From: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
To: Eric Biggers <ebiggers@kernel.org>
Cc: "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"pali@kernel.org" <pali@kernel.org>,
"dsterba@suse.cz" <dsterba@suse.cz>,
"aaptel@suse.com" <aaptel@suse.com>,
"willy@infradead.org" <willy@infradead.org>,
"rdunlap@infradead.org" <rdunlap@infradead.org>,
"joe@perches.com" <joe@perches.com>,
"mark@harmstone.com" <mark@harmstone.com>,
"nborisov@suse.com" <nborisov@suse.com>,
"linux-ntfs-dev@lists.sourceforge.net"
<linux-ntfs-dev@lists.sourceforge.net>,
"anton@tuxera.com" <anton@tuxera.com>,
"dan.carpenter@oracle.com" <dan.carpenter@oracle.com>,
"hch@lst.de" <hch@lst.de>
Subject: RE: [PATCH v14 04/10] fs/ntfs3: Add file operations and implementation
Date: Fri, 11 Dec 2020 16:31:18 +0000 [thread overview]
Message-ID: <229c4a26f2834f8dabf566823936d3e4@paragon-software.com> (raw)
In-Reply-To: <X8qC3NaNv1kmCO4c@sol.localdomain>
From: Eric Biggers <ebiggers@kernel.org>
Sent: Friday, December 4, 2020 9:42 PM
> To: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
> Cc: linux-fsdevel@vger.kernel.org; viro@zeniv.linux.org.uk; linux-kernel@vger.kernel.org; pali@kernel.org; dsterba@suse.cz;
> aaptel@suse.com; willy@infradead.org; rdunlap@infradead.org; joe@perches.com; mark@harmstone.com; nborisov@suse.com;
> linux-ntfs-dev@lists.sourceforge.net; anton@tuxera.com; dan.carpenter@oracle.com; hch@lst.de
> Subject: Re: [PATCH v14 04/10] fs/ntfs3: Add file operations and implementation
>
> On Fri, Dec 04, 2020 at 06:45:54PM +0300, Konstantin Komarov wrote:
> > +/* external compression lzx/xpress */
> > +static int decompress_lzx_xpress(struct ntfs_sb_info *sbi, const char *cmpr,
> > + size_t cmpr_size, void *unc, size_t unc_size,
> > + u32 frame_size)
> > +{
> > + int err;
> > + void *ctx;
> > +
> > + if (cmpr_size == unc_size) {
> > + /* frame not compressed */
> > + memcpy(unc, cmpr, unc_size);
> > + return 0;
> > + }
> > +
> > + err = 0;
> > + ctx = NULL;
> > + spin_lock(&sbi->compress.lock);
> > + if (frame_size == 0x8000) {
> > + /* LZX: frame compressed */
> > + if (!sbi->compress.lzx) {
> > + /* Lazy initialize lzx decompress context */
> > + spin_unlock(&sbi->compress.lock);
> > + ctx = lzx_allocate_decompressor(0x8000);
> > + if (!ctx)
> > + return -ENOMEM;
> > + if (IS_ERR(ctx)) {
> > + /* should never failed */
> > + err = PTR_ERR(ctx);
> > + goto out;
> > + }
> > +
> > + spin_lock(&sbi->compress.lock);
> > + if (!sbi->compress.lzx) {
> > + sbi->compress.lzx = ctx;
> > + ctx = NULL;
> > + }
> > + }
> > +
> > + if (lzx_decompress(sbi->compress.lzx, cmpr, cmpr_size, unc,
> > + unc_size)) {
> > + err = -EINVAL;
> > + }
> > + } else {
> > + /* XPRESS: frame compressed */
> > + if (!sbi->compress.xpress) {
> > + /* Lazy initialize xpress decompress context */
> > + spin_unlock(&sbi->compress.lock);
> > + ctx = xpress_allocate_decompressor();
> > + if (!ctx)
> > + return -ENOMEM;
> > +
> > + spin_lock(&sbi->compress.lock);
> > + if (!sbi->compress.xpress) {
> > + sbi->compress.xpress = ctx;
> > + ctx = NULL;
> > + }
> > + }
> > +
> > + if (xpress_decompress(sbi->compress.xpress, cmpr, cmpr_size,
> > + unc, unc_size)) {
> > + err = -EINVAL;
> > + }
> > + }
> > + spin_unlock(&sbi->compress.lock);
> > +out:
> > + ntfs_free(ctx);
> > + return err;
> > +}
>
> Decompression is a somewhat heavyweight operation. Not the type of thing that
> should be done while holding a spin lock.
>
> - Eric
Hi Eric! We plan to swap spinlock to mutex in the next version.
Best regards!
next prev parent reply other threads:[~2020-12-11 17:36 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-04 15:45 [PATCH v14 00/10] NTFS read-write driver GPL implementation by Paragon Software Konstantin Komarov
2020-12-04 15:45 ` [PATCH v14 01/10] fs/ntfs3: Add headers and misc files Konstantin Komarov
2020-12-04 15:45 ` [PATCH v14 02/10] fs/ntfs3: Add initialization of super block Konstantin Komarov
2020-12-04 15:45 ` [PATCH v14 03/10] fs/ntfs3: Add bitmap Konstantin Komarov
2020-12-04 15:45 ` [PATCH v14 04/10] fs/ntfs3: Add file operations and implementation Konstantin Komarov
2020-12-04 18:41 ` Eric Biggers
2020-12-11 16:31 ` Konstantin Komarov [this message]
2020-12-25 14:27 ` Konstantin Komarov
2020-12-04 15:45 ` [PATCH v14 05/10] fs/ntfs3: Add attrib operations Konstantin Komarov
2020-12-04 15:45 ` [PATCH v14 06/10] fs/ntfs3: Add compression Konstantin Komarov
2020-12-04 18:38 ` Eric Biggers
2020-12-11 16:28 ` Konstantin Komarov
2020-12-25 14:29 ` Konstantin Komarov
2020-12-04 15:45 ` [PATCH v14 07/10] fs/ntfs3: Add NTFS journal Konstantin Komarov
2020-12-04 15:45 ` [PATCH v14 08/10] fs/ntfs3: Add Kconfig, Makefile and doc Konstantin Komarov
2020-12-04 15:45 ` [PATCH v14 09/10] fs/ntfs3: Add NTFS3 in fs/Kconfig and fs/Makefile Konstantin Komarov
2020-12-04 18:51 ` kernel test robot
2020-12-05 0:41 ` kernel test robot
2020-12-04 15:46 ` [PATCH v14 10/10] fs/ntfs3: Add MAINTAINERS Konstantin Komarov
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