main syscalls

Corpus of system calls for evaluation
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Functions
int	soMknod (const char *path, mode_t mode)
	Create a regular file with size 0. More...
int	soLink (const char *path, const char *newPath)
	Make a new link to a file. More...
int	soUnlink (const char *path)
	Delete a link to a file from a directory and possibly the file it refers to from the file system. More...
int	soMkdir (const char *path, mode_t mode)
	Create a directory. More...
int	soRmdir (const char *path)
	Remove an existing directory. More...
int	soRead (const char *path, void *buff, uint32_t count, int32_t pos)
	Read data from an open regular file. More...
int	soWrite (const char *path, void *buff, uint32_t count, int32_t pos)
	Write data into an open regular file. More...
int	soRename (const char *path, const char *newPath)
	Change the name or the location of a file in the directory hierarchy of the file system. More...
int	soTruncate (const char *path, off_t length)
	Truncate a regular file to a specified length. More...
int	soReaddir (const char *path, void *buff, int32_t pos)
	Read a directory entry from a directory. More...
int	soSymlink (const char *effPath, const char *path)
	Creates a symbolic link which contains the given path. More...
int	soReadlink (const char *path, char *buff, size_t size)
	Read the value of a symbolic link. More...

Detailed Description

Corpus of system calls for evaluation

Function Documentation

soMknod()

int sofs19::soMknod	(	const char *	path,
		mode_t	mode
	)

Create a regular file with size 0.

It tries to emulate mknod system call, for regular files.

To get more information, execute in a terminal the command man 2 mknod

Parameters

path	path to the file
mode	permissions to be set

Remarks

• mode must be a bitwise combination of S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IWGRP, S_IXGRP, S_IROTH, S_IWOTH, S_IXOTH
• dirname(path) must exist, be a directory, and write permission on it is required
• basename(path) must not exist within dirname(path)
• In case of success
  • An inode is allocated for the new regular file
  • A direntry named basename(path) is added to dirname(path)
  • lnkcnt of the inode associated to basename(path) is updated in order to include the new incoming arc

Returns

0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

soLink()

int sofs19::soLink	(	const char *	path,
		const char *	newPath
	)

Make a new link to a file.

It tries to emulate link system call.

To get more information, execute in a terminal the command man 2 link

Parameters

path	path to an existing file
newPath	new path to the same file

Remarks

• path must represent an existing regular file or symbolic link
• dirname(newPath) must exist, be a directory, and write permission on it is required
• basename(newPath) must not exist within dirname(newPath)
• In case of success
  • A direntry named basename(newPath) is added to dirname(newPath)
  • Field lnkcnt of the inode associated to basename(path) is updated in order to include with the new incoming arc

Returns

0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

soUnlink()

int sofs19::soUnlink

(

const char *

path

)

Delete a link to a file from a directory and possibly the file it refers to from the file system.

It tries to emulate unlink system call.

To get more information, execute in a terminal the command man 2 unlink

Parameters

path	path to the file to be deleted

Remarks

• dirname(path) must exist, be a directory, and write permission on it is required
• basename(path) must exist within dirname(path) and must be a regular file or symbolic link
• In case of success
  • The direntry named basename(path) is deleted from dirname(path)
  • lnkcnt of the inode associated to path is updated in order to exclude the deleted incoming arc
  • If after that lnkcnt become zero:
    • All data blocks associated to that inode are freed
    • The inode itself is freed

Returns

0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

soMkdir()

int sofs19::soMkdir	(	const char *	path,
		mode_t	mode
	)

Create a directory.

It tries to emulate mkdir system call.

To get more information, execute in a terminal the command man 2 mkdir

Parameters

path	path to the file
mode	permissions to be set

Remarks

• mode must be a bitwise combination of S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IWGRP, S_IXGRP, S_IROTH, S_IWOTH, S_IXOTH
• dirname(path) must exist, be a directory, and write permission on it is required
• base(path) must not exist within dirname(path)
• In case of success
  • An inode is allocated for the new (child) directory
  • The direntries named . and .. are added to the child directory and, as a consequence, a data block is added, blkcnt is set to 1, and size is set to BlockSize
  • A direntry named basename(path) is added to dirname(path)
  • lnkcnt of parent and child directories are updated in order to include the new incoming arcs

Returns

0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

soRmdir()

int sofs19::soRmdir

(

const char *

path

)

Remove an existing directory.

It tries to emulate rmdir system call.

To get more information, execute in a terminal the command man 2 rmdir

Parameters

path	path to the directory to be deleted

Remarks

• dirname(path) must exist, be a directory, and write permission on it is required
• basename(path) must exist within dirname(path), be a directory and be empty
• In case of success
  • All data blocks associated to the deleted (child) directory are freed
  • The inode of the child directory is freed
  • The direntry named basename(path) is deleted from dirname(path)
  • lnkcnt of the inode associated to dirname(path) is updated in order to exclude the deleted incoming arc

Returns

0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

soRead()

int sofs19::soRead	(	const char *	path,
		void *	buff,
		uint32_t	count,
		int32_t	pos
	)

Read data from an open regular file.

It tries to emulate read system call.

To get more information, execute in a terminal the command man 2 read

Parameters

path	path to the file
buff	pointer to the buffer where data to be read is to be stored
count	number of bytes to be read
pos	starting [byte] position in the file data continuum where data is to be read from

Remarks

• The user must have read permission to the inode associated with path
• In case of success
  • In terms of the disk internal structure, only atime is updated

Returns

the number of bytes read, on success; -errno in case of error, being errno the system error that better represents the cause of failure

soWrite()

int sofs19::soWrite	(	const char *	path,
		void *	buff,
		uint32_t	count,
		int32_t	pos
	)

Write data into an open regular file.

It tries to emulate write system call.

To get more information, execute in a terminal the command man 2 write

Parameters

path	path to the file
buff	pointer to the buffer where data to be written is stored
count	number of bytes to be written
pos	starting [byte] position in the file data continuum where data is to be written into

Remarks

• The user must have write permission to the inode associated with path
• In case of success
  • Some data blocks of the associated inode can be updated
  • Some new data blocks can be associated to the inode, in which case blkcnt is updated
  • Field size of the inode can be updated

Returns

the number of bytes written, on success; -errno in case of error, being errno the system error that better represents the cause of failure

soRename()

int sofs19::soRename	(	const char *	path,
		const char *	newPath
	)

Change the name or the location of a file in the directory hierarchy of the file system.

It tries to emulate rename system call.

To get more information, execute in a terminal the command man 2 rename

Parameters

path	path to an existing file
newPath	new path to the same file in replacement of the old one

Returns

0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

soTruncate()

int sofs19::soTruncate	(	const char *	path,
		off_t	length
	)

Truncate a regular file to a specified length.

It tries to emulate truncate system call.

To get more information, execute in a terminal the command man 2 truncate

Parameters

path	path to the file
length	new size for the regular size

Returns

0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

soReaddir()

int sofs19::soReaddir	(	const char *	path,
		void *	buff,
		int32_t	pos
	)

Read a directory entry from a directory.

It tries to emulate getdents system call, but it reads a single directory entry at a time.
Only the field name is read.

Remarks

The returned value is the number of bytes read from the directory in order to get the next in use directory entry.
The point is that the system (through FUSE) uses the returned value to update file position.

To get more information, execute in a terminal the command man readdir

Parameters

path	path to the file
buff	pointer to the buffer where data to be read is to be stored
pos	starting [byte] position in the file data continuum where data is to be read from

Returns

0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

soSymlink()

int sofs19::soSymlink	(	const char *	effPath,
		const char *	path
	)

Creates a symbolic link which contains the given path.

It tries to emulate symlink system call.

Remarks

The permissions set for the symbolic link should have read (r), write (w) and execution (x) permissions for both user, group and other.

To get more information, execute in a terminal the command man 2 symlink

Parameters

effPath	path to be stored in the symbolic link file
path	path to the symbolic link to be created

Returns

0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

soReadlink()

int sofs19::soReadlink	(	const char *	path,
		char *	buff,
		size_t	size
	)

Read the value of a symbolic link.

It tries to emulate readlink system call.

To get more information, execute in a terminal the command man 2 readlink

Parameters

path	path to the symbolic link
buff	pointer to the buffer where data to be read is to be stored
size	buffer size in bytes

Returns

0 on success; -errno in case of error, being errno the system error that better represents the cause of failure