
continue;
}
x = ext4_count_free(bitmap_bh->b_data,
EXT4_INODES_PER_GROUP(sb) / 8);
printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
(unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
bitmap_count += x;
}
brelse(bitmap_bh);
printk(KERN_DEBUG "ext4_count_free_inodes: "
"stored = %u, computed = %lu, %lu\n",
le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
return desc_count;
#else
desc_count = 0;
for (i = 0; i < ngroups; i++) {
gdp = ext4_get_group_desc(sb, i, NULL);
if (!gdp)
continue;
desc_count += ext4_free_inodes_count(sb, gdp);
cond_resched();
}
return desc_count;
#endif
}
/* Called at mount-time, super-block is locked */
unsigned long ext4_count_dirs(struct super_block * sb)
{
unsigned long count = 0;
ext4_group_t i, ngroups = ext4_get_groups_count(sb);
for (i = 0; i < ngroups; i++) {
struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
if (!gdp)
continue;
count += ext4_used_dirs_count(sb, gdp);
}
return count;
}
/*
* Zeroes not yet zeroed inode table - just write zeroes through the whole
* inode table. Must be called without any spinlock held. The only place
* where it is called from on active part of filesystem is ext4lazyinit
* thread, so we do not need any special locks, however we have to prevent
* inode allocation from the current group, so we take alloc_sem lock, to
* block ext4_new_inode() until we are finished.
*/
int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
int barrier)
{
struct ext4_group_info *grp = ext4_get_group_info(sb, group);
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_group_desc *gdp = NULL;
struct buffer_head *group_desc_bh;
handle_t *handle;
ext4_fsblk_t blk;
int num, ret = 0, used_blks = 0;
/* This should not happen, but just to be sure check this */
if (sb->s_flags & MS_RDONLY) {
ret = 1;
goto out;
}
gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
if (!gdp)
goto out;
/*
* We do not need to lock this, because we are the only one
* handling this flag.
*/
if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
goto out;
handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
goto out;
}
down_write(&grp->alloc_sem);
/*
* If inode bitmap was already initialized there may be some
* used inodes so we need to skip blocks with used inodes in
* inode table.
*/
if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
ext4_itable_unused_count(sb, gdp)),
sbi->s_inodes_per_block);
if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) {
ext4_error(sb, "Something is wrong with group %u: "
"used itable blocks: %d; "
"itable unused count: %u",
group, used_blks,
ext4_itable_unused_count(sb, gdp));
ret = 1;
goto err_out;
}
blk = ext4_inode_table(sb, gdp) + used_blks;
num = sbi->s_itb_per_group - used_blks;
BUFFER_TRACE(group_desc_bh, "get_write_access");
ret = ext4_journal_get_write_access(handle,
group_desc_bh);
if (ret)
goto err_out;
/*
* Skip zeroout if the inode table is full. But we set the ZEROED
* flag anyway, because obviously, when it is full it does not need
* further zeroing.
*/
if (unlikely(num == 0))
goto skip_zeroout;
ext4_debug("going to zero out inode table in group %d\n",
group);
ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
if (ret < 0)
goto err_out;
if (barrier)
blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
skip_zeroout:
ext4_lock_group(sb, group);
gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
ext4_group_desc_csum_set(sb, group, gdp);
ext4_unlock_group(sb, group);
BUFFER_TRACE(group_desc_bh,
"call ext4_handle_dirty_metadata");
ret = ext4_handle_dirty_metadata(handle, NULL,
group_desc_bh);
err_out:
up_write(&grp->alloc_sem);
ext4_journal_stop(handle);
out:
return ret;
}
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