diff options
| -rw-r--r-- | nuttx/drivers/loop.c | 98 |
1 files changed, 59 insertions, 39 deletions
diff --git a/nuttx/drivers/loop.c b/nuttx/drivers/loop.c index 40d261ce5..9d51dd746 100644 --- a/nuttx/drivers/loop.c +++ b/nuttx/drivers/loop.c @@ -1,7 +1,7 @@ /**************************************************************************** * drivers/loop.c * - * Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved. + * Copyright (C) 2008-2009, 2011, 2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt <gnutt@nuttx.org> * * Redistribution and use in source and binary forms, with or without @@ -87,16 +87,18 @@ struct loop_struct_s * Private Function Prototypes ****************************************************************************/ -static void loop_semtake(FAR struct loop_struct_s *dev); +static int loop_semtake(FAR struct loop_struct_s *dev); static int loop_open(FAR struct inode *inode); static int loop_close(FAR struct inode *inode); -static ssize_t loop_read(FAR struct inode *inode, unsigned char *buffer, +static ssize_t loop_read(FAR struct inode *inode, FAR unsigned char *buffer, size_t start_sector, unsigned int nsectors); #ifdef CONFIG_FS_WRITABLE -static ssize_t loop_write(FAR struct inode *inode, const unsigned char *buffer, - size_t start_sector, unsigned int nsectors); +static ssize_t loop_write(FAR struct inode *inode, + FAR const unsigned char *buffer, + size_t start_sector, unsigned int nsectors); #endif -static int loop_geometry(FAR struct inode *inode, struct geometry *geometry); +static int loop_geometry(FAR struct inode *inode, + FAR struct geometry *geometry); /**************************************************************************** * Private Data @@ -124,18 +126,26 @@ static const struct block_operations g_bops = * Name: loop_semtake ****************************************************************************/ -static void loop_semtake(FAR struct loop_struct_s *dev) +static int loop_semtake(FAR struct loop_struct_s *dev) { + int ret; + /* Take the semaphore (perhaps waiting) */ - while (sem_wait(&dev->sem) != 0) + ret = sem_wait(&dev->sem); + if (ret < 0) { + int errcode = get_errno(); + /* The only case that an error should occur here is if * the wait was awakened by a signal. */ - ASSERT(get_errno() == EINTR); + ASSERT(errcode == EINTR); + return -ret; } + + return OK; } /**************************************************************************** @@ -148,26 +158,30 @@ static void loop_semtake(FAR struct loop_struct_s *dev) static int loop_open(FAR struct inode *inode) { FAR struct loop_struct_s *dev; - int ret = OK; + int ret; DEBUGASSERT(inode && inode->i_private); dev = (FAR struct loop_struct_s *)inode->i_private; /* Make sure we have exclusive access to the state structure */ - loop_semtake(dev); - if (dev->opencnt == MAX_OPENCNT) + ret = loop_semtake(dev); + if (ret == OK) { - return -EMFILE; - } - else - { - /* Increment the open count */ + if (dev->opencnt == MAX_OPENCNT) + { + ret = -EMFILE; + } + else + { + /* Increment the open count */ - dev->opencnt++; + dev->opencnt++; + } + + loop_semgive(dev); } - loop_semgive(dev); return ret; } @@ -181,38 +195,42 @@ static int loop_open(FAR struct inode *inode) static int loop_close(FAR struct inode *inode) { FAR struct loop_struct_s *dev; - int ret = OK; + int ret; DEBUGASSERT(inode && inode->i_private); dev = (FAR struct loop_struct_s *)inode->i_private; /* Make sure we have exclusive access to the state structure */ - loop_semtake(dev); - if (dev->opencnt == 0) - { - return -EIO; - } - else + ret = loop_semtake(dev); + if (ret == OK) { - /* Decrement the open count */ + if (dev->opencnt == 0) + { + ret = -EIO; + } + else + { + /* Decrement the open count */ + + dev->opencnt--; + } - dev->opencnt--; + loop_semgive(dev); } - loop_semgive(dev); return ret; } /**************************************************************************** * Name: loop_read * - * Description: Read the specified numer of sectors + * Description: Read the specified number of sectors * ****************************************************************************/ -static ssize_t loop_read(FAR struct inode *inode, unsigned char *buffer, - size_t start_sector, unsigned int nsectors) +static ssize_t loop_read(FAR struct inode *inode, FAR unsigned char *buffer, + size_t start_sector, unsigned int nsectors) { FAR struct loop_struct_s *dev; ssize_t nbytesread; @@ -264,8 +282,9 @@ static ssize_t loop_read(FAR struct inode *inode, unsigned char *buffer, ****************************************************************************/ #ifdef CONFIG_FS_WRITABLE -static ssize_t loop_write(FAR struct inode *inode, const unsigned char *buffer, - size_t start_sector, unsigned int nsectors) +static ssize_t loop_write(FAR struct inode *inode, + FAR const unsigned char *buffer, + size_t start_sector, unsigned int nsectors) { FAR struct loop_struct_s *dev; ssize_t nbyteswritten; @@ -310,7 +329,8 @@ static ssize_t loop_write(FAR struct inode *inode, const unsigned char *buffer, * ****************************************************************************/ -static int loop_geometry(FAR struct inode *inode, struct geometry *geometry) +static int loop_geometry(FAR struct inode *inode, + FAR struct geometry *geometry) { FAR struct loop_struct_s *dev; @@ -346,8 +366,8 @@ static int loop_geometry(FAR struct inode *inode, struct geometry *geometry) * ****************************************************************************/ -int losetup(const char *devname, const char *filename, uint16_t sectsize, - off_t offset, bool readonly) +int losetup(FAR const char *devname, FAR const char *filename, + uint16_t sectsize, off_t offset, bool readonly) { FAR struct loop_struct_s *dev; struct stat sb; @@ -453,7 +473,7 @@ errout_with_dev: * ****************************************************************************/ -int loteardown(const char *devname) +int loteardown(FAR const char *devname) { FAR struct loop_struct_s *dev; FAR struct inode *inode; @@ -479,7 +499,7 @@ int loteardown(const char *devname) return ret; } - /* Inode private data is a reference to the loop device stgructure */ + /* Inode private data is a reference to the loop device structure */ dev = (FAR struct loop_struct_s *)inode->i_private; close_blockdriver(inode); |