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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-26 21:52:12 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-26 21:52:12 +0300 |
commit | 3eccc0c886b1796f95a289c9d127c8ca1a254bd5 (patch) | |
tree | 021761894d246df22d53e1c64810f6cbf3ece716 /fs/ocfs2/file.c | |
parent | cc423f6337d0a5ff1906f3b3d465d28c0d1705f6 (diff) | |
parent | 9eee8bd81421c5e961cbb1a3c3fa1a06fad545e8 (diff) | |
download | linux-3eccc0c886b1796f95a289c9d127c8ca1a254bd5.tar.xz |
Merge tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linux
Pull splice updates from Jens Axboe:
"This kills off ITER_PIPE to avoid a race between truncate,
iov_iter_revert() on the pipe and an as-yet incomplete DMA to a bio
with unpinned/unref'ed pages from an O_DIRECT splice read. This causes
memory corruption.
Instead, we either use (a) filemap_splice_read(), which invokes the
buffered file reading code and splices from the pagecache into the
pipe; (b) copy_splice_read(), which bulk-allocates a buffer, reads
into it and then pushes the filled pages into the pipe; or (c) handle
it in filesystem-specific code.
Summary:
- Rename direct_splice_read() to copy_splice_read()
- Simplify the calculations for the number of pages to be reclaimed
in copy_splice_read()
- Turn do_splice_to() into a helper, vfs_splice_read(), so that it
can be used by overlayfs and coda to perform the checks on the
lower fs
- Make vfs_splice_read() jump to copy_splice_read() to handle
direct-I/O and DAX
- Provide shmem with its own splice_read to handle non-existent pages
in the pagecache. We don't want a ->read_folio() as we don't want
to populate holes, but filemap_get_pages() requires it
- Provide overlayfs with its own splice_read to call down to a lower
layer as overlayfs doesn't provide ->read_folio()
- Provide coda with its own splice_read to call down to a lower layer
as coda doesn't provide ->read_folio()
- Direct ->splice_read to copy_splice_read() in tty, procfs, kernfs
and random files as they just copy to the output buffer and don't
splice pages
- Provide wrappers for afs, ceph, ecryptfs, ext4, f2fs, nfs, ntfs3,
ocfs2, orangefs, xfs and zonefs to do locking and/or revalidation
- Make cifs use filemap_splice_read()
- Replace pointers to generic_file_splice_read() with pointers to
filemap_splice_read() as DIO and DAX are handled in the caller;
filesystems can still provide their own alternate ->splice_read()
op
- Remove generic_file_splice_read()
- Remove ITER_PIPE and its paraphernalia as generic_file_splice_read
was the only user"
* tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linux: (31 commits)
splice: kdoc for filemap_splice_read() and copy_splice_read()
iov_iter: Kill ITER_PIPE
splice: Remove generic_file_splice_read()
splice: Use filemap_splice_read() instead of generic_file_splice_read()
cifs: Use filemap_splice_read()
trace: Convert trace/seq to use copy_splice_read()
zonefs: Provide a splice-read wrapper
xfs: Provide a splice-read wrapper
orangefs: Provide a splice-read wrapper
ocfs2: Provide a splice-read wrapper
ntfs3: Provide a splice-read wrapper
nfs: Provide a splice-read wrapper
f2fs: Provide a splice-read wrapper
ext4: Provide a splice-read wrapper
ecryptfs: Provide a splice-read wrapper
ceph: Provide a splice-read wrapper
afs: Provide a splice-read wrapper
9p: Add splice_read wrapper
net: Make sock_splice_read() use copy_splice_read() by default
tty, proc, kernfs, random: Use copy_splice_read()
...
Diffstat (limited to 'fs/ocfs2/file.c')
-rw-r--r-- | fs/ocfs2/file.c | 43 |
1 files changed, 40 insertions, 3 deletions
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index b173c36bcab3..91a194596552 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2558,7 +2558,7 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb, * * Take and drop the meta data lock to update inode fields * like i_size. This allows the checks down below - * generic_file_read_iter() a chance of actually working. + * copy_splice_read() a chance of actually working. */ ret = ocfs2_inode_lock_atime(inode, filp->f_path.mnt, &lock_level, !nowait); @@ -2587,6 +2587,43 @@ bail: return ret; } +static ssize_t ocfs2_file_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, + size_t len, unsigned int flags) +{ + struct inode *inode = file_inode(in); + ssize_t ret = 0; + int lock_level = 0; + + trace_ocfs2_file_splice_read(inode, in, in->f_path.dentry, + (unsigned long long)OCFS2_I(inode)->ip_blkno, + in->f_path.dentry->d_name.len, + in->f_path.dentry->d_name.name, + flags); + + /* + * We're fine letting folks race truncates and extending writes with + * read across the cluster, just like they can locally. Hence no + * rw_lock during read. + * + * Take and drop the meta data lock to update inode fields like i_size. + * This allows the checks down below filemap_splice_read() a chance of + * actually working. + */ + ret = ocfs2_inode_lock_atime(inode, in->f_path.mnt, &lock_level, 1); + if (ret < 0) { + if (ret != -EAGAIN) + mlog_errno(ret); + goto bail; + } + ocfs2_inode_unlock(inode, lock_level); + + ret = filemap_splice_read(in, ppos, pipe, len, flags); + trace_filemap_splice_read_ret(ret); +bail: + return ret; +} + /* Refer generic_file_llseek_unlocked() */ static loff_t ocfs2_file_llseek(struct file *file, loff_t offset, int whence) { @@ -2750,7 +2787,7 @@ const struct file_operations ocfs2_fops = { #endif .lock = ocfs2_lock, .flock = ocfs2_flock, - .splice_read = generic_file_splice_read, + .splice_read = ocfs2_file_splice_read, .splice_write = iter_file_splice_write, .fallocate = ocfs2_fallocate, .remap_file_range = ocfs2_remap_file_range, @@ -2796,7 +2833,7 @@ const struct file_operations ocfs2_fops_no_plocks = { .compat_ioctl = ocfs2_compat_ioctl, #endif .flock = ocfs2_flock, - .splice_read = generic_file_splice_read, + .splice_read = filemap_splice_read, .splice_write = iter_file_splice_write, .fallocate = ocfs2_fallocate, .remap_file_range = ocfs2_remap_file_range, |