diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-25 02:01:30 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-25 02:01:30 (GMT) |
commit | d39dd11c3e6a7af5c20bfac40594db36cf270f42 (patch) | |
tree | 6384e07fa2f347b286cde9754c4507b5a738ab47 /fs | |
parent | 30f5b28e7f937608e0407edaa459cc8161de81d9 (diff) | |
parent | 0b2d0724e26a335cd326eb7ad552c109116a8795 (diff) | |
download | linux-fsl-qoriq-d39dd11c3e6a7af5c20bfac40594db36cf270f42.tar.xz |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
fs: simplify iget & friends
fs: pull inode->i_lock up out of writeback_single_inode
fs: rename inode_lock to inode_hash_lock
fs: move i_wb_list out from under inode_lock
fs: move i_sb_list out from under inode_lock
fs: remove inode_lock from iput_final and prune_icache
fs: Lock the inode LRU list separately
fs: factor inode disposal
fs: protect inode->i_state with inode->i_lock
autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd()
autofs4 - remove autofs4_lock
autofs4 - fix d_manage() return on rcu-walk
autofs4 - fix autofs4_expire_indirect() traversal
autofs4 - fix dentry leak in autofs4_expire_direct()
autofs4 - reinstate last used update on access
vfs - check non-mountpoint dentry might block in __follow_mount_rcu()
Diffstat (limited to 'fs')
-rw-r--r-- | fs/autofs4/autofs_i.h | 2 | ||||
-rw-r--r-- | fs/autofs4/dev-ioctl.c | 4 | ||||
-rw-r--r-- | fs/autofs4/expire.c | 84 | ||||
-rw-r--r-- | fs/autofs4/root.c | 62 | ||||
-rw-r--r-- | fs/autofs4/waitq.c | 6 | ||||
-rw-r--r-- | fs/block_dev.c | 6 | ||||
-rw-r--r-- | fs/buffer.c | 2 | ||||
-rw-r--r-- | fs/drop_caches.c | 18 | ||||
-rw-r--r-- | fs/fs-writeback.c | 141 | ||||
-rw-r--r-- | fs/inode.c | 656 | ||||
-rw-r--r-- | fs/internal.h | 7 | ||||
-rw-r--r-- | fs/logfs/inode.c | 2 | ||||
-rw-r--r-- | fs/namei.c | 23 | ||||
-rw-r--r-- | fs/notify/inode_mark.c | 42 | ||||
-rw-r--r-- | fs/notify/mark.c | 1 | ||||
-rw-r--r-- | fs/notify/vfsmount_mark.c | 1 | ||||
-rw-r--r-- | fs/ntfs/inode.c | 4 | ||||
-rw-r--r-- | fs/quota/dquot.c | 41 |
18 files changed, 586 insertions, 516 deletions
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index 54f9237..475f9c5 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -61,8 +61,6 @@ do { \ current->pid, __func__, ##args); \ } while (0) -extern spinlock_t autofs4_lock; - /* Unified info structure. This is pointed to by both the dentry and inode structures. Each file in the filesystem has an instance of this structure. It holds a reference to the dentry, so dentries are never diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c index 1442da4..509fe1e 100644 --- a/fs/autofs4/dev-ioctl.c +++ b/fs/autofs4/dev-ioctl.c @@ -372,6 +372,10 @@ static int autofs_dev_ioctl_setpipefd(struct file *fp, return -EBUSY; } else { struct file *pipe = fget(pipefd); + if (!pipe) { + err = -EBADF; + goto out; + } if (!pipe->f_op || !pipe->f_op->write) { err = -EPIPE; fput(pipe); diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index f43100b..450f529 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -87,18 +87,70 @@ done: } /* + * Calculate and dget next entry in the subdirs list under root. + */ +static struct dentry *get_next_positive_subdir(struct dentry *prev, + struct dentry *root) +{ + struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb); + struct list_head *next; + struct dentry *p, *q; + + spin_lock(&sbi->lookup_lock); + + if (prev == NULL) { + spin_lock(&root->d_lock); + prev = dget_dlock(root); + next = prev->d_subdirs.next; + p = prev; + goto start; + } + + p = prev; + spin_lock(&p->d_lock); +again: + next = p->d_u.d_child.next; +start: + if (next == &root->d_subdirs) { + spin_unlock(&p->d_lock); + spin_unlock(&sbi->lookup_lock); + dput(prev); + return NULL; + } + + q = list_entry(next, struct dentry, d_u.d_child); + + spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED); + /* Negative dentry - try next */ + if (!simple_positive(q)) { + spin_unlock(&p->d_lock); + p = q; + goto again; + } + dget_dlock(q); + spin_unlock(&q->d_lock); + spin_unlock(&p->d_lock); + spin_unlock(&sbi->lookup_lock); + + dput(prev); + + return q; +} + +/* * Calculate and dget next entry in top down tree traversal. */ static struct dentry *get_next_positive_dentry(struct dentry *prev, struct dentry *root) { + struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb); struct list_head *next; struct dentry *p, *ret; if (prev == NULL) return dget(root); - spin_lock(&autofs4_lock); + spin_lock(&sbi->lookup_lock); relock: p = prev; spin_lock(&p->d_lock); @@ -110,7 +162,7 @@ again: if (p == root) { spin_unlock(&p->d_lock); - spin_unlock(&autofs4_lock); + spin_unlock(&sbi->lookup_lock); dput(prev); return NULL; } @@ -140,7 +192,7 @@ again: dget_dlock(ret); spin_unlock(&ret->d_lock); spin_unlock(&p->d_lock); - spin_unlock(&autofs4_lock); + spin_unlock(&sbi->lookup_lock); dput(prev); @@ -290,11 +342,8 @@ struct dentry *autofs4_expire_direct(struct super_block *sb, spin_lock(&sbi->fs_lock); ino = autofs4_dentry_ino(root); /* No point expiring a pending mount */ - if (ino->flags & AUTOFS_INF_PENDING) { - spin_unlock(&sbi->fs_lock); - return NULL; - } - managed_dentry_set_transit(root); + if (ino->flags & AUTOFS_INF_PENDING) + goto out; if (!autofs4_direct_busy(mnt, root, timeout, do_now)) { struct autofs_info *ino = autofs4_dentry_ino(root); ino->flags |= AUTOFS_INF_EXPIRING; @@ -302,7 +351,7 @@ struct dentry *autofs4_expire_direct(struct super_block *sb, spin_unlock(&sbi->fs_lock); return root; } - managed_dentry_clear_transit(root); +out: spin_unlock(&sbi->fs_lock); dput(root); @@ -336,13 +385,12 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, timeout = sbi->exp_timeout; dentry = NULL; - while ((dentry = get_next_positive_dentry(dentry, root))) { + while ((dentry = get_next_positive_subdir(dentry, root))) { spin_lock(&sbi->fs_lock); ino = autofs4_dentry_ino(dentry); /* No point expiring a pending mount */ if (ino->flags & AUTOFS_INF_PENDING) - goto cont; - managed_dentry_set_transit(dentry); + goto next; /* * Case 1: (i) indirect mount or top level pseudo direct mount @@ -402,8 +450,6 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, } } next: - managed_dentry_clear_transit(dentry); -cont: spin_unlock(&sbi->fs_lock); } return NULL; @@ -415,13 +461,13 @@ found: ino->flags |= AUTOFS_INF_EXPIRING; init_completion(&ino->expire_complete); spin_unlock(&sbi->fs_lock); - spin_lock(&autofs4_lock); + spin_lock(&sbi->lookup_lock); spin_lock(&expired->d_parent->d_lock); spin_lock_nested(&expired->d_lock, DENTRY_D_LOCK_NESTED); list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child); spin_unlock(&expired->d_lock); spin_unlock(&expired->d_parent->d_lock); - spin_unlock(&autofs4_lock); + spin_unlock(&sbi->lookup_lock); return expired; } @@ -484,8 +530,6 @@ int autofs4_expire_run(struct super_block *sb, spin_lock(&sbi->fs_lock); ino = autofs4_dentry_ino(dentry); ino->flags &= ~AUTOFS_INF_EXPIRING; - if (!d_unhashed(dentry)) - managed_dentry_clear_transit(dentry); complete_all(&ino->expire_complete); spin_unlock(&sbi->fs_lock); @@ -513,9 +557,7 @@ int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt, spin_lock(&sbi->fs_lock); ino->flags &= ~AUTOFS_INF_EXPIRING; spin_lock(&dentry->d_lock); - if (ret) - __managed_dentry_clear_transit(dentry); - else { + if (!ret) { if ((IS_ROOT(dentry) || (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent))) && diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index e6f84d2..96804a1 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -23,8 +23,6 @@ #include "autofs_i.h" -DEFINE_SPINLOCK(autofs4_lock); - static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); static int autofs4_dir_unlink(struct inode *,struct dentry *); static int autofs4_dir_rmdir(struct inode *,struct dentry *); @@ -125,15 +123,15 @@ static int autofs4_dir_open(struct inode *inode, struct file *file) * autofs file system so just let the libfs routines handle * it. */ - spin_lock(&autofs4_lock); + spin_lock(&sbi->lookup_lock); spin_lock(&dentry->d_lock); if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { spin_unlock(&dentry->d_lock); - spin_unlock(&autofs4_lock); + spin_unlock(&sbi->lookup_lock); return -ENOENT; } spin_unlock(&dentry->d_lock); - spin_unlock(&autofs4_lock); + spin_unlock(&sbi->lookup_lock); out: return dcache_dir_open(inode, file); @@ -171,7 +169,6 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry) const unsigned char *str = name->name; struct list_head *p, *head; - spin_lock(&autofs4_lock); spin_lock(&sbi->lookup_lock); head = &sbi->active_list; list_for_each(p, head) { @@ -204,14 +201,12 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry) dget_dlock(active); spin_unlock(&active->d_lock); spin_unlock(&sbi->lookup_lock); - spin_unlock(&autofs4_lock); return active; } next: spin_unlock(&active->d_lock); } spin_unlock(&sbi->lookup_lock); - spin_unlock(&autofs4_lock); return NULL; } @@ -226,7 +221,6 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) const unsigned char *str = name->name; struct list_head *p, *head; - spin_lock(&autofs4_lock); spin_lock(&sbi->lookup_lock); head = &sbi->expiring_list; list_for_each(p, head) { @@ -259,14 +253,12 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) dget_dlock(expiring); spin_unlock(&expiring->d_lock); spin_unlock(&sbi->lookup_lock); - spin_unlock(&autofs4_lock); return expiring; } next: spin_unlock(&expiring->d_lock); } spin_unlock(&sbi->lookup_lock); - spin_unlock(&autofs4_lock); return NULL; } @@ -275,17 +267,16 @@ static int autofs4_mount_wait(struct dentry *dentry) { struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); - int status; + int status = 0; if (ino->flags & AUTOFS_INF_PENDING) { DPRINTK("waiting for mount name=%.*s", dentry->d_name.len, dentry->d_name.name); status = autofs4_wait(sbi, dentry, NFY_MOUNT); DPRINTK("mount wait done status=%d", status); - ino->last_used = jiffies; - return status; } - return 0; + ino->last_used = jiffies; + return status; } static int do_expire_wait(struct dentry *dentry) @@ -319,9 +310,12 @@ static struct dentry *autofs4_mountpoint_changed(struct path *path) */ if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { struct dentry *parent = dentry->d_parent; + struct autofs_info *ino; struct dentry *new = d_lookup(parent, &dentry->d_name); if (!new) return NULL; + ino = autofs4_dentry_ino(new); + ino->last_used = jiffies; dput(path->dentry); path->dentry = new; } @@ -338,18 +332,6 @@ static struct vfsmount *autofs4_d_automount(struct path *path) DPRINTK("dentry=%p %.*s", dentry, dentry->d_name.len, dentry->d_name.name); - /* - * Someone may have manually umounted this or it was a submount - * that has gone away. - */ - spin_lock(&dentry->d_lock); - if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { - if (!(dentry->d_flags & DCACHE_MANAGE_TRANSIT) && - (dentry->d_flags & DCACHE_NEED_AUTOMOUNT)) - __managed_dentry_set_transit(path->dentry); - } - spin_unlock(&dentry->d_lock); - /* The daemon never triggers a mount. */ if (autofs4_oz_mode(sbi)) return NULL; @@ -418,18 +400,17 @@ static struct vfsmount *autofs4_d_automount(struct path *path) done: if (!(ino->flags & AUTOFS_INF_EXPIRING)) { /* - * Any needed mounting has been completed and the path updated - * so turn this into a normal dentry so we don't continually - * call ->d_automount() and ->d_manage(). - */ - spin_lock(&dentry->d_lock); - __managed_dentry_clear_transit(dentry); - /* + * Any needed mounting has been completed and the path + * updated so clear DCACHE_NEED_AUTOMOUNT so we don't + * call ->d_automount() on rootless multi-mounts since + * it can lead to an incorrect ELOOP error return. + * * Only clear DMANAGED_AUTOMOUNT for rootless multi-mounts and * symlinks as in all other cases the dentry will be covered by * an actual mount so ->d_automount() won't be called during * the follow. */ + spin_lock(&dentry->d_lock); if ((!d_mountpoint(dentry) && !list_empty(&dentry->d_subdirs)) || (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode))) @@ -455,6 +436,8 @@ int autofs4_d_manage(struct dentry *dentry, bool rcu_walk) /* The daemon never waits. */ if (autofs4_oz_mode(sbi)) { + if (rcu_walk) + return 0; if (!d_mountpoint(dentry)) return -EISDIR; return 0; @@ -612,12 +595,12 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) dir->i_mtime = CURRENT_TIME; - spin_lock(&autofs4_lock); - autofs4_add_expiring(dentry); + spin_lock(&sbi->lookup_lock); + __autofs4_add_expiring(dentry); spin_lock(&dentry->d_lock); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&autofs4_lock); + spin_unlock(&sbi->lookup_lock); return 0; } @@ -686,20 +669,17 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) if (!autofs4_oz_mode(sbi)) return -EACCES; - spin_lock(&autofs4_lock); spin_lock(&sbi->lookup_lock); spin_lock(&dentry->d_lock); if (!list_empty(&dentry->d_subdirs)) { spin_unlock(&dentry->d_lock); spin_unlock(&sbi->lookup_lock); - spin_unlock(&autofs4_lock); return -ENOTEMPTY; } __autofs4_add_expiring(dentry); - spin_unlock(&sbi->lookup_lock); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&autofs4_lock); + spin_unlock(&sbi->lookup_lock); if (sbi->version < 5) autofs_clear_leaf_automount_flags(dentry); diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c index 5601005..2543598 100644 --- a/fs/autofs4/waitq.c +++ b/fs/autofs4/waitq.c @@ -197,12 +197,12 @@ rename_retry: seq = read_seqbegin(&rename_lock); rcu_read_lock(); - spin_lock(&autofs4_lock); + spin_lock(&sbi->fs_lock); for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent) len += tmp->d_name.len + 1; if (!len || --len > NAME_MAX) { - spin_unlock(&autofs4_lock); + spin_unlock(&sbi->fs_lock); rcu_read_unlock(); if (read_seqretry(&rename_lock, seq)) goto rename_retry; @@ -218,7 +218,7 @@ rename_retry: p -= tmp->d_name.len; strncpy(p, tmp->d_name.name, tmp->d_name.len); } - spin_unlock(&autofs4_lock); + spin_unlock(&sbi->fs_lock); rcu_read_unlock(); if (read_seqretry(&rename_lock, seq)) goto rename_retry; diff --git a/fs/block_dev.c b/fs/block_dev.c index 7d02afb..c1511c6 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -55,11 +55,13 @@ EXPORT_SYMBOL(I_BDEV); static void bdev_inode_switch_bdi(struct inode *inode, struct backing_dev_info *dst) { - spin_lock(&inode_lock); + spin_lock(&inode_wb_list_lock); + spin_lock(&inode->i_lock); inode->i_data.backing_dev_info = dst; if (inode->i_state & I_DIRTY) list_move(&inode->i_wb_list, &dst->wb.b_dirty); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_wb_list_lock); } static sector_t max_block(struct block_device *bdev) diff --git a/fs/buffer.c b/fs/buffer.c index 2e6b1a3..a08bb8e 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1138,7 +1138,7 @@ __getblk_slow(struct block_device *bdev, sector_t block, int size) * inode list. * * mark_buffer_dirty() is atomic. It takes bh->b_page->mapping->private_lock, - * mapping->tree_lock and the global inode_lock. + * mapping->tree_lock and mapping->host->i_lock. */ void mark_buffer_dirty(struct buffer_head *bh) { diff --git a/fs/drop_caches.c b/fs/drop_caches.c index 816f88e..98b77c8 100644 --- a/fs/drop_caches.c +++ b/fs/drop_caches.c @@ -8,6 +8,7 @@ #include <linux/writeback.h> #include <linux/sysctl.h> #include <linux/gfp.h> +#include "internal.h" /* A global variable is a bit ugly, but it keeps the code simple */ int sysctl_drop_caches; @@ -16,20 +17,23 @@ static void drop_pagecache_sb(struct super_block *sb, void *unused) { struct inode *inode, *toput_inode = NULL; - spin_lock(&inode_lock); + spin_lock(&inode_sb_list_lock); list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { - if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) - continue; - if (inode->i_mapping->nrpages == 0) + spin_lock(&inode->i_lock); + if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || + (inode->i_mapping->nrpages == 0)) { + spin_unlock(&inode->i_lock); continue; + } __iget(inode); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_sb_list_lock); invalidate_mapping_pages(inode->i_mapping, 0, -1); iput(toput_inode); toput_inode = inode; - spin_lock(&inode_lock); + spin_lock(&inode_sb_list_lock); } - spin_unlock(&inode_lock); + spin_unlock(&inode_sb_list_lock); iput(toput_inode); } diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 59c6e49..b5ed541 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -176,6 +176,17 @@ void bdi_start_background_writeback(struct backing_dev_info *bdi) } /* + * Remove the inode from the writeback list it is on. + */ +void inode_wb_list_del(struct inode *inode) +{ + spin_lock(&inode_wb_list_lock); + list_del_init(&inode->i_wb_list); + spin_unlock(&inode_wb_list_lock); +} + + +/* * Redirty an inode: set its when-it-was dirtied timestamp and move it to the * furthest end of its superblock's dirty-inode list. * @@ -188,6 +199,7 @@ static void redirty_tail(struct inode *inode) { struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; + assert_spin_locked(&inode_wb_list_lock); if (!list_empty(&wb->b_dirty)) { struct inode *tail; @@ -205,14 +217,17 @@ static void requeue_io(struct inode *inode) { struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; + assert_spin_locked(&inode_wb_list_lock); list_move(&inode->i_wb_list, &wb->b_more_io); } static void inode_sync_complete(struct inode *inode) { /* - * Prevent speculative execution through spin_unlock(&inode_lock); + * Prevent speculative execution through + * spin_unlock(&inode_wb_list_lock); */ + smp_mb(); wake_up_bit(&inode->i_state, __I_SYNC); } @@ -286,6 +301,7 @@ static void move_expired_inodes(struct list_head *delaying_queue, */ static void queue_io(struct bdi_writeback *wb, unsigned long *older_than_this) { + assert_spin_locked(&inode_wb_list_lock); list_splice_init(&wb->b_more_io, &wb->b_io); move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this); } @@ -306,25 +322,25 @@ static void inode_wait_for_writeback(struct inode *inode) wait_queue_head_t *wqh; wqh = bit_waitqueue(&inode->i_state, __I_SYNC); - while (inode->i_state & I_SYNC) { - spin_unlock(&inode_lock); + while (inode->i_state & I_SYNC) { + spin_unlock(&inode->i_lock); + spin_unlock(&inode_wb_list_lock); __wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE); - spin_lock(&inode_lock); + spin_lock(&inode_wb_list_lock); + spin_lock(&inode->i_lock); } } /* - * Write out an inode's dirty pages. Called under inode_lock. Either the - * caller has ref on the inode (either via __iget or via syscall against an fd) - * or the inode has I_WILL_FREE set (via generic_forget_inode) + * Write out an inode's dirty pages. Called under inode_wb_list_lock and + * inode->i_lock. Either the caller has an active reference on the inode or + * the inode has I_WILL_FREE set. * * If `wait' is set, wait on the writeout. * * The whole writeout design is quite complex and fragile. We want to avoid * starvation of particular inodes when others are being redirtied, prevent * livelocks, etc. - * - * Called under inode_lock. */ static int writeback_single_inode(struct inode *inode, struct writeback_control *wbc) @@ -333,6 +349,9 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) unsigned dirty; int ret; + assert_spin_locked(&inode_wb_list_lock); + assert_spin_locked(&inode->i_lock); + if (!atomic_read(&inode->i_count)) WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING))); else @@ -363,7 +382,8 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) /* Set I_SYNC, reset I_DIRTY_PAGES */ inode->i_state |= I_SYNC; inode->i_state &= ~I_DIRTY_PAGES; - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_wb_list_lock); ret = do_writepages(mapping, wbc); @@ -383,10 +403,10 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * due to delalloc, clear dirty metadata flags right before * write_inode() */ - spin_lock(&inode_lock); + spin_lock(&inode->i_lock); dirty = inode->i_state & I_DIRTY; inode->i_state &= ~(I_DIRTY_SYNC | I_DIRTY_DATASYNC); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); /* Don't write the inode if only I_DIRTY_PAGES was set */ if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { int err = write_inode(inode, wbc); @@ -394,7 +414,8 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) ret = err; } - spin_lock(&inode_lock); + spin_lock(&inode_wb_list_lock); + spin_lock(&inode->i_lock); inode->i_state &= ~I_SYNC; if (!(inode->i_state & I_FREEING)) { if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { @@ -506,7 +527,9 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, * kind does not need peridic writeout yet, and for the latter * kind writeout is handled by the freer. */ + spin_lock(&inode->i_lock); if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { + spin_unlock(&inode->i_lock); requeue_io(inode); continue; } @@ -515,10 +538,13 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, * Was this inode dirtied after sync_sb_inodes was called? * This keeps sync from extra jobs and livelock. */ - if (inode_dirtied_after(inode, wbc->wb_start)) + if (inode_dirtied_after(inode, wbc->wb_start)) { + spin_unlock(&inode->i_lock); return 1; + } __iget(inode); + pages_skipped = wbc->pages_skipped; writeback_single_inode(inode, wbc); if (wbc->pages_skipped != pages_skipped) { @@ -528,10 +554,11 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, */ redirty_tail(inode); } - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_wb_list_lock); iput(inode); cond_resched(); - spin_lock(&inode_lock); + spin_lock(&inode_wb_list_lock); if (wbc->nr_to_write <= 0) { wbc->more_io = 1; return 1; @@ -550,7 +577,7 @@ void writeback_inodes_wb(struct bdi_writeback *wb, if (!wbc->wb_start) wbc->wb_start = jiffies; /* livelock avoidance */ - spin_lock(&inode_lock); + spin_lock(&inode_wb_list_lock); if (!wbc->for_kupdate || list_empty(&wb->b_io)) queue_io(wb, wbc->older_than_this); @@ -568,7 +595,7 @@ void writeback_inodes_wb(struct bdi_writeback *wb, if (ret) break; } - spin_unlock(&inode_lock); + spin_unlock(&inode_wb_list_lock); /* Leave any unwritten inodes on b_io */ } @@ -577,11 +604,11 @@ static void __writeback_inodes_sb(struct super_block *sb, { WARN_ON(!rwsem_is_locked(&sb->s_umount)); - spin_lock(&inode_lock); + spin_lock(&inode_wb_list_lock); if (!wbc->for_kupdate || list_empty(&wb->b_io)) queue_io(wb, wbc->older_than_this); writeback_sb_inodes(sb, wb, wbc, true); - spin_unlock(&inode_lock); + spin_unlock(&inode_wb_list_lock); } /* @@ -720,13 +747,15 @@ static long wb_writeback(struct bdi_writeback *wb, * become available for writeback. Otherwise * we'll just busyloop. */ - spin_lock(&inode_lock); + spin_lock(&inode_wb_list_lock); if (!list_empty(&wb->b_more_io)) { inode = wb_inode(wb->b_more_io.prev); trace_wbc_writeback_wait(&wbc, wb->bdi); + spin_lock(&inode->i_lock); inode_wait_for_writeback(inode); + spin_unlock(&inode->i_lock); } - spin_unlock(&inode_lock); + spin_unlock(&inode_wb_list_lock); } return wrote; @@ -992,7 +1021,6 @@ void __mark_inode_dirty(struct inode *inode, int flags) { struct super_block *sb = inode->i_sb; struct backing_dev_info *bdi = NULL; - bool wakeup_bdi = false; /* * Don't do this for I_DIRTY_PAGES - that doesn't actually @@ -1016,7 +1044,7 @@ void __mark_inode_dirty(struct inode *inode, int flags) if (unlikely(block_dump)) block_dump___mark_inode_dirty(inode); - spin_lock(&inode_lock); + spin_lock(&inode->i_lock); if ((inode->i_state & flags) != flags) { const int was_dirty = inode->i_state & I_DIRTY; @@ -1028,7 +1056,7 @@ void __mark_inode_dirty(struct inode *inode, int flags) * superblock list, based upon its state. */ if (inode->i_state & I_SYNC) - goto out; + goto out_unlock_inode; /* * Only add valid (hashed) inodes to the superblock's @@ -1036,16 +1064,17 @@ void __mark_inode_dirty(struct inode *inode, int flags) */ if (!S_ISBLK(inode->i_mode)) { if (inode_unhashed(inode)) - goto out; + goto out_unlock_inode; } if (inode->i_state & I_FREEING) - goto out; + goto out_unlock_inode; /* * If the inode was already on b_dirty/b_io/b_more_io, don't * reposition it (that would break b_dirty time-ordering). */ if (!was_dirty) { + bool wakeup_bdi = false; bdi = inode_to_bdi(inode); if (bdi_cap_writeback_dirty(bdi)) { @@ -1062,15 +1091,20 @@ void __mark_inode_dirty(struct inode *inode, int flags) wakeup_bdi = true; } + spin_unlock(&inode->i_lock); + spin_lock(&inode_wb_list_lock); inode->dirtied_when = jiffies; list_move(&inode->i_wb_list, &bdi->wb.b_dirty); + spin_unlock(&inode_wb_list_lock); + + if (wakeup_bdi) + bdi_wakeup_thread_delayed(bdi); + return; } } -out: - spin_unlock(&inode_lock); +out_unlock_inode: + spin_unlock(&inode->i_lock); - if (wakeup_bdi) - bdi_wakeup_thread_delayed(bdi); } EXPORT_SYMBOL(__mark_inode_dirty); @@ -1101,7 +1135,7 @@ static void wait_sb_inodes(struct super_block *sb) */ WARN_ON(!rwsem_is_locked(&sb->s_umount)); - spin_lock(&inode_lock); + spin_lock(&inode_sb_list_lock); /* * Data integrity sync. Must wait for all pages under writeback, @@ -1111,22 +1145,25 @@ static void wait_sb_inodes(struct super_block *sb) * we still have to wait for that writeout. */ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { - struct address_space *mapping; + struct address_space *mapping = inode->i_mapping; - if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) - continue; - mapping = inode->i_mapping; - if (mapping->nrpages == 0) + spin_lock(&inode->i_lock); + if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || + (mapping->nrpages == 0)) { + spin_unlock(&inode->i_lock); continue; + } __iget(inode); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_sb_list_lock); + /* - * We hold a reference to 'inode' so it couldn't have - * been removed from s_inodes list while we dropped the - * inode_lock. We cannot iput the inode now as we can - * be holding the last reference and we cannot iput it - * under inode_lock. So we keep the reference and iput - * it later. + * We hold a reference to 'inode' so it couldn't have been + * removed from s_inodes list while we dropped the + * inode_sb_list_lock. We cannot iput the inode now as we can + * be holding the last reference and we cannot iput it under + * inode_sb_list_lock. So we keep the reference and iput it + * later. */ iput(old_inode); old_inode = inode; @@ -1135,9 +1172,9 @@ static void wait_sb_inodes(struct super_block *sb) cond_resched(); - spin_lock(&inode_lock); + spin_lock(&inode_sb_list_lock); } - spin_unlock(&inode_lock); + spin_unlock(&inode_sb_list_lock); iput(old_inode); } @@ -1271,9 +1308,11 @@ int write_inode_now(struct inode *inode, int sync) wbc.nr_to_write = 0; might_sleep(); - spin_lock(&inode_lock); + spin_lock(&inode_wb_list_lock); + spin_lock(&inode->i_lock); ret = writeback_single_inode(inode, &wbc); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_wb_list_lock); if (sync) inode_sync_wait(inode); return ret; @@ -1295,9 +1334,11 @@ int sync_inode(struct inode *inode, struct writeback_control *wbc) { int ret; - spin_lock(&inode_lock); + spin_lock(&inode_wb_list_lock); + spin_lock(&inode->i_lock); ret = writeback_single_inode(inode, wbc); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_wb_list_lock); return ret; } EXPORT_SYMBOL(sync_inode); @@ -26,6 +26,38 @@ #include <linux/posix_acl.h> #include <linux/ima.h> #include <linux/cred.h> +#include "internal.h" + +/* + * inode locking rules. + * + * inode->i_lock protects: + * inode->i_state, inode->i_hash, __iget() + * inode_lru_lock protects: + * inode_lru, inode->i_lru + * inode_sb_list_lock protects: + * sb->s_inodes, inode->i_sb_list + * inode_wb_list_lock protects: + * bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list + * inode_hash_lock protects: + * inode_hashtable, inode->i_hash + * + * Lock ordering: + * + * inode_sb_list_lock + * inode->i_lock + * inode_lru_lock + * + * inode_wb_list_lock + * inode->i_lock + * + * inode_hash_lock + * inode_sb_list_lock + * inode->i_lock + * + * iunique_lock + * inode_hash_lock + */ /* * This is needed for the following functions: @@ -60,6 +92,8 @@ static unsigned int i_hash_mask __read_mostly; static unsigned int i_hash_shift __read_mostly; +static struct hlist_head *inode_hashtable __read_mostly; +static __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_hash_lock); /* * Each inode can be on two separate lists. One is @@ -74,15 +108,10 @@ static unsigned int i_hash_shift __read_mostly; */ static LIST_HEAD(inode_lru); -static struct hlist_head *inode_hashtable __read_mostly; +static DEFINE_SPINLOCK(inode_lru_lock); -/* - * A simple spinlock to protect the list manipulations. - * - * NOTE! You also have to own the lock if you change - * the i_state of an inode while it is in use.. - */ -DEFINE_SPINLOCK(inode_lock); +__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock); +__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_wb_list_lock); /* * iprune_sem provides exclusion between the icache shrinking and the @@ -137,15 +166,6 @@ int proc_nr_inodes(ctl_table *table, int write, } #endif -static void wake_up_inode(struct inode *inode) -{ - /* - * Prevent speculative execution through spin_unlock(&inode_lock); - */ - smp_mb(); - wake_up_bit(&inode->i_state, __I_NEW); -} - /** * inode_init_always - perform inode structure intialisation * @sb: superblock inode belongs to @@ -336,7 +356,7 @@ static void init_once(void *foo) } /* - * inode_lock must be held + * inode->i_lock must be held */ void __iget(struct inode *inode) { @@ -354,23 +374,22 @@ EXPORT_SYMBOL(ihold); static void inode_lru_list_add(struct inode *inode) { + spin_lock(&inode_lru_lock); if (list_empty(&inode->i_lru)) { list_add(&inode->i_lru, &inode_lru); inodes_stat.nr_unused++; } + spin_unlock(&inode_lru_lock); } static void inode_lru_list_del(struct inode *inode) { + spin_lock(&inode_lru_lock); if (!list_empty(&inode->i_lru)) { list_del_init(&inode->i_lru); inodes_stat.nr_unused--; } -} - -static inline void __inode_sb_list_add(struct inode *inode) -{ - list_add(&inode->i_sb_list, &inode->i_sb->s_inodes); + spin_unlock(&inode_lru_lock); } /** @@ -379,15 +398,17 @@ static inline void __inode_sb_list_add(struct inode *inode) */ void inode_sb_list_add(struct inode *inode) { - spin_lock(&inode_lock); - __inode_sb_list_add(inode); - spin_unlock(&inode_lock); + spin_lock(&inode_sb_list_lock); + list_add(&inode->i_sb_list, &inode->i_sb->s_inodes); + spin_unlock(&inode_sb_list_lock); } EXPORT_SYMBOL_GPL(inode_sb_list_add); -static inline void __inode_sb_list_del(struct inode *inode) +static inline void inode_sb_list_del(struct inode *inode) { + spin_lock(&inode_sb_list_lock); list_del_init(&inode->i_sb_list); + spin_unlock(&inode_sb_list_lock); } static unsigned long hash(struct super_block *sb, unsigned long hashval) @@ -412,24 +433,15 @@ void __insert_inode_hash(struct inode *inode, unsigned long hashval) { struct hlist_head *b = inode_hashtable + hash(inode->i_sb, hashval); - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); + spin_lock(&inode->i_lock); hlist_add_head(&inode->i_hash, b); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_hash_lock); } EXPORT_SYMBOL(__insert_inode_hash); /** - * __remove_inode_hash - remove an inode from the hash - * @inode: inode to unhash - * - * Remove an inode from the superblock. - */ -static void __remove_inode_hash(struct inode *inode) -{ - hlist_del_init(&inode->i_hash); -} - -/** * remove_inode_hash - remove an inode from the hash * @inode: inode to unhash * @@ -437,9 +449,11 @@ static void __remove_inode_hash(struct inode *inode) */ void remove_inode_hash(struct inode *inode) { - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); + spin_lock(&inode->i_lock); hlist_del_init(&inode->i_hash); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_hash_lock); } EXPORT_SYMBOL(remove_inode_hash); @@ -456,10 +470,29 @@ void end_writeback(struct inode *inode) } EXPORT_SYMBOL(end_writeback); +/* + * Free the inode passed in, removing it from the lists it is still connected + * to. We remove any pages still attached to the inode and wait for any IO that + * is still in progress before finally destroying the inode. + * + * An inode must already be marked I_FREEING so that we avoid the inode being + * moved back onto lists if we race with other code that manipulates the lists + * (e.g. writeback_single_inode). The caller is responsible for setting this. + * + * An inode must already be removed from the LRU list before being evicted from + * the cache. This should occur atomically with setting the I_FREEING state + * flag, so no inodes here should ever be on the LRU when being evicted. + */ static void evict(struct inode *inode) { const struct super_operations *op = inode->i_sb->s_op; + BUG_ON(!(inode->i_state & I_FREEING)); + BUG_ON(!list_empty(&inode->i_lru)); + + inode_wb_list_del(inode); + inode_sb_list_del(inode); + if (op->evict_inode) { op->evict_inode(inode); } else { @@ -471,6 +504,15 @@ static void evict(struct inode *inode) bd_forget(inode); if (S_ISCHR(inode->i_mode) && inode->i_cdev) cd_forget(inode); + + remove_inode_hash(inode); + + spin_lock(&inode->i_lock); + wake_up_bit(&inode->i_state, __I_NEW); + BUG_ON(inode->i_state != (I_FREEING | I_CLEAR)); + spin_unlock(&inode->i_lock); + + destroy_inode(inode); } /* @@ -489,14 +531,6 @@ static void dispose_list(struct list_head *head) list_del_init(&inode->i_lru); evict(inode); - - spin_lock(&inode_lock); - __remove_inode_hash(inode); - __inode_sb_list_del(inode); - spin_unlock(&inode_lock); - - wake_up_inode(inode); - destroy_inode(inode); } } @@ -514,25 +548,23 @@ void evict_inodes(struct super_block *sb) struct inode *inode, *next; LIST_HEAD(dispose); - spin_lock(&inode_lock); + spin_lock(&inode_sb_list_lock); list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { if (atomic_read(&inode->i_count)) continue; - if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) + + spin_lock(&inode->i_lock); + if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { + spin_unlock(&inode->i_lock); continue; + } inode->i_state |= I_FREEING; - - /* - * Move the inode off the IO lists and LRU once I_FREEING is - * set so that it won't get moved back on there if it is dirty. - */ - list_move(&inode->i_lru, &dispose); - list_del_init(&inode->i_wb_list); - if (!(inode->i_state & (I_DIRTY | I_SYNC))) - inodes_stat.nr_unused--; + inode_lru_list_del(inode); + spin_unlock(&inode->i_lock); + list_add(&inode->i_lru, &dispose); } - spin_unlock(&inode_lock); + spin_unlock(&inode_sb_list_lock); dispose_list(&dispose); @@ -561,31 +593,30 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty) struct inode *inode, *next; LIST_HEAD(dispose); - spin_lock(&inode_lock); + spin_lock(&inode_sb_list_lock); list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { - if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) + spin_lock(&inode->i_lock); + if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { + spin_unlock(&inode->i_lock); continue; + } if (inode->i_state & I_DIRTY && !kill_dirty) { + spin_unlock(&inode->i_lock); busy = 1; continue; } if (atomic_read(&inode->i_count)) { + spin_unlock(&inode->i_lock); busy = 1; continue; } inode->i_state |= I_FREEING; - - /* - * Move the inode off the IO lists and LRU once I_FREEING is - * set so that it won't get moved back on there if it is dirty. - */ - list_move(&inode->i_lru, &dispose); - list_del_init(&inode->i_wb_list); - if (!(inode->i_state & (I_DIRTY | I_SYNC))) - inodes_stat.nr_unused--; + inode_lru_list_del(inode); + spin_unlock(&inode->i_lock); + list_add(&inode->i_lru, &dispose); } - spin_unlock(&inode_lock); + spin_unlock(&inode_sb_list_lock); dispose_list(&dispose); @@ -607,7 +638,7 @@ static int can_unuse(struct inode *inode) /* * Scan `goal' inodes on the unused list for freeable ones. They are moved to a - * temporary list and then are freed outside inode_lock by dispose_list(). + * temporary list and then are freed outside inode_lru_lock by dispose_list(). * * Any inodes which are pinned purely because of attached pagecache have their * pagecache removed. If the inode has metadata buffers attached to @@ -628,7 +659,7 @@ static void prune_icache(int nr_to_scan) unsigned long reap = 0; down_read(&iprune_sem); - spin_lock(&inode_lock); + spin_lock(&inode_lru_lock); for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { struct inode *inode; @@ -638,53 +669,67 @@ static void prune_icache(int nr_to_scan) inode = list_entry(inode_lru.prev, struct inode, i_lru); /* + * we are inverting the inode_lru_lock/inode->i_lock here, + * so use a trylock. If we fail to get the lock, just move the + * inode to the back of the list so we don't spin on it. + */ + if (!spin_trylock(&inode->i_lock)) { + list_move(&inode->i_lru, &inode_lru); + continue; + } + + /* * Referenced or dirty inodes are still in use. Give them * another pass through the LRU as we canot reclaim them now. */ if (atomic_read(&inode->i_count) || (inode->i_state & ~I_REFERENCED)) { list_del_init(&inode->i_lru); + spin_unlock(&inode->i_lock); inodes_stat.nr_unused--; continue; } /* recently referenced inodes get one more pass */ if (inode->i_state & I_REFERENCED) { - list_move(&inode->i_lru, &inode_lru); inode->i_state &= ~I_REFERENCED; + list_move(&inode->i_lru, &inode_lru); + spin_unlock(&inode->i_lock); continue; } if (inode_has_buffers(inode) || inode->i_data.nrpages) { __iget(inode); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_lru_lock); if (remove_inode_buffers(inode)) reap += invalidate_mapping_pages(&inode->i_data, 0, -1); iput(inode); - spin_lock(&inode_lock); + spin_lock(&inode_lru_lock); if (inode != list_entry(inode_lru.next, struct inode, i_lru)) continue; /* wrong inode or list_empty */ - if (!can_unuse(inode)) + /* avoid lock inversions with trylock */ + if (!spin_trylock(&inode->i_lock)) + continue; + if (!can_unuse(inode)) { + spin_unlock(&inode->i_lock); continue; + } } WARN_ON(inode->i_state & I_NEW); inode->i_state |= I_FREEING; + spin_unlock(&inode->i_lock); - /* - * Move the inode off the IO lists and LRU once I_FREEING is - * set so that it won't get moved back on there if it is dirty. - */ list_move(&inode->i_lru, &freeable); - list_del_init(&inode->i_wb_list); inodes_stat.nr_unused--; } if (current_is_kswapd()) __count_vm_events(KSWAPD_INODESTEAL, reap); else __count_vm_events(PGINODESTEAL, reap); - spin_unlock(&inode_lock); + spin_unlock(&inode_lru_lock); dispose_list(&freeable); up_read(&iprune_sem); @@ -733,15 +778,21 @@ static struct inode *find_inode(struct super_block *sb, repeat: hlist_for_each_entry(inode, node, head, i_hash) { - if (inode->i_sb != sb) + spin_lock(&inode->i_lock); + if (inode->i_sb != sb) { + spin_unlock(&inode->i_lock); continue; - if (!test(inode, data)) + } + if (!test(inode, data)) { + spin_unlock(&inode->i_lock); continue; + } if (inode->i_state & (I_FREEING|I_WILL_FREE)) { __wait_on_freeing_inode(inode); goto repeat; } __iget(inode); + spin_unlock(&inode->i_lock); return inode; } return NULL; @@ -759,15 +810,21 @@ static struct inode *find_inode_fast(struct super_block *sb, repeat: hlist_for_each_entry(inode, node, head, i_hash) { - if (inode->i_ino != ino) + spin_lock(&inode->i_lock); + if (inode->i_ino != ino) { + spin_unlock(&inode->i_lock); continue; - if (inode->i_sb != sb) + } + if (inode->i_sb != sb) { + spin_unlock(&inode->i_lock); continue; + } if (inode->i_state & (I_FREEING|I_WILL_FREE)) { __wait_on_freeing_inode(inode); goto repeat; } __iget(inode); + spin_unlock(&inode->i_lock); return inode; } return NULL; @@ -827,19 +884,26 @@ struct inode *new_inode(struct super_block *sb) { struct inode *inode; - spin_lock_prefetch(&inode_lock); + spin_lock_prefetch(&inode_sb_list_lock); inode = alloc_inode(sb); if (inode) { - spin_lock(&inode_lock); - __inode_sb_list_add(inode); + spin_lock(&inode->i_lock); inode->i_state = 0; - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + inode_sb_list_add(inode); } return inode; } EXPORT_SYMBOL(new_inode); +/** + * unlock_new_inode - clear the I_NEW state and wake up any waiters + * @inode: new inode to unlock + * + * Called when the inode is fully initialised to clear the new state of the + * inode and wake up anyone waiting for the inode to finish initialisation. + */ void unlock_new_inode(struct inode *inode) { #ifdef CONFIG_DEBUG_LOCK_ALLOC @@ -859,51 +923,67 @@ void unlock_new_inode(struct inode *inode) } } #endif - /* - * This is special! We do not need the spinlock when clearing I_NEW, - * because we're guaranteed that nobody else tries to do anything about - * the state of the inode when it is locked, as we just created it (so - * there can be no old holders that haven't tested I_NEW). - * However we must emit the memory barrier so that other CPUs reliably - * see the clearing of I_NEW after the other inode initialisation has - * completed. - */ - smp_mb(); + spin_lock(&inode->i_lock); WARN_ON(!(inode->i_state & I_NEW)); inode->i_state &= ~I_NEW; - wake_up_inode(inode); + wake_up_bit(&inode->i_state, __I_NEW); + spin_unlock(&inode->i_lock); } EXPORT_SYMBOL(unlock_new_inode); -/* - * This is called without the inode lock held.. Be careful. +/** + * iget5_locked - obtain an inode from a mounted file system + * @sb: super block of file system + * @hashval: hash value (usually inode number) to get + * @test: callback used for comparisons between inodes + * @set: callback used to initialize a new struct inode + * @data: opaque data pointer to pass to @test and @set + * + * Search for the inode specified by @hashval and @data in the inode cache, + * and if present it is return it with an increased reference count. This is + * a generalized version of iget_locked() for file systems where the inode + * number is not sufficient for unique identification of an inode. * - * We no longer cache the sb_flags in i_flags - see fs.h - * -- rmk@arm.uk.linux.org + * If the inode is not in cache, allocate a new inode and return it locked, + * hashed, and with the I_NEW flag set. The file system gets to fill it in + * before unlocking it via unlock_new_inode(). + * + * Note both @test and @set are called with the inode_hash_lock held, so can't + * sleep. */ -static struct inode *get_new_inode(struct super_block *sb, - struct hlist_head *head, - int (*test)(struct inode *, void *), - int (*set)(struct inode *, void *), - void *data) +struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, + int (*test)(struct inode *, void *), + int (*set)(struct inode *, void *), void *data) { + struct hlist_head *head = inode_hashtable + hash(sb, hashval); struct inode *inode; + spin_lock(&inode_hash_lock); + inode = find_inode(sb, head, test, data); + spin_unlock(&inode_hash_lock); + + if (inode) { + wait_on_inode(inode); + return inode; + } + inode = alloc_inode(sb); if (inode) { struct inode *old; - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); /* We released the lock, so.. */ old = find_inode(sb, head, test, data); if (!old) { if (set(inode, data)) goto set_failed; - hlist_add_head(&inode->i_hash, head); - __inode_sb_list_add(inode); + spin_lock(&inode->i_lock); inode->i_state = I_NEW; - spin_unlock(&inode_lock); + hlist_add_head(&inode->i_hash, head); + spin_unlock(&inode->i_lock); + inode_sb_list_add(inode); + spin_unlock(&inode_hash_lock); /* Return the locked inode with I_NEW set, the * caller is responsible for filling in the contents @@ -916,7 +996,7 @@ static struct inode *get_new_inode(struct super_block *sb, * us. Use the old inode instead of the one we just * allocated. */ - spin_unlock(&inode_lock); + spin_unlock(&inode_hash_lock); destroy_inode(inode); inode = old; wait_on_inode(inode); @@ -924,33 +1004,53 @@ static struct inode *get_new_inode(struct super_block *sb, return inode; set_failed: - spin_unlock(&inode_lock); + spin_unlock(&inode_hash_lock); destroy_inode(inode); return NULL; } +EXPORT_SYMBOL(iget5_locked); -/* - * get_new_inode_fast is the fast path version of get_new_inode, see the - * comment at iget_locked for details. +/** + * iget_locked - obtain an inode from a mounted file system + * @sb: super block of file system + * @ino: inode number to get + * + * Search for the inode specified by @ino in the inode cache and if present + * return it with an increased reference count. This is for file systems + * where the inode number is sufficient for unique identification of an inode. + * + * If the inode is not in cache, allocate a new inode and return it locked, + * hashed, and with the I_NEW flag set. The file system gets to fill it in + * before unlocking it via unlock_new_inode(). */ -static struct inode *get_new_inode_fast(struct super_block *sb, - struct hlist_head *head, unsigned long ino) +struct inode *iget_locked(struct super_block *sb, unsigned long ino) { + struct hlist_head *head = inode_hashtable + hash(sb, ino); struct inode *inode; + spin_lock(&inode_hash_lock); + inode = find_inode_fast(sb, head, ino); + spin_unlock(&inode_hash_lock); + if (inode) { + wait_on_inode(inode); + return inode; + } + inode = alloc_inode(sb); if (inode) { struct inode *old; - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); /* We released the lock, so.. */ old = find_inode_fast(sb, head, ino); if (!old) { inode->i_ino = ino; - hlist_add_head(&inode->i_hash, head); - __inode_sb_list_add(inode); + spin_lock(&inode->i_lock); inode->i_state = I_NEW; - spin_unlock(&inode_lock); + hlist_add_head(&inode->i_hash, head); + spin_unlock(&inode->i_lock); + inode_sb_list_add(inode); + spin_unlock(&inode_hash_lock); /* Return the locked inode with I_NEW set, the * caller is responsible for filling in the contents @@ -963,13 +1063,14 @@ static struct inode *get_new_inode_fast(struct super_block *sb, * us. Use the old inode instead of the one we just * allocated. */ - spin_unlock(&inode_lock); + spin_unlock(&inode_hash_lock); destroy_inode(inode); inode = old; wait_on_inode(inode); } return inode; } +EXPORT_SYMBOL(iget_locked); /* * search the inode cache for a matching inode number. @@ -984,10 +1085,14 @@ static int test_inode_iunique(struct super_block *sb, unsigned long ino) struct hlist_node *node; struct inode *inode; + spin_lock(&inode_hash_lock); hlist_for_each_entry(inode, node, b, i_hash) { - if (inode->i_ino == ino && inode->i_sb == sb) + if (inode->i_ino == ino && inode->i_sb == sb) { + spin_unlock(&inode_hash_lock); return 0; + } } + spin_unlock(&inode_hash_lock); return 1; } @@ -1017,7 +1122,6 @@ ino_t iunique(struct super_block *sb, ino_t max_reserved) static unsigned int counter; ino_t res; - spin_lock(&inode_lock); spin_lock(&iunique_lock); do { if (counter <= max_reserved) @@ -1025,7 +1129,6 @@ ino_t iunique(struct super_block *sb, ino_t max_reserved) res = counter++; } while (!test_inode_iunique(sb, res)); spin_unlock(&iunique_lock); - spin_unlock(&inode_lock); return res; } @@ -1033,116 +1136,50 @@ EXPORT_SYMBOL(iunique); struct inode *igrab(struct inode *inode) { - spin_lock(&inode_lock); - if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) + spin_lock(&inode->i_lock); + if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) { __iget(inode); - else + spin_unlock(&inode->i_lock); + } else { + spin_unlock(&inode->i_lock); /* * Handle the case where s_op->clear_inode is not been * called yet, and somebody is calling igrab * while the inode is getting freed. */ inode = NULL; - spin_unlock(&inode_lock); + } return inode; } EXPORT_SYMBOL(igrab); /** - * ifind - internal function, you want ilookup5() or iget5(). - * @sb: super block of file system to search - * @head: the head of the list to search - * @test: callback used for comparisons between inodes - * @data: opaque data pointer to pass to @test - * @wait: if true wait for the inode to be unlocked, if false do not - * - * ifind() searches for the inode specified by @data in the inode - * cache. This is a generalized version of ifind_fast() for file systems where - * the inode number is not sufficient for unique identification of an inode. - * - * If the inode is in the cache, the inode is returned with an incremented - * reference count. - * - * Otherwise NULL is returned. - * - * Note, @test is called with the inode_lock held, so can't sleep. - */ -static struct inode *ifind(struct super_block *sb, - struct hlist_head *head, int (*test)(struct inode *, void *), - void *data, const int wait) -{ - struct inode *inode; - - spin_lock(&inode_lock); - inode = find_inode(sb, head, test, data); - if (inode) { - spin_unlock(&inode_lock); - if (likely(wait)) - wait_on_inode(inode); - return inode; - } - spin_unlock(&inode_lock); - return NULL; -} - -/** - * ifind_fast - internal function, you want ilookup() or iget(). - * @sb: super block of file system to search - * @head: head of the list to search - * @ino: inode number to search for - * - * ifind_fast() searches for the inode @ino in the inode cache. This is for - * file systems where the inode number is sufficient for unique identification - * of an inode. - * - * If the inode is in the cache, the inode is returned with an incremented - * reference count. - * - * Otherwise NULL is returned. - */ -static struct inode *ifind_fast(struct super_block *sb, - struct hlist_head *head, unsigned long ino) -{ - struct inode *inode; - - spin_lock(&inode_lock); - inode = find_inode_fast(sb, head, ino); - if (inode) { - spin_unlock(&inode_lock); - wait_on_inode(inode); - return inode; - } - spin_unlock(&inode_lock); - return NULL; -} - -/** * ilookup5_nowait - search for an inode in the inode cache * @sb: super block of file system to search * @hashval: hash value (usually inode number) to search for * @test: callback used for comparisons between inodes * @data: opaque data pointer to pass to @test * - * ilookup5() uses ifind() to search for the inode specified by @hashval and - * @data in the inode cache. This is a generalized version of ilookup() for - * file systems where the inode number is not sufficient for unique - * identification of an inode. - * + * Search for the inode specified by @hashval and @data in the inode cache. * If the inode is in the cache, the inode is returned with an incremented - * reference count. Note, the inode lock is not waited upon so you have to be - * very careful what you do with the returned inode. You probably should be - * using ilookup5() instead. + * reference count. * - * Otherwise NULL is returned. + * Note: I_NEW is not waited upon so you have to be very careful what you do + * with the returned inode. You probably should be using ilookup5() instead. * - * Note, @test is called with the inode_lock held, so can't sleep. + * Note: @test is called with the inode_hash_lock held, so can't sleep. */ struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, int (*test)(struct inode *, void *), void *data) { struct hlist_head *head = inode_hashtable + hash(sb, hashval); + struct inode *inode; + + spin_lock(&inode_hash_lock); + inode = find_inode(sb, head, test, data); + spin_unlock(&inode_hash_lock); - return ifind(sb, head, test, data, 0); + return inode; } EXPORT_SYMBOL(ilookup5_nowait); @@ -1153,24 +1190,24 @@ EXPORT_SYMBOL(ilookup5_nowait); * @test: callback used for comparisons between inodes * @data: opaque data pointer to pass to @test * - * ilookup5() uses ifind() to search for the inode specified by @hashval and - * @data in the inode cache. This is a generalized version of ilookup() for - * file systems where the inode number is not sufficient for unique - * identification of an inode. - * - * If the inode is in the cache, the inode lock is waited upon and the inode is + * Search for the inode specified by @hashval and @data in the inode cache, + * and if the inode is in the cache, return the inode with an incremented + * reference count. Waits on I_NEW before returning the inode. * returned with an incremented reference count. * - * Otherwise NULL is returned. + * This is a generalized version of ilookup() for file systems where the + * inode number is not sufficient for unique identification of an inode. * - * Note, @test is called with the inode_lock held, so can't sleep. + * Note: @test is called with the inode_hash_lock held, so can't sleep. */ struct inode *ilookup5(struct super_block *sb, unsigned long hashval, int (*test)(struct inode *, void *), void *data) { - struct hlist_head *head = inode_hashtable + hash(sb, hashval); + struct inode *inode = ilookup5_nowait(sb, hashval, test, data); - return ifind(sb, head, test, data, 1); + if (inode) + wait_on_inode(inode); + return inode; } EXPORT_SYMBOL(ilookup5); @@ -1179,91 +1216,23 @@ EXPORT_SYMBOL(ilookup5); * @sb: super block of file system to search * @ino: inode number to search for * - * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache. - * This is for file systems where the inode number is sufficient for unique - * identification of an inode. - * - * If the inode is in the cache, the inode is returned with an incremented - * reference count. - * - * Otherwise NULL is returned. + * Search for the inode @ino in the inode cache, and if the inode is in the + * cache, the inode is returned with an incremented reference count. */ struct inode *ilookup(struct super_block *sb, unsigned long ino) { struct hlist_head *head = inode_hashtable + hash(sb, ino); - - return ifind_fast(sb, head, ino); -} -EXPORT_SYMBOL(ilookup); - -/** - * iget5_locked - obtain an inode from a mounted file system - * @sb: super block of file system - * @hashval: hash value (usually inode number) to get - * @test: callback used for comparisons between inodes - * @set: callback used to initialize a new struct inode - * @data: opaque data pointer to pass to @test and @set - * - * iget5_locked() uses ifind() to search for the inode specified by @hashval - * and @data in the inode cache and if present it is returned with an increased - * reference count. This is a generalized version of iget_locked() for file - * systems where the inode number is not sufficient for unique identification - * of an inode. - * - * If the inode is not in cache, get_new_inode() is called to allocate a new - * inode and this is returned locked, hashed, and with the I_NEW flag set. The - * file system gets to fill it in before unlocking it via unlock_new_inode(). - * - * Note both @test and @set are called with the inode_lock held, so can't sleep. - */ -struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, - int (*test)(struct inode *, void *), - int (*set)(struct inode *, void *), void *data) -{ - struct hlist_head *head = inode_hashtable + hash(sb, hashval); struct inode *inode; - inode = ifind(sb, head, test, data, 1); - if (inode) - return inode; - /* - * get_new_inode() will do the right thing, re-trying the search - * in case it had to block at any point. - */ - return get_new_inode(sb, head, test, set, data); -} -EXPORT_SYMBOL(iget5_locked); - -/** - * iget_locked - obtain an inode from a mounted file system - * @sb: super block of file system - * @ino: inode number to get - * - * iget_locked() uses ifind_fast() to search for the inode specified by @ino in - * the inode cache and if present it is returned with an increased reference - * count. This is for file systems where the inode number is sufficient for - * unique identification of an inode. - * - * If the inode is not in cache, get_new_inode_fast() is called to allocate a - * new inode and this is returned locked, hashed, and with the I_NEW flag set. - * The file system gets to fill it in before unlocking it via - * unlock_new_inode(). - */ -struct inode *iget_locked(struct super_block *sb, unsigned long ino) -{ - struct hlist_head *head = inode_hashtable + hash(sb, ino); - struct inode *inode; + spin_lock(&inode_hash_lock); + inode = find_inode_fast(sb, head, ino); + spin_unlock(&inode_hash_lock); - inode = ifind_fast(sb, head, ino); if (inode) - return inode; - /* - * get_new_inode_fast() will do the right thing, re-trying the search - * in case it had to block at any point. - */ - return get_new_inode_fast(sb, head, ino); + wait_on_inode(inode); + return inode; } -EXPORT_SYMBOL(iget_locked); +EXPORT_SYMBOL(ilookup); int insert_inode_locked(struct inode *inode) { @@ -1271,27 +1240,33 @@ int insert_inode_locked(struct inode *inode) ino_t ino = inode->i_ino; struct hlist_head *head = inode_hashtable + hash(sb, ino); - inode->i_state |= I_NEW; while (1) { struct hlist_node *node; struct inode *old = NULL; - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); hlist_for_each_entry(old, node, head, i_hash) { if (old->i_ino != ino) continue; if (old->i_sb != sb) continue; - if (old->i_state & (I_FREEING|I_WILL_FREE)) + spin_lock(&old->i_lock); + if (old->i_state & (I_FREEING|I_WILL_FREE)) { + spin_unlock(&old->i_lock); continue; + } break; } if (likely(!node)) { + spin_lock(&inode->i_lock); + inode->i_state |= I_NEW; hlist_add_head(&inode->i_hash, head); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_hash_lock); return 0; } __iget(old); - spin_unlock(&inode_lock); + spin_unlock(&old->i_lock); + spin_unlock(&inode_hash_lock); wait_on_inode(old); if (unlikely(!inode_unhashed(old))) { iput(old); @@ -1308,29 +1283,34 @@ int insert_inode_locked4(struct inode *inode, unsigned long hashval, struct super_block *sb = inode->i_sb; struct hlist_head *head = inode_hashtable + hash(sb, hashval); - inode->i_state |= I_NEW; - while (1) { struct hlist_node *node; struct inode *old = NULL; - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); hlist_for_each_entry(old, node, head, i_hash) { if (old->i_sb != sb) continue; if (!test(old, data)) continue; - if (old->i_state & (I_FREEING|I_WILL_FREE)) + spin_lock(&old->i_lock); + if (old->i_state & (I_FREEING|I_WILL_FREE)) { + spin_unlock(&old->i_lock); continue; + } break; } if (likely(!node)) { + spin_lock(&inode->i_lock); + inode->i_state |= I_NEW; hlist_add_head(&inode->i_hash, head); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_hash_lock); return 0; } __iget(old); - spin_unlock(&inode_lock); + spin_unlock(&old->i_lock); + spin_unlock(&inode_hash_lock); wait_on_inode(old); if (unlikely(!inode_unhashed(old))) { iput(old); @@ -1375,47 +1355,35 @@ static void iput_final(struct inode *inode) const struct super_operations *op = inode->i_sb->s_op; int drop; + WARN_ON(inode->i_state & I_NEW); + if (op && op->drop_inode) drop = op->drop_inode(inode); else drop = generic_drop_inode(inode); + if (!drop && (sb->s_flags & MS_ACTIVE)) { + inode->i_state |= I_REFERENCED; + if (!(inode->i_state & (I_DIRTY|I_SYNC))) + inode_lru_list_add(inode); + spin_unlock(&inode->i_lock); + return; + } + if (!drop) { - if (sb->s_flags & MS_ACTIVE) { - inode->i_state |= I_REFERENCED; - if (!(inode->i_state & (I_DIRTY|I_SYNC))) { - inode_lru_list_add(inode); - } - spin_unlock(&inode_lock); - return; - } - WARN_ON(inode->i_state & I_NEW); inode->i_state |= I_WILL_FREE; - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); write_inode_now(inode, 1); - spin_lock(&inode_lock); + spin_lock(&inode->i_lock); WARN_ON(inode->i_state & I_NEW); inode->i_state &= ~I_WILL_FREE; - __remove_inode_hash(inode); } - WARN_ON(inode->i_state & I_NEW); inode->i_state |= I_FREEING; - - /* - * Move the inode off the IO lists and LRU once I_FREEING is - * set so that it won't get moved back on there if it is dirty. - */ inode_lru_list_del(inode); - list_del_init(&inode->i_wb_list); + spin_unlock(&inode->i_lock); - __inode_sb_list_del(inode); - spin_unlock(&inode_lock); evict(inode); - remove_inode_hash(inode); - wake_up_inode(inode); - BUG_ON(inode->i_state != (I_FREEING | I_CLEAR)); - destroy_inode(inode); } /** @@ -1432,7 +1400,7 @@ void iput(struct inode *inode) if (inode) { BUG_ON(inode->i_state & I_CLEAR); - if (atomic_dec_and_lock(&inode->i_count, &inode_lock)) + if (atomic_dec_and_lock(&inode->i_count, &inode->i_lock)) iput_final(inode); } } @@ -1611,9 +1579,8 @@ EXPORT_SYMBOL(inode_wait); * to recheck inode state. * * It doesn't matter if I_NEW is not set initially, a call to - * wake_up_inode() after removing from the hash list will DTRT. - * - * This is called with inode_lock held. + * wake_up_bit(&inode->i_state, __I_NEW) after removing from the hash list + * will DTRT. */ static void __wait_on_freeing_inode(struct inode *inode) { @@ -1621,10 +1588,11 @@ static void __wait_on_freeing_inode(struct inode *inode) DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW); wq = bit_waitqueue(&inode->i_state, __I_NEW); prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_hash_lock); schedule(); finish_wait(wq, &wait.wait); - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); } static __initdata unsigned long ihash_entries; diff --git a/fs/internal.h b/fs/internal.h index 8318059..b29c46e 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -125,6 +125,13 @@ extern long do_handle_open(int mountdirfd, /* * inode.c */ +extern spinlock_t inode_sb_list_lock; + +/* + * fs-writeback.c + */ +extern void inode_wb_list_del(struct inode *inode); + extern int get_nr_dirty_inodes(void); extern void evict_inodes(struct super_block *); extern int invalidate_inodes(struct super_block *, bool); diff --git a/fs/logfs/inode.c b/fs/logfs/inode.c index 03b8c24..edfea7a 100644 --- a/fs/logfs/inode.c +++ b/fs/logfs/inode.c @@ -293,7 +293,7 @@ static int logfs_write_inode(struct inode *inode, struct writeback_control *wbc) return ret; } -/* called with inode_lock held */ +/* called with inode->i_lock held */ static int logfs_drop_inode(struct inode *inode) { struct logfs_super *super = logfs_super(inode->i_sb); @@ -992,6 +992,12 @@ int follow_down_one(struct path *path) return 0; } +static inline bool managed_dentry_might_block(struct dentry *dentry) +{ + return (dentry->d_flags & DCACHE_MANAGE_TRANSIT && + dentry->d_op->d_manage(dentry, true) < 0); +} + /* * Skip to top of mountpoint pile in rcuwalk mode. We abort the rcu-walk if we * meet a managed dentry and we're not walking to "..". True is returned to @@ -1000,19 +1006,26 @@ int follow_down_one(struct path *path) static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, struct inode **inode, bool reverse_transit) { - while (d_mountpoint(path->dentry)) { + for (;;) { struct vfsmount *mounted; - if (unlikely(path->dentry->d_flags & DCACHE_MANAGE_TRANSIT) && - !reverse_transit && - path->dentry->d_op->d_manage(path->dentry, true) < 0) + /* + * Don't forget we might have a non-mountpoint managed dentry + * that wants to block transit. + */ + *inode = path->dentry->d_inode; + if (!reverse_transit && + unlikely(managed_dentry_might_block(path->dentry))) return false; + + if (!d_mountpoint(path->dentry)) + break; + mounted = __lookup_mnt(path->mnt, path->dentry, 1); if (!mounted) break; path->mnt = mounted; path->dentry = mounted->mnt_root; nd->seq = read_seqcount_begin(&path->dentry->d_seq); - *inode = path->dentry->d_inode; } if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT)) diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c index 4c29fcf..07ea8d3 100644 --- a/fs/notify/inode_mark.c +++ b/fs/notify/inode_mark.c @@ -22,13 +22,14 @@ #include <linux/module.h> #include <linux/mutex.h> #include <linux/spinlock.h> -#include <linux/writeback.h> /* for inode_lock */ #include <asm/atomic.h> #include <linux/fsnotify_backend.h> #include "fsnotify.h" +#include "../internal.h" + /* * Recalculate the mask of events relevant to a given inode locked. */ @@ -237,15 +238,14 @@ out: * fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes. * @list: list of inodes being unmounted (sb->s_inodes) * - * Called with inode_lock held, protecting the unmounting super block's list - * of inodes, and with iprune_mutex held, keeping shrink_icache_memory() at bay. - * We temporarily drop inode_lock, however, and CAN block. + * Called during unmount with no locks held, so needs to be safe against + * concurrent modifiers. We temporarily drop inode_sb_list_lock and CAN block. */ void fsnotify_unmount_inodes(struct list_head *list) { struct inode *inode, *next_i, *need_iput = NULL; - spin_lock(&inode_lock); + spin_lock(&inode_sb_list_lock); list_for_each_entry_safe(inode, next_i, list, i_sb_list) { struct inode *need_iput_tmp; @@ -254,8 +254,11 @@ void fsnotify_unmount_inodes(struct list_head *list) * I_WILL_FREE, or I_NEW which is fine because by that point * the inode cannot have any associated watches. */ - if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) + spin_lock(&inode->i_lock); + if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) { + spin_unlock(&inode->i_lock); continue; + } /* * If i_count is zero, the inode cannot have any watches and @@ -263,8 +266,10 @@ void fsnotify_unmount_inodes(struct list_head *list) * evict all inodes with zero i_count from icache which is * unnecessarily violent and may in fact be illegal to do. */ - if (!atomic_read(&inode->i_count)) + if (!atomic_read(&inode->i_count)) { + spin_unlock(&inode->i_lock); continue; + } need_iput_tmp = need_iput; need_iput = NULL; @@ -274,22 +279,25 @@ void fsnotify_unmount_inodes(struct list_head *list) __iget(inode); else need_iput_tmp = NULL; + spin_unlock(&inode->i_lock); /* In case the dropping of a reference would nuke next_i. */ if ((&next_i->i_sb_list != list) && - atomic_read(&next_i->i_count) && - !(next_i->i_state & (I_FREEING | I_WILL_FREE))) { - __iget(next_i); - need_iput = next_i; + atomic_read(&next_i->i_count)) { + spin_lock(&next_i->i_lock); + if (!(next_i->i_state & (I_FREEING | I_WILL_FREE))) { + __iget(next_i); + need_iput = next_i; + } + spin_unlock(&next_i->i_lock); } /* - * We can safely drop inode_lock here because we hold + * We can safely drop inode_sb_list_lock here because we hold * references on both inode and next_i. Also no new inodes - * will be added since the umount has begun. Finally, - * iprune_mutex keeps shrink_icache_memory() away. + * will be added since the umount has begun. */ - spin_unlock(&inode_lock); + spin_unlock(&inode_sb_list_lock); if (need_iput_tmp) iput(need_iput_tmp); @@ -301,7 +309,7 @@ void fsnotify_unmount_inodes(struct list_head *list) iput(inode); - spin_lock(&inode_lock); + spin_lock(&inode_sb_list_lock); } - spin_unlock(&inode_lock); + spin_unlock(&inode_sb_list_lock); } diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 325185e..50c0085 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -91,7 +91,6 @@ #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/srcu.h> -#include <linux/writeback.h> /* for inode_lock */ #include <asm/atomic.h> diff --git a/fs/notify/vfsmount_mark.c b/fs/notify/vfsmount_mark.c index 85eebff..e86577d 100644 --- a/fs/notify/vfsmount_mark.c +++ b/fs/notify/vfsmount_mark.c @@ -23,7 +23,6 @@ #include <linux/mount.h> #include <linux/mutex.h> #include <linux/spinlock.h> -#include <linux/writeback.h> /* for inode_lock */ #include <asm/atomic.h> diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c index a627ed8..0b56c6b 100644 --- a/fs/ntfs/inode.c +++ b/fs/ntfs/inode.c @@ -54,7 +54,7 @@ * * Return 1 if the attributes match and 0 if not. * - * NOTE: This function runs with the inode_lock spin lock held so it is not + * NOTE: This function runs with the inode->i_lock spin lock held so it is not * allowed to sleep. */ int ntfs_test_inode(struct inode *vi, ntfs_attr *na) @@ -98,7 +98,7 @@ int ntfs_test_inode(struct inode *vi, ntfs_attr *na) * * Return 0 on success and -errno on error. * - * NOTE: This function runs with the inode_lock spin lock held so it is not + * NOTE: This function runs with the inode->i_lock spin lock held so it is not * allowed to sleep. (Hence the GFP_ATOMIC allocation.) */ static int ntfs_init_locked_inode(struct inode *vi, ntfs_attr *na) diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index a2a622e..fcc8ae7 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -76,7 +76,7 @@ #include <linux/buffer_head.h> #include <linux/capability.h> #include <linux/quotaops.h> -#include <linux/writeback.h> /* for inode_lock, oddly enough.. */ +#include "../internal.h" /* ugh */ #include <asm/uaccess.h> @@ -900,33 +900,38 @@ static void add_dquot_ref(struct super_block *sb, int type) int reserved = 0; #endif - spin_lock(&inode_lock); + spin_lock(&inode_sb_list_lock); list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { - if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) + spin_lock(&inode->i_lock); + if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || + !atomic_read(&inode->i_writecount) || + !dqinit_needed(inode, type)) { + spin_unlock(&inode->i_lock); continue; + } #ifdef CONFIG_QUOTA_DEBUG if (unlikely(inode_get_rsv_space(inode) > 0)) reserved = 1; #endif - if (!atomic_read(&inode->i_writecount)) - continue; - if (!dqinit_needed(inode, type)) - continue; - __iget(inode); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_sb_list_lock); iput(old_inode); __dquot_initialize(inode, type); - /* We hold a reference to 'inode' so it couldn't have been - * removed from s_inodes list while we dropped the inode_lock. - * We cannot iput the inode now as we can be holding the last - * reference and we cannot iput it under inode_lock. So we - * keep the reference and iput it later. */ + + /* + * We hold a reference to 'inode' so it couldn't have been + * removed from s_inodes list while we dropped the + * inode_sb_list_lock We cannot iput the inode now as we can be + * holding the last reference and we cannot iput it under + * inode_sb_list_lock. So we keep the reference and iput it + * later. + */ old_inode = inode; - spin_lock(&inode_lock); + spin_lock(&inode_sb_list_lock); } - spin_unlock(&inode_lock); + spin_unlock(&inode_sb_list_lock); iput(old_inode); #ifdef CONFIG_QUOTA_DEBUG @@ -1007,7 +1012,7 @@ static void remove_dquot_ref(struct super_block *sb, int type, struct inode *inode; int reserved = 0; - spin_lock(&inode_lock); + spin_lock(&inode_sb_list_lock); list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { /* * We have to scan also I_NEW inodes because they can already @@ -1021,7 +1026,7 @@ static void remove_dquot_ref(struct super_block *sb, int type, remove_inode_dquot_ref(inode, type, tofree_head); } } - spin_unlock(&inode_lock); + spin_unlock(&inode_sb_list_lock); #ifdef CONFIG_QUOTA_DEBUG if (reserved) { printk(KERN_WARNING "VFS (%s): Writes happened after quota" |