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| author |   Christoph Hellwig <hch@lst.de> | 2020-05-07 19:33:03 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2020-07-08 08:27:56 +0200 |
| commit | 81238b2cff1469ff5b94390d026cd075105d6dcd (patch) | |
| tree | 5011d4dfb86cad5ac8fd10fb8fb4237cefe0ad19 | |
| parent | fs: check FMODE_WRITE in __kernel_write (diff) | |
| download | linux-dev-81238b2cff1469ff5b94390d026cd075105d6dcd.tar.xz linux-dev-81238b2cff1469ff5b94390d026cd075105d6dcd.zip | |
fs: implement kernel_write using __kernel_write
Consolidate the two in-kernel write helpers to make upcoming changes
easier. The only difference are the missing call to rw_verify_area
in kernel_write, and an access_ok check that doesn't make sense for
kernel buffers to start with.
Signed-off-by: Christoph Hellwig <hch@lst.de>
| -rw-r--r-- | fs/read_write.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index 8f9fc05990ae..5110cd1e6e27 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -499,6 +499,7 @@ static ssize_t __vfs_write(struct file *file, const char __user *p, return -EINVAL; } +/* caller is responsible for file_start_write/file_end_write */ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) { mm_segment_t old_fs; @@ -528,16 +529,16 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t ssize_t kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) { - mm_segment_t old_fs; - ssize_t res; + ssize_t ret; - old_fs = get_fs(); - set_fs(KERNEL_DS); - /* The cast to a user pointer is valid due to the set_fs() */ - res = vfs_write(file, (__force const char __user *)buf, count, pos); - set_fs(old_fs); + ret = rw_verify_area(WRITE, file, pos, count); + if (ret) + return ret; - return res; + file_start_write(file); + ret = __kernel_write(file, buf, count, pos); + file_end_write(file); + return ret; } EXPORT_SYMBOL(kernel_write); |