#include <linux/proc_fs.h>
#include <linux/security.h>
#include <linux/kmod.h>
+#include <linux/pagemap.h>
#include <asm/uaccess.h>
*
* Any operation working on dquots via inode pointers must hold dqptr_sem. If
* operation is just reading pointers from inode (or not using them at all) the
- * read lock is enough. If pointers are altered function must hold write lock.
- * If operation is holding reference to dquot in other way (e.g. quotactl ops)
- * it must be guarded by dqonoff_sem.
+ * read lock is enough. If pointers are altered function must hold write lock
+ * (these locking rules also apply for S_NOQUOTA flag in the inode - note that
+ * for altering the flag i_sem is also needed). If operation is holding
+ * reference to dquot in other way (e.g. quotactl ops) it must be guarded by
+ * dqonoff_sem.
* This locking assures that:
* a) update/access to dquot pointers in inode is serialized
* b) everyone is guarded against invalidate_dquots()
* operations on dquots don't hold dq_lock as they copy data under dq_data_lock
* spinlock to internal buffers before writing.
*
- * Lock ordering (including journal_lock) is following:
- * dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock > dqio_sem
+ * Lock ordering (including related VFS locks) is following:
+ * i_sem > dqonoff_sem > iprune_sem > journal_lock > dqptr_sem >
+ * > dquot->dq_lock > dqio_sem
+ * i_sem on quota files is special (it's below dqio_sem)
*/
-spinlock_t dq_list_lock = SPIN_LOCK_UNLOCKED;
+static spinlock_t dq_list_lock = SPIN_LOCK_UNLOCKED;
spinlock_t dq_data_lock = SPIN_LOCK_UNLOCKED;
static char *quotatypes[] = INITQFNAMES;
static void dqput(struct dquot *dquot);
-static inline int const hashfn(struct super_block *sb, unsigned int id, int type)
+static inline unsigned int
+hashfn(const struct super_block *sb, unsigned int id, int type)
{
- unsigned long tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
+ unsigned long tmp;
+
+ tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
}
int dquot_acquire(struct dquot *dquot)
{
- int ret = 0;
+ int ret = 0, ret2 = 0;
struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
down(&dquot->dq_lock);
/* Instantiate dquot if needed */
if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
+ /* Write the info if needed */
+ if (info_dirty(&dqopt->info[dquot->dq_type]))
+ ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
if (ret < 0)
goto out_iolock;
+ if (ret2 < 0) {
+ ret = ret2;
+ goto out_iolock;
+ }
}
set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
out_iolock:
*/
int dquot_commit(struct dquot *dquot)
{
- int ret = 0;
+ int ret = 0, ret2 = 0;
struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
down(&dqopt->dqio_sem);
spin_unlock(&dq_list_lock);
/* Inactive dquot can be only if there was error during read/init
* => we have better not writing it */
- if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
+ if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
+ if (info_dirty(&dqopt->info[dquot->dq_type]))
+ ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
+ if (ret >= 0)
+ ret = ret2;
+ }
out_sem:
up(&dqopt->dqio_sem);
- if (info_dirty(&dqopt->info[dquot->dq_type]))
- dquot->dq_sb->dq_op->write_info(dquot->dq_sb, dquot->dq_type);
return ret;
}
*/
int dquot_release(struct dquot *dquot)
{
- int ret = 0;
+ int ret = 0, ret2 = 0;
struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
down(&dquot->dq_lock);
if (atomic_read(&dquot->dq_count) > 1)
goto out_dqlock;
down(&dqopt->dqio_sem);
- ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
+ if (dqopt->ops[dquot->dq_type]->release_dqblk) {
+ ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
+ /* Write the info */
+ if (info_dirty(&dqopt->info[dquot->dq_type]))
+ ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
+ if (ret >= 0)
+ ret = ret2;
+ }
clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
up(&dqopt->dqio_sem);
out_dqlock:
clear_dquot_dirty(dquot);
if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
spin_unlock(&dq_list_lock);
- dquot_release(dquot);
+ dquot->dq_sb->dq_op->release_dquot(dquot);
goto we_slept;
}
atomic_dec(&dquot->dq_count);
{
struct dquot *dquot;
- dquot = kmem_cache_alloc(dquot_cachep, SLAB_KERNEL);
+ dquot = kmem_cache_alloc(dquot_cachep, SLAB_NOFS);
if(!dquot)
return NODQUOT;
* finished or it will be canceled due to dq_count > 1 test */
wait_on_dquot(dquot);
/* Read the dquot and instantiate it (everything done only if needed) */
- if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_acquire(dquot) < 0) {
+ if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) {
dqput(dquot);
return NODQUOT;
}
int remove_inode_dquot_ref(struct inode *inode, int type, struct list_head *tofree_head)
{
struct dquot *dquot = inode->i_dquot[type];
- int cnt;
inode->i_dquot[type] = NODQUOT;
- /* any other quota in use? */
- for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
- if (inode->i_dquot[cnt] != NODQUOT)
- goto put_it;
- }
- inode->i_flags &= ~S_QUOTA;
-put_it:
if (dquot != NODQUOT) {
if (dqput_blocks(dquot)) {
#ifdef __DQUOT_PARANOIA
}
}
-/* Function in inode.c - remove pointers to dquots in icache */
-extern void remove_dquot_ref(struct super_block *, int, struct list_head *);
-
/* Gather all references from inodes and drop them */
static void drop_dquot_ref(struct super_block *sb, int type)
{
LIST_HEAD(tofree_head);
+ /* We need to be guarded against prune_icache to reach all the
+ * inodes - otherwise some can be on the local list of prune_icache */
+ down(&iprune_sem);
down_write(&sb_dqopt(sb)->dqptr_sem);
remove_dquot_ref(sb, type, &tofree_head);
up_write(&sb_dqopt(sb)->dqptr_sem);
+ up(&iprune_sem);
put_dquot_list(&tofree_head);
}
break;
}
inode->i_dquot[cnt] = dqget(inode->i_sb, id, cnt);
- if (inode->i_dquot[cnt])
- inode->i_flags |= S_QUOTA;
}
}
out_err:
int cnt;
down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
- inode->i_flags &= ~S_QUOTA;
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (inode->i_dquot[cnt] != NODQUOT) {
dqput(inode->i_dquot[cnt]);
if (transfer_to[cnt] == NODQUOT)
continue;
- dquot_decr_inodes(transfer_from[cnt], 1);
- dquot_decr_space(transfer_from[cnt], space);
+ /* Due to IO error we might not have transfer_from[] structure */
+ if (transfer_from[cnt]) {
+ dquot_decr_inodes(transfer_from[cnt], 1);
+ dquot_decr_space(transfer_from[cnt], space);
+ }
dquot_incr_inodes(transfer_to[cnt], 1);
dquot_incr_space(transfer_to[cnt], space);
.free_inode = dquot_free_inode,
.transfer = dquot_transfer,
.write_dquot = dquot_commit,
+ .acquire_dquot = dquot_acquire,
+ .release_dquot = dquot_release,
.mark_dirty = dquot_mark_dquot_dirty,
.write_info = dquot_commit_info
};
struct quota_info *dqopt = sb_dqopt(sb);
struct dquot *to_drop[MAXQUOTAS];
int error, cnt;
- unsigned int oldflags;
+ unsigned int oldflags = -1;
if (!fmt)
return -ESRCH;
if (!S_ISREG(inode->i_mode))
goto out_fmt;
+ down(&inode->i_sem);
down(&dqopt->dqonoff_sem);
if (sb_has_quota_enabled(sb, type)) {
+ up(&inode->i_sem);
error = -EBUSY;
goto out_lock;
}
- oldflags = inode->i_flags;
+ /* We don't want quota and atime on quota files (deadlocks possible)
+ * We also need to set GFP mask differently because we cannot recurse
+ * into filesystem when allocating page for quota inode */
+ down_write(&dqopt->dqptr_sem);
+ oldflags = inode->i_flags & (S_NOATIME | S_NOQUOTA);
+ inode->i_flags |= S_NOQUOTA | S_NOATIME;
+ up_write(&dqopt->dqptr_sem);
+ up(&inode->i_sem);
+
dqopt->files[type] = f;
error = -EINVAL;
if (!fmt->qf_ops->check_quota_file(sb, type))
goto out_file_init;
- /* We don't want quota and atime on quota files (deadlocks possible) */
+ /*
+ * We write to quota files deep within filesystem code. We don't want
+ * the VFS to reenter filesystem code when it tries to allocate a
+ * pagecache page for the quota file write. So clear __GFP_FS in
+ * the quota file's allocation flags.
+ */
+ mapping_set_gfp_mask(inode->i_mapping,
+ mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
+
down_write(&dqopt->dqptr_sem);
- inode->i_flags |= S_NOQUOTA | S_NOATIME;
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
to_drop[cnt] = inode->i_dquot[cnt];
inode->i_dquot[cnt] = NODQUOT;
}
- inode->i_flags &= ~S_QUOTA;
up_write(&dqopt->dqptr_sem);
/* We must put dquots outside of dqptr_sem because we may need to
* start transaction for dquot_release() */
return 0;
out_file_init:
- inode->i_flags = oldflags;
dqopt->files[type] = NULL;
out_lock:
- up_write(&dqopt->dqptr_sem);
up(&dqopt->dqonoff_sem);
+ if (oldflags != -1) {
+ down(&inode->i_sem);
+ down_write(&dqopt->dqptr_sem);
+ /* Reset the NOATIME flag back. I know it could change in the
+ * mean time but playing with NOATIME flags on a quota file is
+ * never a good idea */
+ inode->i_flags &= ~(S_NOATIME | S_NOQUOTA);
+ inode->i_flags |= oldflags;
+ up_write(&dqopt->dqptr_sem);
+ up(&inode->i_sem);
+ }
out_fmt:
put_quota_format(fmt);
dquot_cachep = kmem_cache_create("dquot",
sizeof(struct dquot), sizeof(unsigned long) * 4,
- SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT, NULL, NULL);
- if (!dquot_cachep)
- panic("Cannot create dquot SLAB cache");
+ SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_PANIC,
+ NULL, NULL);
order = 0;
dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
EXPORT_SYMBOL(register_quota_format);
EXPORT_SYMBOL(unregister_quota_format);
EXPORT_SYMBOL(dqstats);
-EXPORT_SYMBOL(dq_list_lock);
EXPORT_SYMBOL(dq_data_lock);
EXPORT_SYMBOL(vfs_quota_on);
EXPORT_SYMBOL(vfs_quota_on_mount);
EXPORT_SYMBOL(vfs_set_dqblk);
EXPORT_SYMBOL(dquot_commit);
EXPORT_SYMBOL(dquot_commit_info);
+EXPORT_SYMBOL(dquot_acquire);
+EXPORT_SYMBOL(dquot_release);
EXPORT_SYMBOL(dquot_mark_dquot_dirty);
EXPORT_SYMBOL(dquot_initialize);
EXPORT_SYMBOL(dquot_drop);
git://git.onelab.eu / linux-2.6.git / blobdiff