4 files changed, 26 insertions, 18 deletions

diff --git a/fs/fat/cache.c b/fs/fat/cache.c
index fda25479af26..3a9ecac8d61f 100644
--- a/fs/fat/cache.c
+++ b/fs/fat/cache.c
@@ -61,7 +61,7 @@ void fat_cache_destroy(void)
 
 static inline struct fat_cache *fat_cache_alloc(struct inode *inode)
 {
-        return kmem_cache_alloc(fat_cache_cachep, GFP_KERNEL);
+        return kmem_cache_alloc(fat_cache_cachep, GFP_NOFS);
 }
 
 static inline void fat_cache_free(struct fat_cache *cache)
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 486725ee99ae..34541d06e626 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -472,7 +472,7 @@ static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
         loff_t cpos;
         int ret = 0;
 
-        lock_kernel();
+        lock_super(sb);
 
         cpos = filp->f_pos;
         /* Fake . and .. for the root directory. */
@@ -654,7 +654,7 @@ FillFailed:
         if (unicode)
                 __putname(unicode);
 out:
-        unlock_kernel();
+        unlock_super(sb);
         return ret;
 }
 
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 27cc1164ec36..7059928fb351 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -229,7 +229,8 @@ static int fat_free(struct inode *inode, int skip)
 
 void fat_truncate(struct inode *inode)
 {
-        struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+        struct super_block *sb = inode->i_sb;
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
         const unsigned int cluster_size = sbi->cluster_size;
         int nr_clusters;
 
@@ -242,9 +243,9 @@ void fat_truncate(struct inode *inode)
 
         nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits;
 
-        lock_kernel();
+        lock_super(sb);
         fat_free(inode, nr_clusters);
-        unlock_kernel();
+        unlock_super(sb);
         fat_flush_inodes(inode->i_sb, inode, NULL);
 }
 
@@ -297,12 +298,13 @@ static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode)
 
 int fat_setattr(struct dentry *dentry, struct iattr *attr)
 {
+        struct super_block *sb = dentry->d_sb;
         struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
         struct inode *inode = dentry->d_inode;
         int mask, error = 0;
         unsigned int ia_valid;
 
-        lock_kernel();
+        lock_super(sb);
 
         /*
          * Expand the file. Since inode_setattr() updates ->i_size
@@ -356,7 +358,7 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr)
                 mask = sbi->options.fs_fmask;
         inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask);
 out:
-        unlock_kernel();
+        unlock_super(sb);
         return error;
 }
 EXPORT_SYMBOL_GPL(fat_setattr);
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 4e0a3dd9d677..46a4508ffd2e 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -440,14 +440,13 @@ static void fat_delete_inode(struct inode *inode)
 
 static void fat_clear_inode(struct inode *inode)
 {
-        struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+        struct super_block *sb = inode->i_sb;
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
 
-        lock_kernel();
         spin_lock(&sbi->inode_hash_lock);
         fat_cache_inval_inode(inode);
         hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
         spin_unlock(&sbi->inode_hash_lock);
-        unlock_kernel();
 }
 
 static void fat_write_super(struct super_block *sb)
@@ -485,7 +484,7 @@ static struct kmem_cache *fat_inode_cachep;
 static struct inode *fat_alloc_inode(struct super_block *sb)
 {
         struct msdos_inode_info *ei;
-        ei = kmem_cache_alloc(fat_inode_cachep, GFP_KERNEL);
+        ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
         if (!ei)
                 return NULL;
         return &ei->vfs_inode;
@@ -567,7 +566,7 @@ retry:
         if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
                 return 0;
 
-        lock_kernel();
+        lock_super(sb);
         bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
         if (!bh) {
                 printk(KERN_ERR "FAT: unable to read inode block "
@@ -579,7 +578,7 @@ retry:
         if (i_pos != MSDOS_I(inode)->i_pos) {
                 spin_unlock(&sbi->inode_hash_lock);
                 brelse(bh);
-                unlock_kernel();
+                unlock_super(sb);
                 goto retry;
         }
 
@@ -606,7 +605,7 @@ retry:
                 err = sync_dirty_buffer(bh);
         brelse(bh);
 out:
-        unlock_kernel();
+        unlock_super(sb);
         return err;
 }
 
@@ -736,6 +735,7 @@ fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
 
 static struct dentry *fat_get_parent(struct dentry *child)
 {
+        struct super_block *sb = child->d_sb;
         struct buffer_head *bh;
         struct msdos_dir_entry *de;
         loff_t i_pos;
@@ -743,14 +743,14 @@ static struct dentry *fat_get_parent(struct dentry *child)
         struct inode *inode;
         int err;
 
-        lock_kernel();
+        lock_super(sb);
 
         err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
         if (err) {
                 parent = ERR_PTR(err);
                 goto out;
         }
-        inode = fat_build_inode(child->d_sb, de, i_pos);
+        inode = fat_build_inode(sb, de, i_pos);
         brelse(bh);
         if (IS_ERR(inode)) {
                 parent = ERR_CAST(inode);
@@ -762,7 +762,7 @@ static struct dentry *fat_get_parent(struct dentry *child)
                 parent = ERR_PTR(-ENOMEM);
         }
 out:
-        unlock_kernel();
+        unlock_super(sb);
 
         return parent;
 }
@@ -1172,6 +1172,12 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
         long error;
         char buf[50];
 
+        /*
+         * GFP_KERNEL is ok here, because while we do hold the
+         * supeblock lock, memory pressure can't call back into
+         * the filesystem, since we're only just about to mount
+         * it and have no inodes etc active!
+         */
         sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
         if (!sbi)
                 return -ENOMEM;