diff options
Diffstat (limited to 'fs/read_write.c')
| -rw-r--r-- | fs/read_write.c | 976 |
1 files changed, 715 insertions, 261 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index b7f4a1f94d4..009d8542a88 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -9,45 +9,89 @@ #include <linux/fcntl.h> #include <linux/file.h> #include <linux/uio.h> -#include <linux/smp_lock.h> +#include <linux/aio.h> #include <linux/fsnotify.h> #include <linux/security.h> -#include <linux/module.h> +#include <linux/export.h> #include <linux/syscalls.h> #include <linux/pagemap.h> #include <linux/splice.h> -#include "read_write.h" +#include <linux/compat.h> +#include "internal.h" #include <asm/uaccess.h> #include <asm/unistd.h> +typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *); +typedef ssize_t (*iov_fn_t)(struct kiocb *, const struct iovec *, + unsigned long, loff_t); +typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *); + const struct file_operations generic_ro_fops = { .llseek = generic_file_llseek, - .read = do_sync_read, - .aio_read = generic_file_aio_read, + .read = new_sync_read, + .read_iter = generic_file_read_iter, .mmap = generic_file_readonly_mmap, .splice_read = generic_file_splice_read, }; EXPORT_SYMBOL(generic_ro_fops); +static inline int unsigned_offsets(struct file *file) +{ + return file->f_mode & FMODE_UNSIGNED_OFFSET; +} + /** - * generic_file_llseek_unlocked - lockless generic llseek implementation + * vfs_setpos - update the file offset for lseek + * @file: file structure in question + * @offset: file offset to seek to + * @maxsize: maximum file size + * + * This is a low-level filesystem helper for updating the file offset to + * the value specified by @offset if the given offset is valid and it is + * not equal to the current file offset. + * + * Return the specified offset on success and -EINVAL on invalid offset. + */ +loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) +{ + if (offset < 0 && !unsigned_offsets(file)) + return -EINVAL; + if (offset > maxsize) + return -EINVAL; + + if (offset != file->f_pos) { + file->f_pos = offset; + file->f_version = 0; + } + return offset; +} +EXPORT_SYMBOL(vfs_setpos); + +/** + * generic_file_llseek_size - generic llseek implementation for regular files * @file: file structure to seek on * @offset: file offset to seek to - * @origin: type of seek + * @whence: type of seek + * @size: max size of this file in file system + * @eof: offset used for SEEK_END position + * + * This is a variant of generic_file_llseek that allows passing in a custom + * maximum file size and a custom EOF position, for e.g. hashed directories * - * Updates the file offset to the value specified by @offset and @origin. - * Locking must be provided by the caller. + * Synchronization: + * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) + * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. + * read/writes behave like SEEK_SET against seeks. */ loff_t -generic_file_llseek_unlocked(struct file *file, loff_t offset, int origin) +generic_file_llseek_size(struct file *file, loff_t offset, int whence, + loff_t maxsize, loff_t eof) { - struct inode *inode = file->f_mapping->host; - - switch (origin) { + switch (whence) { case SEEK_END: - offset += inode->i_size; + offset += eof; break; case SEEK_CUR: /* @@ -58,59 +102,110 @@ generic_file_llseek_unlocked(struct file *file, loff_t offset, int origin) */ if (offset == 0) return file->f_pos; - offset += file->f_pos; + /* + * f_lock protects against read/modify/write race with other + * SEEK_CURs. Note that parallel writes and reads behave + * like SEEK_SET. + */ + spin_lock(&file->f_lock); + offset = vfs_setpos(file, file->f_pos + offset, maxsize); + spin_unlock(&file->f_lock); + return offset; + case SEEK_DATA: + /* + * In the generic case the entire file is data, so as long as + * offset isn't at the end of the file then the offset is data. + */ + if (offset >= eof) + return -ENXIO; + break; + case SEEK_HOLE: + /* + * There is a virtual hole at the end of the file, so as long as + * offset isn't i_size or larger, return i_size. + */ + if (offset >= eof) + return -ENXIO; + offset = eof; break; } - if (offset < 0 || offset > inode->i_sb->s_maxbytes) - return -EINVAL; - - /* Special lock needed here? */ - if (offset != file->f_pos) { - file->f_pos = offset; - file->f_version = 0; - } - - return offset; + return vfs_setpos(file, offset, maxsize); } -EXPORT_SYMBOL(generic_file_llseek_unlocked); +EXPORT_SYMBOL(generic_file_llseek_size); /** * generic_file_llseek - generic llseek implementation for regular files * @file: file structure to seek on * @offset: file offset to seek to - * @origin: type of seek + * @whence: type of seek * * This is a generic implemenation of ->llseek useable for all normal local * filesystems. It just updates the file offset to the value specified by - * @offset and @origin under i_mutex. + * @offset and @whence. */ -loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) +loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) { - loff_t rval; - - mutex_lock(&file->f_dentry->d_inode->i_mutex); - rval = generic_file_llseek_unlocked(file, offset, origin); - mutex_unlock(&file->f_dentry->d_inode->i_mutex); + struct inode *inode = file->f_mapping->host; - return rval; + return generic_file_llseek_size(file, offset, whence, + inode->i_sb->s_maxbytes, + i_size_read(inode)); } EXPORT_SYMBOL(generic_file_llseek); -loff_t no_llseek(struct file *file, loff_t offset, int origin) +/** + * fixed_size_llseek - llseek implementation for fixed-sized devices + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * @size: size of the file + * + */ +loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) +{ + switch (whence) { + case SEEK_SET: case SEEK_CUR: case SEEK_END: + return generic_file_llseek_size(file, offset, whence, + size, size); + default: + return -EINVAL; + } +} +EXPORT_SYMBOL(fixed_size_llseek); + +/** + * noop_llseek - No Operation Performed llseek implementation + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * + * This is an implementation of ->llseek useable for the rare special case when + * userspace expects the seek to succeed but the (device) file is actually not + * able to perform the seek. In this case you use noop_llseek() instead of + * falling back to the default implementation of ->llseek. + */ +loff_t noop_llseek(struct file *file, loff_t offset, int whence) +{ + return file->f_pos; +} +EXPORT_SYMBOL(noop_llseek); + +loff_t no_llseek(struct file *file, loff_t offset, int whence) { return -ESPIPE; } EXPORT_SYMBOL(no_llseek); -loff_t default_llseek(struct file *file, loff_t offset, int origin) +loff_t default_llseek(struct file *file, loff_t offset, int whence) { + struct inode *inode = file_inode(file); loff_t retval; - lock_kernel(); - switch (origin) { + mutex_lock(&inode->i_mutex); + switch (whence) { case SEEK_END: - offset += i_size_read(file->f_path.dentry->d_inode); + offset += i_size_read(inode); break; case SEEK_CUR: if (offset == 0) { @@ -118,9 +213,33 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin) goto out; } offset += file->f_pos; + break; + case SEEK_DATA: + /* + * In the generic case the entire file is data, so as + * long as offset isn't at the end of the file then the + * offset is data. + */ + if (offset >= inode->i_size) { + retval = -ENXIO; + goto out; + } + break; + case SEEK_HOLE: + /* + * There is a virtual hole at the end of the file, so + * as long as offset isn't i_size or larger, return + * i_size. + */ + if (offset >= inode->i_size) { + retval = -ENXIO; + goto out; + } + offset = inode->i_size; + break; } retval = -EINVAL; - if (offset >= 0) { + if (offset >= 0 || unsigned_offsets(file)) { if (offset != file->f_pos) { file->f_pos = offset; file->f_version = 0; @@ -128,69 +247,79 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin) retval = offset; } out: - unlock_kernel(); + mutex_unlock(&inode->i_mutex); return retval; } EXPORT_SYMBOL(default_llseek); -loff_t vfs_llseek(struct file *file, loff_t offset, int origin) +loff_t vfs_llseek(struct file *file, loff_t offset, int whence) { loff_t (*fn)(struct file *, loff_t, int); fn = no_llseek; if (file->f_mode & FMODE_LSEEK) { - fn = default_llseek; - if (file->f_op && file->f_op->llseek) + if (file->f_op->llseek) fn = file->f_op->llseek; } - return fn(file, offset, origin); + return fn(file, offset, whence); } EXPORT_SYMBOL(vfs_llseek); -SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, origin) +static inline struct fd fdget_pos(int fd) { - off_t retval; - struct file * file; - int fput_needed; + return __to_fd(__fdget_pos(fd)); +} - retval = -EBADF; - file = fget_light(fd, &fput_needed); - if (!file) - goto bad; +static inline void fdput_pos(struct fd f) +{ + if (f.flags & FDPUT_POS_UNLOCK) + mutex_unlock(&f.file->f_pos_lock); + fdput(f); +} + +SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) +{ + off_t retval; + struct fd f = fdget_pos(fd); + if (!f.file) + return -EBADF; retval = -EINVAL; - if (origin <= SEEK_MAX) { - loff_t res = vfs_llseek(file, offset, origin); + if (whence <= SEEK_MAX) { + loff_t res = vfs_llseek(f.file, offset, whence); retval = res; if (res != (loff_t)retval) retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ } - fput_light(file, fput_needed); -bad: + fdput_pos(f); return retval; } +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) +{ + return sys_lseek(fd, offset, whence); +} +#endif + #ifdef __ARCH_WANT_SYS_LLSEEK SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, unsigned long, offset_low, loff_t __user *, result, - unsigned int, origin) + unsigned int, whence) { int retval; - struct file * file; + struct fd f = fdget_pos(fd); loff_t offset; - int fput_needed; - retval = -EBADF; - file = fget_light(fd, &fput_needed); - if (!file) - goto bad; + if (!f.file) + return -EBADF; retval = -EINVAL; - if (origin > SEEK_MAX) + if (whence > SEEK_MAX) goto out_putf; - offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low, - origin); + offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, + whence); retval = (int)offset; if (offset >= 0) { @@ -199,8 +328,7 @@ SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, retval = 0; } out_putf: - fput_light(file, fput_needed); -bad: + fdput_pos(f); return retval; } #endif @@ -210,20 +338,25 @@ bad: * 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) +int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) { struct inode *inode; loff_t pos; int retval = -EINVAL; - inode = file->f_path.dentry->d_inode; + inode = file_inode(file); if (unlikely((ssize_t) count < 0)) return retval; pos = *ppos; - if (unlikely((pos < 0) || (loff_t) (pos + count) < 0)) - return retval; + if (unlikely(pos < 0)) { + if (!unsigned_offsets(file)) + return retval; + if (count >= -pos) /* both values are in 0..LLONG_MAX */ + return -EOVERFLOW; + } else if (unlikely((loff_t) (pos + count) < 0)) { + if (!unsigned_offsets(file)) + return retval; + } if (unlikely(inode->i_flock && mandatory_lock(inode))) { retval = locks_mandatory_area( @@ -239,40 +372,45 @@ int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; } -static void wait_on_retry_sync_kiocb(struct kiocb *iocb) +ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) { - set_current_state(TASK_UNINTERRUPTIBLE); - if (!kiocbIsKicked(iocb)) - schedule(); - else - kiocbClearKicked(iocb); - __set_current_state(TASK_RUNNING); + struct iovec iov = { .iov_base = buf, .iov_len = len }; + struct kiocb kiocb; + ssize_t ret; + + init_sync_kiocb(&kiocb, filp); + kiocb.ki_pos = *ppos; + kiocb.ki_nbytes = len; + + ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); + if (-EIOCBQUEUED == ret) + ret = wait_on_sync_kiocb(&kiocb); + *ppos = kiocb.ki_pos; + return ret; } -ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) +EXPORT_SYMBOL(do_sync_read); + +ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) { struct iovec iov = { .iov_base = buf, .iov_len = len }; struct kiocb kiocb; + struct iov_iter iter; ssize_t ret; init_sync_kiocb(&kiocb, filp); kiocb.ki_pos = *ppos; - kiocb.ki_left = len; - - for (;;) { - ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); - if (ret != -EIOCBRETRY) - break; - wait_on_retry_sync_kiocb(&kiocb); - } + kiocb.ki_nbytes = len; + iov_iter_init(&iter, READ, &iov, 1, len); + ret = filp->f_op->read_iter(&kiocb, &iter); if (-EIOCBQUEUED == ret) ret = wait_on_sync_kiocb(&kiocb); *ppos = kiocb.ki_pos; return ret; } -EXPORT_SYMBOL(do_sync_read); +EXPORT_SYMBOL(new_sync_read); ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) { @@ -280,7 +418,7 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) if (!(file->f_mode & FMODE_READ)) return -EBADF; - if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read)) + if (!(file->f_mode & FMODE_CAN_READ)) return -EINVAL; if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) return -EFAULT; @@ -290,10 +428,12 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) count = ret; if (file->f_op->read) ret = file->f_op->read(file, buf, count, pos); - else + else if (file->f_op->aio_read) ret = do_sync_read(file, buf, count, pos); + else + ret = new_sync_read(file, buf, count, pos); if (ret > 0) { - fsnotify_access(file->f_path.dentry); + fsnotify_access(file); add_rchar(current, ret); } inc_syscr(current); @@ -312,15 +452,9 @@ ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, lof init_sync_kiocb(&kiocb, filp); kiocb.ki_pos = *ppos; - kiocb.ki_left = len; - - for (;;) { - ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); - if (ret != -EIOCBRETRY) - break; - wait_on_retry_sync_kiocb(&kiocb); - } + kiocb.ki_nbytes = len; + ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); if (-EIOCBQUEUED == ret) ret = wait_on_sync_kiocb(&kiocb); *ppos = kiocb.ki_pos; @@ -329,13 +463,63 @@ ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, lof EXPORT_SYMBOL(do_sync_write); +ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) +{ + struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; + struct kiocb kiocb; + struct iov_iter iter; + ssize_t ret; + + init_sync_kiocb(&kiocb, filp); + kiocb.ki_pos = *ppos; + kiocb.ki_nbytes = len; + iov_iter_init(&iter, WRITE, &iov, 1, len); + + ret = filp->f_op->write_iter(&kiocb, &iter); + if (-EIOCBQUEUED == ret) + ret = wait_on_sync_kiocb(&kiocb); + *ppos = kiocb.ki_pos; + return ret; +} + +EXPORT_SYMBOL(new_sync_write); + +ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos) +{ + mm_segment_t old_fs; + const char __user *p; + ssize_t ret; + + if (!(file->f_mode & FMODE_CAN_WRITE)) + return -EINVAL; + + old_fs = get_fs(); + set_fs(get_ds()); + p = (__force const char __user *)buf; + if (count > MAX_RW_COUNT) + count = MAX_RW_COUNT; + if (file->f_op->write) + ret = file->f_op->write(file, p, count, pos); + else if (file->f_op->aio_write) + ret = do_sync_write(file, p, count, pos); + else + ret = new_sync_write(file, p, count, pos); + set_fs(old_fs); + if (ret > 0) { + fsnotify_modify(file); + add_wchar(current, ret); + } + inc_syscw(current); + return ret; +} + ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) { ssize_t ret; if (!(file->f_mode & FMODE_WRITE)) return -EBADF; - if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) + if (!(file->f_mode & FMODE_CAN_WRITE)) return -EINVAL; if (unlikely(!access_ok(VERIFY_READ, buf, count))) return -EFAULT; @@ -343,15 +527,19 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_ ret = rw_verify_area(WRITE, file, pos, count); if (ret >= 0) { count = ret; + file_start_write(file); if (file->f_op->write) ret = file->f_op->write(file, buf, count, pos); - else + else if (file->f_op->aio_write) ret = do_sync_write(file, buf, count, pos); + else + ret = new_sync_write(file, buf, count, pos); if (ret > 0) { - fsnotify_modify(file->f_path.dentry); + fsnotify_modify(file); add_wchar(current, ret); } inc_syscw(current); + file_end_write(file); } return ret; @@ -371,96 +559,75 @@ static inline void file_pos_write(struct file *file, loff_t pos) SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) { - struct file *file; + struct fd f = fdget_pos(fd); ssize_t ret = -EBADF; - int fput_needed; - file = fget_light(fd, &fput_needed); - if (file) { - loff_t pos = file_pos_read(file); - ret = vfs_read(file, buf, count, &pos); - file_pos_write(file, pos); - fput_light(file, fput_needed); + if (f.file) { + loff_t pos = file_pos_read(f.file); + ret = vfs_read(f.file, buf, count, &pos); + if (ret >= 0) + file_pos_write(f.file, pos); + fdput_pos(f); } - return ret; } SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, size_t, count) { - struct file *file; + struct fd f = fdget_pos(fd); ssize_t ret = -EBADF; - int fput_needed; - file = fget_light(fd, &fput_needed); - if (file) { - loff_t pos = file_pos_read(file); - ret = vfs_write(file, buf, count, &pos); - file_pos_write(file, pos); - fput_light(file, fput_needed); + if (f.file) { + loff_t pos = file_pos_read(f.file); + ret = vfs_write(f.file, buf, count, &pos); + if (ret >= 0) + file_pos_write(f.file, pos); + fdput_pos(f); } return ret; } -SYSCALL_DEFINE(pread64)(unsigned int fd, char __user *buf, - size_t count, loff_t pos) +SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, + size_t, count, loff_t, pos) { - struct file *file; + struct fd f; ssize_t ret = -EBADF; - int fput_needed; if (pos < 0) return -EINVAL; - file = fget_light(fd, &fput_needed); - if (file) { + f = fdget(fd); + if (f.file) { ret = -ESPIPE; - if (file->f_mode & FMODE_PREAD) - ret = vfs_read(file, buf, count, &pos); - fput_light(file, fput_needed); + if (f.file->f_mode & FMODE_PREAD) + ret = vfs_read(f.file, buf, count, &pos); + fdput(f); } return ret; } -#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS -asmlinkage long SyS_pread64(long fd, long buf, long count, loff_t pos) -{ - return SYSC_pread64((unsigned int) fd, (char __user *) buf, - (size_t) count, pos); -} -SYSCALL_ALIAS(sys_pread64, SyS_pread64); -#endif -SYSCALL_DEFINE(pwrite64)(unsigned int fd, const char __user *buf, - size_t count, loff_t pos) +SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, + size_t, count, loff_t, pos) { - struct file *file; + struct fd f; ssize_t ret = -EBADF; - int fput_needed; if (pos < 0) return -EINVAL; - file = fget_light(fd, &fput_needed); - if (file) { + f = fdget(fd); + if (f.file) { ret = -ESPIPE; - if (file->f_mode & FMODE_PWRITE) - ret = vfs_write(file, buf, count, &pos); - fput_light(file, fput_needed); + if (f.file->f_mode & FMODE_PWRITE) + ret = vfs_write(f.file, buf, count, &pos); + fdput(f); } return ret; } -#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS -asmlinkage long SyS_pwrite64(long fd, long buf, long count, loff_t pos) -{ - return SYSC_pwrite64((unsigned int) fd, (const char __user *) buf, - (size_t) count, pos); -} -SYSCALL_ALIAS(sys_pwrite64, SyS_pwrite64); -#endif /* * Reduce an iovec's length in-place. Return the resulting number of segments @@ -483,24 +650,36 @@ unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) } EXPORT_SYMBOL(iov_shorten); -ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, - unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) +static ssize_t do_iter_readv_writev(struct file *filp, int rw, const struct iovec *iov, + unsigned long nr_segs, size_t len, loff_t *ppos, iter_fn_t fn) { struct kiocb kiocb; + struct iov_iter iter; ssize_t ret; init_sync_kiocb(&kiocb, filp); kiocb.ki_pos = *ppos; - kiocb.ki_left = len; kiocb.ki_nbytes = len; - for (;;) { - ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); - if (ret != -EIOCBRETRY) - break; - wait_on_retry_sync_kiocb(&kiocb); - } + iov_iter_init(&iter, rw, iov, nr_segs, len); + ret = fn(&kiocb, &iter); + if (ret == -EIOCBQUEUED) + ret = wait_on_sync_kiocb(&kiocb); + *ppos = kiocb.ki_pos; + return ret; +} + +static ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, + unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) +{ + struct kiocb kiocb; + ssize_t ret; + + init_sync_kiocb(&kiocb, filp); + kiocb.ki_pos = *ppos; + kiocb.ki_nbytes = len; + ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); if (ret == -EIOCBQUEUED) ret = wait_on_sync_kiocb(&kiocb); *ppos = kiocb.ki_pos; @@ -508,7 +687,7 @@ ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, } /* Do it by hand, with file-ops */ -ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, +static ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, unsigned long nr_segs, loff_t *ppos, io_fn_t fn) { struct iovec *vector = iov; @@ -546,65 +725,72 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, unsigned long nr_segs, unsigned long fast_segs, struct iovec *fast_pointer, struct iovec **ret_pointer) - { +{ unsigned long seg; - ssize_t ret; + ssize_t ret; struct iovec *iov = fast_pointer; - /* - * SuS says "The readv() function *may* fail if the iovcnt argument - * was less than or equal to 0, or greater than {IOV_MAX}. Linux has - * traditionally returned zero for zero segments, so... - */ + /* + * SuS says "The readv() function *may* fail if the iovcnt argument + * was less than or equal to 0, or greater than {IOV_MAX}. Linux has + * traditionally returned zero for zero segments, so... + */ if (nr_segs == 0) { ret = 0; - goto out; + goto out; } - /* - * First get the "struct iovec" from user memory and - * verify all the pointers - */ + /* + * First get the "struct iovec" from user memory and + * verify all the pointers + */ if (nr_segs > UIO_MAXIOV) { ret = -EINVAL; - goto out; + goto out; } if (nr_segs > fast_segs) { - iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); + iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); if (iov == NULL) { ret = -ENOMEM; - goto out; + goto out; } - } + } if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { ret = -EFAULT; - goto out; + goto out; } - /* + /* * According to the Single Unix Specification we should return EINVAL * if an element length is < 0 when cast to ssize_t or if the * total length would overflow the ssize_t return value of the * system call. - */ + * + * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the + * overflow case. + */ ret = 0; - for (seg = 0; seg < nr_segs; seg++) { - void __user *buf = iov[seg].iov_base; - ssize_t len = (ssize_t)iov[seg].iov_len; + for (seg = 0; seg < nr_segs; seg++) { + void __user *buf = iov[seg].iov_base; + ssize_t len = (ssize_t)iov[seg].iov_len; /* see if we we're about to use an invalid len or if * it's about to overflow ssize_t */ - if (len < 0 || (ret + len < ret)) { + if (len < 0) { ret = -EINVAL; - goto out; + goto out; } - if (unlikely(!access_ok(vrfy_dir(type), buf, len))) { + if (type >= 0 + && unlikely(!access_ok(vrfy_dir(type), buf, len))) { ret = -EFAULT; - goto out; + goto out; + } + if (len > MAX_RW_COUNT - ret) { + len = MAX_RW_COUNT - ret; + iov[seg].iov_len = len; } - ret += len; - } + } out: *ret_pointer = iov; return ret; @@ -620,14 +806,10 @@ static ssize_t do_readv_writev(int type, struct file *file, ssize_t ret; io_fn_t fn; iov_fn_t fnv; - - if (!file->f_op) { - ret = -EINVAL; - goto out; - } + iter_fn_t iter_fn; ret = rw_copy_check_uvector(type, uvector, nr_segs, - ARRAY_SIZE(iovstack), iovstack, &iov); + ARRAY_SIZE(iovstack), iovstack, &iov); if (ret <= 0) goto out; @@ -640,25 +822,34 @@ static ssize_t do_readv_writev(int type, struct file *file, if (type == READ) { fn = file->f_op->read; fnv = file->f_op->aio_read; + iter_fn = file->f_op->read_iter; } else { fn = (io_fn_t)file->f_op->write; fnv = file->f_op->aio_write; + iter_fn = file->f_op->write_iter; + file_start_write(file); } - if (fnv) + if (iter_fn) + ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len, + pos, iter_fn); + else if (fnv) ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, pos, fnv); else ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); + if (type != READ) + file_end_write(file); + out: if (iov != iovstack) kfree(iov); if ((ret + (type == READ)) > 0) { if (type == READ) - fsnotify_access(file->f_path.dentry); + fsnotify_access(file); else - fsnotify_modify(file->f_path.dentry); + fsnotify_modify(file); } return ret; } @@ -668,7 +859,7 @@ ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, { if (!(file->f_mode & FMODE_READ)) return -EBADF; - if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) + if (!(file->f_mode & FMODE_CAN_READ)) return -EINVAL; return do_readv_writev(READ, file, vec, vlen, pos); @@ -681,7 +872,7 @@ ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, { if (!(file->f_mode & FMODE_WRITE)) return -EBADF; - if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) + if (!(file->f_mode & FMODE_CAN_WRITE)) return -EINVAL; return do_readv_writev(WRITE, file, vec, vlen, pos); @@ -692,16 +883,15 @@ EXPORT_SYMBOL(vfs_writev); SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen) { - struct file *file; + struct fd f = fdget_pos(fd); ssize_t ret = -EBADF; - int fput_needed; - file = fget_light(fd, &fput_needed); - if (file) { - loff_t pos = file_pos_read(file); - ret = vfs_readv(file, vec, vlen, &pos); - file_pos_write(file, pos); - fput_light(file, fput_needed); + if (f.file) { + loff_t pos = file_pos_read(f.file); + ret = vfs_readv(f.file, vec, vlen, &pos); + if (ret >= 0) + file_pos_write(f.file, pos); + fdput_pos(f); } if (ret > 0) @@ -713,16 +903,15 @@ SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen) { - struct file *file; + struct fd f = fdget_pos(fd); ssize_t ret = -EBADF; - int fput_needed; - file = fget_light(fd, &fput_needed); - if (file) { - loff_t pos = file_pos_read(file); - ret = vfs_writev(file, vec, vlen, &pos); - file_pos_write(file, pos); - fput_light(file, fput_needed); + if (f.file) { + loff_t pos = file_pos_read(f.file); + ret = vfs_writev(f.file, vec, vlen, &pos); + if (ret >= 0) + file_pos_write(f.file, pos); + fdput_pos(f); } if (ret > 0) @@ -741,19 +930,18 @@ SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) { loff_t pos = pos_from_hilo(pos_h, pos_l); - struct file *file; + struct fd f; ssize_t ret = -EBADF; - int fput_needed; if (pos < 0) return -EINVAL; - file = fget_light(fd, &fput_needed); - if (file) { + f = fdget(fd); + if (f.file) { ret = -ESPIPE; - if (file->f_mode & FMODE_PREAD) - ret = vfs_readv(file, vec, vlen, &pos); - fput_light(file, fput_needed); + if (f.file->f_mode & FMODE_PREAD) + ret = vfs_readv(f.file, vec, vlen, &pos); + fdput(f); } if (ret > 0) @@ -766,19 +954,18 @@ SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) { loff_t pos = pos_from_hilo(pos_h, pos_l); - struct file *file; + struct fd f; ssize_t ret = -EBADF; - int fput_needed; if (pos < 0) return -EINVAL; - file = fget_light(fd, &fput_needed); - if (file) { + f = fdget(fd); + if (f.file) { ret = -ESPIPE; - if (file->f_mode & FMODE_PWRITE) - ret = vfs_writev(file, vec, vlen, &pos); - fput_light(file, fput_needed); + if (f.file->f_mode & FMODE_PWRITE) + ret = vfs_writev(f.file, vec, vlen, &pos); + fdput(f); } if (ret > 0) @@ -787,31 +974,249 @@ SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, return ret; } +#ifdef CONFIG_COMPAT + +static ssize_t compat_do_readv_writev(int type, struct file *file, + const struct compat_iovec __user *uvector, + unsigned long nr_segs, loff_t *pos) +{ + compat_ssize_t tot_len; + struct iovec iovstack[UIO_FASTIOV]; + struct iovec *iov = iovstack; + ssize_t ret; + io_fn_t fn; + iov_fn_t fnv; + iter_fn_t iter_fn; + + ret = compat_rw_copy_check_uvector(type, uvector, nr_segs, + UIO_FASTIOV, iovstack, &iov); + if (ret <= 0) + goto out; + + tot_len = ret; + ret = rw_verify_area(type, file, pos, tot_len); + if (ret < 0) + goto out; + + fnv = NULL; + if (type == READ) { + fn = file->f_op->read; + fnv = file->f_op->aio_read; + iter_fn = file->f_op->read_iter; + } else { + fn = (io_fn_t)file->f_op->write; + fnv = file->f_op->aio_write; + iter_fn = file->f_op->write_iter; + file_start_write(file); + } + + if (iter_fn) + ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len, + pos, iter_fn); + else if (fnv) + ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, + pos, fnv); + else + ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); + + if (type != READ) + file_end_write(file); + +out: + if (iov != iovstack) + kfree(iov); + if ((ret + (type == READ)) > 0) { + if (type == READ) + fsnotify_access(file); + else + fsnotify_modify(file); + } + return ret; +} + +static size_t compat_readv(struct file *file, + const struct compat_iovec __user *vec, + unsigned long vlen, loff_t *pos) +{ + ssize_t ret = -EBADF; + + if (!(file->f_mode & FMODE_READ)) + goto out; + + ret = -EINVAL; + if (!(file->f_mode & FMODE_CAN_READ)) + goto out; + + ret = compat_do_readv_writev(READ, file, vec, vlen, pos); + +out: + if (ret > 0) + add_rchar(current, ret); + inc_syscr(current); + return ret; +} + +COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, + const struct compat_iovec __user *,vec, + compat_ulong_t, vlen) +{ + struct fd f = fdget_pos(fd); + ssize_t ret; + loff_t pos; + + if (!f.file) + return -EBADF; + pos = f.file->f_pos; + ret = compat_readv(f.file, vec, vlen, &pos); + if (ret >= 0) + f.file->f_pos = pos; + fdput_pos(f); + return ret; +} + +static long __compat_sys_preadv64(unsigned long fd, + const struct compat_iovec __user *vec, + unsigned long vlen, loff_t pos) +{ + struct fd f; + ssize_t ret; + + if (pos < 0) + return -EINVAL; + f = fdget(fd); + if (!f.file) + return -EBADF; + ret = -ESPIPE; + if (f.file->f_mode & FMODE_PREAD) + ret = compat_readv(f.file, vec, vlen, &pos); + fdput(f); + return ret; +} + +#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 +COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, + const struct compat_iovec __user *,vec, + unsigned long, vlen, loff_t, pos) +{ + return __compat_sys_preadv64(fd, vec, vlen, pos); +} +#endif + +COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, + const struct compat_iovec __user *,vec, + compat_ulong_t, vlen, u32, pos_low, u32, pos_high) +{ + loff_t pos = ((loff_t)pos_high << 32) | pos_low; + + return __compat_sys_preadv64(fd, vec, vlen, pos); +} + +static size_t compat_writev(struct file *file, + const struct compat_iovec __user *vec, + unsigned long vlen, loff_t *pos) +{ + ssize_t ret = -EBADF; + + if (!(file->f_mode & FMODE_WRITE)) + goto out; + + ret = -EINVAL; + if (!(file->f_mode & FMODE_CAN_WRITE)) + goto out; + + ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); + +out: + if (ret > 0) + add_wchar(current, ret); + inc_syscw(current); + return ret; +} + +COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, + const struct compat_iovec __user *, vec, + compat_ulong_t, vlen) +{ + struct fd f = fdget_pos(fd); + ssize_t ret; + loff_t pos; + + if (!f.file) + return -EBADF; + pos = f.file->f_pos; + ret = compat_writev(f.file, vec, vlen, &pos); + if (ret >= 0) + f.file->f_pos = pos; + fdput_pos(f); + return ret; +} + +static long __compat_sys_pwritev64(unsigned long fd, + const struct compat_iovec __user *vec, + unsigned long vlen, loff_t pos) +{ + struct fd f; + ssize_t ret; + + if (pos < 0) + return -EINVAL; + f = fdget(fd); + if (!f.file) + return -EBADF; + ret = -ESPIPE; + if (f.file->f_mode & FMODE_PWRITE) + ret = compat_writev(f.file, vec, vlen, &pos); + fdput(f); + return ret; +} + +#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 +COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, + const struct compat_iovec __user *,vec, + unsigned long, vlen, loff_t, pos) +{ + return __compat_sys_pwritev64(fd, vec, vlen, pos); +} +#endif + +COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, + const struct compat_iovec __user *,vec, + compat_ulong_t, vlen, u32, pos_low, u32, pos_high) +{ + loff_t pos = ((loff_t)pos_high << 32) | pos_low; + + return __compat_sys_pwritev64(fd, vec, vlen, pos); +} +#endif + static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, - size_t count, loff_t max) + size_t count, loff_t max) { - struct file * in_file, * out_file; - struct inode * in_inode, * out_inode; + struct fd in, out; + struct inode *in_inode, *out_inode; loff_t pos; + loff_t out_pos; ssize_t retval; - int fput_needed_in, fput_needed_out, fl; + int fl; /* * Get input file, and verify that it is ok.. */ retval = -EBADF; - in_file = fget_light(in_fd, &fput_needed_in); - if (!in_file) + in = fdget(in_fd); + if (!in.file) goto out; - if (!(in_file->f_mode & FMODE_READ)) + if (!(in.file->f_mode & FMODE_READ)) goto fput_in; retval = -ESPIPE; - if (!ppos) - ppos = &in_file->f_pos; - else - if (!(in_file->f_mode & FMODE_PREAD)) + if (!ppos) { + pos = in.file->f_pos; + } else { + pos = *ppos; + if (!(in.file->f_mode & FMODE_PREAD)) goto fput_in; - retval = rw_verify_area(READ, in_file, ppos, count); + } + retval = rw_verify_area(READ, in.file, &pos, count); if (retval < 0) goto fput_in; count = retval; @@ -820,15 +1225,16 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, * Get output file, and verify that it is ok.. */ retval = -EBADF; - out_file = fget_light(out_fd, &fput_needed_out); - if (!out_file) + out = fdget(out_fd); + if (!out.file) goto fput_in; - if (!(out_file->f_mode & FMODE_WRITE)) + if (!(out.file->f_mode & FMODE_WRITE)) goto fput_out; retval = -EINVAL; - in_inode = in_file->f_path.dentry->d_inode; - out_inode = out_file->f_path.dentry->d_inode; - retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count); + in_inode = file_inode(in.file); + out_inode = file_inode(out.file); + out_pos = out.file->f_pos; + retval = rw_verify_area(WRITE, out.file, &out_pos, count); if (retval < 0) goto fput_out; count = retval; @@ -836,7 +1242,6 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, if (!max) max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); - pos = *ppos; if (unlikely(pos + count > max)) { retval = -EOVERFLOW; if (pos >= max) @@ -852,25 +1257,34 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, * and the application is arguably buggy if it doesn't expect * EAGAIN on a non-blocking file descriptor. */ - if (in_file->f_flags & O_NONBLOCK) + if (in.file->f_flags & O_NONBLOCK) fl = SPLICE_F_NONBLOCK; #endif - retval = do_splice_direct(in_file, ppos, out_file, count, fl); + file_start_write(out.file); + retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); + file_end_write(out.file); if (retval > 0) { add_rchar(current, retval); add_wchar(current, retval); + fsnotify_access(in.file); + fsnotify_modify(out.file); + out.file->f_pos = out_pos; + if (ppos) + *ppos = pos; + else + in.file->f_pos = pos; } inc_syscr(current); inc_syscw(current); - if (*ppos > max) + if (pos > max) retval = -EOVERFLOW; fput_out: - fput_light(out_file, fput_needed_out); + fdput(out); fput_in: - fput_light(in_file, fput_needed_in); + fdput(in); out: return retval; } @@ -910,3 +1324,43 @@ SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, si return do_sendfile(out_fd, in_fd, NULL, count, 0); } + +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, + compat_off_t __user *, offset, compat_size_t, count) +{ + loff_t pos; + off_t off; + ssize_t ret; + + if (offset) { + if (unlikely(get_user(off, offset))) + return -EFAULT; + pos = off; + ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); + if (unlikely(put_user(pos, offset))) + return -EFAULT; + return ret; + } + + return do_sendfile(out_fd, in_fd, NULL, count, 0); +} + +COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, + compat_loff_t __user *, offset, compat_size_t, count) +{ + loff_t pos; + ssize_t ret; + + if (offset) { + if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) + return -EFAULT; + ret = do_sendfile(out_fd, in_fd, &pos, count, 0); + if (unlikely(put_user(pos, offset))) + return -EFAULT; + return ret; + } + + return do_sendfile(out_fd, in_fd, NULL, count, 0); +} +#endif |
