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ext4: store EXT4_EXT_MIGRATE in i_state instead of i_flags

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EXT4_EXT_MIGRATE is only intended to be used for an in-memory flag,
and the hex value assigned to it collides with FS_DIRECTIO_FL (which
is also stored in i_flags).  There's no reason for the
EXT4_EXT_MIGRATE bit to be stored in i_flags, so we switch it to use
i_state instead.

Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o 2009-09-17 08:32:22 -04:00
parent fb0a387dcd
commit 1b9c12f44c
3 changed files with 13 additions and 15 deletions
Download patch file Download diff file Expand all files Collapse all files

20
fs/ext4/migrate.c
View file

@ -353,17 +353,16 @@ static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
down_write(&EXT4_I(inode)->i_data_sem);
/*
* if EXT4_EXT_MIGRATE is cleared a block allocation
* if EXT4_STATE_EXT_MIGRATE is cleared a block allocation
* happened after we started the migrate. We need to
* fail the migrate
*/
if (!(EXT4_I(inode)->i_flags & EXT4_EXT_MIGRATE)) {
if (!(EXT4_I(inode)->i_state & EXT4_STATE_EXT_MIGRATE)) {
retval = -EAGAIN;
up_write(&EXT4_I(inode)->i_data_sem);
goto err_out;
} else
EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags &
~EXT4_EXT_MIGRATE;
EXT4_I(inode)->i_state &= ~EXT4_STATE_EXT_MIGRATE;
/*
* We have the extent map build with the tmp inode.
* Now copy the i_data across
@ -517,14 +516,15 @@ int ext4_ext_migrate(struct inode *inode)
* when we add extents we extent the journal
*/
/*
* Even though we take i_mutex we can still cause block allocation
* via mmap write to holes. If we have allocated new blocks we fail
* migrate. New block allocation will clear EXT4_EXT_MIGRATE flag.
* The flag is updated with i_data_sem held to prevent racing with
* block allocation.
* Even though we take i_mutex we can still cause block
* allocation via mmap write to holes. If we have allocated
* new blocks we fail migrate. New block allocation will
* clear EXT4_STATE_EXT_MIGRATE flag. The flag is updated
* with i_data_sem held to prevent racing with block
* allocation.
*/
down_read((&EXT4_I(inode)->i_data_sem));
EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags | EXT4_EXT_MIGRATE;
EXT4_I(inode)->i_state |= EXT4_STATE_EXT_MIGRATE;
up_read((&EXT4_I(inode)->i_data_sem));
handle = ext4_journal_start(inode, 1);