[PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_sem

[pandora-kernel.git] / fs / read_write.c

diff --git a/fs/read_write.c b/fs/read_write.c
index a091ee4..3f7a1a6 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -14,6 +14,7 @@
 #include <linux/security.h>
 #include <linux/module.h>
 #include <linux/syscalls.h>
+#include <linux/pagemap.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -32,7 +33,7 @@ loff_t generic_file_llseek(struct file *file, loff_t offset, int origin)
        long long retval;
        struct inode *inode = file->f_mapping->host;
 
-       down(&inode->i_sem);
+       mutex_lock(&inode->i_mutex);
        switch (origin) {
                case 2:
                        offset += inode->i_size;
@@ -48,7 +49,7 @@ loff_t generic_file_llseek(struct file *file, loff_t offset, int origin)
                }
                retval = offset;
        }
-       up(&inode->i_sem);
+       mutex_unlock(&inode->i_mutex);
        return retval;
 }
 
@@ -182,22 +183,33 @@ bad:
 }
 #endif
 
+/*
+ * rw_verify_area doesn't like huge counts. We limit
+ * them to something that fits in "int" so that others
+ * won't have to do range checks all the time.
+ */
+#define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK)
 
 int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count)
 {
        struct inode *inode;
        loff_t pos;
 
-       if (unlikely(count > INT_MAX))
+       if (unlikely((ssize_t) count < 0))
                goto Einval;
        pos = *ppos;
        if (unlikely((pos < 0) || (loff_t) (pos + count) < 0))
                goto Einval;
 
        inode = file->f_dentry->d_inode;
-       if (inode->i_flock && MANDATORY_LOCK(inode))
-               return locks_mandatory_area(read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, inode, file, pos, count);
-       return 0;
+       if (inode->i_flock && MANDATORY_LOCK(inode)) {
+               int retval = locks_mandatory_area(
+                       read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE,
+                       inode, file, pos, count);
+               if (retval < 0)
+                       return retval;
+       }
+       return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
 
 Einval:
        return -EINVAL;
@@ -244,7 +256,8 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
                return -EFAULT;
 
        ret = rw_verify_area(READ, file, pos, count);
-       if (!ret) {
+       if (ret >= 0) {
+               count = ret;
                ret = security_file_permission (file, MAY_READ);
                if (!ret) {
                        if (file->f_op->read)
@@ -295,7 +308,8 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
                return -EFAULT;
 
        ret = rw_verify_area(WRITE, file, pos, count);
-       if (!ret) {
+       if (ret >= 0) {
+               count = ret;
                ret = security_file_permission (file, MAY_WRITE);
                if (!ret) {
                        if (file->f_op->write)
@@ -497,7 +511,7 @@ static ssize_t do_readv_writev(int type, struct file *file,
        }
 
        ret = rw_verify_area(type, file, pos, tot_len);
-       if (ret)
+       if (ret < 0)
                goto out;
        ret = security_file_permission(file, type == READ ? MAY_READ : MAY_WRITE);
        if (ret)
@@ -653,8 +667,9 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
                if (!(in_file->f_mode & FMODE_PREAD))
                        goto fput_in;
        retval = rw_verify_area(READ, in_file, ppos, count);
-       if (retval)
+       if (retval < 0)
                goto fput_in;
+       count = retval;
 
        retval = security_file_permission (in_file, MAY_READ);
        if (retval)
@@ -674,8 +689,9 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
                goto fput_out;
        out_inode = out_file->f_dentry->d_inode;
        retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count);
-       if (retval)
+       if (retval < 0)
                goto fput_out;
+       count = retval;
 
        retval = security_file_permission (out_file, MAY_WRITE);
        if (retval)