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Re: [PATCH 01/32] ext4: xattr-in-inode support

From Theodore Ts'o <tytso@mit.edu>
Newsgroups linux.kernel
Subject Re: [PATCH 01/32] ext4: xattr-in-inode support
Date 2017-06-22 03:20 +0200
Message-ID <tUYWR-5R0-5@gated-at.bofh.it> (permalink)
References <tUVmh-3od-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On Wed, Jun 21, 2017 at 02:21:11PM -0700, Tahsin Erdogan wrote:
> From: Andreas Dilger <andreas.dilger@intel.com>
> 
> Large xattr support is implemented for EXT4_FEATURE_INCOMPAT_EA_INODE.
> 
> If the size of an xattr value is larger than will fit in a single
> external block, then the xattr value will be saved into the body
> of an external xattr inode.
> 
> The also helps support a larger number of xattr, since only the headers
> will be stored in the in-inode space or the single external block.
> 
> The inode is referenced from the xattr header via "e_value_inum",
> which was formerly "e_value_block", but that field was never used.
> The e_value_size still contains the xattr size so that listing
> xattrs does not need to look up the inode if the data is not accessed.
> 
> struct ext4_xattr_entry {
>         __u8    e_name_len;     /* length of name */
>         __u8    e_name_index;   /* attribute name index */
>         __le16  e_value_offs;   /* offset in disk block of value */
>         __le32  e_value_inum;   /* inode in which value is stored */
>         __le32  e_value_size;   /* size of attribute value */
>         __le32  e_hash;         /* hash value of name and value */
>         char    e_name[0];      /* attribute name */
> };
> 
> The xattr inode is marked with the EXT4_EA_INODE_FL flag and also
> holds a back-reference to the owning inode in its i_mtime field,
> allowing the ext4/e2fsck to verify the correct inode is accessed.
> 
> Lustre-Jira: https://jira.hpdd.intel.com/browse/LU-80
> Lustre-bugzilla: https://bugzilla.lustre.org/show_bug.cgi?id=4424
> Signed-off-by: Kalpak Shah <kalpak.shah@sun.com>
> Signed-off-by: James Simmons <uja.ornl@gmail.com>
> Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
> Signed-off-by: Tahsin Erdogan <tahsin@google.com>

Applied, thanks.

					- Ted

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[PATCH 01/32] ext4: xattr-in-inode support Tahsin Erdogan <tahsin@google.com> - 2017-06-21 23:40 +0200
  Re: [PATCH 01/32] ext4: xattr-in-inode support Theodore Ts'o <tytso@mit.edu> - 2017-06-22 03:20 +0200

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